旋风分离器英文文献翻译.

中英文对照外文翻译文献(文档含英文原文和中文翻译)外文文献：DC Motor CalculationsOverviewNow that we have a good understanding of dc generators, we can begin our study of dc motors. Direct-current motors transform electrical energy into mechanical energy. They drive devices such as hoists, fans, pumps, calendars, punch-presses, and cars. These devices may have a definite torque-speed characteristic (such as a pump or fan) or a highly variable one (such as a hoist or automobile). The torque-speed characteristic of the motor must be adapted to the type of the load it has to drive, and this requirement has given rise to three basic types of motors: 1.Shunt motors 2. Series motors 3. Compound motors Direct-current motors are seldom used in ordinary industrial applications because all electric utility systems furnish alternating current. However, for special applications such as in steel mills, mines, and electric trains, it is sometimes advantageous to transform the alternating current into direct current in order to use dc motors. The reason is that the torque-speed characteristics of dc motors can be varied over a wide range while retaining high efficiency. Today, this general statement can be challenged because the availability of sophisticated electronic drives has made it possible to use alternating current motors for variable speed applications. Nevertheless, there are millions of dc motors still in service and thousands more are being produced every year.Counter-electromotive force (cemf)Direct-current motors are built the same way as generators are; consequently, a dc machine can operate either as a motor or as a generator. To illustrate, consider a dc generator in which the armature, initially at rest, is connected to a dc source E s by means of a switch (Fig. 5.1). The armature has a resistance R, and the magnetic field is created by a set of permanent magnets.As soon as the switch is closed, a large current flows in the armature because its resistance is very low. The individual armature conductors are immediately subjected to a force because they are immersed in the magnetic field created by the permanent magnets. These forces add upto produce a powerful torque, causing the armature to rotate.Figure 5.1 Starting a dc motor across the line.On the other hand, as soon as the armature begins to turn, a second phenomenon takes place: the generator effect. We know that a voltage E o is induced in the armature conductors as soon as they cut a magnetic field (Fig. 5.2). This is always true, no matter what causes the rotation. The value and polarity of the induced voltage are the same as those obtained when the machine operates as a generator. The induced voltage E o is therefore proportional to the speed of rotation n of the motor and to the flux F per pole, as previously given by Eq. 5.1:E o = Zn F/60 (5.1)As in the case of a generator, Z is a constant that depends upon the number of turns on the armature and the type of winding. For lap windings Z is equal to the number of armature conductors.In the case of a motor, the induced voltage E o is called counter-electromotive force (cemf) because its polarity always acts against the source voltage E s. It acts against the voltage in the sense that the net voltage acting in the series circuit of Fig. 5.2 is equal to (E s - Eo) volts and not (E s + E o) volts.Figure 5.2 Counter-electromotive force (cemf) in a dc motor.Acceleration of the motorThe net voltage acting in the armature circuit in Fig. 5.2 is (E s- E o) volts. The resulting armature current /is limited only by the armature resistance R, and soI = (E s- E o)IR (5.2)When the motor is at rest, the induced voltage E o= 0, and so the starting current isI = E s/RThe starting current may be 20 to 30 times greater than the nominal full-load current of the motor. In practice, this would cause the fuses to blow or the circuit-breakers to trip. However, if they are absent, the large forces acting on the armature conductors produce a powerful starting torque and a consequent rapid acceleration of the armature.As the speed increases, the counter-emf E o increases, with the result that the value of (E s—E o)diminishes. It follows from Eq. 5.1 that the armature current / drops progressively as the speed increases.Although the armature current decreases, the motor continues to accelerate until it reaches a definite, maximum speed. At no-load this speed produces a counter-emf E o slightly less than the source voltage E s. In effect, if E o were equal to E s the net voltage (E s—E o) would become zero and so, too, would the current /. The driving forces would cease to act on the armature conductors, and the mechanical drag imposed by the fan and the bearings would immediately cause the motor to slow down. As the speed decreases the net voltage (E s—E o) increases and so does the current /. The speed will cease to fall as soon as the torque developed by the armature current is equal to the load torque. Thus, when a motor runs at no-load, the counter-emf must be slightly less than E s so as to enable a small current to flow, sufficient to produce the required torque.Mechanical power and torqueThe power and torque of a dc motor are two of its most important properties. We now derive two simple equations that enable us to calculate them.1. According to Eq. 5.1 the cemf induced in a lap-wound armature is given byE o = Zn F/60Referring to Fig. 5.2, the electrical power P a supplied to the armature is equal to the supply voltage E s multiplied by the armature current I:P a = E s I (5.3)However, E s is equal to the sum of E o plus the IR drop in the armature:E s = E o + IR (5.4)It follows thatP a= E s I= (E o + IR)I=E o I + I2R (5.5)The I2R term represents heat dissipated in the armature, but the very important term E o I is the electrical power that is converted into mechanical power. The mechanical power of the motor is therefore exactly equal to the product of the cemf multiplied by the armature currentP = E o I (5.6)whereP = mechanical power developed by the motor [W]E o= induced voltage in the armature (cemf) [V]I = total current supplied to the armature [A]2. Turning our attention to torque T, we know that the mechanical power P is given by the expressionP = nT/9.55 (5.7)where n is the speed of rotation.Combining Eqs. 5.7,5.1, and 5.6, we obtainnT/9.55 = E o I= ZnFI/60and soT =Z F I/6.28The torque developed by a lap-wound motor is therefore given by the expressionT =Z F I/6.28 (5.8)whereT = torque [N×m]Z = number of conductors on the armatureF = effective flux per pole [Wb]*/ = armature current [A]6.28 = constant, to take care of units[exact value = 2p]Eq. 5.8shows that we can raise the torque of a motor either by raising the armature current or by raising the flux created by the poles.Speed of rotationWhen a dc motor drives a load between no-load and full-load, the IR drop due to armature resistance is always small compared to the supply voltage E s. This means that the counter-emf E s is very nearly equal to E s.On the other hand, we have already seen that Eo may be expressed by the equationE o = Zn F/60Replacing E o by E s we obtainE s = Zn F/60That is,wheren = speed of rotation [r/min]E s = armature voltage [V]Z = total number of armature conductorsThis important equation shows that the speed of the motor is directly proportional to the armature supply voltage and inversely proportional to the flux per pole. We will now study how this equation is applied.Armature speed controlAccording to Eq. 5.8, if the flux per pole F is kept constant (permanent magnet field or field with fixed excitation), the speed depends only upon the armature voltage E s. By raising or lowering E s the motor speed will rise and fall in proportion.In practice, we can vary E s by connecting the motor armature M to a separately excited variable-voltage dc generator G . The field excitation of the motor is kept constant, but the generator excitation I x can be varied from zero to maximum and even reversed. The generator output voltage E s can therefore be varied from zero to maximum, with either positive or negative polarity. Consequently, the motor speed can be varied from zero to maximum in either direction. Note that the generator is driven by an ac motor connected to a 3-phase line. This method of speed control, known as the Ward-Leonard system, is found in steel mills, high-rise elevators, mines, and paper mills.In modem installations the generator is often replaced by a high-power electronic converter that changes the ac power of the electrical utility to dc, by electronic means.What happens to the dc power received by generator G? When G receives electric power, it operates as a motor, driving its own ac motor as an asynchronous generator!* As a result, ac power is fed back into the line that normally feeds the ac motor. The fact that power can be recovered this way makes the Ward-Leonard system very efficient, and constitutes another of its advantages.Rheostat Speed ControlAnother way to control the speed of a dc motor is to place a rheostat in series with the armature . The current in the rheostat produces a voltage drop which subtracts from the fixed source voltage E s, yielding a smaller supply voltage across the armature. This method enables us to reduce the speed below its nominal speed. It is only recommended for small motors because a lot of power and heat is wasted in the rheostat, and the overall efficiency is low. Furthermore, thespeed regulation is poor, even for a fixed setting of the rheostat. In effect, the IR drop across the rheostat increases as the armature current increases. This produces a substantial drop in speed with increasing mechanical load.中文译文：直流电动机的计算概述现在，我们对直流发电机有一个很好的了解，我们可以开始对直流电动机的研究了。

Circuit breaker断路器Compressed air circuit breaker is a mechanical switch equipment, can be i 空气压缩断路器是一种机械开关设备，能够在n normal and special conditions breaking current (such as short circuit cur 正常和特殊情况下开断电流（比如说短路电流）。

rent). For example, air circuit breaker, oil circuit breaker, interference circ 例如空气断路器、油断路器，干扰电路的导体uit conductor for the application of the safety and reliability of the circuit 干扰电路的导体因该安全可靠的应用于其中，breaker, current in arc from is usually divided into the following grades: a 电流断路器按灭弧远离通常被分为如下等级：ir switch circuit breaker, oil circuit breaker, less oil circuit breaker, compr 空气开关断路器、油断路器、少油断路器、压缩空essed air circuit breaker, a degaussing of isolating switch, six sulfur hexaf 气断路器、具有消磁性质的隔离开关、六氟luoride circuit breaker and vacuum breaker. Their parameters of voltage, 化硫断路器和真空断路器。

他们的参数有电压等级、current, insulation level of breaking capacity, instantaneous voltage off ti 开断容量的电流、绝缘等级开断时间的瞬时电压恢复和me of recovery and a bombing. Breaker plate usually include: 1 the maxi 轰炸时间。

The Sunflower Seed Huller and Oil PressBy Jeff Cox-— from Organic Gardening，April 1979, Rodale PressIN 2,500 SQUARE FEET, a family of four can grow each year enough sunflower seed to produce three gallons of homemade vegetable oil suitable for salads or cooking and 20 pounds of nutritious, dehulled seed —- with enough broken seeds left over to f eed a winter’s worth of birds。

Theproblem，heretofore，with sunflower seeds was the difficulty of dehullingthem at home，and the lack of a device for expressing oil from the seeds。

About six months ago, we decided to change all that. The job was to find out who makes a sunflower seed dehuller or to devise one if none were manufactured. And to either locate a home—scale oilseed press or deviseone. No mean task。

Our researches took us from North Dakota -— hub of commercial sunflower activity in the nation —— to a search of the files in the U.S. Patent Office，with stops in between。

机械类英文文献+翻译20.9 MACHINABILITYThe machinability of a material usually defined in terms of four factors:1、Surface finish and integrity of the machined part;2、Tool life obtained;3、Force and power requirements;4、Chip control.Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone.Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. In manufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below.20.9.1 Machinability Of SteelsBecause steels are among the most important engineering materials (as noted in Chapter 5), their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels.Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primary shear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in resulfurized steels.Phosphorus in steels has two major effects. It strengthens the ferrite, causingincreased hardness. Harder steels result in better chip formation and surface finish. Note that soft steels can be difficult to machine, with built-up edge formation and poor surface finish. The second effect is that increased hardness causes the formation of short chips instead of continuous stringy ones, thereby improving machinability.Leaded Steels. A high percentage of lead in steels solidifies at the tip of manganese sulfide inclusions. In non-resulfurized grades of steel, lead takes the form of dispersed fine particles. Lead is insoluble in iron, copper, and alumin um and their alloys. Because of its low shear strength, therefore, lead acts as a solid lubricant (Section 32.11) and is smeared over the tool-chip interface du ring cutting. This behavior has been verified by the presence of high concentra tions of lead on the tool-side face of chips when machining leaded steels.When the temperature is sufficiently high-for instance, at high cutting spee ds and feeds (Section 20.6)—the lead melts directly in front of the tool, acting as a liquid lubricant. In addition to this effect, lead lowers the shear stress in the primary shear zone, reducing cutting forces and power consumption. Lead can be used in every grade of steel, such as 10xx, 11xx, 12xx, 41xx, etc. Le aded steels are identified by the letter L between the second and third numeral s (for example, 10L45). (Note that in stainless steels, similar use of the letter L means 〝low carbon,〞a condition that improves their corrosion resistance.)However, because lead is a well-known toxin and a pollutant, there are se rious environmental concerns about its use in steels (estimated at 4500 tons of lead consumption every year in the production of steels). Consequently, there is a continuing trend toward eliminating the use of lead in steels (lead-free ste els). Bismuth and tin are now being investigated as possible substitutes for lea d in steels.Calcium-Deoxidized Steels. An important development is calcium-deoxidize d steels, in which oxide flakes of calcium silicates (CaSo) are formed. These f lakes, in turn, reduce the strength of the secondary shear zone, decreasing tool-chip interface and wear. Temperature is correspondingly reduced. Consequently, these steels produce less crater wear, especially at high cutting speeds.Stainless Steels. Austenitic (300 series) steels are generally difficult to mac hine. Chatter can be s problem, necessitating machine tools with high stiffness.However, ferritic stainless steels (also 300 series) have good machinability. M artensitic (400 series) steels are abrasive, tend to form a built-up edge, and req uire tool materials with high hot hardness and crater-wear resistance. Precipitati on-hardening stainless steels are strong and abrasive, requiring hard and abrasio n-resistant tool materials.The Effects of Other Elements in Steels on Machinability. The presence of aluminum and silicon in steels is always harmful because these elements com bine with oxygen to form aluminum oxide and silicates, which are hard and a brasive. These compounds increase tool wear and reduce machinability. It is es sential to produce and use clean steels.Carbon and manganese have various effects on the machinability of steels, depending on their composition. Plain low-carbon steels (less than 0.15% C) c an produce poor surface finish by forming a built-up edge. Cast steels are mor e abrasive, although their machinability is similar to that of wrought steels. To ol and die steels are very difficult to machine and usually require annealing pr ior to machining. Machinability of most steels is improved by cold working, w hich hardens the material and reduces the tendency for built-up edge formation.Other alloying elements, such as nickel, chromium, molybdenum, and vana dium, which improve the properties of steels, generally reduce machinability. T he effect of boron is negligible. Gaseous elements such as hydrogen and nitrog en can have particularly detrimental effects on the properties of steel. Oxygen has been shown to have a strong effect on the aspect ratio of the manganese sulfide inclusions; the higher the oxygen content, the lower the aspect ratio an d the higher the machinability.In selecting various elements to improve machinability, we should consider the possible detrimental effects of these elements on the properties and strengt h of the machined part in service. At elevated temperatures, for example, lead causes embrittlement of steels (liquid-metal embrittlement, hot shortness; see Se ction 1.4.3), although at room temperature it has no effect on mechanical prop erties.Sulfur can severely reduce the hot workability of steels, because of the fo rmation of iron sulfide, unless sufficient manganese is present to prevent suchformation. At room temperature, the mechanical properties of resulfurized steels depend on the orientation of the deformed manganese sulfide inclusions (aniso tropy). Rephosphorized steels are significantly less ductile, and are produced so lely to improve machinability.20.9.2 Machinability of Various Other MetalsAluminum is generally very easy to machine, although the softer grades te nd to form a built-up edge, resulting in poor surface finish. High cutting speed s, high rake angles, and high relief angles are recommended. Wrought aluminu m alloys with high silicon content and cast aluminum alloys may be abrasive; they require harder tool materials. Dimensional tolerance control may be a pro blem in machining aluminum, since it has a high thermal coefficient of expans ion and a relatively low elastic modulus.Beryllium is similar to cast irons. Because it is more abrasive and toxic, t hough, it requires machining in a controlled environment.Cast gray irons are generally machinable but are. Free carbides in castings reduce their machinability and cause tool chipping or fracture, necessitating to ols with high toughness. Nodular and malleable irons are machinable with hard tool materials.Cobalt-based alloys are abrasive and highly work-hardening. They require sharp, abrasion-resistant tool materials and low feeds and speeds.Wrought copper can be difficult to machine because of built-up edge form ation, although cast copper alloys are easy to machine. Brasses are easy to ma chine, especially with the addition pf lead (leaded free-machining brass). Bronz es are more difficult to machine than brass.Magnesium is very easy to machine, with good surface finish and prolong ed tool life. However care should be exercised because of its high rate of oxi dation and the danger of fire (the element is pyrophoric).Molybdenum is ductile and work-hardening, so it can produce poor surfac e finish. Sharp tools are necessary.Nickel-based alloys are work-hardening, abrasive, and strong at high tempe ratures. Their machinability is similar to that of stainless steels.Tantalum is very work-hardening, ductile, and soft. It produces a poor surf ace finish; tool wear is high.Titanium and its alloys have poor thermal conductivity (indeed, the lowest of all metals), causing significant temperature rise and built-up edge; they can be difficult to machine.Tungsten is brittle, strong, and very abrasive, so its machinability is low, although it greatly improves at elevated temperatures.Zirconium has good machinability. It requires a coolant-type cutting fluid, however, because of the explosion and fire.20.9.3 Machinability of Various MaterialsGraphite is abrasive; it requires hard, abrasion-resistant, sharp tools.Thermoplastics generally have low thermal conductivity, low elastic modul us, and low softening temperature. Consequently, machining them requires tools with positive rake angles (to reduce cutting forces), large relief angles, small depths of cut and feed, relatively high speeds, and proper support of the work piece. Tools should be sharp.External cooling of the cutting zone may be necessary to keep the chips f rom becoming 〝gummy〞and sticking to the tools. Cooling can usually be a chieved with a jet of air, vapor mist, or water-soluble oils. Residual stresses m ay develop during machining. To relieve these stresses, machined parts can be annealed for a period of time at temperatures ranging from to ( to ), and th en cooled slowly and uniformly to room temperature.Thermosetting plastics are brittle and sensitive to thermal gradients during cutting. Their machinability is generally similar to that of thermoplastics.Because of the fibers present, reinforced plastics are very abrasive and are difficult to machine. Fiber tearing, pulling, and edge delamination are significa nt problems; they can lead to severe reduction in the load-carrying capacity of the component. Furthermore, machining of these materials requires careful rem oval of machining debris to avoid contact with and inhaling of the fibers.The machinability of ceramics has improved steadily with the development of nanoceramics (Section 8.2.5) and with the selection of appropriate processi ng parameters, such as ductile-regime cutting (Section 22.4.2).Metal-matrix and ceramic-matrix composites can be difficult to machine, d epending on the properties of the individual components, i.e., reinforcing or wh iskers, as well as the matrix material.20.9.4 Thermally Assisted MachiningMetals and alloys that are difficult to machine at room temperature can be machined more easily at elevated temperatures. In thermally assisted machinin g (hot machining), the source of heat—a torch, induction coil, high-energy bea m (such as laser or electron beam), or plasma arc—is forces, (b) increased too l life, (c) use of inexpensive cutting-tool materials, (d) higher material-removal rates, and (e) reduced tendency for vibration and chatter.It may be difficult to heat and maintain a uniform temperature distribution within the workpiece. Also, the original microstructure of the workpiece may be adversely affected by elevated temperatures. Most applications of hot machi ning are in the turning of high-strength metals and alloys, although experiment s are in progress to machine ceramics such as silicon nitride.SUMMARYMachinability is usually defined in terms of surface finish, tool life, force and power requirements, and chip control. Machinability of materials depends n ot only on their intrinsic properties and microstructure, but also on proper sele ction and control of process variables.20.9 可机加工性一种材料的可机加工性通常以四种因素的方式定义：1、分的表面光洁性和表面完整性。

Motor and Drive PartsTIMING BELT REPLACEMENT1, Power source must be connected to machine and turned on. Turn the power disconnect/lockout switch to the “O” (OFF) position and lock out. Allow machine to come to a complete stop, then press the “I” (START) button and hold for two seconds to verify that the machine will not start.2, After the green guard locking switch status light illuminates (when all rotating parts are idle) rotate the latch handle on the gear compartment door and open the gear door.3, Remove the belt guard by removing the hand knob that holds the guard (inside the gear compartment).4, Loosen the two pinch fasteners in the jack shaft spindle assembly (Figure 50).5, Loosen the motor mounting fasteners and slide the motor to release belt tension. Remove the belts (Figure51).Figure 50—Loosen pinch fasteners in jack shat spindle assembly (1) Pinch Fasteners,(2) Jack Shaft Spindle AssemblyFigure 51 – Timing Belts(1)TIMING BELT TENSION1, Use the motor tension wrench to slide the motor and apply tension to the timing belts. The pin on the wrench fits in a hole on the support housing(Figure52). The pinch fasteners in the jack shaft spindle assembly must be properly tension both belts. Tighten the motor mounting fasteners, and then tighten the pinch fasteners in the jack shaft spindle assembly.Figure 52 – Using the motor to apply belt tension. (1) Motor Tension Wrench2, Replace belt guard and tighten with the hand knob.3, Close and rotate latch handle connecting the gear compartment door and support housing.Electrical AssemblyINSPECTIONW ARNING: In the event of an electrical problem, only a qualified electrician should inspect or repair the fault. Voltages dangerous to life exist in the starter enclosure! The power disconnect/lockout switch must be in the “O”(OFF) position. Live voltages are still present in the box even though disconnect is off. Always disconnect and lock out power source before beginning electrical inspection or repair.The electrical assembly must be in good working condition before operating this machine. For a description of the amplifier and safety switch operation and method for checking this system. Electrical schematics are located in the starter enclosure. Refer to Figures53 and 54 and inspect the following:Figure 53 –Starter enclosure interior with variable frequency drive. (1) Disconnect Switch, (2) Guard Locking Switch Power Disconnect, (3) Main Fuses, (4) Earthing Terminals, (5) Transformer, (6) Transformer Fuses Block, (7) Variable Frequency Drive, (8) Contactor, (9) Standstill Monitor, (10) Control RelayFigure 54 – Starter enclosure interior, across-the-line start. (1) Disconnect Switch, (2) Guard Locking Switch Power Disconnect, (3) Main Fuses, (4) Earthing Terminals, (5) Transformer, (6) Transformer Fuse Block, (7) Overload Relay, (8) Contactor, (9) Standstill Monitor, (10) Control RelayStarter enclosure: Inspect interior of starter enclosure for corrosion. If a significant amount of water accumulates in the bottom of the starter enclosure, check the breather drain. Breather drain should be free from obstruction. Excess water could also indicate an opening or loose fitting that allows water to enter the enclosure. Check all access points to the enclosure. Check gasket around door and window. Inspect push/pull stop button, “I”(START) push button assemblies, selector switches and pilot light assembly for damage or corrosion. Replace rubber boots and pilot light lens if damaged.NOTE: Electrical components that fail due to water or chemical contamination are not covered under the warranty.Fuses: Remove transformer fuses, located in the transformer fuse blocks. Check with an ohmmeter or continuity light. If one fuse is replaced, all others of that type fuse should also be replaced.Machines equipped with variable frequency drive(VFD):The drive currently in use is the GPD315/V 7. If the digital display on the drive is not illuminated when the machine is energized, contact Urschel Laboratories.Standstill monitor: Terminals should be tight and free from corrosion. Monitor must be replaced if damaged.Power line filter (CE compliant machine with VFD): See the electrical assemblies illustrations in the “Parts” section of this manual for part locations.Guard locking switches:Replace or straighten actuator key if it is damaged or bent. Check cords for cuts or abrasions. If the green guard locking switch status light does not illuminate when power to the machine is connected, contact Urschel Laboratories. Switch must be replaced if it has been forced open while locked. Use only new screws that are supplied with the switch. Manual release must be in “lock” position when removing and replacing lid( Figure 55).Figure 55 – Guard Locking Switch. (1) Green Guard Locking Switch Status Light, (2) Guard Locking Switch Manual ReleaseGreen status light must be inside the lens when replacing the lid. To maintain watertight features, securely tighten the seven screws for the lid until there is no gap between lid and switch assembly. Do not over tighten.NOTE:The two screws located under the lid on the guard locking switch act as special dowel pins locking the switch assembly into place and must not be substituted.Interrupt switch: Terminals should be tight and free from corrosion. Recommended torque is 5.0 inch pounds (80 inch ounces) or 0.56 Newton-meters. Check sensor, actuator and cord for damage. Switch should be replaced if any defect or damage is defected. Check switch alignment. Actuator must be aligned and within 1/32 (8mm) of sensor to complete safety switch circuit (Figure 56).WARNING: Always perform the guard locking/interrupt switch system test before operating the machine.Figure 56 –Interrupt switch sensor and actuator must be aligned and within 1/32”(8mm). (1) Sensor, (2) ActuatorV ARIABLE FREQUENCY DRIVE PROGRAMMINGA replacement variable frequency drive must have frequencies programmed after the drive has been installed into the electrical enclosure. Refer to the “Speed Chart” on your machine or on page 30 in this manual and program the replacement unit according to the following procedure.WARNING: Starter enclosure must be energized in order to program the drive. Voltages dangerous to life exist when equipment is open and energized! Only a qualified electrician should inspect, install, or program variable frequency drive.1, Turn power disconnect/lockout switch to “O”(OFF). Open starter enclosure door. Operate the power disconnect/lockout switch mechanism in the enclosure to turn power on.2, Set the selector switches to the first drive frequency to be programmed. The frequency drive has a digital operator with a display (Figure 57). The display for the GPD 315/V7 drive will read the lowest setting allowed.Figure 57 – FPD 315 Drive, digital operator. (1) Digital Display,(2) Numeral Change Key, (increase), (3) Numeral Change Key, (decrease), (4) Read/Write Key3, Enter the speed in the display in hertz. Increase or decrease the value with the “numeral change” keys. See the chart for frequency settings.CAUTION: Do not attempt to over speed the motor! Over speeding could create a safety hazard and cause excessive wear on machine parts. Under speeding will cause the motor to overheat.4, With the value correctly displayed and flashing, press the “DATA/ENTER” or “ENTER” key. The display will stop flashing, indicating that the value has been entered.NOTE:Altering preprogrammed speeds will permanently change these values. To return to original settings, follow steps 1-4.5, Operate the power disconnect/lockout switch mechanism in the enclosure to turn power off. Close and lock starter enclosure door.Knife CareKNIFE CARE GUIDELINESKnives should be inspected and sharpened or replaced at regular intervals depending upon operating conditions, type of product and hours of operation. Follow these guidelines for bestresults:1, Do not attempt to remove all defects from the knife edge by sharpening.This practice results in shortened knife life. Small defects will not affect knife performance.2, New knives should not be installed beside worn knives. This arrangement may result in poor quality cuts. Keep all the knives from one spindle in a set and sharpen them together. Periodically check knife width or diameter to make sure all the knives in a set are the same size.3, Recommended minimum dimensions: The following minimum dimensions are intended to give satisfactory results for most applications. However, each customer must look at the quality of cut on his product to determine at what point knives are resharpened beyond usefulness. The minimum dimensions stated are intended to give satisfactory results for most applications. Some customers may be able to give satisfactory results from knives ground smaller, but some may notice a deterioration in quality of out before the minimum size is reached. Measure crosscut knives from the cutting edge to the back of the knife unless otherwise noted; measure the diameter of circular knives unless otherwise noted.SHARPENING EQUIPMENTUrschel Laboratories manufactures machines to quickly and efficiently sharpen knives. The following machine are available;Model WG honing machine is used to sharpen slicing knives and crosscut knives (straight cut only). For the Model DC, use workrest 33224 for 42281 and 42446 crosscut knives and slicing knife insert .Use workrest 33225 for 42460 crosscut knives. Use workrest 33256 for all other slicing knives.Model CKG honing machine is used to place the best possible edge on circular knives. The Model CKG can be purchased from the factory ready to sharpen 3-1/2”circular knives for the Model DC. Honers that are not set up to sharpen 3-1/2” circular knives must have certain parts installed. Use the following procedure:W ARNNING: Honers place an extremely sharp edge on knives; handle knives with care!1, Make sure the honer is unplugged from the power source.2, Install hone assembly, knife holder hub and edge roller stud for 3-1/2’’circular knives (Figure 58). The hone assembly (part number 33083) contains the hone bracket and internal parts, the shield and the honing wheel. The stud on the hone bracket is installed in the second hole from the motor shaft (4” knife position). The knife holder hub (part number 33081) is installed with the raised diameter facing out. The edge roller stud (part number 33023) is installed with the set screw in the second spot drilled hole from the outside end (Note that this part number has remained thesame but the part has been modified. The stud should have four spot drilled holes.) 3, Position the hone shield in as far as possible by loosening the screw and sliding the shield. Retighten the screw.4. Pull the knife clamp hub out of the clamping position. Hold a knife against the knife holder hub. Loosen the set screw in the motor shaft hub and slide the hub and knife on the motor shaft until the knife just touches the honing wheel. Tighten the set screw.5, Adjust the knife clamp if necessary. The knife clamp should hold the knife against the hub tight enough so that it cannot be rotated yet not so tight that it drives the motor back and distorts the base (the brake arm assembly must be properly adjusted to test for knife rotation). To adjust the knife clamp, loosen the two locking nuts and move the clamp in or out.6, Place a knife in the honer and sharpen in the normal manner (see the Model CKG instruction manual for more information). If too much of the knife edge is removed, readjust the hub. If insufficient metal is removed, loosen the screw on the hone shield and slide the hone slightly forward against the knife edge.BUFFINGWARNING: Only qualified trained personnel should buff knives. Use adequate eye and respiratory protection, and a properly guarded buffing wheel. Hold knife securely. Never attempt to catch a dropped knife! Should you drop a knife during the buffing operation, move away and let it tall.When crosscut knives are sharpened by grinding, filing or honing, a slight wire edge may be produced. Buffing will remove this wire edge.Install two to four 10" (254 mm) diameter buffing wheels side by side between flanges at least2" (51 mm) in diameter. Buffing wheels and bars of buffing compound are available from Urschel Laboratories (see “Tools", page67).Turn on the buffer (3600RPM) and hold the bar of buffing compound firmly against the outside diameter of the buffing wheels to apply alight coating of compound. Apply compound frequently to obtain sharp edges quickly.NOTE: If excess compound is applied, the wheel will harden, making it ineffective.Should this occur, Use a buffing wheel rake, available from an industrial supplier, to soften the wheel.When holding knives, be cautions and use a firm grip. Hold the knife firmly with the bevel side up, parallel with and just below the center line of the shaft of the buffer (Figure 58). Push the knife edge into the buffing wheel, penetrating the wheel 1/16"-1/8"(1.5-3mm). Move the knife endwise and buff the entire edge across the buffing wheel with a steady rapid movement in each direction. Several rapid passes are better than one or two slow ones. Do not hold the knife in one area of the buffing wheel too long as the edge may heat and burn. If a burr or wire edge remains, turn the knife over and buff with the bevel side down. Continue buffing, switching from side to side, until wire edge or burr is gone.Sharpen all sides of crinkle knife edges by tipping the knife endwise at a slight angle, first in one direction and then in the other. Next, the knife is held straight and level to buff the remainder of the cutting edge.With bevel side up, sharpen side surface of crinkle knife edge by tipping the knife endwise at a slight angle, first in one direction and then in the other. Next, the knife is held straight and level tobuff the remainder of the cutting edge.Figure 58 –Model CKG honing machine set to sharpen 3-1/2”circular knives (1) Hone Bracket, (2) Mounting Position for Hone Assembly, (3) Knife Holder Hub, (4) Set Screw,(5) Edge Roller Stud (set screw seats in second hole), (6) Hone Shield, (7) Screw, (8) Knife Clamp Hub, (9) Locking Nuts, (10) Honing WheelFailure to obtain sharp edges by buffing may be caused by the following:1, Edges may be too dull or blunt. Blunt edges must always be ground or filed to restore a bevel width and angle similar to that found on a new knife.2, Knives must be correctly held against the buffing wheel (Figure 59).3, Too little or too much buffing compound on the wheel.4, Undersize buffing wheels. Discard the buffing wheels when they are worn to8-3/4" (222 mm) diameter.Figure 59 – Correct position (top) and incorrect position (bottom) for knife during buffing .(1) Knife, (2) Buffing WheelPROBLEM CAUSE CORRECTIONMachine Does Not Start Power disconnect lockout switch isin the "O"(OFF)positionTurn power disconnect lockoutswitch to the "I"(ON) position. Manual release on either of theguard locking switches is in the"unlock" positionTurn manual release to the"lock" position on bothswitches, page 17.Guard locking switch powerdisconnect is in the"O"(OFF)positionTurn guard locking switchpower disconnect to the"I"(ON) position, page 54.Push/pull stop button is not pulledout after being pushedPull push/pull stop button out,page 28.Covers and guards not securelyclosedMake certain covers andguards are securely closed.Check for bent or twistedbrackets that will preventswitches from lining up. See"Covers and Guards",pages34-35.VFD fault or warning Not error code displayed onVFD. Turn disconnect off.电机和传动部件同步带置换1，电源必须与机器连接并打开。

screen slot 筛孔screened tender 筛浆工sereenability 筛选性能screened stock 已筛浆料，细浆screened yield 筛选得率，细浆得率screening reject 筛渣screenings 筛渣，浆渣screenings refiner 筛渣再磨机screenman 筛浆工，精选工screw 螺旋；螺杆，螺丝；螺钉screw conveyer 螺旋输送机screw conveyer trough 螺旋输送机底槽screw driver 螺丝起子，螺丝刀，改锥screw elevator 螺丝提升机screw feeder 螺旋喂料器screw press 螺旋压榨screw press for dehydrating bark 螺旋式树皮压榨机screw press washer 螺旋型传感器screw type sensor 螺旋型传感器serim 粗布，麻布scripset 马来酐与苯乙烯共聚物script 低质书写纸scroll （动物皮胶）皮屑scrub oak (quercus ilicifolia wangenheim) 冬青叶栎scrub pine (pinus virginiana l.) 威忌州松scrubber 洗涤器，洗涤塔scrubbing tower 洗涤塔scuff resistance 起毛抗阻性；耐擦性能scuff test 耐擦性试验scuffing （纸张）起毛scum 浮渣；去除浮渣scum mark 油（脂）斑（点）（纸病）scumming 印刷版面沾污，糊版scumming roll 电动调向辊scurf resistance 耐磨强度scutching 梳打seal 封贴；密封seal pit 封闭纹孔seal tank 水封槽sealability 胶粘性sealant 胶粘剂sealer 胶粘器；密封器sealing 密封；封贴sealing machine 封口机；密封机swaling ring 密封环sealing tape 胶粘带sealing wax 火漆seam 线缝；缝合；焊合；铆合；裂开seaming 缝合，接缝seamless 无缝seasonal ring 年轮seasoned wood 风化材seasoning 风化seasoning crack 干裂seasoning tank 脱盐槽seaweed 海藻second growth wood 短小木材second hand 压榨工second press 第二压榨second press felt 第二压榨毛毯second sheets 拷贝纸；副页second sorting 二浆选别second wash 二段洗涤second white shavings 二级白纸纸边secondary acetate 仲醇酸酯secondary action 副作用secondary air 二次风，次级空气secondary air duct 二次风道secondary alcohol 仲醇secondary fiber 二次纤维，废纸secondary forest 次生林secondary growth 二次生长，直径生长secondary headbox 第二流浆箱，副流浆箱secondary hydroxyl group 仲醇羟基secondary phloem 次生韧皮部secondary ray 次生射线secondary reaction 次级反应secondary screen 二道筛secondary steam 二次蒸汽secondary stock 二次纤维，废纸浆secondary treatment 二级处理secondary wall 次生壁secondary winding 复卷seconds 次品sectional (individual) drive （多电机）分部传动security measures 安全措施sediment 沉积（物）sedimentation 沉降，沉积sedimentation capacity 沉降能力sedimentation pond 沉降池sedimentation potential 沉积电势sedimentation test 沉降试验sedimentation tester 沉降试验器seed 种子seed bed 种子床seed cotton 原棉seed fiber 种子纤维seed hair fiber 种毛纤维seeding 粒状色斑（纸病）seedling 种子繁殖seepage 渗出segment 节；段；部分；断片；弓形segment cutting 分段裁切selectifier (screen)))) 旋翼筛selection forest 择伐林selectivity 选择性selector 选择器selectrap 卧式圆筒除渣器selectrifiner 磨选机self-doctoring roll 自动刮刀辊self-grinding machine 自动磨床self-ignition 自燃self priming 自动吸引self priming pump 自吸泵self-regulation 自动调节self-sealing wrapping 自封包装self-soured casein 自行发酝酪素selleger reagent selleger染色剂selvage 边缘；织边；（纸卷准备切去的）边semi-bending chip 草浆纸板制纸箱semi-bleached 半漂semi-bordered pit pair 半具缘纹孔对semi-chemical bleaching 半化学浆漂白semi-chemical corrugating medium 半化学浆瓦楞芯层semi-conductor 半导体semi-continuous 半连续性semi-manufactured product 半成品semi-opaque 半透明semi-permeable membrane 半渗透薄膜semi-ring porouswood 半环孔材semi-shrub 小灌木；亚灌木semi-synthetic fiber 半合成纤维semimat 半光泽sensing head 传感器，探头sensitive film 感光胶卷ssensitivity 敏感性，灵敏度，灵敏性sensitizer 敏化剂sensor 传感器；传感元件；探测器，探测设备sensor amplifier 读出放大器separan 高分子絮凝剂（商业名称）separate beating 分别打浆separator 分离器，分离塔sequence 序列；程序sequence control 程序控制，序列控制sequencing 排列程序，程序设计sequoua 红杉seriated 齿轮的；齿状的series 序列；系列；数列；级数series circuit 串联电路serigraphy 绢布印刷service 服务；保养；检修service life 使用寿命service shop 机修车间service side 操作侧，操作面servo-mechanism 伺服机构set 凝固；放置；装置；安装set-asides 废料；废纸set-off 衬垫纸；在邻近纸页上构成铅字印痕set screw 固定螺丝set time 凝固时间set-up box 折叠纸箱set-up drinking cup 折叠式纸杯set value 给定值；凝固值setting 凝固；装置；安装；调整setting device 落刀装置setting mortar 灰泥凝固setting pressure 落刀压力setting time 凝固时间setting up 安装，安设settling basin 沉降池，澄清池settling off 涂料过多；油墨过多settling tank 澄清槽seventy-two mo 72开sewage 污水，污物；用污水灌溉sewer 下水道，排水沟sewer loss 随排水的流失sewer valve 排污阀sexto-decimo 16开sextuple effect 六效蒸发器shade 色调shade craft watermark 阴暗水印shade magching room 调色室shading 色泽shadow mark （真空压榨吸水欠均匀的）湿痕（纸病）shaft 轴；树干，茎shaft hesd 轴头shaftless winder 无轴式复卷机shake 振动shake amplitude 振幅shake frequency 振次，振动频率shake unit 振动装置shaker 振动器shaker knot screen 振动除节机shaker type (flat) chip screen 振动式木片平筛shaker type straw duster 谷草振动除尘机shaking 振动（的）shaking conveyer 振动式运输机shaking device 振动器shaking screen 振动筛shaking table 振动网案shale 页岩，板岩shallow dam 挡板；隔板shangles 胶料亮斑（纸病）sharp beating 游离状打浆sharp-edged 锐端sharp stone 锐石sharp tackle 锐刀；重刀打浆sharpener 磨刀器sharpening 刻石sharpening device 刻石器sharper 牛头刨sharpness 锐度shalter 震裂；碎片shartle hydraclone 自动排渣涡旋除渣器shartle machine 剥皮机；刨薄片机shavings 纸边shavings exhaust installation 废屑排除装置shavings exhauster 废屑排除器shaw 丛林shear 切变；剪切shear cut 剪切shear cut slitter 剪切法切割机shear cut winder 剪切型复卷机shear float (type) sensor 切变浮杆传感器shear rate 切变速率shear strength 抗切强度，抗剪强度shear stress 切变应力shear test 切变试验shear winder 剪切型复卷机shearing 切变sheathing 建筑纸板sheave 滑轮纸板sheave 滑轮；皮带轮；麻杆屑shee box 对开瓦楞纸盒sheen 光泽sheen glossmeter 光泽计sheet 纸页sheet and half demy 英国纸张标准（22的1/2英寸×26的1/2英寸）sheet and third foolscap 英国纸张标准（29的3/4英寸×13的1/4英寸）sheet and third foolscap 英国纸张标准（大页纸张1的1/3倍）sheet breaker 平板纸压光机sheet calender 平板纸压光机sheet counter 数纸器sheet counting device 数纸器sheet cutter 平板切纸机sheet dryer 纸页干燥器sheet feeding 续纸sheet fed 递纸sheet finisher 完成工sheet formation 纸张组织sheet former 纸页成形器sheet forming 纸幅成形sheet forming quality 纸页成形质量sheet guide 导纸辊sheet laying table 接纸台sheet lining 挂面纸sheet machine 抄片器sheet-makintg apparatus 抄片器sheet of paper 纸张sheet packer 平板纸打包机sheet papermachine 纸页手抄器sheet pasting machine 包装粘糊机sheet pit 损纸坑sheet press 纸页压榨器sheet roll 纸卷sheet size 纸张规格sheet waxer 纸张上蜡机sheetage 纸张比重；纸张表面积比率sheeter （平板纸）切纸机；数纸器sheeting （平板纸）裁切sheeting equipment （平板纸）裁切机sheeting mould 手抄纸器sheffield smoothchek instrument sheffield平滑度测定仪sheffield smoothness sheffield平滑度sheffield tester sheffield平滑度测定仪shelf life 存放稳定性shell 外壳shell and silide box 抽匣式真空吸水箱shell bars 定子刀片shell fillings 定子嵌木shell knife 定子刀片shell side lining 蒸煮锅外衬里shell steels （锥形磨浆机）底刀sdshellac 紫胶，虫胶shield 屏障shift foreman 值班长shifter 移动装置shikimic acid 莽草酸shim 长方形薄垫片shine (spots) （填料）透明点（纸病）shiners （填料）透明点（纸病）shiny stuff 粘状浆shipping container 货运纸箱shipping sack 货运袋纸shipping roll 成品纸卷shipping tag 货运标签shirt protector 衬衣背衬包装纸shive 浆块，碎浆，碎片shive content 碎片含量；纤维素含量shivy 破碎的shock 震动shock drying 冲击干燥shock resistance 抗震shopping bag 采购用纸袋shopping bag yarn 采购纸袋用纸绳shops 商店用包装纸shore durometer 肖氏（橡胶）硬度计shore hardness 肖氏硬度。

附录 AClutch between engine and transmission installed in the car to travel from the start the whole process, often need to use the clutch. Its role is to make the engine and transmission can be gradually between the joint, thus ensuring a smooth start car; temporarily cut off the link between the engine and transmission to shift at the time of shift and reduce the impact; When the car when emergency braking from Separate role in preventing the transmission and other drive system overload, play a protective role.Clutch similar to the switch, splice or break away from the power transmission and, accordingly, have any form of auto clutch, but the form is different.By the friction plate clutch, springs, pressure plate and the power output shaft composed, arranged between the engine and gearbox, the engine flywheel to the torque is passed to the stored transmission, to ensure that vehicles in different driving conditions passed to the driver Wheel driving force and the right amount of torque, is the scope of the powertrain. In the half-time of linkage, clutch and power input power output allowed speed difference, that is, the speed error to achieve through its transfer an appropriate amount of power. Clutch is divided into three work status, ie the clutch all connections, some of the half clutch linkage and the clutch is not linked.When a vehicle in normal driving, the pressure plate is jammed against the friction plate on the flywheel, pressure plate and friction plate at this time the friction between the largest between the input shaft and output shaft remained relatively static friction, both the same speed . When the vehicle is started, the driver depresses the clutch, clutch pedal movement by pulling back pressure plate, which is the separation of the pressure plate and friction disc, pressure plate and flywheel at this time no contact, but also the relative friction does not exist. Last one, that is, half of the clutch linkage status. At this point, the pressure plate and friction disc friction less than the full-linked state. Clutch pressure plate and flywheel friction plate on the sliding friction between the state. Flywheel speed is greater than the output shaft speed, transmission out of the power from the flywheel to the transmission part of the pass. Between the engine and driving wheels at this time is equivalent to a soft connection status.In general, the clutch and the shift in the vehicle when starting to play a role, this time a transmission shaft and the speed difference between the two shafts, engine power must be cut with a shaft after the synchronizer can be very good a shaft speed will be kept synchronized with the second axis, gear hanging up after, and then through the clutch shaft and the engine power will be a combination of the power continue to be transmitted. In the clutch, there is an essential buffer device, which consists of two similar to the flywheel with the disc, the disc hit a rectangular groove, the groove arrangement of the spring, in the face of fierce shock between the two disc springs between the elastic effect, buffer external stimuli. Effective protection of the engine and clutch. Various parts of the clutch, pressure plate spring strength, friction coefficient of friction plate, clutch diameter, location, and the clutch friction disc clutch performance is to determine the number of key factors, the greater the stiffness of the spring, the higher the friction coefficient of friction plates, the larger the diameter of the clutch, clutch performance, the better.附录 B离合器安装在发动机与变速器之间，汽车从启动到行驶的整个过程中，经常需要使用离合器。

减速器论文中英文对照资料外文翻译文献What is a Gearbox?A XXX.1.The n of a Gearbox1) The gearbox ces the speed while increasing the output torque。

The torque output。

is the motor output multiplied by the n。

but it should not exceed the XXX.2) The gearbox also ces the inertia of the load。

which decreases by the square of the n。

Most motors have an inertia value that can be XXX.2.Types of GearboxesCommon gearboxes include bevel gear cers (including parallel-axis bevel gear cers。

worm gear cers。

and cone gear cers)。

ary gear cers。

cycloid cers。

worm gear cers。

XXX.mon Gearboxes1) The main feature of the worm gear cer is its reverse self-locking n。

which can achieve a large n。

The input and output shafts are not on the same axis or in the same plane。

However。

it generally has a large volume。

low n efficiency。

and low n.2) XXX and power。

It has a small size and high n。

外文文献翻译(含：英文原文及中文译文)英文原文Failure Analysis, Dimensional Determination And Analysis , ApplicationsOf CamsINTRODUCTIONIt is absolutely essential that a design engineer know how and why parts fail so that reliable machines that require minimum maintenance can be designed. Sometimes a failure can be serious, such as when a tire blows out on an automobile traveling at high speed. On the other hand, a failure may be no more than a nuisance. An example is the loosening of the radiator hose in an automobile cooling system. The consequence of this latter failure is usually the loss of some radiator coolant, a condition that is readily detected and corrected. The type of load a part absorbs is just as significant as the magnitude . Generally speaking , dynamic loads with direction reversals cause greater difficulty than static loads, and therefore, fatigue strength must be considered. Another concern is whether the material is ductile or brittle. For example, brittle materials are considered to be unacceptable where fatigue is involved.Many people mistakingly interpret the word failure to mean the actual breakage of a part . However , a design engineer must consider abroader understanding of what appreciable deformation occurs. A ductile material, however will deform a large amount prior to rupture. Excessive deformation, without fracture, may cause a machine to fail because the deformed part interferes with a moving second part . Therefore , a part fails(even if it has not physically broken)whenever it no longer fulfills its required function . Sometimes failure may be due to abnormal friction or vibration between two mating parts. Failure also may be due to a phenomenon called creep, which is the plastic flow of a material under load at elevated temperatures. In addition, the actual shape of a part may be responsible for failure . For example , stress concentrations due to sudden changes in contour must be taken into account . Evaluation of stress considerations is especially important when there are dynamic loads with direction reversals and the material is not very ductile.In general, the design engineer must consider all possible modes of failure, which include the following.—— Stress—— Deformation—— Wear—— Corrosion—— Vibration—— Environmental damage—— Loosening of fastening devicesThe part sizes and shapes selected also must take into account many dimensional factors that produce external load effects , such as geometric discontinuities , residual stresses due to forming of desired contours, and the application of interference fit joints.Cams are among the most versatile mechanisms available . A cam is a simple two-member device. The input member is the cam itself, while the output member is called the follower. Through the use of cams, a simple input motion can be modified into almost any conceivable output motion that is desired. Some of the common applications of cams are : —— Camshaft and distributor shaft of automotive engine—— Production machine tools—— Automatic record players—— Printing machines—— Automatic washing machines—— Automatic dishwashersThe contour of high-speed cams (cam speed in excess of 1000 rpm) must be determined mathematically. However , the vast majority of cams operate at low speeds(less than 500 rpm) or medium-speed cams can be determined graphically using a large-scale layout . In general, the greater the cam speed and output load, the greater must be the precision with which the cam contour is machined.DESIGN PROPERTIES OF MATERIALSThe following design properties of materials are defined as they relate to the tensile test .Static Strength. The strength of a part is the maximum stress that the part can sustain without losing its ability to perform its required function. Thus the static strength may be considered to be approximately equal to the proportional limit , since no plastic deformation takes place and no damage theoretically is done to the material.Stiffness . Stiffness is the deformation-resisting property of a material. The slope of the modulus line and , hence , the modulus of elasticity are measures of the stiffness of a material .Resilience . R esilience is the property of a material that permits it to absorb energy without permanent deformation. The amount of energy absorbed is represented by the area underneath the stress-strain diagram within the elastic region.Toughness . Resilience and toughness are similar properties. However , toughness is the ability to absorb energy without rupture. Thus toughness is represented by the total area underneath the stress-strain diagram , as depicted in Figure 2. 8b . Obviously , the toughness and resilience of brittle materials are very low and are approximately equal. Brittleness . A brittle material is one that ruptures before any appreciable plastic deformation takes place. Brittle materials are generally considered undesirable for machine components because they are unable to yieldlocally at locations of high stress because of geometric stress raisers such as shoulders, holes , notches , or keyways.Ductility . A ductility material exhibits a large amount of plastic deformation prior to rupture. Ductility is measured by the percent of area and percent elongation of a part loaded to rupture. A 5%elongation at rupture is considered to be the dividing line between ductile and brittle materials.Malleability . Malleability is essentially a measure of the compressive ductility of a material and, as such, is an important characteristic of metals that are to be rolled into sheets .Hardness . The hardness of a material is its ability to resist indentation or scratching . Generally speaking, the harder a material, the more brittle it is and, hence , the less resilient. Also , the ultimate strength of a material is roughly proportional to its hardness .Machinability . M achinability is a measure of the relative ease with which a material can be machined. In general, the harder the material, the more difficult it is to machine.Figure 2.8COMPRESSION AND SHEAR STATIC STRENGTHIn addition to the tensile tests, there are other types of static load testing that provide valuable information.Compression Testing. Most ductile materials have approximately thesame properties in compression as in tension. The ultimate strength, however , can not be evaluated for compression . As a ductile specimen flows plastically in compression, the material bulges out , but there is no physical rupture as is the case in tension. Therefore , a ductile material fails in compression as a result of deformation, not stress.Shear Testing. Shafts, bolts , rivets , and welds are located in such a way that shear stresses are produced. A plot of the tensile test. The ultimate shearing strength is defined as the stress at which failure occurs. The ultimate strength in shear, however , does not equal the ultimate strength in tension . For example , in the case of steel , the ultimate shear strength is approximately 75% of the ultimate strength in tension. This difference must be taken into account when shear stresses are encountered in machine components.DYNAMIC LOADSAn applied force that does not vary in any manner is called a static or steady load. It is also common practice to consider applied forces that seldom vary to be static loads. The force that is gradually applied during a tensile test is therefore a static load.On the other hand, forces that vary frequently in magnitude and direction are called dynamic loads. Dynamic loads can be subdivided to the following three categories. Varying Load. With varying loads , the magnitude changes , but the direction does not . For example, the loadmay produce high and low tensile stresses but no compressive stresses .Reversing Load. In this case, both the magnitude and direction change. These load reversals produce alternately varying tensile and compressive stresses that are commonly referred to as stress reversals.Shock Load. This type of load is due to impact. One example is an elevator dropping on a nest of springs at the bottom of a chute. The resulting maximum spring force can be many times greater than the weight of the elevator, The same type of shock load occurs in automobile springs when a tire hits a bump or hole in the road.FATIGUE FAILURE-THE ENDURANCE LIMIT DIAGRAMThe test specimen in Figure 2.10a . , after a given number of stress reversals will experience a crack at the outer surface where the stress is greatest. The initial crack starts where the stress exceeds the strength of the grain on which it acts. This is usually where there is a small surface defect, such as a material flaw or a tiny scratch. As the number of cycles increases, the initial crack begins to propagate into a continuous series of cracks all around the periphery of the shaft . The conception of the initial crack is itself a stress concentration that accelerates the crack propagation phenomenon . Once the entire periphery becomes cracked , the cracks start to move toward the center of the shaft . Finally , when the remaining solid inner area becomes small enough , the stress exceeds the ultimate strength and the shaft suddenly breaks. Inspection of the break reveals avery interesting pattern, as shown in Figure 2.13. The outer annular area is relatively smooth because mating cracked surfaces had rubbed against each other . However , the center portion is rough, indicating a sudden rupture similar to that experienced with the fracture of brittle materials.This brings out an interesting fact. When actual machine parts fail as a result of static loads , they normally deform appreciably because of the ductility of the material.Thus many static failures can be avoided by making frequent visual observations and replacing all deformed parts. However , fatigue failures give to warning. Fatigue fail mated that over 90% of broken automobile parts have failed through fatigue.The fatigue strength of a material is its ability to resist the propagation of cracks under stress reversals. Endurance limit is a parameter used to measure the fatigue strength of a material . By definition, the endurance limit is the stress value below which an infinite number of cycles will not cause failure.Let us return our attention to the fatigue testing machine in Figure 2.9. The test is run as follows:A small weight is inserted and the motor is turned on. At failure of the test specimen , the counter registers the number of cycles N, and the corresponding maximum bending stress is calculated from Equation 2.5. The broken specimen is then replaced by an identical one, and an additional weight is inserted to increase the load. Anew value of stress is calculated, and the procedure is repeated until failure requires only one complete cycle . A plot is then made of stress versus number of cycles to failure. Figure 2.14a shows the plot, which is called the endurance limit or S-N curve. Since it would take forever to achieve an infinite number of cycles, 1 million cycles is used as a reference. Hence the endurance limit can be found from Figure 2.14a by noting that it is the stress level below which the material can sustain 1 million cycles without failure.The relationship depicted in Figure 2.14 is typical for steel, because the curve becomes horizontal as N approaches a very large number. Thus the endurance limit equals the stress level where the curve approaches a horizontal tangent. Owing to the large number of cycles involved , N is usually plotted on a logarithmic scale, as shown in Figure 2.14b. When this is done , the endurance limit value can be readily detected by the horizontal straight line . For steel , the endurance limit equals approximately 50% of the ultimate strength . However , if the surface finish is not of polished equality , the value of the endurance limit will be lower. For example, for steel parts with a machined surface finish of 63 microinches ( μin. ) , the percentage drops to about 40%. For rough surfaces (300μin. or greater), the percentage may be as low as 25%.The most common type of fatigue is that due to bending. The next most frequent is torsion failure, whereas fatigue due to axial loads occursvery seldom. Spring materials are usually tested by applying variable shear stresses that alternate from zero to a maximum value , simulating the actual stress patterns.In the case of some nonferrous metals , the fatigue curve does not level off as the number of cycles becomes very large . This continuing toward zero stress means that a large number of stress reversals will cause failure regardless of how small the value of stress is. Such a material is said to have no endurance limit. For most nonferrous metals having an endurance limit, the value is about 25% of the ultimate strength.EFFECTS OF TEMPERATURE ON YIELD STRENGTH AND MODULUS OF ELASTICITYGenerally speaking , when stating that a material possesses specified values of properties such as modulus of elasticity and yield strength, it is implied that these values exist at room temperature. At low or elevated temperatures, the properties of materials may be drastically different. For example, many metals are more brittle at low temperatures. In addition , the modulus of elasticity and yield strength deteriorate as the temperature increases . Figure 2.23 shows that the yield strength for mild steel is reduced by about 70% in going from room temperature to 1000o F .Figure 2.24 shows the reduction in the modulus of elasticity E for mild steel as the temperature increases. As can be seen from the graph, a 30% reduction in modulus of elasticity occurs in going from roomtemperature to 1000o F . In this figure, we also can see that a part loaded below the proportional limit at room temperature can be permanently deformed under the same load at elevated temperatures.CREEP: A PLASTIC PHENOMENONTemperature effects bring us to a phenomenon called creep, which is the increasing plastic deformation of a part under constant load as a function of time. Creep also occurs at room temperature, but the process is so slow that it rarely becomes significant during the expected life of the temperature is raised to 300o C or more , the increasing plastic deformation can become significant within a relatively short period of time . The creep strength of a material is its ability to resist creep, and creep strength data can be obtained by conducting long-time creep tests simulating actual part operating conditions. During the test , the plastic strain is monitored for given material at specified temperatures.Since creep is a plastic deformation phenomenon , the dimensions of a part experiencing creep are permanently altered. Thus , if a part operates with tight clearances, the design engineer must accurately predict the amount of creep that will occur during the life of the machine. Otherwise , problems such binding or interference can occur. Creep also can be a problem in the case where bolts are used to clamp tow parts together at elevated temperatures. The bolts, under tension, will creep as a function of time . Since the deformation is plastic, loss of clamping forcewill result in an undesirable loosening of the bolted joint. The extent of this particular phenomenon, called relaxation, can be determined by running appropriate creep strength tests.SUMMARYThe machine designer must understand the purpose of the static tensile strength test . This test determines a number of mechanical properties of metals that are used in design equations. Such terms as modulus of elasticity, proportional limit, yield strength, ultimate strength, resilience , and ductility define properties that can be determined from the tensile test.Dynamic loads are those which vary in magnitude and direction and may require an investigation of the machine part’s resistance to failure. Stress reversals may require that the allowable design stress be based on the endurance limit of the material rather than on the yield strength or ultimate strength.Stress concentration occurs at locations where a machine part changes size, such as a hole in a flat plate or a sudden change in width of a flat plate or a groove or fillet on a circular shaft. Note that for the case of a hole in a flat or bar, the value of the maximum stress becomes much larger in relation to the average stress as the size of the hole decreases . Methods of reducing the effect of stress concentration usually involve making the shape change more gradual.Machine parts are designed to operate at some allowable stress below the yield strength or ultimate strength. This approach is used to take care of such unknown factors as material property variations and residual stresses produced during manufacture and the fact that the equations used may be approximate rather that exact . The factor of safety is applied to the yield strength or the ultimate strength to determine the allowable stress. Temperature can affect the mechanical properties of metals. Increases in temperature may cause a metal to expand and creep and may reduce its yield strength and its modulus of elasticity . If most metals are not allowed to expand or contract with a change in temperature , then stresses are set up that may be added to the stresses from the load. This phenomenon is useful in assembling parts by means of interference fits. A hub or ring has an inside diameter slightly smaller than the mating shaft or post. The hub is then heated so that it expands enough to slip over the shaft. When it cools, it exerts a pressure on the shaft resulting in a strong frictional force that prevents loosening.中文译文失效分析，尺寸确定与分析，凸轮的应用引言设计工程师知道如何以及为什么部件出现故障是绝对必要的，这样可以设计出需要最少维护的可靠机器。

电动机控制中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：Control of Electric winchFor motor control, we know the best way is to use the style buttons to move the many simple manual console. And this console, in some applications may still be a good choice, as some complex control headache can also be used. This article describes in your design, build or purchase winch controller, you have the motor's basic electrical equipment and you will need to address the user interface command addressed.First, the manual should be a manual control console type, so if you remove your finger buttons, hoist will stop. In addition, each control station equipped with an emergency need to brake, hoist the emergency brake to cut off all power, not just the control circuit. Think about it, if the hoist at the stop, it did not stop, you do need a way to cut off the fault line protection power. Set the table in the control of a key operated switch, is also a very good idea, especially in the line leading to theworkstation can not control, you can use the switch.(in the design of the console, even the simplest manual console, but also consider setting by specialized personnel to operate the safe operation of the keys.) Constant speed motor controlFor a fixed speed winch actual control device is a three-phase starter. Turn the motor is reversed, by a simple switch controlled phase transformation sequence from ABC to CBA. These actions are completed by two three-pole contactor-style, and they are interlocked, so that they can not be simultaneously closed. NEC, required in addition to overload and short circuit protection devices. To protect the motor against overload due to mechanical effects caused by overheating in the heat to be installed inside the starter overload delay device. When the heat overload delay device overheating, it has a long double off the metal motor power. In addition In addition, you can also select a thermistor can be installed in the motor winding way, it can be used to monitor motor temperature changes. For the short-circuit protection, we generally used by motor fuses to achieve.A linear current independent contactors, the contactors are configured should be more than the current main circuit contactor, so as to achieve the purpose of redundancy. This sets the current contactor is controlled by the security circuit, such as: emergency brake and the more-way limits.We can use the limit switches to achieve the above operation. When you reach the end of the normal travel limit position, the hoist will stop, and you can only move the winch in the opposite direction (ie, the direction away from the limit position.) There is also need for a more limited way just in case, due to electrical or mechanical problems, leaving the operation of hoist limit bit more than normal. If you run into more limiter, linear contactor will open, therefore, can not be driven winch will exceed this limit position. If this happens, you need to ask a professional technician to check the lead to meet the more specific reasons limiter. Then, you can use thestarter toggle switch inside the elastic recovery process to deal with more problems, rather than tripping device or a hand-off the current contacts.A necessary condition for speedOf course, the simple fixed speed starter is replaced by variable speed drives. This makes things start to get interesting again! At a minimum, you need to add a speed control dial operation platform. Joystick is a better user interface, because it makes you move parts of a more intuitive control.Unfortunately, you can not just from your local console to send commands to control the old variable speed drives, in addition, you can not want it in the initial stages, will be able to enhance the safe and reliable and decentralized facilities. Most of the variable speed drive can not achieve these requirements, because they are not designed to do upgrading work. Drivers need to be set to release the brake before the motor can generate torque, and when parking, that is, before the revocation of torque, the brake will be the first action.For many years, DC motors and drives provide a number of common solutions, such as when they are in a variety of speeds with good torque characteristics. For most of the hoist of the large demand for DC motor is very expensive, and that the same type of AC motor than the much more expensive. Although the early AC drives are not very useful, as they have a very limited scope of application of the speed, but produced only a small low-speed torque. Now, with the DC drives the development of low cost and a large number of available AC motors has led to a communication-driven revolution.Variable speed AC drives in two series. Frequency converter has been widely known and, indeed, easy to use. These drives convert AC into DC, and then, and then convert it back to exchange, the exchange after the conversion is a different frequency. If the drive produced the exchange of 30Hz, 60Hz a normal motor will run at half speed. Theoretically, this is very good, but in practice, this will have a lot of problems. First of all, a typical linear motor 60Hz frequencies below 2Hz 3Hz area or there will be errors, and start cog (that urgent push, yank), or parking. This will limit your speed range lower than 20:1, almost not adapted to the operational phase of the fine adjustment. Second, many low-cost converter is not able to provide the rated torque at low speeds. Use of these drives, will result in the rapid move to upgrade the components or complete failure, precisely, when you try to upgrade a stable scientific instruments, you do not want to see this situation. Some new inverter is a closed-loop system (to get feedback from the motor to provide a more accurate speed control), and the motor will work quite well.Another series of AC drives is the flow vector type drive. These components require installation of the spindle motor encoder, encoder makes use of these drivescan accurately monitor the rotation of the motor armature. Processor accurately measured magnetic flux vector values that are required to make the armature at a given speed rotation. These drives allow infinite speed, so you actually can produce at zero speed to rated torque. These drives provide precise speed and position control, so these drives in high performance applications to be welcomed.(Based on PLC controllers provide system status and control options. This screen shows the operator full access to the nine-story elevator enhance the control panel.) PLC-based systemsIs the full name of a PLC programmable logic controller. First of all, PLC controller developed to replace the fifties and sixties-based industrial control system relay, they work in harsh industrial indoor environments. These are modular systems that have a large variety of I / O modules. The modular system can easily achieve the semi-custom hardware configuration assembled, and the resulting configuration is also very reasonable price. These modules include: position control module, the counter, A / D and D / A converter, and a variety of physical state or physical contact with closed output module. Large number of different types of I / O components and PLC module property makes it an effective way to assemble custom and semi custom control system.The biggest shortcoming of PLC systems is the lack of the real number of display to tell you what is being done and the PLC on the PLC program to help you.T he first is professional entertainment for the large-scale PLC system is one of the original in Las Vegas, MGM (now Bailey Company) of the riding and carriage system. Many manufacturers offer a standard PLC-based semi-automated acoustic systems and a host of signs, set the location of the command line interpreter, and the upgrading of the control system is also available. Using standard modules to set user-defined system configuration capability is based on the PLC controller of the greatest advantage.High-end controllerFor complex transmission, the controller became complex, more than speed, time and location control. They include complex instructions to write and record the movement contour, and the processing can immediately run the ability to multi-point instructions.Many large opera house is toward the direction of point lift system, where each one is equipped with a rope to enhance independent winches, rope equivalent to those of each dimmer circuit. When more than one hoist is used to enhance the individual part, the hoist must be fully synchronous, or the load to shift, so will lead to a separate winch becomes the risk of overload. Control system must be able to be selected to keep pace winch, or a hoist winch is not able to maintain synchronization with the other, can provide the same high-speed parking capacity. For a typical speed of 240 ft / min and a winch to maintain the rate of error of between 1 / 8 points of equipment, you only have less than three microseconds of time to identify problems and try to correct the error The hoist speed, make sure you fail, you start all the winch stop the group. This will require a large amount of computation, fast I / O interface, and easy to use to write software.For large rope control system has two very different solutions. The first is to use a separate console, the problem in general terms, this console should be installed in the appropriate location of the operator perspective. However, this not only from one angle to another angle, but still can not get an instruction to another instruction from the control. These difficulties have been partially resolved. Installed in different locations through the use of video cameras, and these cameras connected to the three-dimensional display graphics, these graphics enables the operator to observe from the perspective of any of the three coordinates in the expected direction of rope movement. These operators can make from a console for him at the actual angle, or closed circuit camera practical perspective, to observe the movement of the rope on the screen. For the complex interrelated moving parts, makes the implementation of the above observation Failure to control and find out easier.Another solution to the problem is a distributed system that uses multiple light console. This will allow the different operators in the same way the different aspects of control gear, we have improved the manual control device. A vivid example is the flower in a vegetable market in central London, the Royal Opera House, the program uses the above, where the control console 240 with ten motors. Each console has five playback device, and has been open, so that each motor has been assigned to a single console. An operator and a console can control all the devices, however, often may be running a console platform screen upgrade, another console is a console on the transmission device, and the third console is used to the necessary backgroundin the background image down.(edge-type portable console allows the operator many advantages from the start to control the movement of the machine, and provide three-dimensional image display.)ConclusionA huge change in the rope control system, a workstation has been developed from a push-button to complex multi-user computerized control system. When the control system to buy rope, you can always find to meet your needs. Control system performance is the most important security and reliability. These are the true value of the property, and you can expect the price to buy a suitable way of security. With a certain product manufacturers to work, he will make you know how to install it. And he will make contact with you and the users, those users have with similar requests.译文：电动卷扬机的控制对于电动机的控制，我们所知道的最好的方式就是使用由许多点动式按钮组成的简单的手工操作台。