外文翻译--变速液压装置-精品

液压装置压力之源——泵和压缩机从原理上讲，适于泵送流体的大多数泵都可以泵送空气或气体，尽管大多数油泵几乎不作为空气压缩机来用，而某些压缩机未作调整则不可以输送非压缩性流体。

考虑原则。

对一台可以传送足够大压力以供实际使用的液压泵能力的主要要求是：a控制流体泄漏的措施。

要么用特殊密封要么紧缩加工间隙。

b要真正均匀而非脉冲式输送。

c在运行中不存在空穴现象，因为作为实际用途的流体都是非压缩性的。

d机械平衡达到足够程度以使泵能尽可能快地旋转，目的是已定输出流量时减小泵的体积。

e由于泵内有内压力，要有充分的措施，以最大限度减小工作零件、泵壳等的变形的影响。

f间隙量要小，以便在起动期间很快动作，对含气流体，泵可像压缩机那样，把空气通过输送管线排出，而不让它潴留在泵中。

g配置适当的进油阀或配流装置，以使泵能产生良好真空吸油作用，或者另一种情况下即飞机上高空飞行操作的液压装置或较高粘度作为液压油时更应采取这些措施，应该注意的是入口阀或油门开启的时间，这几乎和油口尺寸一样重要。

一台良好压缩机的主要要求是：a）与机械间隙相适应的尽可能小的间隙容积。

这是因为在间隙容积中被压缩的任何气体都将再次膨胀而不是被排放掉。

相反，不仅将影响泵的输出，而且影响可能产生的最高压力。

b）除低压泵外，要有两个或更多的压缩阶段。

使阶段间有尽可能多的中间冷却。

由于气体是进行绝热压缩的而不是等温过程压缩的，因此，首先希望减少功和输出量的损失。

其次，由于间隙容积的原因，要减少总体上的输出损失。

c）泵中空气预压缩压力升高到输送管线中压力。

尽管标准往复泵因具有自动阀或受压弹簧阀能保证这点，但某些旋转式压缩机则必须专门配上气阀来配流，以便获得预压缩，而另一些泵则全然不可能做到。

泵内无预压力，一旦输气阀口打开，管线中气体膨胀而回到泵内，泵内全部流体不得不再次被压缩。

具有预压缩装置的旋转压缩机不可能输送油流。

d）缸体气冷或水冷措施，使得压缩机中气体温度尽可能保持等温状态，而被输送的气体体积相应增加。

原文Solving Vibration Problems In HydraulicMachineryAbstractIn the current paper, various cases of vibration problems detected in hydraulic machinery are presented.These cases were found during several years of vibration monitoring.the problems have been classified depending on their origin.For all of them,a systematic approach is given indicating the symptoms,the exciatation provoking them,the possibilities of amplification due to resonance and the remedies that have been applied.IntroductionVibration problems are common in hydraulic machinery.Solving them helps to increase the machine life and to reduce maintenance costs.Many cases have been found and solved during last years of monitoring (Egusquiza 1998 and Egusquiza et.2000).Some of them have been due to design or mounting problems and others due to damage in machine elements.The cases presented here correspond to large machine with vertical shaft and rigid coupling.The problems found have been classified in the following types:Type 1: Excessive excitations of hydraulic originType 2: Hrust bearing problemsType 3: Unbalance and misalignmentType 4: Electromagnetic problemA methodology to solve these types of vibration problems is proposed in the paper.The steps to follow are indicated in Fig,1.Once the abnormal high vibration amplitudes have been detected through scheduled monitoring or machine malfunctioning.Vibration analysis has to be proformde to identify the origin of the exciation provoking them.Various techniques are availabledepending on the type of excitation under consideration,whether it is hydraulic,mechanic orEletromagnetion.The resulting high vibration levels may also be due to some type of resonace in the hydraulic system or in the mechanical compoents.Therefore, this possibility must be checed before a correct diagnostic can be made.Finally, remedies to the probiem are proposed and their success is confirmed comparing the vibrations after the modification with theprevious ones.Type 1: Excessive Hydraulic Excitation.Typical vibrations of hydraulic origin are generated by rotor-stator interaction (RSI) and by cacitation.RSI is due to the interference between the runner blades and guide vanes.It can generate pressure pulsations of high amplitude in hydraulic machines.As a result,cracks in runners and excessive vibrationlevels in machine and piping can be produced.RSI identification is normally easy with spectral analysis of vibration.The problem is to know if the vibration is high due to the excitation itself,to a high hydraulic system is high due to the excitation resonse or to a runner/motor resonance.The vibration will be at a frequency f b given by:F b=n*f*z b=With maximum amplitude at the lowest diametrical mode excited k according to the following equation(tanaka 1990):n*z v+-k=m*z bAnother typical phenomenon that can generate vibrations is cavitation.Cavitation can take several forms and can result in vibrations,losses of performance and erosion. The most common type of cavitation is part load suige. Its negative effects are usually mitigated by means of air entrapment in draft tube. On the other hand, inlet cacitation provoking erosion of runner blades is also a concern due to its destructive effects.Here there are some examples for both types of hydraulic excitations. High vibrations in thecasingof a multistage pumpA multistage pump had high vibration levels in the casing during operation. The generated vibrations produced the burst of pipes and other elements. Initially, it was thought that the vibrations were due to wear or damage(malfunctioning). As a result, the pump was completely dismantled and repaird. Surprisingly, the vibration did not disappear.A general scheme of the pump is given in fig,2.During pumping the machine delivers a flow rate of 2.8 m3/s to a head of 935 m.Other machine characteristics are listed in Table 1.To understand the cause of the high vibertion levels some experimental measurements and a theoretical analysis were carried out.From the spectral analysis it was found that the vibration amplitude occurred at 150 Hz which is f b(see Fig,5).therefore,the vibration has a fluid dynamic origin and its high amplitude might be due to several reasons such as high RSI excitation due to design,mounting,damage,or resonance. In this case,the RSI analysis gives a pressure pulsation around the impeller with a diametrical mode k=-2 rotating in the opposite direction of the impeller st f b.First of all, the hydraulic system response of the return channel was calculated using a transfer matrix method. No frequencies around 150Hz were found. Furthermore, the analysis of the measurements(phase and amplitude variation)at different roating speeds neither showed resonance around the excitation frequency.Modal analysis from the impacts done with an insteumented hammer was carried out to check the possibility of mechuanical resonance in the casing or impeller.For the casing,no resonance was found at around the frequency of 150 Hz as it can be seen in Fig,3. Atheoretical analysis with FEM gave similar results.The frequency response functions obtained from impacts in the impeller areindicated in Fig,4. They show the presence of a mode at 472 Hz. This mode was susceptible of excitation because it corresponded to diametrical mode 2. Estimating a reduction factor of 0.45 to 0.5in order to consider the added mass and the casing boundary,the actual natural frequency would lie between 212 and 236 Hz. So, there was a low probability of resonance. In fact, no high vibration levels were present at the bearings.Finally, analyzing the phasing of the pressure pulsation and vibration in the casing, the diagnosis was that the high vibrations were caused by the interaction of the pressure pulsation inside the machine.In this case the solution was to change the relative position between impellers. After that, vibration was reduced considerably as it is shown in Fig,5 where RSI vibrations before and after repair are compare.Vibration on runner of a pump-turbine.In this case, the machine was a single stage reversible pump-turbine. Its main characteristics are listed in table 2. this pump suffered form cracks in the impeller blades.For the Z b and Z v combinations, the diametrical mode k=-2 occurs at 2*f b(=140 Hz) and should be the most important excitation. This is exactly what can be seen in the vibration spectrum shown in Fig, 6.After analyzing the system response, checking the natural frequencies of runner and rotor, it was found that a rotor naturalfrequency was was close to the excitation frequency. As the system could not be changed physically, the solution of the problem was devised as modifying the runner lacation where cracks appeared to reduce stresses on blades.Partial load surge and inlet cavitation erosion on blades of a francis turbine.This unie was a vertical shaft francis turbine operating up to a maximum output power of 65 MW. The total nominal flow rate and the net head were 57.5m3/s and 122.5m. the rest of characteristics are listed in Table 3.In this case two problems had been detected. The first one was excessivevibration levels in the draft tube. The second one was advanced erosion on the suction side of the blades.In Fig, 7 overall vibration levels measured for the entire range of power outputs indicate that amplitudes are more important during operation at partial loads. In the Fig,8, spectral analysis of shaft displacement using proximity probes can be observed at 20 and 55MW. When operating at 20MW, a frequency peak at 0.27*f f predominates but disappears at 55 MW. This analysis indicated the presence of a hub rope in the draft tube at partial loads.Spectral analysis is enough to detect partial load surge but it is not useful for other types of cavitation. This is the case of erosive cavitation is especially destructive.Another technique to be used is to demodulate high frequency vibrations. In Fig,9, the spectra of the envelope in the frequency band form 30k to 40k Hz are plotted. Again, at 20 MW the presence of the part load surge is well detected in the top of the Fig.So,the possible remedies such as optimization of air injection fins are currently being analyzed. Meanwhile, it has been recommended to avoid operation at loads below 35 MW.For the detection of erosive cavitation high frequency vibrations also had to be measured (Escaler et al.2002). Amplitude demodulation of high frequency bands, shown in the bottom of Fig,9, indicated the presence of a pulsating cavity in the runner at f v at 55MW. The maximum amplitude of this peak was found at 60 MW, thus indicating the maximum cavitation aggressiveness. Therefore, the solution consisted in limiting the time of operation around 60MW whenever possible. A refurbishing of the runner (new hydrodynamic design) is expected to be the solution in this case.Type 2: thrust bearing problemsAnother type of problem sometimes found in vertical shaft machines is rubbing in thrust bearing which can provoke its rapid destruction. In guidebearings,radial loading is usually low and they are not so affected.Machines are prone to have friction during start-up and coast-down if only hydrodynamic lubrication exists. During operating, vibration can be generated especially when load on the pads is not evenly distributed. A possibility for detection is to install a vertical proximity probe or an absolute vibration sensor located next to the bearing pads in axial direction. The use of joint-time frequency analysis is very adequate to idenfuty such frictions that can occur in very short periods of time.At steady operation, spectral analysis helps to identify potential problems by looking at the pad passing frequency. For instance, in Fig,10,this frequency disappears from the vibration signature after repairing the bearing. Although detection is easy,to quantify the level of the damage is diffcult from the vibration signature and the peak amplitude. A proximity probe is convenient as well as oil analysis to complete the diagnostic.In Fig, 11, another example is shown. The predominant peak at passing frequency indicates a damage in the bearing. Its amplitude decreased significantly after repair.Type 3: unbalance and misalignmentUnbalance and especially misalignment are common problem in vertical shaft machine with rigid coupling.Unbalbance detection and solution is not diffcult except when hydraulic or magnetic forces or a resonance zre involved in it. It is important to identify the type of unbalance before doing the repair. Vibration measurements at different loads and with the machine idle are necessary. In Fig, 12 the spectrum of a machine with unbalance produced by a blockage in runner channels can be observed. In this case, it was observed that the f f. another situation which is potentially dangerous is when a small part of the runner breaks off due to fatigue. Here, the change in unbalance is mot large and damage is diffcult to detect.Other cases difficilt to solve are when there is resonance with a rotornatural frequency. In Fig,13，a case with misalignment can be observed. The first rotor lateral frequency is almost coincident with a times the rotating frequency. Here the machine has some degree of misalignment which is enhanced by the resonance. In the top of the Fig,14,the 2*f f peak has an RMS amplitude around 1.2 mm/s when the machine operates at full load. Meanwhile,in the bottom of the same Fig,the same peak shows an amplitude of about 0.4 mm/s at 40% of the load.As the natural frequency varies depending on the machine load and other paraments, the vibration amplitudes change continuosly what makes diffcult to have an accurate ternd analysis in the monitoring. In this case the solution is not straightforward.Rotordynamic analysis based in FEM can be used to model the motor,to identify the type of resonance and to find a remedy. Inaccuracies arise when simulating an installed machine due to the lack of exact geometrical data, bearing stiffness,and so on. Therefore simulation must be checked with some experimental data. Thisis rather complex because the natural frequency are diffcult to excite in a large machine. Joint time frequency analysis can be used during transients or after impacting tha machine when in operation in order to identify them,as shown in Fig,14.Type 4: electromagnetic problemsThis type of problems are basically due to eccentricity or damage in generator.In Fig,15,spectra of a machine before(front) and after excessive vibration in the generatoe are shown. The predominant vibration occurs at two times the electrical line frequency,in our case 100Hz. After repair of the stator, where some damage was found,the vibration amplitude at 100Hz was considerably reduced.翻译部分液压机械装置振动问题处理摘要：在本篇论文中，我们将讨论液压机械装置不同情况下的各种振动问题。

附录Hydraulic SystemHydraulic presser drive and air pressure drive hydraulic fluid as the transmission is made according to the 17th century, Pascal's principle of hydrostatic pressure to drive the development of an emerging technology, the United Kingdom in 1795 •Barman Joseph (Joseph Barman, 1749-1814), in London water as a medium to form hydraulic press used in industry, the birth of the world's first hydraulic press. Media work in 1905 will be replaced by oil-water and further improved.After the World War I (1914-1918) ,because of the extensive application of hydraulic transmission, especially after 1920, more rapid development. Hydraulic components in the late 19th century about the early 20th century, 20 years, only started to enter the formal phase of industrial production. 1925 Vickers (F. Vickers) the invention of the pressure balanced vane pump, hydraulic components for the modern industrial or hydraulic transmission of the gradual establishment of the foundation. The early 20th century G • Constantia scofluctuations of the energy carried out by passing theoretical and practical research; in 1910 on the hydraulic trans- mission (hydraulic coupling, hydraulic torque converter, etc.) contributions, so that these two areas of development.The Second World War (1941-1945) period, in the United States 30% of machine tool applications in the hydraulic transmission. It should be noted that the development of hydraulic transmission in Japan than Europe and the United States and other countries fornearly 20 years later. Before and after in 1955, the rapid development of Japan's hydraulic drive, set up in 1956, "Hydraulic Industry." Nearly 20 to 30 years, the development of Japan's fast hydraulic transmission, a world leader.Hydraulic transmission There are many outstanding advantages, it is widely used, such as general industrial use of plastics processing machinery, the pressure of machinery, machine tools, etc.; operating machinery engineering machinery, construction machinery, agricultural machinery, automobiles, etc.; iron and steel industry metallurgical machinery, lifting equipment, such as roller adjustment device; civil water projects with flood control and dam gate devices, bed lifts installations, bridges and other manipulation of institutions; speed turbine power plant installations, nuclear power plants, etc.; ship from the deck heavy machinery (winch), the bow doors, bulkhead valve, stern thruster, etc.; special antenna technology giant with control devices, measurement buoys, movements such as rotating stage; military-industrial control devices used in artillery, ship anti- rolling devices, aircraft simulation, aircraft retractable landing gear and rudder control devices and other devices.A complete hydraulic system consists of five parts, namely, power components, the implementation of components, control components, auxiliary components and hydraulic oil.The role of dynamic components of the original motive fluid into mechanical energy to the pressure that the hydraulic system of pumps, it is to power the entire hydraulic system. The structure of the form of hydra- ulic pump gears are generally pump, vane pump and piston pump.Implementation of components (such as hydraulic cylinders and hydraulic motors) which isthe pressure of the liquid can be converted to mechanical energy to drive the load for a straight line reciprocating movement or rotational movement.Control components (that is, the various hydraulic valves) in the hydraulic system to control and regulate the pressure of liquid, flow rate and direction. According to the different control functions, hydraulic pressure control valve can be divided into valves, flow control valves and directional control valve. Pressure control valves are divided into benefits flow valve (safety valve), pressure relief valve, sequence valve, pressure relays, etc.; flow control valves including throttle, adjusting the valves, flow diversion valve sets, etc.; directional control valve includes a one-way valve , one-way fluid control valve, shuttle valve, valve and so on. Under the control of different ways, can be divided into the hydraulic valve control switch valve, control valve and set the value of the ratio control valve.Auxiliary components, including fuel tanks, oil filters, tubing and pipe joints, seals, pressure gauge, oil level, such as oil dollars.Hydraulic oil in the hydraulic system is the work of the energy transfer medium, there are a variety of mineral oil, emulsion oil hydraulic molding Hop categories.The role of the hydraulic system is to help humanity work. Mainly by the implementation of components to rotate or pressure into a reciprocating motion.Hydraulic system and hydraulic power control signal is composed of two parts, the signal control of some parts of the hydraulic power used to drive the control valve movement.Part of the hydraulic power means that the circuit diagram used to show the differentfunctions of the interrelationship between components. Containing the source of hydraulic pump, hydraulic motor and auxiliary components; hydraulic control part contains a variety of control valves, used to control the flow of oil, pressure and direction; operative or hydraulic cylinder with hydraulic motors, according to the actual requirements of their choice.In the analysis and design of the actual task, the general block diagram shows the actual operation of equipment. Hollow arrow indicates the signal flow, while the solid arrows that energy flow.Basic hydraulic circuit of the action sequence - Control components (two four-way valve) and the spring to reset for the implementation of components (double-acting hydraulic cylinder), as well as the extending and retracting the relief valve opened and closed. For the implementation of components and control components, presentations are based on the corresponding circuit diagram symbols, it also introduced ready made circuit diagram symbols.Working principle of the system, you can turn on all circuits to code. If the first implementation of components numbered 0, the control components associated with the identifier is 1. Out with the implementation of components corresponding to the identifier for the even components, then retracting and implementation of components corresponding to the identifier for the odd components. Hydraulic circuit carried out not only to deal with numbers, but also to deal with the actual device ID, in order to detect system failures.DIN ISO1219-2 standard definition of the number of component composition, which includes the following four parts: device ID, circuit ID, component ID and component ID.The entire system if only one device, device number may be omitted.Practice, another way is to code all of the hydraulic system components for numbers at this time, components and component code should be consistent with the list of numbers. This method is particularly applicable to complex hydraulic control system, each control loop are the corresponding number with the systemWith mechanical transmission, electrical transmission compared to the hydraulic drive has the following advantages:1. a variety of hydraulic components can easily and flexibly to layout.2. light weight, small size, small inertia, fast response.3. to facilitate manipulation of control, enabling a wide range of stepless speed regulation (speed range of 2000:1).4. to achieve overload protection automatically.5. the general use of mineral oil as a working medium, the relative motion can be self-lubricating surface, long service life;6. it is easy to achieve linear motion .7. it is easy to achieve the automation of machines, when the joint control of the use of electro-hydraulic, not only can achieve a higher degree of process automation, and remote control can be achieved.The shortcomings of the hydraulic system:1. as a result of the resistance to fluid flow and leakage of the larger, so less efficient. If not handled properly, leakage is not only contaminated sites, but also may cause fire and explosion.2. vulnerable performance as a result of the impact of temperature change, it would be inappropriate in the high or low temperature conditions.3. the manufacture of precision hydraulic components require a higher, more expensive and hence the price.4. due to the leakage of liquid medium and the compressibility and can not be strictly the transmission ratio.5. hydraulic transmission is not easy to find out the reasons for failure; the use and maintenance requirements for a higher level of technology.In the hydraulic system and its system, the sealing device to prevent leakage of the work of media within and outside the dust and the intrusion of foreign bodies. Seals played the role of components, namely seals. Medium will result in leakage of waste, pollution and environmental machinery and even give rise to malfunctioning machinery and equipment for personal accident. Leakage within the hydraulic system will cause a sharp drop in volumetric efficiency, amounting to less than the required pressure, can not even work. Micro-invasive system of dust particles, can cause or exacerbate friction hydraulic component wear, and further lead to leakage.Therefore, seals and sealing device is an important hydraulic equipment components. The reliability of its work and life, is a measure of the hydraulic system an important indicator of good or bad. In addition to the closed space, are the use of seals, so that two adjacent coupling surface of the gap between the need to control the liquid can be sealed following the smallest gap. In the contact seal, pressed into self-seal-style and self-styled self-tight seal (ie, sealed lips) two.The three hydraulic system diseases1. as a result of heat transmission medium (hydraulic oil) in the flow velocity in various parts of the existence of different, resulting in the existence of a liquid within the internal friction of liquids and pipelines at the same time there is friction between the inner wall, which are a result of hydraulic the reasons for the oil temperature. Temperature will lead to increased internal and external leakage, reducing its mechanical efficiency. At the same time as a result of high temperature, hydraulic oil expansion will occur, resulting in increased com- pression, so that action can not be very good control of transmission. Solution: heat is the inherent characteristics of the hydraulic system, not only to minimize eradication. Use a good quality hydraulic oil, hydraulic piping arrangement should be avoided as far as possible the emergence of bend, the use of high-quality pipe and fittings, hydraulic valves, etc.2. the vibration of the vibration of the hydraulic system is also one of its malaise. As a result of hydraulic oil in the pipeline flow of high-speed impact and the control valve to open the closure of the impact of the process are the reasons for the vibration system. Strong vibration control action will cause the system to error, the system will also be some of the more sophisticated equipment error, resulting in system failures. Solutions: hydraulic pipe should be fixed to avoid sharp bends. To avoid frequent changes in flow direction, can not avoid damping measures should be doing a good job. The entire hydraulic system should have a good damping measures, while avoiding the external local oscillator on the system.3. the leakage of the hydraulic system leak into inside and outside the leakage. Leakagerefers to the process with the leak occurred in the system, such as hydraulic piston-cylinder on both sides of the leakage, the control valve spool and valve body, such as between the leakage. Although no internal leakage of hydra- ulic fluid loss, but due to leakage, the control of the established movements may be affected until the cause system failures. Outside means the occurrence of leakage in the system and the leakage between the external environment. Direct leakage of hydraulic oil into the environment, in addition to the system will affect the working environment, not enough pressure will cause the system to trigger a fault. Leakage into the environment of the hydraulic oil was also the danger of fire. Solution: the use of better quality seals to improve the machining accuracy of equipment.Another: the hydraulic system for the three diseases, it was summed up: "fever, with a father拉稀" (This is the summary of the northeast people). Hydraulic system for the lifts, excavators, pumping station, dynamic, crane, and so on large-scale industry, construction, factories, enterprises, as well as elevators, lifting platforms, Deng Axle industry and so on.Hydraulic components will be high-performance, high-quality, high reliability, the system sets the direction of development; to the low power, low noise, vibration, without leakage, as well as pollution control, water-based media applications to adapt to environmental requirements, such as the direction of development; the development of highly integrated high power density, intelligence, macaronis and micro-light mini-hydraulic components; active use of new techniques, new materials and electronics, sensing and other high-tech.---- Hydraulic coupling to high-speed high-power and integrated development of hydraulic transmission equipment, development of water hydraulic coupling medium speedand the field of automotive applications to develop hydraulic reducer, improve product reliability and working hours MTBF; hydraulic torque converter to the development of high-power products, parts and components to improve the manufacturing process technology to improve reliability, promote computer-aided technology, the development of hydraulic torque converter and power shift transmission technology supporting the use of ; Clutch fluid viscosity should increase the quality of products, the formation of bulk to the high-power and high-speed direction.Pneumatic Industry:---- Products to small size, light weight, low power consumption, integrated portfolio of development, the implementation of the various types of components, compact structure, high positioning accuracy of the direction of development; pneumatic components and electronic technology, to the intelligent direction of development; component performance to high-speed, high-frequency, high-response, high-life, high temp- erature, high voltage direction, commonly used oil-free lubrication, application of new technology, new technology and new materials.1. Used high-pressure hydraulic components and the pressure of continuous work to reach 40Mpa, the maximum pressure to achieve instant 48Mpa;2. Diversification of regulation and control;3. To further improve the regulation performance, increase the efficiency of the power train;4. Development and mechanical, hydraulic, power transmission of the composite portfolio adjustment gear;5. Development of energy saving, energy efficient system function;6. To further reduce the noise;7. Application of Hydraulic Cartridge Valves thread technology, compact structure, to reduce the oil spill.液压系统液压传动和气压传动称为流体传动，是根据17世纪帕斯卡提出的液体静压力传动原理而发展起来的一门新兴技术，1795年英国约瑟夫•布拉曼(Joseph Braman,1749-1814)，在伦敦用水作为工作介质，以水压机的形式将其应用于工业上，诞生了世界上第一台水压机。

附录AHydraulic Brake SystemsWhen you step on the brake pedal,you expect the vehicle to stop.The brake pedal operates a hydraulic that is used for two reasons.First,fluid under pressure can be carried to all parts of the vehicle by small hoses or metal lines without taking up a lot of room of causing routing problems.Second,the hydraulic fluid offers a great mechanical advantage-little foot pressure is required on the pedal,but a great deal of pressure is generated at the wheels.The brake pedal is linked to a piston in the brake master cylinder containing a small piston and a fluid reservoir.Modern master cylinders are actually two separate cylinders.Such a system is called a dual circuit,because the front cylinder is connected to the front brakes and the rear cylinder to the rear brakes.(Some vehicles are connected diagonally).The two cylinders are actually separated,allowing for emergency stopping power should one part of the system fail.The entire hydraulic system from the master cylinder to the wheels is full of hydraulic brake fluid.When the brake pedal is depressed,the piston in the master cylinder are forced to move,exerting tremendous force on the fluid in the lines.The fluid has nowhere to go,and forces the wheel cylinder pistons(drum brakes) orcaliper pistons(disc brakes) to exert pressure on the brake shoes or pads.The friction between the brake shoe and wheel drum or the brake pad and rotor (disc) slows the vehiche and eventually stops it.Also attached to the brake pedal si a switch that lights the brake lights as the pedal is depressed.The lights stay on until the brake pedal is released and returns to its normal position.Each wheel cylinder in a drum brake system contains two pistons,one at either end,which push outward in opposite directions.In disc brake systems,the wheel cylinders are part of the caliper (there can be as many as four or as few as one ).Whether disc or drum type,all pistons use some type of rubber seal to prevent leakage around thepiston,and a rubber dust boot seals the outer of the wheel cylinders against dirt and moisture.When the brake pedal is released,a spring pushes the master cylinder pistons back to their normal positions.Check valves in the master cylinder piston allow fluid to flow toward the wheel cylinders or calipers as the piston returns.Then as the brake shoe return springs pull the brake shoes back to the released position,excess fluid returns to the master cylinder through compensating ports,which have been uncovered as the pistons move back.Any fluid that has leaked from the system will also be replaced through the compensating ports.All dual circuit brake systems use a switch to activate a light,warning of brake failure.The switch si located in a valve mounted near the master cylinder.A piston in the valve reveives pressure on each end from the front and rear brake circuits.When the pressures are balanced,the piston remains stationary,but when one circuit has a leak,greater pressure during the application of the brakes will force the piston to one side or the other,closing the switch and activating the warning light.The light can also be activated by the ignition switch during engine starting or by the parking brake.Front disc,rear drum brake systems also have a metering valve to prevent the front disc brakes from engaging before the rear brakes have contacted the drums.This ensures that the front brakes will not normally be used alone to stop the vehicle.A proportioning valve is also used to limit pressure to the rear brakes to prevent rear wheel lock-up during hard braking.Brake shoes and pads are constructed in a similar.The pad or shoe is composed of a metal backing plate and a priction lining.The lining is either bonded(glued) to the metal,or riveted.Generally,riveted linings provide superior performance,but good quality bonded linings are perfectly adequate.Friction materials will vary between manufacturers and type of pad and the material compound may be referred to as asbestos,organic,semi-metallic,metallic.The difference between these compounds lies in the types and percentages of friction materials used,material binders and performance modifiers.Generally speaking,organic and non-metallic asbestos compound brakes are quiet,easy on rotors and provide good feel.But this comes at the expense of high temperature operation,so they may not be your best choice for heavy duty use or mountiandriving.In most cases,these linings will wear somewhat faster than metallic compound pads,so you will usually replace them more often.But,when using these pads,rotors tend to last longer.Semi-metallic or metallic compound brake linings will vary in performance based on the metallic contents of the compound.Again,generally speaking,the higher the metallic content,the better the friction material will resist heat.This makes them more appropriate for heavy duty applications,but at the expense of braking performance before the pad reaches operating temperature.The first few applications on a cold morning may not give strong braking.Also,metallics and semi-metallics are more likely to squeal,In most cases,metallic compounds last longer than non-metallic pads,but they tend to cause more wear on the rotors.If you use metallic pads,expect to replace the rotors more often.When deciding what type of brake lining is right for you,keep in mind that today’s modern cars have brake materials which are matched to the expected vehicle’s performance capabilities.Changing the material from OEM specification could adversely addect brake feel or responsiveness.Before changing the brake materials,talk to your deaker or parts supplier to help decide what is most appropriate for your application. Remenber that use applications such as towing,stop and go driving,driving down mountain roads,and racing may require a change to a higher performance material.Some more exotic materials are also used in brake linings,among which are Kevlar and carbon compounds.These materials have the capability of extremely good performance for towing,mountain driving or racing.Wear characteristics can be similar to either applications tend to wear like metallic linings,while many of the streetapplications aremore like the non-metallics.附录B液压制动系统当踩下制动踏板，您希望该车辆停下。

附录1：外文翻译自动五速手动变速箱- EASYTRONIC 3.0。

The new Opel/Vauxhall公司在2014年秋季推出了自动化五速手动变速箱(MTA) Easytronic 3.0。

该变速器使用电动液压离合器和位移控制，其主要部件主来自手动变速箱(F17-5)。

这个新的变速器新增了停止/启动功能，而他的控制系统是根据安全标准ISO 26262设计的。

DIPL.-ING。

THOMAS ZEMMRICH是德国Adam Opel公司变速器自动化MT系统组长和技术专家。

持续战略2014年秋季，欧宝/沃克斯豪尔公司引进了新一代自动化手动变速器MTA(手动变速器) Easytronic 3.0。

这延续了公司自2001年开始战略，通过这种低成本的变速器有效代替小型车辆的常规自动变速器。

由于传统变速器在传动过程中有扭矩中断会使车辆在驾驶时舒适度不佳。

因此，他们设计了与传统变速箱相比操作操作更简便，燃油经济性更好的，并且带有运动驾驶风格的自动化变速器。

这篇文章介绍了欧宝新推出的MTA 的设计和性能特点。

变速器的设计这款新推出的变速器是在Opel公司五速手动变速箱(F17-5)的基础上开发的，它的扭矩容量为190Nm。

这款变速器用在中小型汽油发动机手动档车型上的排量高达1.4L，用在材油机手动挡车型上的排量为1.3L。

虽然拥有高达200Nm转矩容量的6速变速箱越来越受到欢迎，但是考虑到成本，目前五速版的变速箱任是小型汽车的首选。

这款变速器采用拨叉和同步器进行换档，所选的齿轮组传动比范围为5.53，这对于一个五速变速箱来说是一个相当大的传动比范围。

由于较大的传动比范围，使得一档工作时不需要输入较大的转矩，使驾驶舒适性能得到提高，且在五档工作时不需要发动机输入较高的转速就可以获得较高的驾驶速度，还能够降低噪音，提高燃油经济性。

后者是实现自动手动变速器而不损失任何性能，因为加速度可以通过快速自动降档来实现。

外文文献翻译(含：英文原文及中文译文)英文原文Hydraulic systemW Arnold1 IntroductionThe hydraulic station is called a hydraulic pump station and is an independent hydraulic device. It is step by step to supply oil. And control the direction of hydraulic oil flow, pressure and flow, suitable for the host and hydraulic equipment can be separated on the various hydraulic machinery.After the purchase, the user only needs to connect the hydraulic station and the actuator (hydraulic or oil motor) on the mainframe with different tubings. The hydraulic machine can realize various specified actions and working cycles.The hydraulic station is a combination of manifolds, pump units or valve assemblies, electrical boxes, and tank electrical boxes. Each part function is:The pump unit is equipped with a motor and an oil pump, which is the power source of the hydraulic station and can convert mechanical energy into hydraulic oil pressure energy.V alve combination - its plate valve is mounted on the vertical plate, and the rear plate is connected with the same function as the manifold.Oil manifolds - assembled from hydraulic valves and channel bodies. It regulates hydraulic oil pressure, direction and flow.Box--a semi-closed container for plate welding. It is also equipped with an oil screen, an air filter, etc., which is used for cooling and filtering of oil and oil.Electrical box - divided into two types: one is to set the external lead terminal board; one is equipped with a full set of control appliances.The working principle of the hydraulic station: The motor drives the oil pump to rotate, then the pump sucks oil from the oil tank and supplies oil, converts the mechanical energy into hydraulic pressure energy, and the hydraulic oil passes through the manifold (or valve assembly) to adjust the direction, pressure and flow and then passes through the external tube. The way to the hydraulic cylinder or oil motor in the hydraulic machinery, so as to control the direction of the hydraulic motor, the strength of the speed and speed, to promote all kinds of hydraulic machinery to do work.(1) Development history of hydraulic pressureThe development history of hydraulics (including hydraulic power, the same below), pneumatics, and seals industry in China can be roughly divided into three stages, namely: the starting stage in the early 1950s to the early 60s; and the professional in the 60s and 70s. The growth stage of the production system; the 80-90's is a stage of rapid development. Among them, the hydraulic industry began in the early 1950s with thedevelopment of hydraulic machines such as Grinding Machines, broaching machines, and profiling lathes, which were produced by the machine tool industry. The hydraulic components were produced by the hydraulic workshop in the machine tool factory, and were produced for self use. After entering the 1960s, the application of hydraulic technology was gradually promoted from the machine tool to the agricultural machinery and engineering machinery. The original hydraulic workshop attached to the main engine plant was independent and became a professional manufacturer of hydraulic components. In the late 1960s and early 1970s, with the continuous development of mechanization of production, particularly in the provision of highly efficient and automated equipment for the second automobile manufacturing plant, the hydraulic component manufacturing industry witnessed rapid development. The batch of small and medium-sized enterprises also began to become specialized manufacturers of hydraulic parts. In 1968, the annual output of hydraulic components in China was close to 200,000 pieces. In 1973, in the fields of machine tools, agricultural machinery, construction machinery and other industries, the professional factory for the production of hydraulic parts has grown to over 100, and its annual output exceeds 1 million pieces. Such an independent hydraulic component manufacturing industry has taken shape. At this time, the hydraulic product has evolved from the original imitation Su product intoa combination of imported technology and self-designed products. The pressure has been developed towards medium and high pressures, and electro-hydraulic servo valves and systems have been developed. The application of hydraulics has been further expanded. The pneumatic industry started a few years later than hydraulics, and it was only in 1967 that it began to establish a professional pneumatic components factory. Pneumatic components began to be manufactured and sold as commodities. Its sealing industry including rubber seals, flexible graphite seals, and mechanical seals started from the production of common O-rings, oil seals, and other extruded rubber seals and asbestos seal products in the early 1950s. In the early 1960s, it began to develop and produce flexible products. Graphite seals and mechanical seals and other products. In the 1970s, a batch of batches of professional production plants began to be established one after another in the systems of the former Ministry of Combustion, the Ministry of Agriculture, and the Ministry of Agricultural Machinery, formally forming the industry, which laid the foundation for the development of the seal industry.In the 1980s, under the guidance of the national policy of reform and opening up, with the continuous development of the machinery industry, the contradiction between the basic components lags behind the host computer has become increasingly prominent and caused the attention of all relevant departments. To this end, the former Ministry of Machinesestablished the General Infrastructure Industry Bureau in 1982, and unified the original pneumatic, hydraulic, and seal specialties that were scattered in the industries of machine tools, agricultural machinery, and construction machinery, etc. The management of a piece of office, so that the industry in the planning, investment, the introduction of technology and scientific research and development and other aspects of the basic parts of the bureau's guidance and support. This has entered a period of rapid development, it has introduced more than 60 foreign advanced technology, of which more than 40 hydraulic, pneumatic 7, after digestion and absorption and technological transformation, are now mass production, and has become the industry's leading products . In recent years, the industry has intensified its technological transformation. From 1991 to 1998, the total investment of national, local, and corporate self-raised funds totaled about 2 billion yuan, of which more than 1.6 billion were hydraulic. After continuous technological transformation and technological breakthroughs, the technical level of a group of major enterprises has been further improved, and technological equipment has also been greatly improved, laying a good foundation for forming a high starting point, specialization, and mass production. In recent years, under the guidance of the principle of common development of multiple ownership systems in the country, various small and medium-sized enterprises with different ownership have rapidly emerged and haveshown great vitality. With the further opening up of the country, foreign-funded enterprises have developed rapidly, which plays an important role in raising industry standards and expanding exports. So far China has established joint ventures with famous manufacturers in the United States, Germany, Japan and other countries or directly established piston pumps/motors, planetary speed reducers, hydraulic control valves, steering gears, hydraulic systems, hydrostatic transmissions, and hydraulic components. The company has more than 50 manufacturing enterprises such as castings, pneumatic control valves, cylinders, gas processing triplets, rubber seals, and mechanical seals, and has attracted more than 200 million U.S. dollars in foreign capital.(2) Current statusBasic profileAfter more than 40 years of hard work, China's hydraulics, pneumatics and seals industry has formed a complete industrial system with a certain level of production capacity and technical level. According to the statistics of the third n ational industrial census in 1995, China’s state-owned, privately-owned, cooperative, village-run, individual, and “funded enterprises” have annual sales income of more than 1 million yuan in hydraulic, pneumatic, and seal industrial townships and above. There are a total of more than 1,300 companies, including about 700 hydraulics, and about 300 pneumatic and sealing parts. According to thestatistics of the international industry in 1996, the total output value of the hydraulic industry in China was about 2.448 billion yuan, accounting for the 6th in the world; the total output value of the pneumatic industry was about 419 million yuan, accounting for the world’s10 people.2. Current supply and demand profileWith the introduction of technology, independent development and technological transformation, the technical level of the first batch of high-pressure plunger pumps, vane pumps, gear pumps, general hydraulic valves, oil cylinders, oil-free pneumatic components and various types of seals has become remarkable. Improve, and can be stable mass production, provide guarantees for all types of host to improve product quality. In addition, certain achievements have also been made in the aspects of CAD, pollution control, and proportional servo technology for hydraulic pneumatic components and systems, and have been used for production. So far, the hydraulic, pneumatic and seal products have a total of about 3,000 varieties and more than 23,000 specifications. Among them, there are about 1,200 types of hydraulic pressure, more than 10,000 specifications (including 60 types of hydrodynamic products, 500 specifications); about 1350 types of pneumatic, more than 8,000 specifications; there are also 350 types of rubber seals, more than 5000 The specifications are now basically able to adapt to the general needs ofvarious types of mainframe products. The matching rate for major equipment sets can reach more than 60%, and a small amount of exports has started.In 1998, the domestic production of hydraulic components was 4.8 million pieces, with sales of about 2.8 billion yuan (of which mechanical systems accounted for 70%); output of pneumatic components was 3.6 million pieces, and sales were about 550 million yuan (including mechanical systems accounting for about 60%) The production of seals is about 800 million pieces, and the sales volume is about 1 billion yuan (including about 50% of mechanical systems). According to the statistics of the annual report of the China Hydraulic and Pneumatic Sealing Industry Association in 1998, the production and sales rate of hydraulic products was 97.5% (101% of hydraulic power), 95.9% of air pressure, and 98.7% of seal. This fully reflects the basic convergence of production and sales.Although China's hydraulic, pneumatic and sealing industries have made great progress, there are still many gaps compared with the development needs of the mainframe and the world's advanced level, which are mainly reflected in the variety, performance and reliability of products. . Take hydraulic products as an example, the product varieties are only 1/3 of the foreign country, and the life expectancy is 1/2 of that of foreign countries. In order to meet the needs of key hosts, imported hosts, and majortechnical equipment, China has a large number of imported hydraulic, pneumatic, and sealing products every year. According to customs statistics and relevant data analysis, in 1998, the import volume of hydraulic, pneumatic and seal products was about 200 million U.S. dollars, of which the hydraulic pressure was about 140 million U.S. dollars, the pneumatics were 30 million U.S. dollars, and the seal was about 0.3 billion U.S. dollars. The year is slightly lower. In terms of amount, the current domestic market share of imported products is about 30%. In 1998, the total demand for hydraulic parts in the domestic market was about 6 million pieces, and the total sales volume was 4 billion yuan; the total demand for pneumatic parts was about 5 million pieces, and the total sales volume was over 700 million yuan; the total demand for seals was about 1.1 billion yuan. Pieces, total sales of about 1.3 billion yuan. (3) Future developments1. The main factors affecting development(1) The company's product development capability is not strong, and the level and speed of technology development can not fully meet the current needs for advanced mainframe products, major technical equipment and imported equipment and maintenance;(2) Many companies have lagged behind in manufacturing process, equipment level and management level, and their sense of quality is not strong, resulting in low level of product performance, unstable quality,poor reliability, and insufficiency of service, and lack of user satisfaction. And trusted branded products;(3) The degree of professional specialization in the industry is low, the power is scattered, the duplication of the low level is serious, the product convergence between the region and the enterprise leads to blind competition, and the prices are reduced each other, thus the efficiency of the enterprise is reduced, the funds are lacking, and the turnover is difficult. Insufficient investment in development and technological transformation has severely restricted the overall level of the industry and its competitive strength.(4) When the degree of internationalization of the domestic market is increasing, foreign companies have gradually entered the Chinese market to participate in competition, coupled with the rise of domestic private, cooperative, foreign-funded, and individual enterprises, resulting in increasing impact on state-owned enterprises. .2. Development trendWith the continuous deepening of the socialist market economy, the relationship between supply and demand in the hydraulic, pneumatic and sealed products has undergone major changes. The seller market characterized by “shortage” has basically become a buyer’s market characterized by “structured surplus”. Replaced by. From the perspective of overall capacity, it is already in a trend of oversupply, and in particular,general low-grade hydraulic, pneumatic and seals are generally oversupply; and like high-tech products with high technological content and high value and high value-added products that are urgently needed by the host, Can not meet the needs of the market, can only rely on imports. After China's entry into the WTO, its impact may be greater. Therefore, during the “10th Five-Y ear Plan” period, the growth of the industry’s output value must not only rely on the growth of quantity. Instead, it should focus on the structural contradiction of the industry and intensify efforts to adjust the industrial structure and product structure. It should be based on the improvement of quality. Product technology upgrades in order to adapt to and stimulate market demand, and seek greater development.2. Hydraulic application on power slide(1) Introduction of Power Sliding TableUsing the binding force curve diagram and the state space analysis method to analyze and study the sliding effect and the smoothness of the sliding table of the combined machine tool, the dynamics of the hydraulic drive system of the sliding table—the self-regulating back pressure regulating system are established. mathematical model. Through the digital simulation system of the computer, the causes and main influencing factors of the slide impact and the motion instability are analyzed. What kind of conclusions can be drawn from those, if we canreasonably design the structural dimensions of hydraulic cylinders and self-regulating back pressure regulators ——The symbols used in the text are as follows:s 1 - flow source, that is, the flow rate of the governor valve outlet;S el —— sliding friction of the sliding table;R - the equivalent viscous friction coefficient of the slide;I 1 - quality of slides and cylinders;12 - self-adjusting back pressure valve core quality;C 1, c 2 - liquid volume without cylinder chamber and rod chamber;C 2 - Self-adjusting back pressure valve spring compliance;R 1, R2 - Self-adjusting back pressure valve damping orifice fluid resistance;R 9 - Self-adjusting back pressure valve valve fluid resistance;S e2——initial pre-tightening force of self-adjusting back pressure valve spring;I 4, I5 - Equivalent liquid sense of the pipeline;C 5, C 6 - equivalent liquid capacity of the pipeline;R 5, R7 - Equivalent liquid resistance of the pipeline;V 3, V4 - cylinder rodless cavity and rod cavity volume;P 3, P4—pressure of the rodless cavity and rod cavity of the cylinder;F - the slide bears the load;V - speed of slide motion;In this paper, the power bond diagram and the state space splitting method are used to establish the system's motion mathematical model, and the dynamic characteristics of the slide table can be significantly improved.In the normal operation of the combined machine tool, the magnitude of the speed of the slide, its direction and the load changes it undergoes will affect its performance in varying degrees. Especially in the process of work-in-process, the unsteady movement caused by the advancing of the load on the slide table and the cyclical change of the load will affect the surface quality of the workpiece to be machined. In severe cases, the tool will break. According to the requirements of the Dalian Machine Tool Plant, the author used the binding force curve diagram and the state space analysis method to establish a dynamic mathematical model of a self-adjusting back pressure and speed adjustment system for the new hydraulic drive system of the combined machine tool slide. In order to improve the dynamic characteristics of the sliding table, it is necessary to analyze the causes and main influencing factors of the impetus and movement of the sliding table. However, it must pass the computer's digital simulation and the final results obtained from the research.(2) Dynamic Mathematical ModelThe working principle diagram of the self-adjusting back pressure speedregulation system of the combined machine tool slide hydraulic drive system is shown in the figure. This system is used to complete the work-cycle-stop-rewind. When the sliding table is working, the three-position four-way reversing valve is in the illustrated position. The oil supply pressure of the oil pump will remain approximately constant under the effective action of the overflow valve, and the oil flow passes through the reversing valve and adjusts the speed. The valve enters the rodless chamber of the cylinder to push the slide forward. At the same time, the pressurized oil discharged from the rod chamber of the cylinder will flow back to the tank through the self-regulating back pressure valve and the reversing valve. During this process, there was no change in the operating status of both the one-way valve and the relief valve. The complex and nonlinear system of the hydraulic drive system of the self-adjusting back pressure governor system is a kind of self-adjusting back-pressure governor system. To facilitate the study of its dynamic characteristics, a simple and reasonable dynamic mathematical model that only considers the main influencing factors is established. Especially important [1][2]. From the theoretical analysis and the experimental study, we can see that the system process time is much longer than the process time of the speed control valve. When the effective pressure bearing area of the rodless cavity of the fuel tank is large, the flow rate at the outlet of the speed control valve is instantaneous. The overshoot is reflected in thesmall change in speed of the slide motion [2]. In order to further broaden and deeply study the dynamic characteristics of the system so that the research work can be effectively performed on a miniature computer, this article will further simplify the original model [2], assuming that the speed control valve is output during the entire system pass. When the flow is constant, this is considered to be the source of the flow. The schematic diagram of the dynamic model structure of this system is shown in Fig. 2. It consists of a cylinder, a sliding table, a self-adjusting back pressure valve, and a connecting pipe.The power bond graph is a power flow graph. It is based on the transmission mode of the system energy, based on the actual structure, and uses the centralized parameters to represent the role of the subsystems abstractly as a resistive element R, a perceptual element I, and a capacitive element. Three kinds of role of C. Using this method, the physical concept of modeling is clear, and combined with the state-space analysis method, the linear system can be described and analyzed more accurately. This method is an effective method to study the dynamic characteristics of complex nonlinear systems in the time domain. According to the main characteristics of each component of the self-adjusting back pressure control system and the modeling rules [1], the power bond diagram of the system is obtained. The upper half of each key in the figure represents the power flow. The two variables that makeup the power are the force variables (oil pressure P and force F) and the flow variables (flow q and velocity v). The O node indicates that the system is connected in parallel, and the force variables on each key are equal and the sum of the flow variables is zero; 1 The nodes represent the series connection in the system, the flow variables on each key are equal and the sum of the force variables is Zero. TF denotes a transformer between different energy forms. The TF subscripted letter represents the conversion ratio of the flow variable or the force variable. The short bar on the key indicates the causal relationship between the two variables on the key. The full arrow indicates the control relationship. There are integral or differential relationships between the force and flow variables of the capacitive and perceptual elements in the three types of action elements. Therefore, a complex nonlinear equation of state with nine state variables can be derived from Fig. 3 . In this paper, the research on the dynamic characteristics of the sliding table starts from the two aspects of the slide's hedging and the smoothness of the motion. The fourth-order fixed-length Runge-Kutta is used for digital simulation on the IBM-PC microcomputer.(3) Slide advanceThe swaying phenomenon of the slide table is caused by the sudden disappearance of the load acting on the slide table (such as drilling work conditions). In this process, the table load F, the moving speed V, and thepressure in the two chambers of the cylinder P3 and P4 can be seen from the simulation results in Fig. 4. When the sliding table moves at a uniform speed under the load, the oil pressure in the rodless cavity of the oil cylinder is high, and a large amount of energy is accumulated in the oil. When the load suddenly disappears, the oil pressure of the cavity is rapidly reduced, and the oil is rapidly reduced. When the high-pressure state is transferred to the low-pressure state, a lot of energy is released to the system, resulting in a high-speed forward impact of the slide. However, the front slide of the sliding table causes the pressure in the rod cavity of the oil cylinder to cause the back pressure to rise, thereby consuming part of the energy in the system, which has a certain effect on the kicking of the slide table. We should see that in the studied system, the inlet pressure of the self-adjusting back pressure valve is subject to the comprehensive effect of the two-chamber oil pressure of the oil cylinder. When the load suddenly disappears, the pressure of the self-adjusting back pressure valve rapidly rises and stably exceeds the initial back pressure value. It can be seen from the figure that self-adjusting back pressure in the speed control system when the load disappears, the back pressure of the cylinder rises more than the traditional speed control system, so the oil in the rod cavity of the cylinder absorbs more energy, resulting in the amount of forward momentum of the slide It will be about 20% smaller than traditionalspeed control systems. It can be seen from this that the use of self-adjusting back-gear speed control system as a drive system slider has good characteristics in suppressing the forward punch, in which the self-adjusting back pressure valve plays a very large role.(4) The smoothness of the slideWhen the load acting on the slide changes periodically (such as in the case of milling), the speed of the slide will have to fluctuate. In order to ensure the processing quality requirements, it must reduce its speed fluctuation range as much as possible. From the perspective of the convenience of the discussion of the problem, assume that the load changes according to a sine wave law, and the resulting digital simulation results are shown in Figure 5. From this we can see that this system has the same variation rules and very close numerical values as the conventional speed control system. The reason is that when the change of the load is not large, the pressure in the two chambers of the fuel tank will not have a large change, which will eventually lead to the self-regulating back pressure valve not showing its effect clearly.(5) Improvement measuresThe results of the research show that the dynamic performance of a sliding table with self-regulating back pressure control system as a drive system is better than that of a traditional speed control system. To reduce the amount of kick in the slide, it is necessary to rapidly increase the backpressure of the rod cavity when the load disappears. To increase the smoothness of the sliding table, it is necessary to increase the rigidity of the system. The main measure is to reduce the volume of oil. From the system structure, it is known that the cylinder has a large volume between the rod cavity and the oil discharge pipe, as shown in Fig. 6a. Its existence in terms of delay and attenuation of the self-regulating back pressure valve function, on the other hand, also reduces the rigidity of the system, it will limit the further improvement of the propulsion characteristics and the smoothness of the motion. Thus, improving the dynamic characteristics of the sliding table can be handled by two methods: changing the cylinder volume or changing the size of the self-regulating back pressure valve. Through the simulation calculation of the structural parameters of the system and the comparison of the results, it can be concluded that the ratio of the volume V4 between the rod cavity and the oil discharge pipe to the volume V3 between the rodless cavity and the oil inlet pipe is changed from 5.5 to 5.5. At 1 oclock, as shown in the figure, the diameter of the bottom end of the self-adjusting back pressure valve is increased from the original 10mm to 13mm, and the length of the damper triangle groove is reduced from the original lmm to 0.7mm, which will enable the front of the slide table. The impulse is reduced by 30%, the transition time is obviously shortened, and the smoothness of the slide motion will also be greatly improved.中文译文液压系统W Arnold1. 绪论液压站称液压泵站,是独立的液压装置。

中文1829字Hydraulic MachineFrom: The Columbia Encyclopedia, Sixth Edition Date: 2008Hydrulic machine that derives its power from the motion or pressure of water or some other liquid. Hydraulic equipment and technology is something that we are all at least passingly familiar with. If we think about it, we know that the principles of hydraulics are applied to make many common machines work. For example hydraulics are used in agricultural equipment, giant earth moving and mining machines, they are used to steer and stabilize giant ocean liners, help airplanes climb and turn, and make the brakes in our cars work. So hydraulics can provide great force, are obviously very adaptable and used in all kinds of applications, but how do they actually work?What is this hydraulics stuff?Hydraulics is based on a very simple fact of nature - you cannot compress a liquid. You can compress a gas (think about putting more and more air into a tire, the more you put in, the higher the pressure). If you're really strong you can compress a solid mass as well. But no matter how much pressure you apply onto a liquid, it isn't possible to compress it. Now if you put that liquid into a sealed system and push on it at one end, that pressure is transmitted through the liquid to the other end of the system. The pressure is not diminished.. Hydraulics is Old StuffThe basic concept of hydraulics is not new. The Greeks understood about using water to provide lift and force, and the name hydraulics come form the Latin word for water - "HYDRA". In the middle Ages, Leonardo da Vinci formulated the basic principle of hydraulics called continuity and Galileo experimented with hydraulics.Hydraulics were even used during the construction of the Eiffel Tower in Paris in the late 1880's. Hydraulic jacks were used to level the tower and align the metal girders to an accuracy of 1 millimeter。

液压方面的英语单词目录按字母排序 (1)按分类排序 (10)其他总结的词汇 (13)按字母排序Aability 性能；能力load-carrying ability 承载能力absorber 吸收器；吸收剂；过滤器；减震器accessories 辅件，附件，配件hydraulic accessories 液压辅件accumulate 储存；蓄能；累积accumulator 蓄能器；蓄电池；累加器accuracy 准确性；精度action 作用；动作；作用力；行程actuated 操纵，控制directly actuated 直接操纵的，直接控制的pilot actuated 先导控制的，液控的actuator 执行元件；液压缸；马达adapter 接头；衬套；压环；连接件pipe adapter 管接头admission 供给，供油，供气alignment 找正，定心，对中amplifier 放大器differential pressure amplifier 压差放大器flow amplifier 流量放大器assembly 组合，组件，机组axis 轴Bback-flow 回流back-up 支撑hydrostatic back-up 静压支撑barrel 桶，缸体base 底座；支座bearing 支承；轴承；方位radial ball bearing 径向球轴承rolling bearing 滚动轴承sliding bearing 滑动轴承thrust bearing 止推轴承bed 台pump test bed 泵试验台behavior 性能；工况bend 弯头；弯管blade 叶片flat blade 平面叶片forward inclined blade 前倾叶片guide blade 导叶radial blade 径向叶片bleed 排气air bleed 排气阀bleeder 排气孔block 块；封闭；块体cartridge valve block 插装阀块体choke block 节流板directional control block 多路阀，方向控制阀组panel block 阀板组body 体；缸筒；阀体，壳体pump body 泵体tank body 箱体valve body 阀体bolt 螺栓；插销；螺杆boss 轮毂bottom 底；底部cylinder bottom 缸底；缸后盖bracket 支架pump bracket 泵架bubble-tight 气密的buffer 缓冲器，阻尼器bush(ing) 套，导向套；衬套Ccap 帽,盖,罩,塞cylinder end cap 缸端盖cylinder head cap 缸前盖capacity 容量;功率;排量;流量effective capacity 有效排量,实际排量geometric capacity 几何排量,理论排量casing 套,壳,罩gear casing 齿轮箱，变速箱pump casing 泵体cavitation 气蚀cavity 腔centering 中心调整，定心chamber 腔，室；容积；油腔；气腔chamfer 槽；倒角changement 换向机构characteristic 特性曲线；特征线charger 加载装置charging 充液；充压choke 节流；节流口chord 弦circlip 弹性挡圈circuit 回路clearance 间隙clog 阻塞；堵塞cock 龙头collar 圈；法兰盘cushion collar 缓冲套locating collar 定位凸缘套loose collar 轴肩挡圈thrust collar 止推环connection 连接；连接管路；接头consumption 消耗量cylinder 缸；液压缸Ddebugging 排除故障；调试deflation 排气delivery 流量differential 差动的；微分的displacement 压出；排出；排量；位移dowel 定位销drained 泄油的duty 负载，功率；工况Eeffect 作用;效应cavitate effect 气蚀效应choking effect 节流作用elbow 弯头electro-hydraulic 电液的entrap 困油escape 泄漏,逸出,排出etching 蚀刻;腐蚀gas etching 气蚀exhaust 排泄;回油;Ffailure 故障;事故;损坏,失效fastener 紧固件fatigue 疲劳feedback 反馈filler 加油口,注油口;填料;垫片filter 滤油器flow 流;液流;流程;流束;流量;流动nominal flow 公称流量rated flow 额定流量stationary flow 定常流,定常流动streamline flow 层流turbulent flow 紊流volume flow 体积流量flowline 管路;流线flow-regulator 流量调节阀fluctuation 脉动fluid 流体,液体;射流hydraulic operating fluid 液压油incompressible fluid 不可压缩流体frame 座,架Ggain 增益flow gain 流量增益feedback gain 反馈增益gap 间隙,缝隙gear 齿轮,装置,机构governing 调节,控制Hhead 缸头,头部;盖;水头;扬程cylinder head 缸头static head 静压头theoretic head 理论能头total head 总能头water head 水头hole 孔,洞air hole 气孔blind hole 盲孔bolt hole 螺栓孔bose 胶管,软管housing 壳体;槽hub 毂;衬套hydrostatics 液压技术,液体静力学Iidling 空转impact 冲击,撞击impeller 叶轮closed impeller 闭式叶轮open impeller 开式叶轮pump impeller 泵叶轮incidence 入射;入射角blade incidence 叶片安装角incompressible 不可压缩的inlet 进口;吸入intensifier 增压器intensity 强度Jjack (柱塞)缸;千斤顶joint 接头;关节cross joint 十字接头flange joint 法兰式接头screwed joint 螺纹接头journal 轴颈jump 跳动;振动pressure jump 压力突变Kkeyway 键槽Llag 滞后;延迟servovalve phase lag 伺服阀相位滞后laminar 层流的latch 插销;锁紧装置;锁定leak 漏;漏油;渗漏处;漏出物line 管路;线路liner 衬套;导向套;内层胶liquid 液体(的);液力的load 负载;载荷location 位置;定位;安装lock 锁;闭锁;液压卡紧loop 环;环路;回路;循环control loop 控制回路,调节回路main loop 主回路servo loop 伺服回路loss 损失bend loss 弯头损失blade loss 叶片损失line loss 管路损失local pressure loss 局部压力损失partial loss 局部损失lubricate 润滑lug 耳轴lifting lug 吊环Mmandrel 心轴;芯棒manometer 压力机,压力表meter 米;仪表;计量;节制;控制(流量);流量计meter-in 进口节流meter-out 出口节流motion 动作alternative motion 往复运动lost motion 空转synchronized motion 同步运动motor 发动机,液压马达axial piston motor 轴向柱塞马达bent axis piston motor 斜轴式轴向柱塞马达cam plate type axial piston motor 斜盘式轴向柱塞马达constant displacement motor 定量马达radial motor 径向马达sliding vane motor 叶片马达swing motor 摆动马达Nnominal 额定的,公称的notch 凹槽relief notch 卸荷槽null 零位Ooff-load 卸荷oil 油oiler 注油器olive 球面卡套grooved olive 迷宫密封环operation 运行;操作;运算orifice 小孔;节流孔O-ring O型密封圈output 输出;排量;流量overload 过载Ppack 包,捆;组合件,部件,单元power pack 液压泵站package包,捆;组件,单元hydraulic package 液压泵站power package 泵站packing 密封;密封装置;填料密封pad 衬垫;底座asbestos pad 石棉垫valve pad 阀垫parameter 参数part 部分;零件;部件partition 隔板passage 流道;通道;通过pedestal 支座,底座motor pedestal 电动机座phenomenon 现象stick-alip phenomenon 爬行现象trapping phenomenon 困油现象piece 零件,部件pilot(-actuate,-operate) 先导控制;液控piloted 先导控制的pin 销;插头alignment pin 定位销cottar pin 开口销locking pin 锁紧销piston pin 活塞销straight pin 圆柱销pipe 管子,管道(尤指铸铁管和钢管) piston 活塞;柱塞;阀芯double acting piston 双作用活塞double rod piston 双杆活塞hollow piston 空心活塞single-rod piston 单杆活塞pit 坑;槽pitch 节距pitting 凹痕;锈斑;点蚀plug 堵塞;阻塞;堵头air release plug 排气塞plug-in 插入式的,组合式的poppet 提动阀芯,座阀芯,锥阀芯,碟形阀芯pore 孔;孔隙port 油口;连接口position 位置;状态;定位center valve position 阀的中间位置neutral position 中位;零位three position 三位two position 二位pressure 压力,压强;气压pulsation 脉动,波动pump 泵bent axis axial piston pump 斜轴式轴向柱塞泵booster pump 辅助泵,充液泵cam plate type axial piston pump 斜盘式轴向柱塞泵centrifugal pump 离心泵constant delivery pump 定量泵cycloid rotor pump 摆线转子泵double action vane pump 双作用叶片泵gear pump 齿轮泵multi-stage pump 多级泵single action vane pump 单作用叶片泵vane pump 叶片泵variable capacity pump 变量泵Rrabbet 球铰rack 齿条;机架racing 空转radian 弧度radius 半径range 范围,量程rated 额定的regulation 调节,调整regulator 调节器,调压阀differential pressure regulator 定差减压阀proportional pressure regulator 定比减压阀relay 继电器relief 释压;溢流;卸荷reset 复位restriction 节流;阻尼,节流口,阻尼孔restrictor 节流阀;节流口;阻尼孔reversal 反转,倒转revolution 旋转;转数rider 导向套ring 环,圈anti-extrusion ring 密封挡圈,挡圈back support ring 后支承环back-up ring 挡圈bearing ring 导向套dust ring 防尘圈retainer ring 卡环seal ring 密封圈;密封环rod 杆;活塞杆Sscrew 螺杆,螺钉,丝杆,螺旋seal 密封;封口;密封件;密封装置seat 阀座,座seizure 卡死,咬住,擦伤selector 换向阀servo 伺服;伺服机构,伺服系统servomotor 伺服马达servopump 伺服泵servovalve 伺服阀set 组件;定位;集合shaft 轴pump shaft 泵轴sleeve 套;套管;卡套;阀套slot 缝,隙,槽spring 弹簧stroke 行程symbol 符号functional symbol 职能符号Ttank 箱,缸;油箱;容器tee 三通接头,三通throttle 节流;节流阀trapping 困油travel 位移;行程tube 管子(尤指有色金属和无缝钢管) tubeline 管路Uunion 中间接头;直通接头Vvalve 阀back pressure valve 背压阀bypass valve 旁通阀;溢流阀change valve 换向阀check valve 单向阀direct operated solenoid valve 电磁阀flow regulating valve 调速阀four port valve 四通阀four position valve 四位阀hand operated valve 手动阀hydraulic operated check valve 液控单向阀overflow valve 溢流阀overload relief valve 安全阀;过载溢流阀piloted valve 先导式阀vane 叶片diffusion vane 导叶vent 放气;排气孔volume 容积,体积displacement volume 排量Wwasher 垫圈;衬垫wiper 防尘圈Zzone 地带;区(域)dead zone 死区high pressure zone 高压区low pressure zone 低压区按分类排序一、阀类出口节流回路meter-out circuit同步回路synchronizing circuit开式回路open circuit闭式回路closed circuit管路布置pipe-work管卡clamper联轴器drive shaft coupling操作台control console控制屏control panel避震喉compensator粘度viscosity运动粘度kinematic viscosity密度density含水量water content闪点flash point防锈性rust protection抗腐蚀性anti-corrosive quality便携式颗粒检测仪portable particle counter 电磁阀Solenoid valve单向阀Check valve插装阀Cartridge valve叠加阀Sandwich plate valve先导阀Pilot valve液控单向阀Pilot operated check valve板式安装Sub-plate mount集成块Manifold block压力溢流阀Pressure relief valve流量阀Flow valve节流阀Throttle valve双单向节流阀Double throttle check valve 旋钮Rotary knob节流板Rectifier plate伺服阀Servo valve比例阀Proportional valve位置反馈Position feedback渐增流量Progressive flow电磁铁释放De-energizing of solenoid二、介质类磷酸甘油酯Phosphate ester (HFD-R)水-乙二醇Water-glycol (HFC)乳化液Emulsion缓蚀剂Inhibitor合成油Synthetic lubricating oil三、液压安装工程污染Contamination灌浆Grout失效Failure点动Jog爬行Creep摩擦Abrasion（活塞杆）伸出Retract（活塞杆）缩回Extension误动作Malfunction酸洗Pickling冲洗Flushing槽式酸洗Dipping process循环Re-circulation钝化Passivity柠檬酸Nitric acid氩气Argon对接焊Butt welding套管焊Socket welding惰性气体焊Inert gas welding四、管接头Bite type fittings 卡套式管接头Tube to tube fittings接管接头union 直通接管接头union elbow 直角管接头union tee 三通管接头union cross 四通管接头Mal stud fittings 端直通管接头Bulkhead fittings 长直通管接头Weld fittings 焊接式管接头Female connector fittings 接头螺母Reducers extenders 变径管接头Banjo fittings 铰接式管接头Adjustable fittings/swivel nut 旋转接头五、伺服阀及伺服系统性能参数Dynamic response 动态频响DDV-direct drive valve 直动式伺服阀NFPA-National Fluid Power Association 美国流体控制学会Phase lag 相位滞后Nozzle flapper valve 喷嘴挡板阀Servo-jet pilot valve 射流管阀Dither 颤振电流Coil impedance 线圈阻抗Flow saturation 流量饱和Linearity 线形度Symmetry 对称性Hysterics 滞环Threshold 灵敏度Lap 滞后Pressure gain 压力增益Null 零位Null bias 零偏Null shift 零飘Frequency response 频率响应Slope 曲线斜坡液压系统（hydraulic system）执行元件（actuator）液压缸（cylinder）液压马达（motor）液压回路（circuit）压力控制回路（pressure control）流量（速度）控制回路（speed control）方向控制回路（directional valve control）安全回路（security control）定位回路（position control）同步回路（synchronise circuit）顺序动作回路（sequeunt circuit）液压泵（pump）阀（valve）压力控制阀（pressure valve）流量控制阀（flow valve）方向控制阀（directional valve）液压辅件（accessory）普通阀（common valve）其他总结的词汇流体传动hydraulic power液压技术hydraulics液力技术hydrodynamics气液技术hydropneumatics运行工况operating conditions额定工况rated conditions极限工况limited conditions瞬态工况instantaneous conditions稳态工况steady-state conditions许用工况acceptable conditions连续工况continuous working conditions 实际工况actual conditions效率efficiency旋转方向direction of rotation公称压力nominal pressure工作压力working pressure进口压力inlet pressure出口压力outlet pressure压降pressure drop；differential pressure背压back pressure启动压力breakout pressure充油压力charge pressure开启压力cracking pressure峰值压力peak pressure运行压力operating pressure耐压试验压力proof pressure冲击压力surge pressure静压力static pressure系统压力system pressure控制压力pilot pressure充气压力pre-charge pressure吸入压力suction pressure调压偏差override pressure额定压力rated pressure耗气量air consumption泄漏leakage内泄漏internal leakage外泄漏external leakage层流laminar flow紊流turbulent flow气穴cavitation流量flow rate排量displacement额定流量rated flow供给流量supply flow流量系数flower factor滞环hysteresis图形符号graphical symbol液压气动元件图形符号symbols for hydraulic and pneumatic components 流体逻辑元件图形符号symbols for fluid logic devices逻辑功能图形符号symbols for logic functions回路图circuit diagram压力－时间图pressure time diagram功能图function diagram循环circle自动循环automatic cycle工作循环working cycle循环速度cycling speed工步phase停止工步dwell phase工作工步working phase快进工步rapid advance phase快退工步rapid return phase频率响应frequency response重复性repeat ability复现性reproducibility漂移drift波动ripple线性度linearity线性区linear region液压锁紧hydraulic lock液压卡紧sticking变量泵variable displacement pump 泵的控制control of pump齿轮泵gear pump叶片泵vane pump柱塞泵piston pump轴向柱塞泵axial piston pump法兰安装flange mounting底座安装foot mounting液压马达hydraulic motor刚度stiffness中位neutral position零位zero position自由位free position缸cylinder有杆端rod end无杆端rear end外伸行程extend stroke内缩行程retract stroke缓冲cushioning工作行程working stroke负载压力induced pressure输出力force实际输出力actual force单作用缸single-acting cylinder双作用缸double-acting cylinder差动缸differential cylinder伸缩缸telescopic cylinder阀valve底板sub-plate油路块manifold block板式阀sub-plate valve叠加阀sandwich valve插装阀cartridge valve滑阀slide valve锥阀poppet valve阀芯valve element阀芯位置valve element position单向阀check valve液控单向阀pilot-controlled check valve 梭阀shuttle valve压力控制阀pressure relief valve溢流阀pressure relief valve顺序阀sequence valve减压阀pressure reducing平衡阀counterbalance valve卸荷阀unloading valve直动式directly operated type先导式pilot-operated type机械控制式mechanically controlled type 手动式manually operated type液控式hydraulic controlled type流量控制阀flow control valve固定节流阀fixed restrictive valve可调节流阀adjustable restrictive valve 单向节流阀one-way restrictive valve调速阀speed regulator valve分流阀flow divider valve集流阀flow-combining valve截止阀shut-off valve球阀global(ball) valve针阀needle valve闸阀gate valve膜片阀diaphragm valve蝶阀butterfly valve噪声等级noise level放大器amplifier模拟放大器analogue amplifier数字放大器digital amplifier传感器sensor阈值threshold伺服阀servo-valve四通阀four-way valve喷嘴挡板nozzle flapper液压放大器hydraulic amplifier颤振dither阀极性valve polarity流量增益flow gain对称度symmetry流量极限flow limit零位内泄漏null(quiescent) leakage 遮盖lap零遮盖zero lap正遮盖over lap负遮盖under lap开口opening零偏null bias零漂null drift阀压降valve pressure drop分辨率resolution频率响应frequency response幅值比amplitude ratio相位移phase lag传递函数transfer function管路flow line硬管rigid tube软管flexible hose工作管路working line回油管路return line补液管路replenishing line控制管路pilot line泄油管路drain line放气管路bleed line接头fitting；connection焊接式接头welded fitting扩口式接头flared fitting快换接头quick release coupling法兰接头flange connection弯头elbow异径接头reducer fitting流道flow pass油口port闭式油箱sealed reservoir油箱容量reservoir fluid capacity气囊式蓄能器bladder accumulator 空气污染air contamination固体颗粒污染solid contamination 液体污染liquid contamination空气过滤器air filter油雾气lubricator热交换器heat exchanger冷却器cooler加热器heater温度控制器thermostat消声器silencer双筒过滤器duplex filter过滤器压降filter pressure drop有效过滤面积effective filtration area公称过滤精度nominal filtration rating压溃压力collapse pressure填料密封packing seal机械密封mechanical seal径向密封radial seal旋转密封rotary seal活塞密封piston seal活塞杆密封rod seal防尘圈密封wiper seal；scraper组合垫圈bonded washer复合密封件composite seal弹性密封件elastomer seal丁腈橡胶nitrile butadiene rubber；NBR 聚四氟乙烯polytetrafluoroethene；PTFE 优先控制override control压力表pressure gauge压力传感器electrical pressure transducer 压差计differential pressure instrument液位计liquid level measuring instrument 流量计flow meter压力开关pressure switch脉冲发生器pulse generator液压泵站power station空气处理单元air conditioner unit压力控制回路pressure control circuit安全回路safety circuit差动回路differential circuit调速回路flow control circuit进口节流回路meter-in circuit。

附件2、外文资料翻译译文液压驱动的无级变速器控制4. 液压约束CVT 的比率控制器（实际上）控制初级和次级压力。

几个压力的限制，必须考虑到该控制器：1. 转矩限制P α≥P α的扭矩，防止打滑的滑轮;2. 较低压力的约束P α≥P α，以保持两个电路注满油。

在这里，相当任意的的PPlow=3[bar]选择.为使有足够的油流Qsa 的附件电路和用于被动阀在该电路的一个适当的操作是必要的Qsa 大于最小流Qsa ，最小。

最小压力Ps 低4[bar]转 证明是不够的;3. 上部压力限制P α≤P αmax 以防止损坏液压管路汽缸和活塞.因此，Ppmax=25[bar]PS 最大值=50[bar];4. 液压约束P α≥P α液压，以保证主电路能快速放掉够向漏和次级电路可以提供足够的流动朝向初级电路.压力Pp ，的扭矩和Ps 扭矩限制1依赖于关键的夹紧力 Fcrit 方程（5）.估计转矩Tp 是使用固定式发动机的的扭矩计算 地图，变矩器特性和锁止离合器模式，随着惯性作用一起发动机轮和主齿轮箱轴.安全系数Ks=0.3相对于估计最大的主转矩Tpmax 已被引入到占上干扰估计转矩Tp ，例如冲击负荷的车轮。

然后带轮的夹紧力（相等的两个滑轮，而忽略了变速器效率）所需的扭矩传递变成了：,max cos()()2p p s torquepu k T T FR ϕ∙+∙=∙因此，所产生的压力，可以很容易地使用公式推导（12）和（13）：()21.Ptorque p ppA pc F ω=- (26)()201..s torque s s spr s sc k s P F F Aω=--- (27)一模一样的夹紧装置已被以前使用参考。

[ 3 ]试验台用于测量这款变速箱与测试车路。

无滑移已经实现，在任何这些实验中这项工作的主要目标是改进比跟踪行为，夹紧装置维持不变。

进一步的阐述制约4是基于质量守恒的定律初级电路。

首先，应当指出，对于本论述的泄漏流量Q p ，泄露漏和可压缩长期oil p ppv κ∙∙可忽略不计相比。

外文资料与中文翻译外文资料：Hydraulic Station and the development of hydraulic components Profiles Hydraulic Pump Station also known as the stations are independent h- ydraulic device.It requested by the oil gradually. And controlling the hydraulic oil flow direction, pressure and flow rate, applied to the mainframe and hy- draulic devices separability of hydraulic machinery.Users will be provided after the purchase hydraulic station and host of implementing agencies (motor oil or fuel tanks) connected with tubing, Hydraulic machinery can be realized from these movements and the work cycle.Hydraulic pump station is installed, Manifold or valve combination, t- anks, a combination of electrical boxes.Functional components :Pump device -- is equipped with motors and pumps, hydraulic station is the source of power. to mechanical energy into hydraulic oil pressure can be.Manifold -- from hydraulic valve body and channel assembled. Right direction for implementation of hydraulic oil, pressure and flow control.Valve portfolio -- plate valve is installed in up board after board conn-ects with the same functional IC.Tank -- plate welding semi-closed containers, also loaded with oil filtering network, air filters, used oil, oil filters and cooling.Electrical boxes -- at the two patterns. A set of external fuse terminal plate; distribution of a full range of electrical control.Hydraulic Station principle : motor driven pump rotation, which pump oil absorption from the oil tank. to mechanical energy into hydraulic pressure to the station, hydraulic oil through Manifold (or valve combinations) realized the direction, pressure, After adjusting flow pipe and external to the cylinder hydraulic machinery or motor oil, so as to control the direction of the motive fluid transformation force the size and speed the pace of promoting the various acting hydraulic machinery.A development courseChina Hydraulic (including hydraulic, the same below), pneumatic and seals industrial development process can be broadly divided into three phases, namely : 20 early 1950sto the early 1960s, the initial stage; 60's and 70 for specialized production system ;80~90's growth stage for the rapid development stage. Which, hydraulic industry in the early 1950s from the machine tool industry production of fake Su-grinder, broaching machine, copying lathe, and other hydraulic drive started, Hydraulic Components from the plant hydraulic machine shop, self-occupied. After entering the 1960s, the application of hydraulic technology from the machine gradually extended to the agricultural machinery and mechanical engineering fields, attached to the original velocity of hydraulic shop some stand out as pieces of hydraulic professional production. To the late 1960s, early 1970s, with the development of mechanized production, especially in the second automobile factory in providing efficient, automated equipment, along with the Hydraulic Components manufacturing has experienced rapid development of the situation, a group of SMEs have become professional hydraulic parts factory. 1968 China's annual output of hydraulic components have nearly 200,000 in 1973, machine tools, agricultural machinery, mechanical engineering industries, the production of hydraulic parts factory has been the professional development of more than 100 and an annual output more than one million. an independent hydraulic manufacturing industry has begun to take shape. Then, hydraulic pieces of fake products fromthe Soviet Union for the introduction of the product development and technical design combining the products to the pressure, Hypertension, and the development of the electro-hydraulic servo valves and systems, hydraulic application areas further expanded. Aerodynamic than the start of the industrial hydraulic years later, in 1967 began to establish professional pneumatic components factory, Pneumatic Components only as commodity production and sales. Sealed with rubber and plastics, mechanical seals and sealing flexible graphite sealing industry, the early 1950s from the production ordinary O-rings. rubber and plastics extrusion, such as oil seal sealing and seal asbestos products start to the early 1960s, begun production of mechanical seals and flexible graphite sealing products. 1970s, the burning of the former Ministry, a Ministry, the Ministry of Agricultural Mechanization System, a group of professional production plants have been established, and the official establishment of industries to seal industrial development has laid the foundation for growth.Since the 1980s, in the country's reform and opening up policy guidelines, with the development of the machinery industry, based mainframe pieces behind the conflicts have become increasingly prominent and attracted the attention of the relevant departments. To this end, the Ministry of the original one in 1982, formed the basis of common piecesof Industry, will be scattered in the original machine tools, agricultural machinery, mechanical engineering industries centralized hydraulic, pneumatic and seals specialized factories, placing them under common management infrastructure pieces Bureau, so that the industry in the planning, investment, technology and scientific research and development in areas such as infrastructure pieces Bureau of guidance and support. Since then entered a phase of rapid development, has introduced more than 60 items of advanced technology from abroad, including more than 40 items of hydraulic, pneumatic 7. After digestion and absorption and transformation, now have mass production, and industry-leading products. In recent years, the industry increased the technological transformation efforts, in 1991, Local enterprises and the self-financing total input of about 20 billion yuan, of which more than 1.6 billion yuan Hydraulic. Through technological transformation and technology research, and a number of major enterprises to further improve the level of technology, technique and equipment to be greatly improved. In order to form a higher starting point, specialization, and run production has laid a good foundation. In recent years, many countries in the development of common ownership guidelines, under different ownership SMEs rapid rise showing great vitality. With the further opening up,three-funded enterprises rapid development of industry standards for improving and expanding exports play an important role. Today, China has and the United States, Japan, Germany and other countries famous manufacturers joint ventures or wholly-owned by foreign manufacturers to establish a piston pump / motor, planetary reduction gears, steering gear, hydraulic control valve, hydraulic system, hydrostatic transmission, hydraulic Casting. pneumatic control valve, cylinder, gas processing triple pieces, mechanical seals, rubber and seal products more than 50 production enterprises, attracting foreign investment over 200 million U.S. dollars.Second, the current situation(1) Basic ProfilesAfter 40 years of efforts, China hydraulic, pneumatic and sealing industry has formed a relatively complete categories. a certain level of technical capacity and the industrial system. According to the 1995 Third National Industrial Census statistics, hydraulic, Pneumatic seals and industrial 370,000 annual sales income of 100 million yuan in state-owned, village-run, private and cooperative enterprises, individual, "three capital" enterprises with a total of more than 1,300, of which about 700 hydraulic, Pneumatic seals and the approximately 300 thousand. By 1996 with the international trade statistics, the total outputvalue of China's industry hydraulic 2.348 billion yuan, accounting for the world's 6; Pneumatic industry output 419 million yuan, accounting for world No. 10.(2) the current supply and demand profilesThrough the introduction of technology, independent development and technological innovation, and high-pressure piston pump, gear pumps, vane pump, General Motors hydraulic valves, tanks, Non-lubricated aerodynamic pieces and various seals of the first large technology products has increased noticeably. stability of the mass production may, for various mainframe products provide a level of assurance. In addition, hydraulic and pneumatic components of the CAD system, pollution control, proportional servo technology has scored some achievements, and is already in production. Currently, hydraulic, pneumatic and seals products total about 3,000 species, more than 23,000 specifications. Among them, there are 1,200 hydraulic varieties, more than 10,000 specifications (including hydraulic products 60 varieties 500 specifications); Pneumatic are 1,350 varieties, more than 8,000 specifications; Rubber seal 350 species more than 5,000 specifications have been basically cater to the different types of mainframe products to the general needs, complete sets of equipment for major varieties of matching rate was over 60%, and started a small amount of exports.1998 pieces of homemade hydraulic output 4.8 million. sales of about 28 billion (of which about 70% mechanical systems); aerodynamic pieces yield 3.6 million. sales of about 5.5 billion (of which about 60% of mechanical systems); Seals output of about 800 million. sales of about 10 billion (of which about 50% mechanical systems). According to the China Hydraulic Pneumatic Seals Industry Association 1998 annual report, hydraulic product sales rate of 97. 5% (101% for hydraulic), pneumatic 95.9%, 98.7% sealed. This fully reflects the basic marketing convergence.My hydraulic, pneumatic and sealing industry has attained a great deal of progress, but with mainframe development needs, and the world's advanced level, there are still many gaps, mainly reflected in the product variety, performance and reliability, and so on. Hydraulic products as an example, products abroad only one-third, life for half abroad. In order to meet key mainframe, and mainframe imports of major technology and equipment needs, every year a large number of hydraulic, pneumatic and sealing products imports. According to customs statistics and the analysis of data, in 1998 hydraulic, pneumatic and seals in the import about 200 million U.S. dollars, Hydraulic which about 1.4 billion dollars, aerodynamic nearly 030 million U.S. dollars, sealed about 030 million U.S. dollars. compared with a slight decline in 1997. By sums, currentlyimported products on the domestic market share of about 30%. 1998 pieces of the domestic market demand for hydraulic total of about six million, the total sales of nearly 40 billion; aerodynamic pieces of the total demand of about 5 million, with sales more than 700 million yuan; Seals total demand of about 1.1 billion. total sales of about 1.3 billion.Third, the development trend of the future1, affect the development of the main factors(1) product development ability, and the level of technological development and speed can not completely meet the advanced mainframe products, major equipment and technology imported equipment and maintenance support;(2) the number of enterprises manufacturing technology, the level of equipment and management standards are comparatively backward, coupled with a strong sense of quality, resulting in low levels of product performance, quality, Reliability poor services in a timely manner, lack of user satisfaction and trust of the brand-name products;(3) industry specialization of production low, scattered strength, low repeat serious, between regions and enterprises of convergence products, blindly compete with each other, driving down prices, the decline of enterprise returns, lack of funds, liquidity difficulties, product development and technological transformation is inadequateand seriously restricted the industry to improve the overall level of competition and the increase of strength;(4) The internationalization of the domestic market and the increasing degree of foreign companies have entered the Chinese market and participate in competition with the domestic private and cooperative enterprises, individuals, foreign-funded enterprises, such as the rise of state-owned enterprises due to the growing impact.2, the development trendAs the socialist market economy continues to deepen, hydraulic, pneumatic and sealing products in the market supply and demand and there is a greater change, long ago to a "shortage" of the seller's market has basically become a "structural surplus" of the characteristics of the buyer's market place . Overall capacity, is already in oversupply situation, in particular the general low level of hydraulic, pneumatic and seals, the general oversupply; and the host of urgent high-tech high-parameter, high value-added high-end products, and they do not satisfy the market needs, only dependent on imports. China joins the WTO, its impact may be even greater. Therefore, the "15" during the growth of the output value of industry, must not depend on volume growth and the industry should address the structural problems of their own, increase the intensity of the adjustment of the industrial structure and productmix, is, we should rely on the improvement of quality, and promote technical upgrading of products to meet market demand and stimulating, seek greater development.中文翻译：液压站及液压元件发展概况液压站又称液压泵站，是独立的液压装置。

毕业设计(论文)外文资料翻译学院(系)：机械工程学院专业：机械工程及自动化姓名：学号：外文出处：Manufacturing Engineering (用外文写)and Technology-Machining附件： 1.外文资料翻译译文；2.外文原文。

指导教师评语：此翻译文章简单介绍Komatsu先进的液压系统，并详细介绍了先进的液压传动装置，并对计算机控制的自动变速系统进行了详细的描述，翻译用词比较准确，文笔也较为通顺，为在以后工作中接触英文资料打下了基础。

签名：年月日附件1：外文资料翻译译文Komatsu先进的液压系统操作舒适，生产能力大人性化设计的驾驶室——既宽敞又实用。

宽大的有色玻璃窗给操作员极大的视线。

带扶手五挡调节座椅，短行程手摇杆，上位开启前窗和带杠杆的驾驶用的脚踏板，所有这些都起到有助于操作员最大限度地提高产量的作用。

操作噪声低——这完全是因为有先进的OLSS液压系统以及封闭式发动机室和具有橡胶支垫的发动机。

所有这一切都有助于降低驾驶室的噪声。

手控操作杆——使得施工设备的操作轻而易举。

安装在扶手上的手控操作杆最大行程仅为65mm(2.6in),KOMATSU比例压力控制操作系统能减少准确控制施工设备所需的操作强度。

回转制动装置——即使推土机停泊在坡路上也能自动防止液压漂移。

操作员不再需要在施工设备作业的过程中用手握住制动装置。

此外，回转控制装备还配置有封闭式滑阀，以便顺利的启动和停止。

行驶/驾驶控制装置——脚踏板控制装置配有可拆卸的控制杆。

两者可根据实际运用和操作员的偏爱加以选择使用。

支垫机构——在臂缸悬臂首端、铲斗缸和底部卸料缸中，能消减液压缸伸展和收缩引起的震动，从而增加操作的舒适性，延长部件的寿命。

燃耗最低两种模式选择系统，挖掘效率高——模式选择开关可选定泵驱动功率的两种模式：S（标准模式）或（轻负荷模式）。

当需要大功率挖掘时，选择标准模式；当挖掘机用来运送轻材料或平地时，选择轻负载模式。

毕业设计(论文)外文资料翻译学院(系)：机械工程学院专业：机械工程及其自动化姓名：学号：外文出处：Transmission of Fluid附件： 1.外文资料翻译译文；2.外文原文。

注：请将该封面与附件装订成册。

附件1：外文资料翻译译文流体传动流体传动包括气体(压)传动和液体传动，液体传动分为液压传动、液力传动和液粘传动。

液压传动基于帕卡定律，以液体的压能来传递动力；液力传动基于欧拉方程，以液体动量短的变化来传递动力；液粘传动基于牛顿内摩擦定律，以液体的粘性来传递动力。

液力传动的基本元件是液力偶合器和液力变矩器。

液力偶合器的基本构件是具有若干径向平面叶片的、构成工作腔的泵轮和涡轮。

液力传动油在工作腔里高速循环流动传递动力，油液随从泵轮做牵连运动的同时因受离心力作用而做离心运动，从泵轮(及输入轴)吸收机械能并转化为动量矩(mVR)增量，高速液流从泵轮冲入涡轮做向心流动释放动量矩，推动涡轮(及输出轴)旋转，带动工作机(及负载)做功。

液力变矩器的基本构件是泵轮、涡轮和导轮，它们均是具有空间(弯曲)叶片的工作轮，按相关顺序排列构成工作腔。

液力传动油在工作腔中被泵轮涡轮搅动，使液流获得动量矩增量，经过导轮调转液流方向后冲入涡轮，释放动量矩(动能)推动涡轮带动工作机旋转做功。

我国液力元件近年发展较快，2003年液力偶合器的全国年产量约7万台。

广泛应用于带式输送机、刮板输送机、球磨机、风机、压缩机、水泵和油泵等设备的传动中，提高传动品质并节约能源。

当前我国液力偶合器的最高输出转速为6500r/min，最小功率为0.3kW，最大功率为7100kW。

液力偶合器的发展趋势是高转速、大功率。

国际上液力偶合器产品以德国福依特公司最为著名，据资料称已有转速达20000r/min、功率达55000kW的产品，可见我国与之尚有相当大的差距。

当然，功率大的液力元件对液力传动油的要求较高。

液力变矩器主要用于工程机械、石油机械和内燃机车。

附录A液压系统设计液压技术被引入工业领域已经有一百多年的历史了，随着工业的迅猛发展，液压技术更日新月异。

伴随着数学、控制理论、计算机、电子器件和液压流体学的发展，出现了液压伺服系统，并作为一门应用科学已经发展成熟，形成自己的体系和一套行之有效的分析和设计方法。

好了，不多说了，现在我和大家来说说液压系统设计的方法和注意问题。

举个液压系统在机床运用的例子来和大家聊，并欢迎大家提出意见。

1 设计机床液压传动系统的依据1.机床的总体布局和工艺要求，包括采用液压传动所完成的机床运动种类、机械设计时提出可能用的液压执行元件的种类和型号、执行元件的位置及其空间的尺寸范围、要求的自动化程度等。

2.机床的工作循环、执行机构的运动方式（移动、转动或摆动），以及完成的工作范围。

3.液压执行元件的运动速度、调速范围、工作行程、载荷性质和变化范围。

4.机床各部件的动作顺序和互锁要求，以及各部件的工作环境与占地面积等。

5.液压系统的工作性能，如工作平稳性、可靠性、换向精度、停留时间和冲出量等方面的要求。

6.其它要求，如污染、腐蚀性、易燃性以及液压装置的质量、外形尺寸和经济性等。

2 设计液压传动系统的步骤1.明确对液压传动系统的工作要求，是设计液压传动系统的依据，由使用部门以技术任务书的形式提出。

2. 拟定液压传动系统图。

(1) 根据工作部件的运动形式，合理地选择液压执行元件；(2) 根据工作部件的性能要求和动作顺序，列出可能实现的各种基本回路。

此时应注意选择合适的调速方案、速度换接方案，确定安全措施和卸荷措施，保证自动工作循环的完成和顺序动作和可靠。

液压传动方案拟定后，应按国家标准规定的图形符号绘制正式原理图。

图中应标注出各液压元件的型号规格，还应有执行元件的动作循环图和电气元件的动作循环表。

3. 计算液压系统的主要参数和选择液压元件。

(1) 计算液压缸的主要参数；(2) 计算液压缸所需的流量并选用液压泵；(3) 选用油管；(4) 选取元件规格；(5) 计算系统实际工作压力；(6) 计算功率，选用电动机；(7) 发热和油箱容积计算；4.进行必要的液压系统验算。

液压中英文对照表液压中英文对照：流体传动hydraulic power液压技术hydraulics液力技术hydrodynamics气液技术hydropneumatics运行工况operating conditions额定工况rated conditions极限工况limited conditions瞬态工况instantaneous conditions稳态工况steady-state conditions许用工况acceptableconditions连续工况continuous working conditions 实际工况actual conditions效率efficiency旋转方向direction of rotation公称压力nominal pressure工作压力working pressure进口压力inlet pressure出口压力outlet pressure压降pressure drop；differential pressure 背压back pressure启动压力breakout pressure充油压力charge pressure开启压力cracking pressure峰值压力peak pressure运行压力operating pressure耐压试验压力proof pressure冲击压力surge pressure静压力static pressure系统压力system pressure控制压力pilot pressure充气压力pre-charge pressure吸入压力suction pressure调压偏差override pressure额定压力rated pressure耗气量air consumption泄漏leakage内泄漏internal leakage外泄漏external leakage层流laminar flow紊流turbulent flow气穴cavitation 流量flow rate排量displacement额定流量rated flow供给流量supply flow流量系数flower factor滞环hysteresis图形符号graphical symbol液压气动元件图形符号symbols for hydraulic and pneumatic components流体逻辑元件图形符号symbols for fluid logic devices逻辑功能图形符号symbols for logic functions回路图circuit diagram压力－时间图pressure time diagram 功能图function diagram 循环circle自动循环automatic cycle工作循环working cycle循环速度cycling speed工步phase停止工步dwell phase工作工步working phase快进工步rapid advance phase快退工步rapid return phase频率响应frequency response Hysterics 滞环Threshold 灵敏度Lap 滞后Pressure gain 压力增益Null 零位Null bias 零偏Null shift 零飘Frequency response 频率响应Slope 曲线斜坡液压系统（hydraulic system）执行元件（actuator）液压缸（cylinder）液压马达（motor）液压回路（circuit）压力控制回路（pressure control）流量（速度）控制回路（speed control）方向控制回路（direction alvalve control）安全回路（security control）定位回路（position control）同步回路（synchronisecircuit）顺序动作回路（sequeuntcircuit）液压泵（pump）阀（valve）压力控制阀（pressure valve）、流量控制阀（flow valve）方向控制阀（direction alvalve）液压辅件（accessory）普通阀（common valve）插装阀（cartridge valve）叠加阀（superimposed valve四、管接头Bite type fittings 卡套式管接头Tube to tube fittings 接管接头union 直通接管接头union elbow 直角管接头union tee 三通管接头union cross 四通管接头Mal stud fittings 端直通管接头Bulkhead fittings 长直通管接头Weld fittings 焊接式管接头Female connector fittings 接头螺母Reducers extenders 变径管接头Banjo fittings 铰接式管接头Adjustable fittings/swivel nut 旋转接头五、伺服阀及伺服系统性能参数Dynamic response 动态频响DDV-direct drive valve 直动式伺服阀NFPA-National Fluid Power Association 美国流体控制学会Phase lag 相位滞后Nozzle flapper valve 喷嘴挡板阀Servo-jet pilot valve 射流管阀Dither 颤振电流Coil impedance 线圈阻抗Flow saturation 流量饱和Linearity 线形度Symmetry 对称性Throttle valve 节流阀Double throttle check valve 双单向节流阀Rotary knob 旋钮Rectifier plate 节流板Servo valve 伺服阀Proportional valve 比例阀Position feedback 位置反馈Progressive flow 渐增流量De-energizing of solenoid 电磁铁释放二、介质类Phosphate ester (HFD-R) 磷酸甘油酯Water-glycol (HFC) 水-乙二醇Emulsion 乳化液Inhibitor缓蚀剂Synthetic lubricating oil 合成油三、液压安装工程Contamination 污染Grout 灌浆Failure 失效Jog 点动Creep爬行Abrasion 摩擦Retract（活塞杆）伸出Extension （活塞杆）缩回Malfunction 误动作Pickling 酸洗Flushing 冲洗Dipping process 槽式酸洗Re-circulation 循环Passivity 钝化Nitric acid 柠檬酸Argon 氩气Butt welding 对接焊Socket welding 套管焊Inert gas welding 惰性气体焊空气处理单元air conditioner unit压力控制回路pressure control circuit安全回路safety circuit差动回路differential circuit调速回路flow control circuit进口节流回路meter-incircuit出口节流回路meter-outcircuit同步回路synchronizing circuit开式回路open circuit闭式回路closed circuit管路布置pipe-work管卡clamper联轴器drive shaft coupling操作台control console控制屏control panel避震喉compensator粘度viscosity运动粘度kinematicviscosity密度density含水量water content闪点flash point防锈性rust protection抗腐蚀性anti-corrosive quality便携式颗粒检测仪portable particle counterSolenoid valve 电磁阀Check valve 单向阀Cartridge valve 插装阀Sandwich plate valve 叠加阀Pilot valve 先导阀Pilot operated check valve 液控单向阀Sub-plate mount 板式安装Manifold block 集成块Pressure relief valve 压力溢流阀Flow valve 流量阀冷却器cooler加热器heater温度控制器thermostat消声器silencer双筒过滤器duplex filter过滤器压降filter pressure drop有效过滤面积effective filtration area 公称过滤精度nominal filtration rating压溃压力collapse pressure填料密封packing seal机械密封mechanical seal径向密封radial seal旋转密封rotary seal活塞密封piston seal活塞杆密封rod seal防尘圈密封wiper seal；scraper组合垫圈bonded washer复合密封件composite seal弹性密封件elastomer seal丁腈橡胶nitrilebutadiene rubber；NBR聚四氟乙烯polytetrafluoroethene；PTFE优先控制overridecontrol压力表pressure gauge压力传感器electrical pressure transducer压差计differential pressure instrument液位计liquid level measuring instrument流量计flow meter压力开关pressure switch脉冲发生器pulse generator液压泵站power station遮盖lap零遮盖zero lap正遮盖over lap负遮盖under lap开口opening零偏null bias零漂null drift阀压降valve pressure drop分辨率resolution频率响应frequency response幅值比amplitude ratio相位移phase lag传递函数transfer function管路flow line硬管rigid tube软管flexible hose工作管路working line回油管路return line补液管路replenishing line控制管路pilot line泄油管路drain line放气管路bleed line接头fitting；connection焊接式接头welded fitting扩口式接头flared fitting快换接头quick release coupling 法兰接头flange connection 弯头elbow异径接头reducer fitting流道flow pass油口port闭式油箱sealed reservoir油箱容量reservoir fluid capacity 气囊式蓄能器bladder accumulator 空气污染air contamination固体颗粒污染solid contamination 液体污染liquid contamination空气过滤器air filter油雾气lubricator热交换器heat exchanger分流阀flow divider valve集流阀flow-combining valve截止阀shut-off valve球阀global(ball) valve针阀needle valve闸阀gate valve膜片阀diaphragm valve蝶阀butterfly valve噪声等级noise level 放大器amplifier模拟放大器analogue amplifier数字放大器digital amplifier传感器sensor阈值threshold伺服阀servo-valve四通阀four-way valve喷嘴挡板nozzle flapper液压放大器hydraulic amplifier颤振dither阀极性valve polarity流量增益flow gain对称度symmetry流量极限flow limit零位内泄漏null(quiescent) leakage 重复性repeat ability复现性reproducibility漂移drift波动ripple线性度linearity线性区linear region液压锁紧hydraulic clock液压卡紧sticking变量泵variable displacement pump 泵的控制control of pump齿轮泵gear pump叶片泵vane pump柱塞泵piston pump轴向柱塞泵axial piston pump法兰安装flange mounting底座安装foot mounting液压马达hydraulic motor刚度stiffness中位neutral position零位zero position自由位free position缸cylinder有杆端rod end无杆端rear end外伸行程extend stroke内缩行程retract stroke缓冲cushioning工作行程working stroke负载压力induced pressure输出力force实际输出力actual force单作用缸single-acting cylinder双作用缸double-acting cylinder差动缸differential cylinder伸缩缸telescopic cylinder阀valve底板sub-plate油路块manifold block板式阀sub-plate valve叠加阀sandwich valve插装阀cartridge valve滑阀slide valve锥阀poppet valve阀芯valve element阀芯位置valve element position单向阀check valve液控单向阀pilot-controlled check valve 梭阀shuttle valve压力控制阀pressure relief valve溢流阀pressure relief valve顺序阀sequence valve减压阀pressure reducing valve平衡阀counterbalance valve卸荷阀unloading valve直动式directly operated type先导式pilot-operated type机械控制式mechanically controlled type 手动式manually operated type液控式hydraulic controlled type流量控制阀flow control valve固定节流阀fixed restrictive valve可调节流阀adjustable restrictive valve单向节流阀one-way restrictive valve 调速阀speed regulator valve。

液压系统和气压系统外文文献翻译、中英文翻译Hydraulic system and Peumatic SystemHui-xiong wan1,Jun Fan2Abstract:Hydraulic system is widely used in industry, such as stamping, grinding of steel type work and general processing industries, agriculture, mining, space technology, deep sea exploration, transportation, marine technology, offshore gas and oil exploration industries, in short, Few people in their daily lives do not get certain benefits from the hydraulic technology. Successful and widely used in the hydraulic system's secret lies in its versatility and ease of maneuverability. Hydraulic power transmission mechanical systems as being not like the machine geometry constraints, In addition, the hydraulic system does not like the electrical system, as constrained by the physical properties of materials, it passed almost no amount of power constraints.Keywords: Hydraulic system,Pressure system,FluidThe history of hydraulic power is a long one, dating from man’s prehistoric efforts to harness the energy in the world around him. The only source readily available were the water and the wind—two free and moving streams.The watermill, the first hydraulic motor, was an early invention. One is pictured on a mosatic at the Great Palace in Byzantium, dating from the early fifth century. The mill had been built by the Romans. But the first record of a watermill goes back even further, to around 100BC, and the origins may indeed have been much earlier. The domestication of grain began some 5000 years before and some enterprising farmer is bound to have become tired of pounding or grinding the grain by hand. Perhaps,in fact, the inventor were some farmer’s wives. Since the often drew the heavy jobs.Fluid is a substance which may flow; that is, its constituent particles may continuously change their positions relative to one another. Moreover, it offers no lasting resistance to the displacement, however great, of one layer over another. This means that, if the fluid is at rest, no shear force (that is a force tangential to the surface on which it acts) can exist in it.Fluid may be classified as Newtonian or non--Newtonian. In Newtonian fluid there is a linear relation between the magnitude of applied shear stresses and the resulting rate of angular deformation. In non—Newtonian fluid there is a nonlinear relation between the magnitude of applied shear stress and the rate of angulardeformation.The flow of fluids may be classified in many ways, such as steady or non steady, rotational or irrotational, compressible or incompressible, and viscous or no viscous.All hydraulic systems depend on Pascal’s law, such as steady or pipeexerts equal force on all of the surfaces of the container.In actual hydraulic systems, Pas cal’s law defines the basis of results which are obtained from the system. Thus, a pump moves the liquid in the system. The intake of the pump is connected to a liquid source, usually called the tank or reservoir. Atmospheric pressure, pressing on the liquid in the reservoir, forces the liquid into the pump. When the pump operates, it forces liquid from the tank into the discharge pipe at a suitable pressure.The flow of the pressurized liquid discharged by the pump is controlled by valves. Three control functions are used in most hydraulic systems: (1) control of the liquid pressure, （2）controlof the liquid flow rate, and (3) control of the direction of flow of the liquid.Hydraulic drives are used in preference to mechanical systems when(1) powers is to be transmitted between point too far apart for chains or belts; (2) high torque at low speed in required; (3) a very compact unit is needed; (4) a smooth transmission, free of vibration, is required;(5) easy control of speed and direction is necessary; and (6) output speed is varied steplessly.Fig. 1 gives a diagrammatic presentation of the components of a hydraulic installation. Electrically driven oil pressure pumps establish an oil flow for energy transmission, which is fed to hydraulic motors or hydraulic cylinders, converting it into mechanical energy. The control of the oil flow is by means of valves. The pressurized oil flow produces linear or rotary mechanical motion. The kinetic energy of the oil flow is comparatively low, and therefore the term hydrostatic driver is sometimes used. There is little constructional difference between hydraulic motors and pumps. Any pump may be used as a motor. The quantity of oil flowing at any given time may be varied by means of regulating valves( as shown in Fig.7.1) or the use of variable-delivery pumps.The application of hydraulic power to the operation of machine tools is by no means new, though its adoption on such a wide scale as exists at present is comparatively recent. It was in fact in development of the modern self-contained pump unit that stimulated the growth of this form of machine tool operation.Hydraulic machine tool drive offers a great many advantages. One of them is that it can give infinitely-variable speed control over wide ranges. In addition, they can change the direction ofdrive as easily as they can vary the speed. As in many other types of machine, many complex mechanical linkages can be simplified or even wholly eliminated by the use of hydraulics.The flexibility and resilience of hydraulic power is another great virtue of this form of drive. Apart from the smoothness of operation thus obtained, a great improvement is usually found in the surface finish on the work and the tool can make heavier cuts without detriment and will last considerably longer without regrinding.Hydraulic and pneumatic systemThere are only three basic methods of transmitting power:electrical,mechanical,and fluid power.Most applications actually use a combination of the three methods to obtain the most efficient overall system. To properly determine which principle method to use,it is important to know the salient features of each type. For example, fluid systems can transmit power more economically over greater distances than can mechanical types. However, fluid systems are restricted to shorter distances than are electrical systems.Hydraulic power transmission system are concerned with the generation, modelation, and control of pressure and flow，and in general such systems include:1.Pumps which convert available power from the prime mover to hydraulic power at the actuator.2.Valves which control the direction of pump-flow, the level of power produced, and the amount of fluid-flow to the actuators. The power level is determined by controlling both the flow and pressure level.3.Actcators which convert hydtaulic power to usable mechanical power output at the point required.4.The medium, which is a liquid, provides rigid transmission and control as well as lubrication of componts, sealing in valves, and cooling of the system.5.Conncetots which link the various system components, provide power conductors for the fluid under pressure, and fluid flow return to tank(reservoir).6.Fluid storage and conditioning equipment which ensure sufficient quality and quantity as well as cooling of the fluid.Hydraulic systems are used in industrial applications such as stamping presses, steel mills, and general manufacturing, agricultural machines, mining industry,aviation, space technology, deep-sea exploration, transportion, marine technology, and offshore gas and petroleum exploration. In short, very few people get through a day of their lives without somehow benefiting from the technology of hydraulicks.The secret of hydraulic system’s success and widespread use is its versatility and manageability. Fluid power is not hindered by the geometry of the machine as is the case in mechanical systems. Also, power can be transmitted in almost limitless quantities because fluid systems are not so limited by the physical limitations of materials as are the electrical systems. For example, the performance of an electromangnet is limited by the saturation limit of steel. On the other hand, the power limit of fluid systems is limited only by the strength capacity of the material.Industry is going to depend more and more on automation in order to increase productivity. This includes remote and direct control of production operations, manufacturing processes, and materials handling. Fluid power is the muscle of automationbecause of advantages in the following four major categories.1.Ease and accuracy of control. By the use of simple levers and push buttons, the operator of a fluid power system can readily start, stop, speed up or slow down, and position forces which provide any desired horsepower with tolerances as precise as one ten-thousandth of an inch.2.Multiplication of force. A fluid power system(without using cumbersome gears, pulleys, and levers) can multiply forces simply and efficiently from a fraction of an ounce to several hundred tons of output.3.Constant force or torque. Only fluid power systems are capable of providing contant force or torque regardless of speed changes. This is accomplished whether the work output moves a few inches per hour, several hundred inches per minute, a few revolutions per hour, or thousands of revolutions per minute.4.Simplicity, safely, economy. In general, fluid power systems use fewer moving parts than comparable mechanical or electrical systems. Thus, they are simpler to maintain and operate. This, in turn, maximizes safety, companctness, and reliability. For example, a new power steering control designed has made all other kinds of power systems obsolete on many off-highway vehicles. The steering unit consists of a manually operated directional control valve and meter in a single body. Because the steering unit is fully fluid-linked, mechanical linkages, universal joints, bearings, reduction gears, etc, are eliminated. This provides a simple, compact system. In addition, very little input torque is required to produce the control needed for the toughest applications. This is important where limitations of control space require a small steering wheel and it becomes necessary to reduce operatot\r fatique.Additonal benefits of fluid power systems include instantly reversible motion, automatic protection against overloads, and infinitely variable speed control. Fluid power systems also have the highest horsepower per weight ratio of any known power source. In spite of all these highly desirable features of fluid power, it is not a panacea for all power transmission problems. Hydraulic systems also have some drawbacks. Hydraulic oils are messy, and leakage is impossible to completely eliminate. Also, most hydraulic oils can cause fires if an oils occurs in an area of hot equipment.Peumatic SystemPneumatic systems use pressurized gases to tansmit and control power. A s the name implies, pneumatic systems typically use air(rather than some other gas) as the fluid medium because air is a safe, low-cost, and readily available fluid. It is particularly safe in environments where an electrical spark could ignite leaks from system components.In pneumatic systems ,compressors are used to compress and supply the necessary quantities of air. Compressors are typically of the piston, vane or screw type. Basically a compressor increases the pressure of a gas by reducing its volume as described by the perfect gas laws.Pneumatic systems normally use a large centralized air compressor which is considered to be an infinite air source similar to an electrical system where you merely plug into an electrical outlut for electricity. In this way, pressurized air can be piped from one source to various locations throughout an entire industrial plant. The air then flows through a pressue regulator which redeces the pressure to the desired level for the particular circuit application. Because air is not a good lubircant（contains about 20% oxygen）, pneumaticssystems required a lubricator to inject a very fine mist of oil into the air discharging from the pressure regulator. This prevents wear of the closely fitting moving parts of pneumatic components.Free air from the atmosphere contains varying amounts of moisure. This moisure can be harmful in that it can wash away lubricants and thus cause excessive wear and corrosion. Hence ,in some applications ,air driers are needed to remove this undesirable moisture. Since pneumatics systems exhaust directly into the atmosphere, they are capable of generating excessive noise. Therefore, mufflers are mounted on exhaust ports of air valves and actuators to reduce noise and prevent operating personnel from injury resulting not only from exposure to noise but also from high-speed airborne particles.There are several reasons for considering the use of pneumatic systems instead of hydraulic systems. Liquids exhibit greater inertia than do gases. Therefore, in hydraulic systems the weight of oil is a potential problem when accelerating and decelerating actuators and when suddenly opening and closing valves. Due to Newton’s law of motion(force equals mass multiplied by acceleration), the force required to accelerate oil is many times greater than that required to accelerate an equal volume of air. Liquids also exhibit greater viscosity than do gases. This results in larger frictional pressure and power losses. Also ,since hydraulic systems use a fluid foreign to the atmosphere, they require special reservoirs and noleak system designs. Pneumatic system use air which is exhausted directly back into the surrounding environment. Generally speaking, pneumatic systems are less expensive than hydraulic systems.However, because of the compressibility of air, it isimpossible to obtain precise controlled actuator velocities with pneumatic systems. Also, precise positioning control is not obtainable. While pneumatics pressures are quite low due to compressor design limitations(less than 250 psi), hydraulic pressures can be as high as 10000 psi. Thus, hydraulics can be high-power systems, whereas pneumatics are confined to low-power applications. Industrial applications of pneumatics systems are growing at a rapid pace. Typical examples include stamping, drilling, hoist, punching, clamping, assembling, riveting, materials handling, and logic controlling operations.液压系统和气压系统万辉雄1，范军2摘要：液压系统在工业中应用广泛，例如冲压、钢类工件的磨削及一般加工业、农业、矿业、航天技术、深海勘探、运输、海洋技术，近海天然气和石油勘探等行业，简而言之，在日常生活中很少有人不从液压技术得到某些益处。

Transmission减速器reducer中间齿轮intermediate gear(counter gear)副轴齿轮counter shaft gear副轴counter shaft变速器输入轴transmission imput shaft变速器输出轴transmission output shaft变速器主动齿轮轴transmission drive gear shaft变速器主轴transmission main shaft变速器中间轴transmission countershaft变速器轴的刚度rigidity of shaft变速齿轮比（变速比）transmission gear ratio传动比gear ratio主压力line pressure调制压力modulated pressure真空调制压力vacuum modulator pressure速控压力governor pressure缓冲压力compensator or trimmer pressure 限档压力hold presure前油泵front pump (input pump )液力传动装置充油压力hydrodynamic unit change pressure 后油泵gear pump (output pump )scavenge oil pump调压阀pressure -regulator vavle电磁阀调压阀solenoid regulator valve液力变矩器旁通阀converter bypass valve速控阀governor valve选档阀selectro valve换档阀shift valve信号阀signal valve继动阀relay valve换档指令发生器shift pattern generator档位指示器shift indicator(shift torwer)先导阀priority valve流量阀flow valve重迭阀overlap valve液力减速器控制阀retarder control valve液力起步fluid start零速起动stall start液力变矩器锁止converter lockup全液压自动换档系统hydraulic automatic control system 电液式自动换档系统electronic -hydraulic automatiec换档shift升档upshiftdownshift动力换档power shfit单向离合器换档freewheel shfit人工换档manual shfit自动换档automaitc shfit抑制换档inhibited shift超限换档overrun shift强制换档forced shift换档点shift point叶片转位blade angle shift换档滞后shift hysteresis换档循环shift schedule换档规律process of power shift动力换档过程timing换档定时property of automatic shift 换档品质property of automatic shft 换档元件engaging element换档机构gearshift操纵杆control lever变速杆stick shift(gear shift lever) （副变速器）变速杆range selector变速叉shifting fork (gear shift fork)分动箱控制杆transfer gear shift fork变速踏板gear shift pedal变速轨（拨叉道轨）shift rail直接变速direct change(direct control)方向盘式变速column shift (handle change)按钮控制finger-tip control槽导变速gate change空档位置neutral position直接驱动direct drive高速档top gear(high gear)低速档bottom gear(low speed gear)第一档first gear第二档second gear超速档overdirve gear经济档economic gear倒档reverse gear爬行档creeper gear驱动特性drive performance反拖特性coast performance定输入扭矩特性constant input torque performance全油门特性full throttle performance寄生损失特性no load (parasitic losses)performanceprimary characteristic响应特性response characteristic吸收特性absorption characteristic全特性total external characteristic输入特性characteristic of enhance输出特性characteristic of exit力矩特性torque factor(coefficient of moment) 过载系数overloading ratio变矩系数torque ratio能容系数capacity factorr几何相似geometry similarity运动相似kinematic similarity动力相似dynamic similarity透穿性transparency万向节和传动轴universal joint and drive shaft万向节universal joint非等速万向节nonconstant velocity universal joint 等速万向节constant velocity universal joint准等速万向节near constant velocity universal joint 自承式万向节self-supporting universal joint非自承式万各节non self suporting universal joint回转直径swing diameterconstant velocity plane万向节夹角true joint angle十字轴式万向节cardan (hookes)universal joint 万向节叉yoke突缘叉flange york滑动叉slip yoke滑动节，伸缩节slip joint花键轴叉slip shaft yoke轴管叉（焊接叉）tube(weld yoke)十字轴cross(spider)十字轴总成cross assembly挠性元件总成flexible universal joint球销式万向节flexible member assembly双柱槽壳housing球环ball球头轴ball head球头钉button中心球和座centering ball and seat球笼式万向节rzeppa universal joint钟形壳outer race星型套inner race保持架cage可轴向移动的球笼式万向节plunging constant velocity joint筒形壳cylinder outer race柱形滚道星形套inner race withcylinder ball grooves 偏心保持架non-concentric cage滚动花键球笼式万向节ball spline rzeppa universal joint外壳outer housing内壳体inner housing球叉式万向节weiss universal joint球叉ball yoke定心钢球centering ball三球销万向节tripod universal joint三柱槽壳housing三销架spider双联万向节double cardan universal joint凸块式万向节tracta universal joint凸块叉fork yoke榫槽凸块tongue and groove couplijng凹槽凸块groove coupling传动轴drive shaft(propeller shaft)传动轴系drive line传动轴形式drive shaft type两万向节滑动的传动轴two -joint inboard slip ddiveshaft两万向节外侧滑动传动轴two joint ouboard slip drive shaft单万向节传动轴single joint coupling shaft组合式传动轴unitized drive shaft传动轴减振器drive shaft absorber传动轴中间轴承drive shaft center bearing传动轴管焊接合件weld drive shaft tube assembly传动轴特征长度drive shaft length传动轴谐振噪声resonant noise of rive shaft传动轴的临界转速critical speed of drive shaft传动轴总成的平衡balance of drive shaft assembly允许滑动量slip相位角phase angle传动轴安全圈drive shaft safety strap驱动桥drive axle(driving axle)类型type断开式驱动桥divided axle非独立悬架式驱动桥rigid dirve axle独立悬架式驱动桥independent suspension drive axle 转向驱动桥steering drive axle贯通式驱动桥tandem axles“三速”贯通轴"three-speed" tandem axles单驱动桥single drive axle多桥驱动multiaxle drive减速器reducer主减速器final drive单级主减速器single reduction final drive双级主减速器double reduction final drive前置式双级主减速器front mounted double reduction final drive后置式双级主减速器rear mounted double reduction final drive上置式双级主减速器top mounted double reducton final drive行星齿轮式双级主减速器planetary double reduction final drive贯通式主减速器thru-drive双速主减速器two speed final drive行星齿轮式双速主减速器two speed planetary final drive双级双速主减速器two speed double reduction final drive轮边减速器wheel reductor(hub reductro)行星圆柱齿轮式轮边减速器planetary wheel reductor行星锥齿轮式轮边减速器differential geared wheel reductor(bevelepicyclick hub reductor) 外啮合圆柱齿轮式轮边减速器spur geared wheel reductor差速器differential锥齿轮式差速器bevel gear differential圆柱齿轮式差速器spur gear differential防滑式差速器limited -slip differential磨擦片式自锁差速器multi-disc self -locking differential凸轮滑滑块自锁差速器self-locking differential with side ring and radial cam plate 自动离合式自锁差速器automotive positive locking differential强制锁止式差速器locking differential液压差速器hydraulic differential轴间差速器interaxial differential差速器壳differential carrieer(case)主降速齿轮final reduction gear驱动轴减速比axle ratio总减速比total reduction ratio主降速齿轮减速比final reduction gear ratio双减速齿轮double reduction gear差速器主齿轮轴differential pinion-shaft差速器侧齿轮differential side gear行星齿轮spider gear(planetary pinion)螺旋锥齿轮spiral bevel gear双曲面齿轮hypoid gear格里林齿制gleason tooth奥林康型齿制oerlikon tooth锥齿轮齿数number of teeth in bevel gears and hypoid gears锥齿轮齿宽face width of tooth in bevel gears and hypoid gears平面锥齿轮plane bevel gear奥克托齿形octoid formcontrate gear齿面接触区circular tooth contact齿侧间隙backlash in circular tooth差速器十字轴differential spider差速器锁止机构differential locking -device差速器锁止系数differential locking factor差速器壳轴承carrier bearing桥壳axle housing整体式桥壳banjo housing可分式桥壳trumpet-type axle housing组合式桥壳unitized carrier-type axle housing 对分式桥壳split housing冲压焊接桥壳press-welding axle housing钢管扩张桥壳expanded tube axle housing锻压焊接桥壳forge welding axle housing整体铸造式桥壳cast rigid axle housing半轴axle shaft全浮式半轴full-floating axle shaft半浮式半轴semi-floating axle shaft四分之三浮式半轴three-quarter floating axle shaft 驱动桥最大附着扭矩slip torque驱动桥额定桥荷能力rating axle capactiydriveaxle ratio驱动桥质量drive axle mass单铰接式摆动轴single-joint swing axle双铰接式摆动轴double joint swig axle悬架系suspension system悬架suspension类型type非独立悬架rigid axle suspension独立悬架independent suspension平衡悬架equalizing type of suspension 组合式悬架combination suspension可变刚度悬架variable rate suspension纵置板簧式parallel leaf spring type上置板簧式over slung type下置板簧式under slung type双横臂式double with-bone arm type横置板簧式transversal leaf spring type双纵臂式double trailing arm type单横臂式single transverse arm type双横臂式double -wishbone type单横臂式singe trailing arm type双纵臂式double-trailing arm type单斜臂式single oblique arm tyep四连杆式four link type扭矩套管式torque tube drive type第迪安式De Dion type烛式sliding pillar type麦弗逊式MacPherson type金属弹簧式metal spring type空气弹簧式air spring type油气弹簧式hydro-pneumatic spring type 橡胶液体弹簧式hydro-rubber spring type橡胶弹簧式rubber spring type液体弹簧式hydraulic spring type三点悬架three-point suspension四点悬架four-point suspension部件assembly and parts悬架臂suspension arm上悬架臂upper suspension arm控制臂control arm上控制臂upper control arm下控制臂lower control arm纵臂trailing arm横臂transverse arm斜臂oblique arm支撑梁support beam横向推力杆lateral rod纵向推力杆longitudinal rod拉杆tension rod压杆strut bar支撑杆strut bar扭矩套管torque tube变截面弹簧tapered spring钢板弹簧leaf spring(laminated spring) 副钢板弹簧auxiliary spring非对称钢板弹簧unsymmetrical leaf spring单片式钢板弹簧single leaf spring多片式钢板弹簧muotileaved spring纵向钢板弹簧longitudinal leaf spring螺旋弹簧coil spring (helicalspring)空气弹簧air spring囊式空气弹簧bellow type air spring膜式空气弹簧diaphragm typeair spring橡胶弹簧rubber spring type液体弹簧hydraulic spring油气弹簧hydro-pneumatic spring type单气室油气弹簧single chamber hydragas spring双气室油气弹簧double chamber hydragas spring液体弹簧hydraulic spring底盘弹簧chassis spring四分之一椭圆形弹簧quarter elliptic spring半椭圆形弹簧half-elliptic spring(semi-elliptic spring) 四分之三椭圆形弹簧three quarter elliptic spring全椭圆形弹簧full elliptic spring悬臂弹簧cantilever spring簧上质量sprung weight簧下质量unsprung weight垫上弹簧载荷量spring capacity at pad地面弹簧载荷量spring capacity at ground弹簧静挠度spring static deflection弹簧跳动间隙bump clearance of spring弹簧中心距distance between spring centers减振器shock absorber筒式减振器telescopic shock absorber油压缓冲器hydraulic buffer负荷调平式减振器load -levelling shock absorber液压减振器dydraulic shock absorber可调减振器adjustable shock absorber摇臂式减振器lever type shock absorber 磨擦式减振器frictional shock absorber充气减振器gas-filled shock absorber动力减振器dynamic shock absorber减振器卸荷阀shock absorber relief valve 减振器进油阀shock absorber intake valve 减振器示功图damper indicator diagram 减振器液damper fluid横向稳定器stabilizer anti-roll bar滑动座sliding seat滑板sliding plate弹簧架spring bracket弹簧主片spring leaf钢板弹簧吊耳leaf spring shackle钢板弹簧衬套leaf spring bushing钢板弹簧销leaf spring pin弹簧卷耳spring eyeU型螺栓U bolt钢板弹簧中心螺栓leaf spring center bolt橡胶衬套rubber bushing缓冲块buffer stopper限位块limiting stopper平衡轴trunnion shaft平衡轴支座trunnion base臂轴arm shaft平横臂equalizer螺纹衬套screw bushing（车身）高度阀levelling valve车架auxiliary tank整体车架unitized frame上弯式梁架upswept frame (kick up frame) 短型车架stub frame发动机支架engine mounting半径杆radius rod平衡杆stabilizer bar制动反应杆brake reaction rod分开式车身和车架separated body and frame车轮wheel车轮尺寸名称wheelsize designation车轮类型wheel type单式车轮single wheel双式车轮dual wheel整体轮毂式车轮wheel with integral hub组装轮辋式车轮demountable rim wheeldivided wheel可调车轮adustable wheel辐板式车轮disc wheel可反装式车轮reversible wheel辐条式车轮wire wheel安装面attachment face安装面直径attachment face diameter 双轮中心距dual spacing半双轮中心距half dual spacing轮缘flange固定轮缘fixed flange轮缘规格代号flange size disignation轮缘高度flange height轮缘半径flange radius轮级端部半径flange edge radius轮级宽度flange width内轴承座肩inner bearing cup shoulder 内移距inset横向跳动lateral run-out外移距outset径向跳动radius run-out轮辋rimrim size disignation轮辋宽度rim width标定轮辋宽度specified rim width轮辋直径rim diameter标定轮辋直径specified rim diameter轮辋类型rim types整体式（深槽式）one-piece(drop -center DC)半深槽式semi-drop center (SDC)二件式two-piece三件式three-piece四件式four-piece轮毂座hub seat五件式five-piece轮辋轮廓类型rim contour classification深槽轮辋drop center rim(DC)深槽宽轮辋wide drop center rim(WDC)半深槽轮辋semi-drop center rim(SDC)平底轮辋flat base rim平底宽轮辋wide flat base rim (WFB)全斜底轮辋full tapered bead seat rim (TB) 可拆卸轮辋demountable rim wheel对开式轮辋divided rim(DT)轮辋基体rim base轮辋基体偏移距rim base offset轮辋偏移距rim bevel distance气门嘴孔valve hole气门嘴孔的位置rim hole location锁圈槽gutter锁圈槽沟gutter groove锁圈槽顶gutter tip隔圈spaceband隔圈宽度spacerband width标定轮辋直径specified rim diameter 标定轮辋宽度specified rim width花键spline弹性锁圈spring lock ring辐条式车轮轮毂shell (wire shell)轮辋槽well槽角well angle槽深well depth槽底半径well iner radius槽的位置well position槽顶圆角半径well radius top槽宽度well width中心孔center hole中心线center line夹紧块clamp夹紧螺栓clamping bolt锥型座（螺帽定位用）cone seat (for retaining nut)可拆卸档圈detachable endless flange可拆卸弹簧档圈detachable spring flange可拆卸锥形座圈detachable endless taper bead seat ring 轮辐disc辐条wire spoke零移距zeroset弯距bending moment动态径向疲劳试验dynamic radial fatigue test横向疲劳试验cornering fatigue test轴安装axel mounting轴颈安装journal mounting孔径bore轮胎tyre (tire)轮胎系列tyre series轮胎规格tyre size轮胎标志tyre marking速度符号speed symbol胎面磨耗标志tread wear indicator骨架材料framework material层数number of plies层级ply rating外胎cover内胎inner tube胀大轮胎grown tyre充气轮胎pneumatic tyre新胎new tyre有内胎轮胎tubed tyre无内胎轮胎tubeless tyre水胎curing bag保留生产轮胎reserved old series of tyre 普通断面轮胎conventional section tyre 低断面轮胎low section tyre超低断面轮胎super low section tyre宽基轮胎wide base tyre斜交轮胎diagonal tyre子午线轮胎radial ply tyre活胎面轮胎removable tread tyre越野轮胎cross-country tyre沙漠轮胎sand tyrecast tyre调压轮胎adjustable inflation tyre海棉轮胎foam filled tyre常压轮胎atomospheric pressure tyre 内支撑轮胎internal supporter tyre拱形轮胎arch tyre椭圆形轮胎elliptical tyre实心轮胎solid tyre粘结式实心轮胎cured on solid tyre非粘结式实心轮胎pressed on solid tyre圆柱实心轮胎cylindrical base solid tyre斜底实心轮胎conical base solid tyre抗静电实心轮胎anti-static solid tyre导电实心轮胎conductive solid tyre耐油实心轮胎oil-resistance solid tyre高负荷实心轮胎high load capacity solid tyre 胎面花纹treadpattern纵向花纹circumferetial pattern横向花纹transverse pattern公路花纹highway tread pattern越野花纹cross-country tread pattern 混合花纹dual purpose tread patterndirectional tread pattern 雪泥花纹mud and snow pattern 花纹细缝pattern sipe花纹块pattern block花纹条pattern rib花纹沟groove花纹加强盘tie-bar of pattern花纹角度pattern angle花纹纹深度pattern depth花纹展开图patttern plan光胎面smooth tread胎冠crown胎面tread胎面行驶面tread cap胎面基部tread base胎面基部胶tread slab base胎面过渡胶transition rubber of tread 缓冲层breaker带束层belt缓冲胶片breaker strip包边胶tie-in strip完带层cap ply胎体carcass帘面层cord ply隔离胶insulation rubber 封口胶sealing rubber胎里tyre cavity内衬层inside liner气密层innerliner胎肩shoulder胎肩区shoulder area胎肩垫胶shoulder wedge胎侧sidewall屈挠区flexing area胎侧胶sidewall rubber装饰胎侧decorative sidewall 装饰线decorative rib装配线fitting line防擦线kerbing rib胎圈bead钢丝圈bead ring钢丝包胶wire covering胎圈座bead seat胎圈座角度beat seat angle胎圈座圆角半径bead seat radius胎圈座宽度bead seat width可选择的胎圈座轮廓bead seat optional contours 凹陷型center-pente(CP)平峰型flat hump(FH)凸峰型round hump(RH)特殊座架special ledge(SL)胎圈芯bead core三角胶apex胎圈补强带bead reinforcing strip胎圈包布chafer胎圈外护胶bead filler rubber胎踵bead heel胎趾bead toe胎圈底部bead base内胎胎身tube body断面宽度section width断面高度section height高宽比（H/S）aspect ratio(H/S)外直径overall diameter自由半径free radius转向系steering system类型type机械转向系manual steering system动力转向系power steering system转向操纵机构steering control mechanism直列式转向器in-line steering gear四边联杆式转向机构parallelogram linkage steering整体式动力转向机构integral type power steering总成和部件assemblies and parts转向万向节steering universal joint转向传动轴steering inner articulated shaft转向管柱steering column球轴承套管式转向管柱tube and ball type steering column 可伸缩式转向管柱telescopic steering column折叠式转向管柱collapsible steering column倾斜和缩进式转向管柱tilt and telescopic steering column 吸能式转向管柱energy-absorbing steering column 网络状转向柱管net type steering column转向轴steering shaft转向横轴cross shaft转向盘steering wheel倾斜式方向盘tilt steering wheel机构转向器manual steering gear蜗杆滚轮式转向器worm and roller steering gear转向器盖cover of steering gear壳体housing转向蜗杆steering worm滚轮roller滚轮轴roller shaft侧盖side cover摇臂轴pitman arm shaft循环球式转向器recirculating ball steering gear循环球和螺母式转向器recirculating ball and nut steering gear循环球齿条齿扇式转向器recirculating ball-rack and sector steering gear 转向螺母steering nut钢球ball转向螺杆steering screw循环球-曲柄销式转向器recirculating ball-lever and peg steering gear指销stud蜗杆指销式转向器worm and peg steering gear转向齿轮steering pinion转向齿条steering rack动力转向器power steering stgear整体式动力转向器integral power steering gear常压式液压动力转向器constant pressure hydraulic power steering gear常流式液压动力转向器constant flow hydraulic power steering gear 螺杆螺线式转向器screw and nut steering gear蜗杆指销式转向器worm and peg steering gear齿轮齿条式转向器rack and pinion steering gear变传动比转向器steering gear with variable ratio转向控制阀steering control valve滑阀式转向控制器spool valve type阀体valve housing滑阀valve spool转阀式转向控制阀rotary valve type扭杆torsion bar转向动力缸power cylinder转向油泵power steerig pump转向油罐oil reservoir转向传动杆系steering linkage动力转向系布置power steering system layout反作用阀reactive valve梯形转向机构ackerman steering整体式转向梯形杆系ackerman steering linkdage分段式转向梯形杆系divided ackerman steering linkage中间转向杆intermediate steering rod转向摇臂pitman arm转向直拉杆steering drag link中间转向联杆center steering linkdage端部螺塞end plug球头销ball stud球头座ball cup压缩弹簧compression spring梯形机构tie rod linkage梯形臂tie rod arm转向横拉杆steering tie rod接头socket横拉杆端接头tie rod end分段式梯形机构split tie rod type tie rod linkage摆臂swing arm动力转向power steering气压式动力转向air-power steering液压式动力转向hydraulic power steerig液压常流式动力转向hydraulic constant flow type power steering 液压储能式动力转向hydraulic accumulator power steering慢速转向slow steeirng快速转向fast steering (quick steering)过度转向oversteering转向不足understeering转向系刚度steering system stiffness转向盘自由行程free play of steering wheel转向器转动力矩rotating torque of steering gear转向力矩steering mometn转向阻力矩steering resisting torque转向力steering force转向传动比steering gear ratio (steering ratio0恒定转向传动比constant ratio steering可变转向传动比variable ratio steering转向系角传动比steering system angle ratio转向器角传动比steering gear angle ratio转向传动机构角传动比steering linkage angle ratio转向器传动效率steerign gear efficiency正效率forward efficiency逆效率reverse efficiency转向器扭转刚度torsional stiffness of steering gear转向盘总圈数total number of steering wheel turns转向器总圈数total turns of steering gaer转向器传动间隙steering gar cleanrance摇臂轴最大转角max.rotating angle of pitman arm shaft 转向摇臂最大摆角max. Swing angle of steering pitman arm 转向器反驱动力矩reverse rotating torque of steering gear转向器最大输出扭矩steering gear max. Output torque最大工作压力max. Working pressure额定工作压力rated working pressure转向油泵理论排量theoretical displacement of pump限制流量limited flow转向控制阀预开隙pre-opened play of steering contol valve转向控制阀全开隙totally -opened play of steering control valve转向控制阀内泄漏量internal leakage in steering control valve转向控制阀压力降pressure loss in steering control valve转向器角传动比特性steering gear angle ratio characteristic转向器传动间隙特性steering gear clearance characterstic转向器传动效率特性steering gear efficeieny characteristic转向力特性steering force characteristic动力转向系灵敏度特性power steering systme response characteristic 转向控制阀压力降特性steeirn gcontrol valve presrue loss characteristtic 前桥front axle工字梁I-beam双工字梁twin I-beam非驱动桥dead axle转向节steering knuckle挂车转向装置steering system of trailer中央主销式转向装置central king pin type steering systme无主销转向装置no king pin type steering system全杆式转向装置all linkage tyep steering system球销式转向节ball and socket steering knuckle转向节止推轴承steering knuckle thrust bearing前轮轴front wheel spindle转向盘轴steering spindle转向节轴knuckle spindle转向节臂steering knuckle arm（转向节）主销knuckle pin(King pin)反拳式前桥reverse elliott axle反拳式转向节reverse elliott steering knuckle叉式前桥elliott type axle叉式转向节elliott steering knuckle制动系braking ssytem类型tyep行车制动系统service braking sytem应急制动系统secondary (emergency )braking sytem 驻车制动系统parking braking system辅助制动系统auxiliary braking system自动制动系统automatic braking sytem人力制动系统muscular energy braking sytem助力制动系统energy assisted braking system动力制动系统non-muscular energy braking system 惯性制动系统inertial braking styem重力制动系统gravity braking sytem单回路制动系统single-circuit braking system双回路制动系统dual -ciurcuit braking system单管路制动系统single-line braking system双管路制动系统dual braking sytem多管路制动系统multi-line braking sytem连续制动系统continuous braking sytem半连续制动系统semi-continuous braking sytemm非连续制动系统non-continuous braking system伺服制动系统servo braking system液压制动系统hydraulic braking sytem电磁制动系统electormagnetic braking sytem机械制动系统mechanical braking sytem组合制动系统combination braking sytem基本术语bsic terms制动装备braking equipment组成部件constituent elements制动力学braking mechanics渐进制动gradual braking制动能源braking energy source制动力矩braking torque总制动力total braking force干扰后效制动力矩distrubing residual braking torque 总制动距离total braking distance有效制动距离active braking。

外文原文：The Analysis of Cavitation Problems in the Axial Piston Pumpshu WangEaton Corporation,14615 Lone Oak Road,Eden Prairie, MN 55344This paper discusses and analyzes the control volume of a piston bore constrained by the valve plate in axial piston pumps. The vacuum within the piston bore caused by the rise volume needs to be compensated by the flow; otherwise, the low pressure may cause the cavitations and aerations. In the research, the valve plate geometry can be optimized by some analytical limitations to prevent the piston pressure below the vapor pressure. The limitations provide the design guide of the timings and overlap areas between valve plate ports and barrel kidneys to consider the cavitations and aerations. _DOI: 10.1115/1.4002058_Keywords: cavitation , optimization, valve plate, pressure undershoots1 IntroductionIn hydrostatic machines, cavitations mean that cavities or bubbles form in the hydraulic liquid at the low pressure and collapse at the high pressure region, which causes noise, vibration, and less efficiency.Cavitations are undesirable in the pump since the shock waves formed by collapsed may be strong enough to damage components. The hydraulic fluid will vaporize when its pressure becomes too low or when the temperature is too high. In practice, a number of approaches are mostly used to deal with the problems: (1) raise the liquid level in the tank, (2) pressurize the tank, (3) booster the inlet pressure of the pump, (4) lower the pumping fluid temperature, and (5) design deliberately the pump itself.Many research efforts have been made on cavitation phenomena in hydraulic machine designs. The cavitation is classified into two types in piston pumps: trapping phenomenon related one (which can be preventedby the proper design of the valve plate) and the one observed on the layers after the contraction or enlargement of flow passages (caused by rotating group designs) in Ref. (1). The relationship between the cavitation and the measured cylinder pressure is addressed in this study. Edge and Darling (2) reported an experimental study of the cylinder pressure within an axial piston pump. The inclusion of fluid momentum effects and cavitations within the cylinder bore are predicted at both high speed and high load conditions. Another study in Ref. (3) provides an overview of hydraulic fluid impacting on the inlet condition and cavitation potential. It indicates that physical properties (such as vapor pressure, viscosity, density, and bulk modulus) are vital to properly evaluate the effects on lubrication and cavitation. A homogeneous cavitation model based on the thermodynamic properties of the liquid and steam is used to understand the basic physical phenomena of mass flow reduction and wave motion influences in the hydraulic tools and injection systems (4). Dular et al. (5, 6) developed an expert system for monitoring and control of cavitations in hydraulic machines and investigated the possibility of cavitation erosion by using the computational fluid dynamics (CFD) tools. The erosion effects of cavitations have been measured and validated by a simple single hydrofoil configuration in a cavitation tunnel. It is assumed that the severe erosion is often due to the repeated collapse of the traveling vortex generated by a leading edge cavity in Ref. (7). Then, the cavitation erosion intensity may be scaled by a simple set of flow parameters: the upstream velocity, the Strouhal number, the cavity length, and the pressure. A new cavitation erosion device, called vortex cavitation generator, is introduced to comparatively study various erosion situations (8).More previous research has been concentrated on the valve plate designs, piston, and pump pressure dynamics that can be associated with cavitations in axial piston pumps. The control volume approach and instantaneous flows (leakage) are profoundly studied in Ref. [9]. Berta et al. [10] used the finite volume concept to develop a mathematical model in which the effects of port plate relief grooves have been modeled andthe gaseous cavitation is considered in a simplified manner. An improved model is proposed in Ref. [11] and validated by experimental results. The model may analyze the cylinder pressure and flow ripples influenced by port plate and relief groove design. Manring compared principal advantages of various valve plate slots (i.e., the slots with constant, linearly varying, and quadratic varying areas) in axial piston pumps [12]. Four different numerical models are focused on the characteristics of hydraulic fluid, and cavitations are taken into account in different ways to assist the reduction in flow oscillations [13].The experiences of piston pump developments show that the optimization of the cavitations/aerations shall include the following issues: occurring cavitation and air release, pump acoustics caused by the induced noises, maximal amplitudes of pressure fluctuations, rotational torque progression, etc. However, the aim of this study is to modify the valve plate design to prevent cavitation erosions caused by collapsing steam or air bubbles on the walls of axial pump components. In contrastto literature studies, the research focuses on the development of analytical relationship between the valve plate geometrics and cavitations. The optimization method is applied to analyze the pressure undershoots compared with the saturated vapor pressure within the piston bore.The appropriate design of instantaneous flow areas between the valveplate and barrel kidney can be decided consequently.2 The Axial Piston Pump and Valve PlateThe typical schematic of the design of the axis piston pump is shown in Fig. 1. The shaft offset e is designed in this case to generate stroking containment moments for reducing cost purposes.The variation between the pivot center of the slipper and swash rotating center is shown as a. The swash angle αis the variable that determines the amount of fluid pumped per shaft revolution. In Fig. 1, the n th piston-slipper assembly is located at the angle ofθ. The displacement of the n thnpiston-slipper assembly along the x-axis can be written asx n= R tan（α）sin（θ）+ a sec（α）+ e tan(α) (1)nwhere R is the pitch radius of the rotating group.Then, the instantaneous velocity of the n th piston isx˙n = R 2sec ()αsin （n θ）α+ R tan （α）cos （n θ）ω+ R 2sec ()αsin （α）α + e 2sec ()αα (2)where the shaft rotating speed of the pump is ω=d n θ / dt .The valve plate is the most significant device to constraint flow inpiston pumps. The geometry of intake/discharge ports on the valve plateand its instantaneous relative positions with respect to barrel kidneys areusually referred to the valve plate timing. The ports of the valve plateoverlap with each barrel kidneys to construct a flow area or passage,which confines the fluid dynamics of the pump. In Fig. 2, the timingangles of the discharge and intake ports on the valve plate are listed as(,)T i d δ and (,)B i d δ. The opening angle of the barrel kidney is referred to asϕ. In some designs, there exists a simultaneous overlap between thebarrel kidney and intake/discharge slots at the locations of the top deadcenter (TDC) or bottom dead center (BDC) on the valve plate on whichthe overlap area appears together referred to as “cross -porting” in thepump design engineering. The cross-porting communicates the dischargeand intake ports, which may usually lower the volumetric efficiency. Thetrapped-volume design is compared with the design of the cross-porting,and it can achieve better efficiency 14]. However, the cross-porting isFig. 1 The typical axis piston pumpcommonly used to benefit the noise issue and pump stability in practice.3 The Control Volume of a Piston BoreIn the piston pump, the fluid within one piston is embraced by the piston bore, cylinder barrel, slipper, valve plate, and swash plate shown in Fig. 3. There exist some types of slip flow by virtue of relativeFig. 2 Timing of the valve platemotions and clearances between thos e components. Within the control volume of each piston bore, the instantaneous mass is calculated asM= n V(3)nwhere ρ and n V are the instantaneous density and volumesuch that themass time rate of change can be given asFig. 3 The control volume of the piston boren n n dM dV d V dt dt dtρρ=+ (4) where d n V is the varying of the volume.Based on the conservation equation, the mass rate in the control volume isn n dM q dtρ= (5)where n q is the instantaneous flow rate in and out of one piston. From the definition of the bulk modulus,n dP d dt dtρρβ= (6) where Pn is the instantaneous pressure within the piston bore. Substituting Eqs. (5) and (6) into Eq. (4) yields(?)n n n n n ndP q dV d V w d βθθ=- (7) where the shaft speed of the pump is n d dtθω=. The instantaneous volume of one piston bore can be calculated by using Eq. (1) asn V = 0V + P A [R tan （α）sin （n θ）+ a sec （α） + e tan(α) ] (8)where P A is the piston sectional area and 0V is the volume of eachpiston, which has zero displacement along the x-axis (when n θ=0, π).The volume rate of change can be calculated at the certain swash angle, i.e., α =0, such thattan cos n p n ndV A R d αθθ=（）（） (9) in which it is noted that the piston bore volume increases or decreaseswith respect to the rotating angle of n θ.Substituting Eqs. (8) and (9) into Eq. (7) yields0[tan()cos()] [tan sin sec tan() ]n P n n n p n q A R dP d V A R a e βαθωθαθαα-=-++（）（）（）(10)4 Optimal DesignsTo find the extrema of pressure overshoots and undershoots in the control volume of piston bores, the optimization method can be used in Eq. (10). In a nonlinear function, reaching global maxima and minima is usually the goal of optimization. If the function is continuous on a closed interval, global maxima and minima exist. Furthermore, the global maximum (or minimum) either must be a local maximum (or minimum) in the interior of the domain or must lie on the boundary of the domain. So, the method of finding a global maximum (or minimum) is to detect all the local maxima (or minima) in the interior, evaluate the maxima (or minima) points on the boundary, and select the biggest (or smallest) one. Local maximum or local minimum can be searched by using the first derivative test that the potential extrema of a function f( · ), with derivative ()f ', can solve the equation at the critical points of ()f '=0 [15].The pressure of control volumes in the piston bore may be found as either a minimum or maximum value as dP/ dt=0. Thus, letting the left side of Eq. (10) be equal to zero yieldstan()cos()0n p n q A R ωαθ-= (11)In a piston bore, the quantity of n q offsets the volume varying and thendecreases the overshoots and undershoots of the piston pressure. In this study, the most interesting are undershoots of the pressure, which may fall below the vapor pressure or gas desorption pressure to cause cavitations. The term oftan()cos()p n A R ωαθ in Eq. (11) has the positive value in the range of intake ports (22ππθ-≤≤), shown in Fig. 2, which means that the piston volume arises. Therefore, the piston needs the sufficient flow in; otherwise, the pressure may drop.In the piston, the flow of n q may get through in a few scenariosshown in Fig. 3: (I) the clearance between the valve plate and cylinder barrel, (II) the clearance between the cylinder bore and piston, (III) the clearance between the piston and slipper, (IV) the clearance between the slipper and swash plate, and (V) the overlapping area between the barrel kidney and valve plate ports. As pumps operate stably, the flows in the as laminar flows, which can be calculated as [16]312IV k k Ln i I k h q p L ωμ==∑ (12)where k h is the height of the clearance, k L is the passage length,scenarios I –IV mostly have low Reynolds numbers and can be regarded k ω is the width of the clearance (note that in the scenario II, k ω =2π· r, in which r is the piston radius), and p is the pressure drop defined in the intake ports as p =c p -n p (13)where c p is the case pressure of the pump. The fluid films through theabove clearances were extensively investigated in previous research. The effects of the main related dimensions of pump and the operating conditions on the film are numerically clarified inRefs. [17,18]. The dynamic behavior of slipper pads and the clearance between the slipper and swash plate can be referred to Refs. [19,20]. Manring et al. [21,22] investigated the flow rate and load carrying capacity of the slipper bearing in theoretical and experimental methods under different deformation conditions. A simulation tool calledCASPAR is used to estimate the nonisothermal gap flow between the cylinder barrel and the valve plate by Huang and Ivantysynova [23]. The simulation program also considers the surface deformations to predict gap heights, frictions, etc., between the piston and barrel andbetween the swash plate and slipper. All these clearance geometrics in Eq.(12) are nonlinear and operation based, which is a complicated issue. In this study, the experimental measurements of the gap flows are preferred. If it is not possible, the worst cases of the geometrics or tolerances with empirical adjustments may be used to consider the cavitation issue, i.e., minimum gap flows.For scenario V, the flow is mostly in high velocity and can be described by using the turbulent orifice equation as((Tn d i d d q c A c A θθ= (14)where Pi and Pd are the intake and discharge pressure of the pump and ()i A θ and ()d A θ are the instantaneous overlap area between barrel kidneys and inlet/discharge ports of the valve plate individually.The areas are nonlinear functions of the rotating angle, which is defined by the geometrics of the barrel kidney, valve plate ports,silencing grooves, decompression holes, and so forth. Combining Eqs.(11) –(14), the area can be obtained as3()K IV A θ==(15)where ()A θ is the total overlap area of ()A θ=()()i d A A θλθ+, and λ is defined as=In the piston bore, the pressure varies from low tohigh while passing over the intake and discharge ports of the valve plates. It is possible that the instantaneous pressure achieves extremely low values during the intake area( 22ππθ-≤≤ shown in Fig. 2) that may be located below the vapor pressure vp p , i.e., n vp p p ≤;then cavitations canhappen. To prevent the phenomena, the total overlap area of ()A θ mightbe designed to be satisfied with30()K IV A θ=≥(16)where 0()A θ is the minimum area of 0()A θ=0()()i d A A θλθ+ and 0λis a constant that is0λ=gaseous form. The vapor pressure of any substance increases nonlinearly with temperature according to the Clausius –Clapeyron relation. With the incremental increase in temperature, the vapor pressure becomes sufficient to overcome particle attraction and make the liquid form bubbles inside the substance. For pure components, the vapor pressure can be determined by the temperature using the Antoine equation as /()10A B C T --, where T is the temperature, and A, B, and C are constants[24].As a piston traverse the intake port, the pressure varies dependent on the cosine function in Eq. (10). It is noted that there are some typical positions of the piston with respect to the intake port, the beginning and ending of overlap, i.e., TDC and BDC (/2,/2θππ=- ) and the zero displacement position (θ =0). The two situations will be discussed as follows:(1) When /2,/2θππ=-, it is not always necessary to maintain the overlap area of 0()A θ because slip flows may provide filling up for the vacuum. From Eq. (16), letting 0()A θ=0,the timing angles at the TDC and BDC may be designed as31cos ()tan()122IV c vpk k i I P k p p h A r L ωϕδωαμ--≤+∑ (17) in which the open angle of the barrel kidney is . There is nocross-porting flow with the timing in the intake port.(2) When θ =0, the function of cos θ has the maximum value, which can provide another limitation of the overlap area to prevent the low pressure undershoots suchthat 30(0)K IVA =≥ (18)where 0(0)A is the minimum overlap area of 0(0)(0)i A A =.To prevent the low piston pressure building bubbles, the vaporpressure is considered as the lower limitation for the pressure settings in Eq. (16). The overall of overlap areas then can be derived to have adesign limitation. The limitation is determined by the leakage conditions, vapor pressure, rotating speed, etc. It indicates that the higher the pumping speed, the more severe cavitation may happen, and then the designs need more overlap area to let flow in the piston bore. On the other side, the low vapor pressure of the hydraulic fluid is preferred to reduce the opportunities to reach the cavitation conditions. As a result, only the vapor pressure of the pure fluid is considered in Eqs. (16)–(18). In fact, air release starts in the higher pressure than the pure cavitation process mainly in turbulent shear layers, which occur in scenario V.Therefore, the vapor pressure might be adjusted to design the overlap area by Eq. (16) if there exists substantial trapped and dissolved air in the fluid.The laminar leakages through the clearances aforementioned are a tradeoff in the design. It is demonstrated that the more leakage from the pump case to piston may relieve cavitation problems.However, the more leakage may degrade the pump efficiency in the discharge ports. In some design cases, the maximum timing angles can be determined by Eq. (17)to not have both simultaneous overlapping and highly low pressure at the TDC and BDC.While the piston rotates to have the zero displacement, the minimum overlap area can be determined by Eq. 18 , which may assist the piston not to have the large pressure undershoots during flow intake.6 ConclusionsThe valve plate design is a critical issue in addressing the cavitation or aeration phenomena in the piston pump. This study uses the control volume method to analyze the flow, pressure, and leakages within one piston bore related to the valve plate timings. If the overlap area developed by barrel kidneys and valve plate ports is not properly designed, no sufficient flow replenishes the rise volume by the rotating movement. Therefore, the piston pressure may drop below the saturated vapor pressure of the liquid and air ingress to form the vapor bubbles. To control the damaging cavitations, the optimization approach is used to detect the lowest pressure constricted by valve plate timings. The analytical limitation of the overlap area needs to be satisfied to remain the pressure to not have large undershoots so that the system can be largely enhanced on cavitation/aeration issues.In this study, the dynamics of the piston control volume is developed by using several assumptions such as constant discharge coefficients and laminar leakages. The discharge coefficient is practically nonlinear based on the geometrics, flow number, etc. Leakage clearances of the control volume may not keep the constant height and width as well in practice due to vibrations and dynamical ripples. All these issues are complicated and very empirical and need further consideration in the future. Theresults presented in this paper can be more accurate in estimating the cavitations with these extensive studies.Nomenclature0(),()A A θθ= the total overlap area between valve plate ports and barrel kidneys 2()mmAp = piston section area 2()mmA, B, C= constantsA= offset between the piston-slipper joint and surface of the swash plate 2()mmd C = orifice discharge coefficiente= offset between the swash plate pivot and the shaft centerline of the pump 2()mmk h = the height of the clearance 2()mmk L = the passage length of the clearance 2()mmM= mass of the fluid within a single piston (kg)N= number of pistonsn = piston and slipper counter,p p = fluid pressure and pressure drop (bar)Pc= the case pressure of the pump (bar)Pd= pump discharge pressure (bar)Pi = pump intake pressure (bar)Pn = fluid pressure within the nth piston bore (bar)Pvp = the vapor pressure of the hydraulic fluid(bar)qn, qLn, qTn = the instantaneous flow rate of each piston(l/min)R = piston pitch radius 2()mmr = piston radius (mm)t =time (s)V = volume 3()mmwk = the width of the clearance (mm)x ,x ˙= piston displacement and velocity along the shaft axis (m, m/s) x y z --=Cartesian coordinates with an origin on the shaft centerline x y z '''--= Cartesian coordinates with an origin on swash plate pivot ,αα=swash plate angle and velocity (rad, rad/s)β= fluid bulk modulus (bar)δδ= timing angle of valve plates at the BDC and TDC (rad),B Tϕ= the open angle of the barrel kidney(rad)ρ= fluid density(kg/m3),θω= angular position and velocity of the rotating kit (rad, rad/s)μ=absolute viscosity(Cp),λλ= coefficients related to the pressure drop外文中文翻译：在轴向柱塞泵气蚀问题的分析本论文讨论和分析了一个柱塞孔与配流盘限制在轴向柱塞泵的控制量设计。

TRANSMISSIONEngine output speed is very high, the power and the maximum torque in certain areas of the speed. In order to exert the engine, you must have the best performance, to coordinate the speed of the engine and the actual speeds. Transmission in automobile driving process between the engine and wheels, in different ratios, through the shift in the engine can work under the condition of the best performance. The development trend of the transmission is more complex, more and more is also high automation degree, automatic transmission is the mainstream of the future.Car engines in certain speed can reach the best state, the output power of the bigger, fuel economy and better. Therefore, we hope in the best condition engine always work. But, in the use of the car to have different speed, the contradictions. This contradiction through the transmission to solve.Auto transmission function in a single sentence, is called the speed change, which reduced growth slowing or thickening twist. Why can increase twist, and slowing growth and to reduce twist? Put the power output unchanged, the engine power can be expressed as N = wT, w is turning, T is the angular torque. When N fixed, w and T is inversely proportional to the. So the growth will be reduced, slow increase twist. Auto transmission gear transmission is based on the principle of variable twist, each corresponding to different into gear transmission, in order to adapt to the different operating conditions.General manual transmission shaft set the input and output shaft, and say, another three axis reverse axis. Three main transmission shaft type is the speed of the input shaft structure, the speed of the engine, is also the output shaft speed is presented. By output shaft gear generated between different speeds. The gear is different with different ratio, also have different speed. Such as Zhen Zhou Nissan ZN6481W2G type SUV driver’s dynamic transmission, it is respectively: 1 ratio of 1:3.704 gears, 2.202 2:1, 3:1; 1.414 4 gears, - 5 (1): overdrive dependent.When the car started when the driver choose 1 files, dial 1 1/2 shift fork synchronizer backward joints and 1 shift gear lock on the output shaft, and the power input shaft, and the output shaft shift gears, 1 shift gear drive output shaft, output shaft will power to transmission (red arrows). The typical one shift gear ratio is 3:1, i.e. input shaft turn 3 laps, output shaft turn 1 lap.When the car growth drivers choose 2 files, dial 1 1/2 shift fork synchronizer and 1 separateness from 2 after mating locking output shaft gear and power transmission line, which is similar to the output shaft gear with 2, 1 files output shaft gear. The typical 2 shift gear ratio is 2.2:1, input, output shaft turning 2.2 pivot, 1-1 RPMincreases, torque shift.When gas growth drivers choose 3, dial 1 1/2 shift fork to synchronizer, and back to space three/four file synchronizer will move until 3 gear lock in the output shaft, make the power from the first shaft -- -- on the output shaft transmission gears, 3 through the output shaft gear shifting speed. The typical 3 ratio was 1.7:1, the input shaft turning circle, the output shaft 1.7 turn 1 ring, is further growth.When gas growth drivers choose 4 gears, fork will 3/4 file synchronizer from 3 gear directly with the input shaft driving gear engagement, power transmission directly from the input shaft to the output shaft, and the output shaft is 1:1 ratio and the input shaft speed. Due to the force, and the direct oart shift, the gear transmission efficiency ratio. Cars run most time in order to achieve the best directly file fuel economy.Shift to go into space, transmission in the transmission gears have locked in the output shaft, they cannot drive the output shaft rotation, no power output.General car manual transmission ratio main points above 1-4, usually designers to first identify the lowest (1) and (4) transmission, the ratio between after general distribution according to form. In addition, there is a reverse and overdrive, overdrive called 5 files.When the car to accelerate whether isolated car drivers choose more than 5, 5 gear transmission is typical 0.87:1, namely with big gear drive pinion gear turns, when active 0.87 lap, passive gear has turned over one lap.When the reverse in the opposite direction to the output shaft rotation. If a gear when reverse rotation, plus a gear will become a positive spin. Using this principle, will add a reverse gear do "medium", the direction of rotation axis, so has reversed a reverse axis. Reverse transmission shaft independent in housing, and parallel axis, when oart in gear and gear and oart output shaft gear, output shaft to will instead.Usually the reverse synchronizer is controlled by the jointing, so May 5 files and reverse position is in the same side. Due to the middle, reverse gear transmission is generally greater than 1 gear transmission ratio, twist, some cars met with forward instead of steep open up in reverse.From driving gear transmission is smooth; more is better, more adjacent gear shift between the transmission ratio, shift easy and smooth. But the gear transmission fault is more complex structure, big volume and light auto transmission is now commonly 4-5. At the same time, the transmission ratio is not an integer, but with the decimal point, this is not the whole number of meshing gears, two gear ratio is the euploid number will lead to two gear surface non-uniform wear, tooth surface quality of differences.Manual transmission and synchronizerManual transmission is one of the most common transmissions, referred to as MT. Its basic structure in a single sentence is a central axis, two input shaft, namely, the axial and axial oart, they constituted the transmission of the subject, and, of course, a reverse axis. Manual transmission gear transmission and manual, contain can in axial sliding gears, through different meshing gears to change gear of torsional purpose. The typical structure and principle of the manual transmission.Input shaft also says, it's in front of the spline shaft directly with clutch platen, thus the spline set by the engine relay of torque. The first shaft gear meshing gears, often with oart as input shaft, and the gear on oart will turn. Also called shaft, because even more solid shaft of gear. The output shaft, and the second shaft position have the drive shaft gear, may at any time and under the influence of the control devices and the corresponding oart gear, thus changing the speed and torque itself. The output shaft is associated with tail spline shaft torque transmission shaft, through to drive to gear reducer.Predictably, transmission gear drive forward path is: input shaft gear - oart gnaws gear - because the second shaft gear - corresponding gear. Pour on the axle gear can also control device, by moving axis in the strike, and the output shaft gear and oart gear, in the opposite direction.Most cars have five forward and reverse gear, each one has certain ratio, the majority of gear transmission more than 1, 4 gears transmission is 1, called directly, and ratio is less than 1 of article 5 gear shift accelerated called. The output axis gear in the mesh position, can accept power transmission.Due to the gearbox output shaft to input shaft and the speed of their gear rotating, transform a "synchronization problem". Two rotating speed different meshing gears forcibly inevitable impact and collision damage gear. Therefore, the old transmission shift to use "two feet on-off" method, accelerate in neutral position shift to stay for a while, in the space location on the door, in order to reduce gear speed. But this operation is more complex, difficult to grasp accurately. Therefore designers to create "synchronizer", through the synchronizer will make the meshing gears reach speed and smooth.Currently the synchronous transmission adopts is inertial synchronizer, it mainly consists of joints, synchronizer lock ring etc, it is characteristic of the friction effect on achieving synchronization. Mating, synchronizer and mating locking ring gear tooth circle have chamfering (locking horns), the synchronizer lock ring inside surface of gear engagement ring and the friction surface contact. The lock horns with cone when designing the proper choice, has been made to the surface friction of meshinggears with gear synchronous, also can rapid produces a locking function, prevent the synchronous before meshing gears. When synchronous lock ring of gear engagement with surface contact surface, the outer circle in friction torque under the action of gear speed rapid decrease (increase) or to synchronous speed equal, both locking ring spun concurrent, relative to lock ring gear synchronous speed is zero, thus inertia moment also disappear, then in force, driven by the junction of unimpeded with synchronous lock ring gear engagement, and further to engagement with the engagement ring gear tooth and complete shift process变速器发动机的输出转速非常高，最大功率及最大扭矩在一定的转速区出现。

Hydraulic MachineFrom: The Columbia Encyclopedia, Sixth Edition Date: 2008Hydraulic machine that derives its power from the motion or pressure of water or some other liquid. Hydraulic equipment and technology is something that we are all at least passingly familiar with. If we think about it, we know that the principles of hydraulics are applied to make many common machines work. For example hydraulics are used in agricultural equipment, giant earth moving and mining machines, they are used to steer and stabilize giant ocean liners, help airplanes climb and turn, and make the brakes in our cars work. So hydraulics can provide great force, are obviously very adaptable and used in all kinds of applications, but how do they actually work?What is this hydraulics stuff?Hydraulics is based on a very simple fact of nature - you cannot compress a liquid. You can compress a gas (think about putting more and more air into a tire, the more you put in, the higher the pressure). If you're really strong you can compress a solid mass as well. But no matter how much pressure you apply onto a liquid, it isn't possible to compress it. Now if you put that liquid into a sealed system and push on it at one end, that pressure is transmitted through the liquid to the other end of the system. The pressure is not diminished.. Hydraulics is Old StuffThe basic concept of hydraulics is not new. The Greeks understood about using water to provide lift and force, and the name hydraulics come form the Latin word for water - "HYDRA". In the middle Ages, Leonardo da Vinci formulated the basic principle of hydraulics called continuity and Galileo experimented with hydraulics. Hydraulics were even used during the construction of the Eiffel Tower in Paris in the late 1880's. Hydraulic jacks were used to level the tower and align the metal girders toan accuracy of 1 millimeter。