外文翻译--有关带式输送机驱动装置设计的一些研究
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附件A高速带式输送机的设计G. Lodewijks,荷兰摘要本文主要探讨高速带式输送机设计方面的问题。
带式输送机的输送量取决于输送带的速度、传送带宽度和托辊槽形角。
然而输送带速度的选择又受到各种实际条件的限制,在本文有这方面的讨论。
输送带速度也影响传送带的性能,例如它的能源消耗和它连续运行的稳定性。
一种计算输送带的能源消耗的方法就是通过考虑运输过程中的各种能量损耗来进行估算的。
输送带速度的不同使得安全系数的要求也各不相同,这也影响输送带所要求的强度。
一种新的计算输送带速度对安全系数的影响的方法在本文中被介绍。
最后,输送带速度的冲击对各组成部分的选择和对中转站设计的影响也在本文中被讨论。
1 概述过去的研究已经证实使用窄带输送机的经济可行性,输送带的速度变快要求输送带的宽度随之变宽,低速输送机适于长距离输送。
例如图[1] - [5]。
现在,传送带以8 m/s 的速度运行是没有问题的。
无论怎样,输送带速度在10m/s到20 m/s在技术上是(动态地)可行的,并且也许在经济上也是可行的。
本文将输送带速度在10和20 m/s之间的定义为高速。
输送带速度在10m/s之下的定义为低速。
使用高速输送带的目的并不在于它本身。
如果使用高速输送带不是经济上有利,或则,如果安全和可靠的操作没有保证的,那么就应该选择低速输送带。
输送带速度的选择是总的设计过程的一部分。
静态或稳定的设计方法决定了带式输送机的优化设计。
在这些设计方法中输送带被认为是刚性的,静止的。
这增加了输送机稳定运行的质量和也决定了带式输送机各零部件的尺寸。
稳定操作包括传送带稳定运行时的张力、相对各种物料载荷的能量消耗和相关的工作环境情况。
应该体会到找到最优的设计不是一次性的努力,而是一个反复的过程[6]。
优化设计,开始于优化的决心,终于符合要求的确定的控制算法和组成输送机的各零部件确定的位置和尺寸的大小,例如驱动,闸和飞轮,可由动态设计方法确定。
在这些设计方法中,也涉及动态分析,输送带可看作是一个三维的弹性体。
外文资料Belt conveyor driveReduced voltage starting with increase of transmitting a driving power, during the acceleration control winding rotor induction motor around the rotor induction motor directly connected to the driving system; direct current (DC) motor transport most drive using a DC shunt motor; 1.2 hydraulic coupler; hydrodynamic coupling device is often referred to as hydraulic coupler, consists of three basic single; between the shaft and the driven shaft don't need any mechanical connection; a fixed charge hydraulic coupler fixed charge hydraulic coupler is in the structure is simple; the variable filled hydraulic coupler is also known for the moment type hydraulic coupler; spoon control of hydraulic couplingThe buck starts with the increase of the transmission drive power in the During acceleration control motor torque becomes more and more important. Because the motor torque is a function of the voltage, the voltage applied to the motor must be under control, general with silicon controlled rectifier (SCR} a buck start-up device, sincere and low voltage tension conveyor belt, and linear increase in supply voltage until the full voltage and maximum speed. However this starting in a way that does not produce stable acceleration, when the acceleration is completed, the motor voltage of the SCR control lock in the guide, themotor provides full pressure. Such control power can reach 750kW.Wound rotor induction motor winding rotor induction motor directly connected to the drive system Reducer through in the rotor windings of the motor in series resistance torque control of motor. In at the start of a transmission device, the resistor in series in the rotor to generate a low torque, when the conveyor belt speed, the resistance is gradually reduced steadily increasing torque. In multi drive system, an additional slip resistance may will always be connected in series in the circuit of rotor winding to help load sharing. The motor system design is relatively simple, but the control system may very complex, because they are based on the computer control of the resistive switching. Nowadays, the majority control system is custom designed to meet the specifications of transmission system around the rotor motor is suitable for 400 KVV above the system.Drive direct current (DC) motor transport most use DC shunt motor, the motor armature in the external connection. Controlled DC drive technique is generally used for SCR device, which allows continuous variable speed operation of DC drive system in machinery is simple, but design of electronic circuits, monitoring and control the whole system, compared to other soft start system is expensive, but in torque, load sharing and transmission for the main consideration occasions, it is a reliable, saving the cost of the DC motor general use in larger power conveying device, including should play the conveying belt tension control of multi drive Dynamic systems and transmission devices that require a wide range of transmission.Hydrodynamic coupling is often referred to as the hydrauliccoupler, consists of three basic units: as the impeller of the centrifugal pump, promote hydraulic turbine and put into the shell of the two power components. Fluid from the impeller to the turbine, on the driven shaft torque. Torque and speed because of the circulating fluid in driving Shaft and the driven shaft does not need any mechanical connection. This connection power generated by the decision to hydraulic coupling of the filling quantity, the torque is proportional to the input speed. Because in the fluid coupling output speed less than the input rate, the difference therebetween said to slip, generally 1% - 3%. Transmission power of up to several thousand kilowatts.A fixed charge hydraulic coupler fixed charge hydraulic coupler is in relatively simple in structure and has only limited the bending part of the conveying device most commonly used soft start device, the structure is relatively simple and low cost, can provide excellent soft start effect on now use most of the conveyor.Variable filled hydraulic coupler, also known as torque hydraulic coupler limited. Coupling of the impeller installed in the AC motor, turbine is installed on the driven gear for high-speed shaft on, containing the operating components of the axle box is installed on the driving base. Coupling the rotating shell with an overflow outlet allow the liquid to continuously from the working chamber midstream Into a separate auxiliary chamber, oil from the auxiliary chamber through a heat exchanger pump to control electromagnetic valve of coupler filling liquid quantity. In order to control the starting torque of the single motor driving system must be monitoring of AC motor current to the solenoid valve control provide feedback. Variable filled hydraulic coupler can beused in power delivery system and the power can reach thousands of kilowatts the drive is very complex both in mechanical, or electrical driving system at moderate cost.Spoon pipe control hydraulic coupler is also known for the variable speed fluid couplings. This hydraulic coupler is also by three standard coupling unit form, i.e., an impeller, a turbine and a A housing containing loop. This hydraulic coupler need outside the working chamber setting catheter (also known as spoon pipe) and luminal and rely on adjusting device to change the spoon pipe opening (scoop tube and the top end of the rotation of the shell of spacing) artificially change the working cavity of the filling quantity, so as to realize the output speed regulation. This control provides a reasonably smooth acceleration, but the computer control system is very complex. Spoon pipe control hydraulic coupler can be used in single or multiple machine drive system, power range for 150kW-750kW.Variable frequency controlVariable frequency control is also a direct drive mode, it has a very unique high performance.VFC Device for induction motor with changes in the frequency and voltage, excellent starting torque and acceleration.VFC equipment is a power electronic controller, first of all, the AC is rectified into DC, then using the inverter, then transforms the DC frequency, driving voltage controllable AC. VFC adopts vector control or direct torque control (DTC) technology, can according to different load with different speed.VFC driving energy according to the given s curves start or stop, to achieve automatic tracking started or stopped curve.VFC drive for conveying belt started to provide excellentcontrol of speed and torque, also can for the multi machine drive system For load sharing.VFC controller can be easily installed on the conveyor drive power is small. Past when in high voltage, VFC device structure due to the power semiconductor devices rated voltage value restrictions become very complex, high voltage transmission often use low-voltage inverter, and then use the step-up transformer at the output, or using a plurality of low voltage inverter in series to solve. And simple device series connection of two level inverter system compared due to the series between devices easily pressure and output can be a better harmonic characteristics, three level voltage type PWI inverter system in several megawatts industrial transmission in recent years won 750kW/ system has been successfully installed in the belt conveyor drive system of the long 2 71m two in the coal mine of three 2.3kv VFC.Neutral point three level inverter using IGBTDue to tandem device voltage sharing easy, low device each time the switch of DV / dt and output good harmonic performance, the three-level voltage inverter in high power drive applications become more and more popular. V oltage IGBT (HV-IGBT) makes application of three-level neutral point box have a principle of high-voltage inverter design Greater scope of application. This inverter can now be achieved from 2. RV to 4. 16Kv full scope of application.HV-IGBT module series can be used in 3. RV and 4. 16Kv equipments2. A V each inverter switch only needs a HV-IGBT[2,3].Main power inverter circuitHigh voltage AC drive applications. Compared with a two-levelvoltage type inverter, three-level midpoint box voltage type inverter provides three voltage levels to the output terminal, for the same quality of output current, the switching frequency can be reduced to the original 1 / 4, the switching devices of rated voltage S2u s4u and S3u and S2u S1u trunk additional value can be reduced to the original 1 / 2, attached to the motor transient voltage stress may also be reduced to the original 1 / 2. Three level neutral point voltage type inverter switch state can be summarized in Table 1, u, V and W respectively represents three, P, N and G is a DC bus three points. For example, when the switch is closed, u are in a state of P (positive bus bar voltage), on the contrary, when the switch is closed, u are in a state of n (negative bus voltage). In the neutral case, the phase in the o state, then on the basis of the phase current polarity is positive or negative, or conduction or s In order to ensure that the neutral point voltage is balanced, the average current injected at the o point should be zero at 3U.As commonly used 12 pulse diode rectifier to the DC link capacitor charging, introduced at the input end of the harmonic is very small. If the input harmonic have higher requirements, using a 24 pulse diode rectifier as input converter. The need to have the ability to regenerate more advanced, you can use an active input converter instead of diode rectifier and then input rectifier and inverter output for the same structure.Inverter controlMotor controlled induction motor control can be used in rotor field oriented vector control Is implemented through the use of PWM modulator completed the constant torque and high speed in the fieldweakening region. Figure 2 shows the indirect vector control block diagram of figure in the flux command a psi R is function of velocity, velocity feedback and feedforward slip control signal Sichuan HMU. The addition results of frequency signal integration, although after generation unit vector (COS theta E and sinO theta E) and finally through the vector rotator generate voltage V 'angle theta control PWM modulator.Inverter. Its basic principle is that the three level PWM modulator uses two reference waves to recognize Ur1 and Ur2, but only use a triangular wave. It is determined in an optimized way every time Switch time.Switching frequency harmonics generated by as much as possible is small, the use is as low as possible to minimize the switching losses; the zero sequence components are added to each reference Tripoli to the relative position of the maximization of fundamental voltage. An additional degree of freedom as the reference wave and triangle wave can be changed, it can be for the current balance of DC link midpoint.Three level inverter 3V of three 750kW/ after Zhuang coal mine 2.7 km. Long belt conveyor drive system successfully installed, on the performance of the variable frequency drive system (VFC) were tested. The test results show that the control system using VFC belt The excellent characteristics of conveyor. Figure 3 for test results and waveforms. Shown by the figures, curve 1 shows controlled belt speed, belt speed with the S-shaped curve shape curve 2,3, respectively, which indicated that current and torque, curve 4 shows tension belt. From the figure can be found with the tension fluctuation range is small, all testresults show a belt conveyor drive system satisfactory characteristics.In recent years, conveyor drive control technology have been more reliable, consistent with the cost-effective and efficient driving drive system provides users with a choice. In these choices, variable frequency control (VFC) showing in the future long distance conveying belt conveyor Plays an important role. Using the midpoint of the high-pressure work GBT block three level inverter itself can provide high voltage power supply to the motor terminals, so that the inverter control application more simple. By Zhuang coal mine 2. 7 km long belt conveyor in the midpoint of the clamped three-level inverter VVVF (VFC) control system test results show that, using the midpoint of the BV-IGBT block three level inverter and rotor flux vector control strategy of induction motor variable frequency drive is used, the belt conveyor drive system has very good performance, showing a good application prospect.中文译文皮带输送机的驱动降压启动随着传送驱动功率的增加,在加速期间控制使绕线转子感应电机绕线转子感应电机直接连接到驱动系;直流(DC)电机大多数传送驱动使用DC并励电机,;1.2液力偶合器;流体动力偶合器通常被称为液力偶合器,由三个基本单;轴和从动轴之间不需要任何机械连接;固定充液液力偶合器固定充液液力偶合器是在结构较简;可变充液液力偶合器也称为限矩型液力偶合器;勺管控制液力偶合降压启动随着传送驱动功率的增加,在加速期间控制使用的电机扭矩变得越来越重要。
中英文翻译Development of belt conveyor driving systemAbstract A short review for the existing various driving methods for belt conveyor was given, which include the analysis and comparison about the advantages, disadvantages and suitable application range of these methods. Based on this the variable-frequency-control(VFC} method for belt conveyor drive was fully discussed with focus on its application in medium-high voltage range. The principle of Neutral Point Clamped (NPC) Three一Level Inverter using high-voltage IGBTs together with the control strategy of rotor field-oriented vector control for induction motor drive were illustrated.Key words belt conveyor driving system, variable-frequency-control, three-level inverter Among the methods of material conveying employed,belt conveyors play a very important part in the reliable carrying of material over long distances at competitive cost.Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so.Nowadays,bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine).The ability to control drive acceleration torque is critical to belt conveyors’ performance.An efficient drive system should be able to provide smooth,soft starts while maintaining belt tensions within the specified safe limits.For load sharing on multiple drives.torque and speed control are also important considerations in the drive system’s design. Due to the advances in conveyor drive control technology,at present many more reliable.Cost-effective and performance-driven conveyor driv e systems covering a wide range of power are available for customers’choices[1].1 Analysis on conveyor drive technologies1.1 Direct drivesFull-voltage starters.With a full-voltage starter design,the conveyor head shaft is direct-coupled to the motor through the gear drive.Direct full-voltage starters are adequate for relativelylow-power, simple-profile conveyors.With direct fu11-voltage starters.no control is provided for various conveyor loads and.depending on the ratio between fu11- and no-1oad power requirements,empty starting times can be three or four times faster than full load.The maintenance-free starting system is simple,low-cost and very reliable.However, they cannot control starting torque and maximum stall torque;therefore.they are limited to the low-power,simple-profile conveyor belt drives.Reduced-voltage starters.As conveyor power requirements increase,controlling the applied motor torque during the acceleration period becomes increasingly important.Because motor torque 1s a function of voltage,motor voltage must be controlled.This can be achieved through reduced-voltage starters by employing a silicon controlled rectifier(SCR).A common starting method with SCR reduced-voltage starters is to apply low voltage initially to take up conveyor belt slack.and then to apply a timed linear ramp up to full voltage and belt speed.However, this starting method will not produce constant conveyor belt acceleration.When acceleration is complete.the SCRs, which control the applied voltage to the electric motor.are locked in full conduction, providing fu11-line voltage to the motor.Motors with higher torque and pull—up torque,can provide better starting torque when combined with the SCR starters, which are available in sizes up to 750 KW.Wound rotor induction motors.Wound rotor induction motors are connected directly to the drive system reducer and are a modified configuration of a standard AC induction motor.By inserting resistance in series with the motor’s rotor windings.the modified motor control system controls motor torque.For conveyor starting,resistance is placed in series with the rotor for low initial torque.As the conveyor accelerates,the resistance is reduced slowly to maintain a constant acceleration torque.On multiple-drive systems.an external slip resistor may be left in series with the rotor windings to aid in load sharing.The motor systems have a relatively simple design.However, the control systems for these can be highly complex,because they are based on computer control of the resistance switching.Today,the majority of control systems are custom designed to meet a conveyor system’s particular specifications.Wound rotor motors are appropriate for systems requiring more than 400 kW .DC motor.DC motors.available from a fraction of thousands of kW ,are designed to deliver constant torque below base speed and constant kW above base speed to the maximum allowable revolutions per minute(r/min).with the majority of conveyor drives, a DC shunt wound motor is used.Wherein the motor’s rotating arma ture is connected externally.The most common technology for controlling DC drives is a SCR device.which allows for continual variable-speed operation.The DC drive system is mechanically simple, but can include complex custom-designed electronics to monitor and control the complete system.This system option is expensive in comparison to other soft-start systems.but it is a reliable, cost-effective drive inapplications in which torque,1oad sharing and variable speed are primary considerations.DC motors generally are used with higher-power conveyors,including complex profile conveyors with multiple-drive systems,booster tripper systems needing belt tension control and conveyors requiring a wide variable-speed range.1.2 Hydrokinetic couplingHydrokinetic couplings,commonly referred to as fluid couplings.are composed of three basic elements; the driven impeller, which acts as a centrifugal pump;the driving hydraulic turbine known as the runner and a casing that encloses the two power components.Hydraulic fluid is pumped from the driven impeller to the driving runner, producing torque at the driven shaft.Because circulating hydraulic fluid produces the torque and speed,no mechanical connection is required between the driving and driven shafts.The power produced by this coupling is based on the circulated fluid’s amount and density and the torque in proportion to input speed.Because the pumping action within the fluid coupling depends on centrifugal forces.the output speed is less than the input speed.Referred to as slip.this normally is between l% and 3%.Basic hydrokinetic couplings are available in configurations from fractional to several thousand kW .Fixed-fill fluid couplings.Fixed-fill fluid couplings are the most commonly used soft-start devices for conveyors with simpler belt profiles and limited convex/concave sections.They are relatively simple,1ow-cost,reliable,maintenance free devices that provide excellent soft starting results to the majority of belt conveyors in use today.Variable-fill drain couplings.Drainable-fluid couplings work on the same principle as fixed-fill couplings.The coupling’s impellers are mounted on the AC motor and the runners on the driven reducer high-speed shaft.Housing mounted to the drive base encloses the working circuit.The c oupling’s rotating casing contains bleed-off orifices that continually allow fluid to exit the working circuit into a separate hydraulic reservoir.Oil from the reservoir is pumped through a heat exchanger to a solenoid-operated hydraulic valve that controls the filling of the fluid coupling.To control the starting torque of a single-drive conveyor system,the AC motor current must be monitored to provide feedback to the solenoid control valve.Variable fill drain couplings are used in medium to high-kW conveyor systems and are available in sizes up to thousands of kW .The drives can be mechanically complex and depending on the control parameters.the system can be electronically intricate.The drive system cost is medium to high,depending upon size specified.Hydrokinetic scoop control drive.The scoop control fluid coupling consists of the three standard fluid coupling components:a driven impeller, a driving runner and a casing that encloses the working circuit.The casing is fitted with fixed orifices that bleed a predetermined amount of fluid into a reservoir.When the scoop tube is fully extended into the reservoir, the coupling is l00 percent filled.The scoop tube, extending outside the fluid coupling,is positioned using an electric actuator to engage the tube from the fully retracted to the fully engaged position.This control provides reasonably smooth acceleration rates.to but the computer-based control system is very complex.Scoop control couplings are applied on conveyors requiring single or multiple drives from l50 kW to 750 kW.1.3 Variable-frequency control(VFC)Variable frequency control is also one of the direct drive methods.The emphasizing discussion about it here is because that it has so unique characteristic and so good performance compared with other driving methods for belt conveyor.VFC devices Provide variable frequency and voltage to the induction motor, resulting in an excellent starting torque and acceleration rate for belt conveyor drives.VFC drives.available from fractional to several thousand(kW ), are electronic controllers that rectify AC line power to DC and,through an inverter, convert DC back to AC with frequency and voltage contro1.VFC drives adopt vector control or direct torque control(DTC)technology,and can adopt different operating speeds according to different loads.VFC drives can make starting or stalling according to any givenS-curves.realizing the automatic track for starting or stalling curves.VFC drives provide excellent speed and torque control for starting conveyor belts.and can also be designed to provide load sharing for multiple drives.easily VFC controllers are frequently installed on lower-powered conveyor drives,but when used at the range of medium-high voltage in the past.the structure of VFC controllers becomes very complicated due to the limitation of voltage rating of power semiconductor devices,the combination of medium-high voltage drives and variable speed is often solved with low-voltage inverters using step-up transformer at the output,or with multiple low-voltage inverters connected in series.Three-level voltage-fed PWM converter systems are recently showing increasing popularity for multi-megawatt industrial drive applications because of easy voltage sharing between the series devices and improved harmonic quality at the output compared to two-level converter systems With simple series connection ofdevices.This kind of VFC system with three 750 kW /2.3kV inverters has been successfully installed in ChengZhuang Mine for one 2.7-km long belt conveyor driving system in following the principle of three-level inverter will be discussed in detail.2 Neutral point clamped(NPC)three-level inverter using IGBTsThree-level voltage-fed inverters have recently become more and more popular for higher power drive applications because of their easy voltage sharing features.1ower dv/dt per switching for each of the devices,and superior harmonic quality at the output.The availability of HV-IGBTs has led to the design of a new range of medium-high voltage inverter usingthree-level NPC topology.This kind of inverter can realize a whole range with a voltage rating from 2.3 kV to 4.1 6 kV Series connection of HV-IGBT modules is used in the 3.3 kV and 4.1 6 kV devices.The 2.3 kV inverters need only one HV-IGBT per switch[2,3].2.1 Power sectionTo meet the demands for medium voltage applications.a three-level neutral point clamped inverter realizes the power section.In comparison to a two-level inverter.the NPC inverter offers the benefit that three voltage levels can be supplied to the output terminals,so for the same output current quality,only 1/4 of the switching frequency is necessary.Moreover the voltage ratings of the switches in NPC inverter topology will be reduced to 1/2.and the additional transient voltage stress on the motor can also be reduced to 1/2 compared to that of a two-level inverter.The switching states of a three-level inverter are summarized in Table 1.U.V and W denote each of the three phases respectively;P N and O are the dc bus points.The phase U,for example,is in state P(positive bus voltage)when the switches S1u and S2u are closed,whereas it is in state N (negative bus voltage) when the switches S3u and S4u are closed.At neutral point clamping,the phase is in O state when either S2u or S3u conducts depending on positive or negative phase current polarity,respectively.For neutral point voltage balancing,the average current injected at O should be zero.2.2 Line side converterFor standard applications.a l2-pulse diode rectifier feeds the divided DC-link capacitor.This topology introduces low harmonics on the line side.For even higher requirements a 24-pulse diode rectifier can be used as an input converter.For more advanced applications where regeneration capability is necessary, an active front.end converter can replace the dioderectifier, using the same structure as the inverter.2.3 Inverter controlMotor Contro1.Motor control of induction machines is realized by using a rotor flux.oriented vector controller.Fig.2 shows the block diagram of indirect vector controlled drive that incorporates both constant torque and high speed field-weakening regions where the PW M modulator was used.Inthis figure,the command flux is generated as function of speed.The feedback speed isadded with the feed forward slip command signal . the resulting frequency signal isintegrated and then the unit vector signals(cos and sin)are generated.The vector rotatorgenerates the voltage and angle commands for the PW M as shown.PWM Modulator.The demanded voltage vector is generated using an elaborate PWM modulator.The modulator extends the concepts of space-vector modulation to the three-level inverter.The operation can be explained by starting from a regularly sampled sine-triangle comparison from two-level inverter.Instead of using one set of reference waveforms and one triangle defining the switching frequency,the three-level modulator uses two sets of reference waveforms U r1 and U r2 and just one triangle.Thus, each switching transition is used in an optimal way so that several objectives are reached at the same time.Very low harmonics are generated.The switching frequency is low and thus switching losses are minimized.As in a two-level inverter, a zero-sequence component can be added to each set of reference waveform s in order to maximize the fundamental voltage component.As an additional degree of freedom,the position of the reference waveform s within the triangle can be changed.This can be used for current balance in the two halves of the DC-1ink.3 Testing resultsAfter Successful installation of three 750 kW /2.3 kV three-level inverters for one 2.7 km long belt conveyor driving system in Chengzhuang Mine.The performance of the whole VFC system was tested.Fig.3 is taken from the test,which shows the excellent characteristic of the belt conveyor driving system with VFC controller.Fig.3 includes four curves.The curve 1 shows the belt tension.From the curve it can be find that the fluctuation range of the belt tension is very smal1.Curve 2 and curve 3 indicate current and torque separately.Curve 4 shows the velocity of the controlled belt.The belt velocityhave the“s”shape characteristic.A1l the results of the test show a very satisfied characteristic for belt driving system.4 ConclusionsAdvances in conveyor drive control technology in recent years have resulted in many more reliable.Cost-effective and performance-driven conveyor drive system choices for users.Among these choices,the Variable frequency control (VFC) method shows promising use in the future for long distance belt conveyor drives due to its excellent performances.The NPC three-level inverter using high voltage IGBTs make the Variable frequency control in medium voltage applications become much more simple because the inverter itself can provide the medium voltage needed at the motor terminals,thus eliminating the step-up transformer in most applications in the past.The testing results taken from the VFC control system with NPC three.1evel inverters used in a 2.7 km long belt conveyor drives in Chengzhuang Mine indicates that the performance of NPC three-level inverter using HV-IGBTs together with the control strategy of rotor field-oriented vector control for induction motor drive is excellent for belt conveyor driving system.References[l] Jim Ehler. Conveyor drive technologies offer smooth, soft starts[J]. Motors& Drives, 2001(4): 28-35.[2] Sommer R, Mertens A. Medium voltage drive system with three-level NPC inverter using IGBTs[A]. IEE Colloquium on PWM Medium V oltage Drives[C]. Birmingham,2000[3] Mertens A, Sommer R, Brunotte C. Applications of medium voltage drives with IGBT three-level inverter[A]. IEE colloquium on PWM medium voltage drives[C]. Birmingham,2000中文译文:带式输送机及其牵引系统在运送大量的物料时,带式输送机在长距离的运输中起到了非常重要的竞争作用。
摘要带式输送机驱动装置是输送机的动力的来源,主要由电动机通过联轴器、减速器、带动传动滚筒转动。
本驱动装置设计中,首先根据输送机的工作要求确定传动方案,然后确定电动机,由电机及工作机进行减速器设计, 驱动装置,驱动装置架,传动滚筒,滚筒头架设计。
关键词:带式输送机驱动装置减速器滚筒AbstractConveyor belt conveyor drive is the driving force of the source. The main belt conveyor drive motor through a coupling, reducer, driving drum driven rotation. With drum and the friction of the belt, the belt movement, a tilt of the belt conveyor also set up for brakes and stop.In this drive in accordance with the design of the first conveyor requirements for the work programme identified transmission, and then determine Motors, electrical and machine reducer design work, drive, drive planes, driving drum, drum-head design .Keywords: Beltconveyor DrivingDevice Reducer Drum毕业设计(论文)原创性声明和使用授权说明原创性声明本人郑重承诺:所呈交的毕业设计(论文),是我个人在指导教师的指导下进行的研究工作及取得的成果。
尽我所知,除文中特别加以标注和致谢的地方外,不包含其他人或组织已经发表或公布过的研究成果,也不包含我为获得及其它教育机构的学位或学历而使用过的材料。
翻译部分英文原文1.1 The take type transports the characteristics and the application of the machineThe take type transports machine since 1795 was disheveled hair and clear,through the development of more than twocenturies,already drive electric power、metallurgy、coal、chemical engineering、mineral mountain、portetc.every trade adopts extensively.Especially the Industrial Revolution brings material,lately technical adoption for the third time lately and makes the take type transport the development of the machine to follow a new era.In now days ,whether appraise from carry、length、economy-effectiveness and so on.It can be the same train,automobile transport to match the situation as it stands,and become the first to the development of industries.1.1.1The take type transports the characteristics of the machine:(1)The structure is simple.Followed by belt conveyor drive pully to one drum,or idlerroller components、drives、conveyors several large components.Only a dozen or morecomponents,production can be standardized and may require portfolio assembly,thestructure is very simple;(2)Transport the material scope extensively.Conveyor belt with wear,corrosionresistance ,oil resistance,such as fire-retardant properties,and high-resistance,lowtemperature,may be required to produce,which will transport all kinds of stuff,blockmaterials,chemicals,the Health clinker and concrete;(3)Transport to have great capacity.V olume per hour from a few kilograms to severalthousands of tons,but is uninterrupted deliveryThis is the train,the automobile conveyance is too far behind to catch up;(4)The luck is apart from to grow.Single length of up to 10 kilometers an abroad,is verypopular,in the middle reproduced without any points.Cross-countrily the take type transports machine to often use to rub to drive a way inthe center,making to transport the restriction that the length is free from the beltconveyer strength.(5)It is strong to the circuit adaptability.Modern belt conveyor in layingcross-country,from the trough to tube-shaped,it can be horizontal and vertical planetumed breaking the mold conveyor or not bend the restrictions,which will rely onmountain water,and walk along the terrain,can save a lot of a tunnel,bridgeinfrastructure investment;(6)Pack to unload very convenient.Under the belt conveyor process needs,may at anypoint on the equipment and dump;Pipe conveyor as well.Can also pack,unload to anticipate on the return journey segment ,carry on anti-toconveyance;(7)The credibility is high .As simple structure,moving parts light weight ,as long as thebelt is not torn,with a life span of 10 years,metal components,as long as antirustgood,for the past several decades is not a bad idea;(8)The operation fee is cheap.Wear parts belt conveyor idlers and only roller,conveyorlongevity,a high degree of automation,use of the staff is small,per km on average lessthan one,the consumption of oil and electricity rarely;(9)Can consume low,the efficiency is high.Since moving parts as light weight,low voidshipped in all non-continuous and continuous transport,Belt conveyor energyminimum,maximum efficiency;(10)Maintain a fee little .Belt conveyor is the only moving parts and idler pulley,belt wearis very.Compare under,the train,automobile wears away a parts to want many,and replace towear away a piece also more multifarious;On the other say,the take type transports the superiority of the machine already veryobviously,it is the key equipments of the indispensability in the nationaleconomy .Moreover,Internet the realization has been greatly shortened the beltconveyor design,development,manufacture,sales cycles,make it more competitive. 1.2 The take type transports the present condition and the development of the machineTake type’s transporting machine is the coal mine is the most ideal to transport an equipments efficiently and continuously,compared with other conveyance equipmentses have distance of transport long,the carrying capacity is big and continue to transport etc.advantage,and circulate credibility,be easy to the realization automation and concentrate to turn a control,particularly to high produce efficiently the mineral well,the take type transports the key equipments that the machine has become coal to mine the machine electricity integral whole to turn a technique and equips.Along with the our country is high to produe of mineral well efficiently now,the take type that is originally possessed’s transporting machine is a regardless main parameter to still circulate functions and all have already can’t satisfy a request,have to the long pull,high take soon,big carrying capacity,big power of large turn the direction development,and want improve and raise to circulate function, insure safe credibility.The take type that the our country production make transports the species,type of the machine more.In the”Enghth Five-Year Plan”period,the national one-stop “Nissan 10,000 tons fully mechanized equipment”projects,conveyor technology has-greatly improved,and mine with high power .The key to long-distance belt conveyor technology research and development of new products ,LU has made considerable progress.Such as the big cape long pull take type transport machine to become a set an equipments,high produce to work efficiently noodles fluently slot the flexible take type transport machine ,etc.all filled up local bland ,and transport machine to turn down the key technique to the take type and it main dollar the parts carried on the theories research and the product development,develop successfully variety soft start and make to move equip and take PLC as core of the programmable electricity control device,driving the system adoption to adjust soon type the liquid dint matches the machine and the planet wheel gear to decelerate a machine accidentally.The coal mine take type transports technical development trend of machine .The equipments is large to turn,the exaltation transport an ability:For adapt high produce efficiently intensive turn the demand of the production,the take type transports machine to transport an ability to want enlargement.Long-distance,high belt speed,large-capacity,high-power future is the inecitable trend of development,as well as transport for the high-technology development direction.Transport quantity and raise to the 3000-4000 ts/h in the 10 as of aftertime also raise to the 4-6 ms/s soon,transport length to transport to the flexible take type confidential attain a 3000ms.For strength steel belt conveyor take longer to 5,000 m above single-driven power demand reached 1,000~1,500 kw,conveyor tensile strength reached 6,000 N/mm (steel cord)and 2500 N/mm (steel cord).By the coal mine well to descend agreeable slot particularly flexible transport a technical development,along with high produce efficiently continuously develop of the emergence and the coal science and technology of work the noodles,the original flexible take type transports machine,is a regardless main parameter,still circulate functions all hard adapt high produce efficiently a request of work the noodles,the coal mine needs main parameter urgently on the scene greater ,the technique is more advanced,function more dependable long pull ,big carrying capacity 、big power fluently slot the flexible take type transport machine ,transporting technical design level of machine by the exaltation our country take type,filling up local bland,near to and catch up the technique level of the international advanced industrial country.It contains seven of the key technologies:(1) belt conveyor dynamic analysis and control technology;(2)soft start with the power balance technology;(3)Intermediate Driver;(4)automatic tensioning technology .(5)new lifetime high technology high-speed roller;(6)rapid shift from the tail;(7)with efficient storage technology.Raise 1 dollar parts function and credibicity :The equipments switch on rate of high and low mainly be decided by the function and the credibility of 1 dollar parts.In addition to further improving and enhancing the existing yuan parts of the performance and reliability,we will continue to research and development of new technologies and metadata components,such as high-performance technical controllable soft start,Dynamic Analysis and Monitoring Technology,and efficient storage devices with rapid shift from the tail,high-speed roller,belt conveyor so that the performance can be further raised.Extend function ,a machine uses to turn much:Expan a luck a person,carry to anticipate or double to conveyance etc.function,attain a machine to use much,make it the exertive and biddest economic performance.Develop a special type a take type to transport machine,if the flection take type transports the machine,big cape or perpend cularity to promote to transport machine etc.The big cape take type transports the extreme limit that the machine broke the last luck cape 25°s,expand,mine for the coal mine and the main and inclined well transported an equipments to choose a type to develop a new path,also transporting the equipments that the system changed an extension to provide economy efficiently for the current inclined well,to raise a yield and decline low cost have important meaning.The level take type transports machine to have amplitude in the our country mineral mountain the production of applied foregroune,especially in the coal mine.My more inclind seam,16~25° tilt seam exist in large numbers.The take type transports the function success to used for the bottom of the well,since can reduce tunnel to expand the quantity and equipments.中文译文1.1带式输送机的的特点与应用带式输送机自1795年被发明以来,经过两个多世纪的发展,已被电力、冶金、煤炭、化工、矿山、港口等各行各业广泛采用,特别是第三次工业革命带来了新材料、新技术的采用使带式输送机的发展步入了一个新纪元。
Design Of Belt Conveyor Transporting machine to press the operation way can is divided into:1:The leather belt type transports machine 2:Is spiral to transport machine 3:The Dou type promotes machine 4:The roller transports machine 5:Calculate to transport machine 6:The plank chain transports machine 7:The net takes to transport machine 8:The chain transports machine.1.ParameterIs general according to various condition of request, material shipping point that the material transports system, relevant of the production craft process and material of characteristic etc. to make sure each main parameter.①Transport ability:The ability of transporting the transporting of machine means unit for time inside transport of material quantity.While transporting to spread a form material, with the quality or physical volume calculation that the per hour transports a material;At transport into a piece product, with the number of items calculation that the per hour transports.②Transport speed:The exaltation transports speed to improve the ability of transporting.When being making to lead a piece by belt conveyer and transporting length was more big, transport speed to gradually enlarge.But the take type of high-speed operation transports machine to need to notice vibration, Zao voice and start and make etc. problem.For use chain as lead a piece of transport machine, transporting the speed should not lead greatly, in order to prevent the aggrandizement power carry a lotus.Carry on transporting of craft operation machine at the same time, transporting the speed should press to produce a craft to request an assurance.③Reach a size:Transport reaching of machine a size to include belt conveyer width, lath width and anticipate Dou capacity, piping diameter and container all of etc.s.These reach a sizes to all directly influence to transport machine of transport ability.④Transport length and Qing Cape:Transport circuit length and Qing Cape size to directly influence the total resistance of transporting the machine and need of power.2.Transport a machine the spot application wayConstitute to carry on explaining in detail from the take type machine system first:Leather belt's transporting machine is to spread a form material to transport and pack to unload an equipments most importantly, can extensively used for the mineral mountain, metallurgy, building materials, chemical engineering, electric power, industrial realms like food processing,etc, in the coal mine, metal mineral, the steel business enterprise, port, grounds like cement works,etc a great deal of application that can see skin machine, transporting the machine can not only complete to spread a transporting of form material, but also can transport into a piece material, but basis use location, work environment, transport the dissimilarity of material category, will also have bigger difference in its design and the application;Modernization of transport the machine system has higher request to the dust palliative, is this, in each the device that transfer place and establish and sprinkle water and gather a dust, transport machine and follow line in the tape will establish and defend a breeze cover or block an aerofoil, system from list the machine constitute of, to work in the whole machine system of operate and fix to say, want and have a foothold and divide the single machine of the tube at oneself, and want to understand mutual contact between systems, list machine again is constitute to°from many partses, only work well the daily maintenance of each parts maintains and makes it is placed in good work status so as to ensure the safe movement of equipments;We generally will transport the use place, work environment of machine according to the take type, technique function and transport material category to wait various dissimilarity with satisfy various forms of homework work condition, in addition to in addition to transporting machine, the in general use leather belt of more adoption also various special kind tapes of new structure transport machine and have a mainly having of the representative among them:Big Qing Cape take type machine, deep slot take type machine and press take type machine, take care of the form take type, the air cushion take type, the flat surface turn take type, the line friction type, wave-like in shape the belt conveyer type blocking a side transport machine etc. andcarry on a thin method for turning and canning exist various classifications and make following introduction now:Press the use classification, there is in general use ambulation type, under the well choice type, the strip mine is used a fixed type, special kind structure type, can move a place type and transport machine, load machine appropriation redistribution function type, the big Qing Cape type transports machine etc., generally speaking transport machine inside the short distance factory can complete level, up the luck or bottom carries, canning go against the wood grain type leather belt machine can be used for double to transport a material, hang arm machine usually install anticipate on board in the heap, and can turn round, line up the function of soil or cloth by realization, but Gao Jia Ji propped up by in the door usually match with other spread and anticipate and handle an equipments common use, for example give or get an electric shock and constuct a medium application in water, can install standard in the center frame, the machine's mounting places on the track Zhen, easy to move and place;Press the category of transporting the material to categorize, have the generally lax material is used of, the strong and tough material is used of and list piece the leather belt used in material transport machine etc. and press the rubber conveyance takes a loading segment of position to categorize, include a leather belt loading segment at top of and loading segment at underneath of and at the same time loading segment at up underneath of double to transport machine three, the use double can distinguish to transporting machine at up branch and bottom branch transport a material, but for keeping material contact noodles don't produce a change and need to bring in to go to the rubber to be periodically inside out.3.CategorizeTransporting machine generally and pressing already didn't lead piece to carry on a classification and had to lead a transporting of piece machine to generally include to lead a piece, loading to reach a piece, drive device, bring to the stretch device and change to accept an etc. to the device and.Lead a piece to in order to deliver to lead dint, can adopt belt conveyer and lead chain or steel wire rope;The loading reaches apiece to in order to accept to put a material and has already anticipated Dou and bracket or mourns to have...etc.;Drive device to transport machine with the power, generally from electric motor, decelerate a machine and make machine(stop a machine) etc. to constitute;Bring to the stretch to equip to generally have the Luo pole the type and heavy hammer type 2 kind, can make to lead a piece to keep certain tension and hang a degree, transport machine by assurance normal operation;Pay to accept a piece to in order to accept to give to lead piece or loading to reach a piece, can adopt to give Gun and roll an etc..Having the structure characteristics that lead the transporting of piece machine is:Be delivered a material and pack reaching with the loading leading a link together inside the piece, or directly pack in leading a piece(is like belt conveyer), led a piece to once round each roller or the chain round beginning and end and connect with each other, formation include and deliver a having of material carry branch and don't deliver a material of have never carried shutting of branch and match wreath road, make use of lead continuous sport of piece and transport a material.This type ofly transporting model is numerous, there is mainly a take type transporting a machine, plank type and transporting a machine, small car type and transporting machine, escalator, automatic sidewalk, paring off plank and transporting machine, covering up and paring off plank and transporting a machine, Dou type and transporting a machine, Dou type and promoting machine and hanging and transporting machine and build on stilts a cableway...etc..The structure that didn't lead transporting of piece machine constitutes each not same, use to the work of transporting the material to reach a piece as well not same.Their structure characteristicses are:Make use of a work to reach a revolving of piece to exercise or the back and forth exercise, or make use of lie quality to make the material transport forward in the fluxion in the piping.For example, the Gun son transports the work of machine to reach the piece as a series of Gun son, the Gun son makes to revolve sport to transport a material;Is spiral to transport the work of machine to reach a piece for spiral, helix at anticipate and make to revolve sport in the slot with follow anticipate slot to push to send a material;The vibration transports the work of machine to reach piece in order to anticipate slot, anticipate slot to make backand forth sport with transport Be placed to among them of material etc..Install(1)The fixed type transports machine should by rule gearing method gearing at fix of foundation up.The ambulation type transports machine formally before circulating and should live wheel with the wedge Xie or uses to make a machine to stop.So as not to take place to take a stroll in the work, there is the passage that many sets , between machine and machine, there shoulded be one meter between wall and machine while transporting a parallel homework of machine.(2)The beard checks an each operation part, tape to take to button up to equip with loading before using whether normal, whether protection equipments is well-found.The tape rises a tight degree beard before starting the adjustment is to suitable extent.(3)Leather belt's transporting machine should get empty to carry a start.Waiting to revolve normal rear can go into to anticipate.Drive after forbiding to go into first to anticipate.(4)There are few set that when transport machine to establish to circulate should from unload to anticipate to carry a beginning, the sequence starts.After revolving as usual all, the square can go into to anticipate.(5)Appear in the movement when the tape runs to be partial to a phenomenon should park the car adjustment, can not force an use, so as not to wear away edge and increment burden.(6)Work environment and be sent material temperature not to must be higher than 50 ℃ and be lower than-10 ℃ .Can not transport the material of having sour alkaline oil and organic melting agent composition.(7)Forbid pedestrian or multiply by a person on the belt conveyer.(8)Have to stop going into first to anticipate before parking the car, wait leather belt up save to anticipate to unload to the utmost a square can park the car.(9)Transporting the machine electric motor has to insulate good.The ambulation type transports machine electric cable to pull and drag along indiscriminately.The dynamoelectric confidential credibility connects ground.(10)The leather belt beats slippery strictly forbid to by hand pull leather belt, so as not to take place trouble.5.Adjust to try(1) Each equipments with meticulous care adjusts to try to transport machine after installing and satisfies a drawing request.(2) Each deceleration machine exercises parts to add to note to correspond lubricant.(3) The gearing after transporting machine to attain to request each single set equipments carries on beginning to work to make run-in, and knot to put together to adjust to try to transport machine to satisfy an operative request.(4) Adjust to try the electricity part of transporting the machine.Include to connect adjusting of line and action to try to the normal regulations electricity, make the equipments have good function, attain the function and status of design.6.Transport machine to block knothole 2 kinds of boring crafts(1)Blow up boring:The material after the irradiation of continuous laser and centrally forms one cave pit, then from and laser beam the coaxial oxygen flow to clean meltdown material and form one bore very quickly.The size of general bore is as thick relevant as plank, blow up to bore hole the average diameter as thick plank half, therefore blow up to bore hole bore path bigger to thicker plank, and not circle, should not in requesting higher spare parts use(if the petroleum Shai sews a tube), can be used for a waste up.In addition because of bore hole use of oxygen pressure with incise homology, splash a little bit greatly.(2)Pulse boring:The pulse laser that adopts high peak value power makes a little amount material melt or vaporizes, in common use air or nitrogen spirit are to lend support to air and oxidize to make bore expand because of putting heat by decrease, the air pressure more incises of the oxygen pressure is small.The particle jet with small creation of each pulse laser gradually goes deep into, therefore slab boring time takes several seconds.Once bore hole completion, immediately change assistance air into oxygen to carry on incising.Boring hole diameter like this is smaller, its boring quality is better than to blow up boring.Not only should have higher exportationpower for the laser machine used by this;The time and space characteristic that more important time ties, therefore the general crosscurrent carbon dioxide laser machine can not adapt to the request that the laser incises.In addition the pulse bores hole to also have the more dependable spirit road the control system to carry out cutting over of air category, air pressure and bore hole a horary control.皮带输送机输送机械按运作方式可以分为:1:皮带式传输机2:螺旋输送机3:斗式提升机4:滚筒运送机5:计量运输机6:板链式运送机7:网带输送机8:链条运输机。
附录Ⅰ英文文献翻译附录A带式输送机技术的最新发展M. A. AlspaughOverland Conveyor Co., Inc.MINExpo 2004拉斯维加斯, 内华达州,美国,2004.9.27摘要粒状材料运输要求带式输送机具有更远的输送距离、更复杂的输送路线和更大的输送量。
为了适应社会的发展,输送机需要在系统设计、系统分析、数值仿真领域向更高层次发展。
传统水平曲线和现代中间驱动的应用改变和扩大了带式输送机发展的可能性。
本文回顾了为保证输送机的可靠性和可用性而运用数字工具的一些复杂带式输送机。
前言虽然这篇文章的标题表明在皮带输送机技术中将提出“新”发展,但是提到的大多思想和方法都已存在很长时间了。
我们不怀疑被提出一些部件或想法将是“新”的对你们大部分人来说。
所谓的“新”就是利用成熟的技术和部件组成特别的、复杂的系统;“新”就是利用系统设计工具和方法,汇集一些部件组成独特的输送机系统,并解决大量粒状原料的装卸问题;“新”就是在第一次系统试验(委任)之前利用日益成熟的计算机技术进行准确节能计算机模拟。
同样,本文的重点是特定复杂系统设计及满足长距离输送的要求。
这四个具体课题将覆盖:1、托辊阻力2、节能3、动力分散4、分析与仿真节能减小设备整体电力消费是所有项目的一个重要方面,皮带输送机是也不例外。
虽然与其他运输方法比较皮带输送机总是运输大吨位高效率的手段,但是减少带式输送机的功率消耗的方法还是很多的。
皮带输送机的主要阻力组成部分有:a.托辊阻力b.托辊与皮带的摩擦力c.材料或输送带弯曲下垂引起的阻力这些阻力加上一些混杂阻力组成输送材料所需的力。
1在一台输送长度400米的典型短距离输送机中,力可以分为如图1所示的几个部分,图中可以看出提升力所占比例最大,而阻力还是占绝大部分。
图1在高倾斜输送带中如矿用露天倾斜输送带,所受力可分解为图2所示的几个部分,其中提升力仍占巨大比例。
由于重力是无法避免的,因此没有好的方法减少倾斜式输送机所受力。
皮带机输送机中英文对照外文翻译文献中英文资料翻译中文:带式输送机及其牵引系统在运送大量的物料时,带式输送机在长距离的运输中起到了非常重要的竞争作用。
输送系统将会变得更大、更复杂,而驱动系统也己经历了一个演变过程,并将继续这样下去。
如今,较大的输送带和多驱动系统需耍更大的功率,比如3驱动系统需耍给输送带750KW(成庄煤矿输送机驱动系统的要求)。
控制驱动力和加速度扭矩是输送机的关键。
一个高效的驱动系统应该能顺利的运行,同时保持输送带张紧力在指定的安全极限负荷内。
为了负载分配在多个驱动上,扭矩和速度控制在驱动系统的设计中也是很重要的因素。
由于输送机驱动系统控制技术的进步,目前更多可靠的低成本和高效驱动的驱动系统可供顾客选择[1]1带式输送机驱动1. 1带式输送机驱动方式全电压启动在全电压启动设计中,带式输送机驱动轴通过齿轮传动直接连接到电机。
直接全压驱动没有为变化的传送负载提供任何控制,根据满载和空载功率需求的比率,空载启动时比满载可能快3-4倍。
此种方式的优点是:免维护,启动系统简单,低成本,可靠性高。
但是,不能控制启动扭矩和最大停止扭矩。
因此,这种方式只用于低功率,结构简单的传送驱动中。
降压启动随着传送驱动功率的增加,在加速期间控制使用的电机扭矩变得越来越重要。
由于电机扭矩是电压的函数,电机电压必须得到控制,一般用可控硅整流器(SCR}构成的降压启动装置,先施加低电压拉紧输送带,然后线性的增加供电电压直到全电压和最大带速。
但是,这种启动方式不会产生稳定的加速度,当加速完成时,控制电机电压的SCR 锁定在全导通,为电机提供全压。
此种控制方式功率可达到750kW。
绕线转子感应电机绕线转子感应电机直接连接到驱动系统减速机上,通过在电机转子绕组中串联电阻控制电机转矩。
在传送装置启动时,把电阻串联进转子产生较低的转矩,当传送带加速时,电阻逐渐减少保持稳定增加转矩。
在多驱动系统中,一个外加的滑差电阻可能将总是串联在转子绕组回路中以帮助均分负载。
外文文献Belt COnVeyOr is a machinery for COnVeying goods WithOUt end COnVeyer belt moving COntinUOUSly ・ It has SimPIe StI e UCtUre , IOW COSt , IOng transportation distance and high PrOdUCtiVity ・With the development Of modern industrial SCienCe and technology , belt COnVeyOr has become more and more important in industrial PrOdUCtiOn ・ With the development Of belt joint technology, belt COnVeyOr has developed to a high level. In the 17th century, the PrOtOtyPe Of modern bucket hoists and SCraPer COnVeyOrS began to USe aerial ropeway to transport IOOSe materials. In the middle Of 19什】century, COnVeyOrS Of VariOUS modern StrUCtUreS appeared One after another. In 1868, Belt COnVeyOr appeared in England, SCreW COnVeyOr in AmeriCa in 1887, Steel belt COnVeyOr in SWitZerland in 1905, inertial COnVeyOr in EngIand and Germany in 1906・ After that, the COnVeyOr receives The impact Of tec hnological PrOgreSS in the mechanical manufacturing, electrical machineιy, ChemiCal and metallurgical industries has been COntinUOUSly improved, gradually from the COnIPletiOn Of the internal transportation Of the WOrkShOP to the COmPIetiOn Of material handling Within the enterprise, between enterprises and even between cities, BeCOme an indispensable Part Of material handling SyStem mechanization and automation ・1.Belt COnVeyOr having a CirCUIating COnVeying belt, COmPrising: Carrying rollers ar ranged between a top Strand and a bottom Strand Of the CirCUlating COnVeying belt; UP Per and IOWer guide rollers acting On UPPer and IOWer beads On the CirCUlating COnVey ing belt and forcing the CirCUlating COnVeying belt radially outward, the UPPer and IOW er beads being formed OPPOSite to each Other On the CirCUlating COnVeying belt; at IeaS t One toothed ring interacting With at IeaSt One toothed belt arranged On the CirCUlating COnVeying belt, Whereby the UPPer bead is neighbored to the toothed belt; and a drive device for moving the CirCUlating COnVeying belt.2.BeIt COnVeyOr according to Claim 1, Wherein the toothed belt is arranged On the U nderside Of the CirCUlating COnVeying belt, in the running CiireCtiOn Of the CirCUIating C OnVeying belt ・3.Belt COnVeyOr according to CIainl 2, Wherein the toothed ring is arranged at the e nd Of the Carrying rollers, and Wherein PrOjeCting from the end Of a first Carrying ro∏e r is a journal for the COnneCtiOn Of the drive device・4.Belt COnVeyOr according to Claim 3, Wherein the toothed belt extends in the regio n Of the Side border Of the CirCUlating COnVeying belt・5.BeIt COnVeyOr according to Claim 1, Wherein the toothed belt and the toothed rin g have InUltiSPIining・6.Belt COnVeyOr according to CIaim 1, Wherein KeVIar filaments are incorporated i n the toothed belt・7.BeIt COnVeyOr according to CIaim 1, Wherein the toothed belt is attached On the C irculating COnVeying belt Via One Of welding, vulcanizing, and adhesively bonding the reto.8.BeIt COnVeyOr having a CirCUIating COnVeying belt, comprising: Carrying rollers a rranged between a top Strand and a bottom Strand Of the CirCUlating COnVeying belt; an d a drive device and a force-transmission device for moving the COnVeying belt, Where in a Pair Of elements WhiCh interact WitIl One another With a form fit is PrOVided for fo rce-transmission purposes, One Of Said elements being assigned to die force-transmissi On device and the Other Of Said elements being assigned to the COnVeying belt, Wherei n the force-transmission CieViCe COnIPriSeS at IeaSt One toothed ring, and Wherein the Ci rculating COnVeying belt has at IeaSt One toothed belt, the toothed ring and toothed belt interacting With a form fit, Wherein the toothed belt is a COnStitUent Part Of a toothed- belt COmPOnent WhiCh is Of essentially U-ShaPed design in the transverse direction Of t he toothed belt and engages around the side-border region Of the COnVeying belt・9.Belt COnVeyOr according to CIaim & Wherein the toothed ring is assigned at IeaSt t o a first belt-conveyor Carrying roller, WhiCh is OPeratiVeIy COnneCted to the drive devi10.BeIt COnVeyOr according to CIaim 8, further COmPriSing a COUnterPreSSUre devic e, WhiCh acts On that region Of the toothed-belt COmPOnent WhiCh extends On the top Si de Of the CirCUIating COnVeying belt・11.BeIt COnVeyOr according to Claim 8, Wherein the free ends Of the essentially U・ ShaPed toothed-belt COmPOnent are designed as a bead・12.BeIt COnVeyOr according to Claim & further COmPriSing guide rollers, WhiCh act On One Of the toothed belt and the toothed-belt COmPOnent.13.Belt COnVeyOr having a CirCUlating COnVeying belt, comprising: Carrying rollers arranged between a top Strand and a bottom Strand Of the CirCulating COnVeying belt; U PPer and IOWer guide rollers acting On UPPer and IOWer beads On the CirCUIating COnVe ying belt and forcing the CirCUIating COnVeying belt radially outward, the UPPer and Io Wer beads being formed OPPOSite to each Other On the CirCUlating COnVeying belt; at Ie ast One toothed ring interacting With at IeaStOne toothed belt formed On the CirCUlating COnVeying belt, Whereby the UPPer bead is neighbored to the toothed belt; and a drive device for moving the CirCUlating COnVeying belt, Wherein a Pair Of Said guide rollers are arranged On angled retaining arms SUCh that the guide rollers act On One Of the toot hed belt and the UPPer and IOWer beads, by Way Of inclined running SUrfaCeS・14.BeIt COnVeyOr according to CIaim 12, Wherein in each CaSe One Pair Of guide rol IerS On the top Strand and On the bottom Strand Of the CirCUlating COnVeying belt act On One Of the toothed belt and the toothed-belt COmPOnent, extending OVer the entire bor der region Of the CirCUIating COnVeying belt.15.Belt COnVeyOr according to CIaim 1, Wherein the Carrying rollers are Of COniCal COnfigUratiOn and form a belt curve, and Wherein the toothed ring UndergOeS a form-fi tting COnneCtiOn in relation to the CirCUlating COnVeying belt at the Iarger-diameter end Of the respective Carrying roller On the OUter radius Of the belt CUrVe.16.The belt driving device Of CIaim 1, Wherein One Of Said toothed ring and Said to Othed belt is releasably fixed to the Carrying rollers.Belt COnVeyOr according to ClaiIn 16, Wherein One Of Said toothed ring and Said toot hed belt is releasably fixed to the force-transmission device by One of.The PreSent invention relates to a belt COnVeyOr having a CirCUIating COnVeying belt ,having Carrying rollers, WhiCh are arranged between the top Strand and the bottom Str and Of the COnVeying belt, and having a drive device and a force-transmission device f Or moving the COnVeying belt・BACKGROUND OF THE INVENTIONIt is known from PraCtiCe for force to be transmitted from the drive device to the CO nveying belt Of a belt COnVeyOr Via friction fitting・ The friction between a driven Carry ing roller and the COnVeying belt, for example, may even be SUffiCient for this PUrPOSe ・ The rest Of the Carrying rollers are mounted in a movable manner and rotate along・DE 42 44 170 C2DiSClOSeS a belt COnVeyOr having an endless COnVeying belt, the Iatter being driven by means Of a force-transmission device WhiCh is PreSent in the form Of a friction Whe el. A drive Shaft extends beneath the bottom Strand Of the COnVeying belt. On the inner radius Of the belt curve, a motor is COnneCted as a drive device to the drive Shaft and, in the region Of the OUter radius, a friction Wheel is Seated On the drive Shaft and is in C OntaCt With the OUter SUrfaCeOf the COnVeying belt. In this case, the friction Wheel inte racts With a Carrying roller functioning as COUnterPreSSUre roller. The drive Shaft is mo Unted SUCh that it Can be InOVed at an angle both in the region Of the OUter radius and i n the region Of the inner radius Of the belt cuι*ve・Theangle mounting Of the drive Shaft allows adaptation Of the exent toWhiCh the friction movablewheel is PreSSed against the COnVeying belt in PrOPOrtiOn t o the actual IOad・ In this way, the Wear is reduced if, in Part-IOad OPeration, the COnVe ying beltis OnIy SUbjeCted to the COntaCt-PreSSUre force WhiCh is necessary for this pur POSe ・AlthOUgh the belt COnVeyOr known from DE 42 44 170 C2 reduces the Wear Of the C OnVeying belt, it CannOt rule it OUt altogether・ The task Of COnVeying foodstuffs Or Othe r goods WhiCh are to be kept CIean involves, in addition to the mechanical damage to t he COnVeying belt, the aspect Of hygiene and Of keeping goods CIean・ The abraded SUrf ace PartiCIeS Of the COnVeying belt COUId have a COnSiderabIe adverse effect On the qua Iity Of the goods WhiCh are to be COnVeyed・ MOreOVer,什w known belt COnVeyOr requir es an extremely high IeVel Of StrUCtUral OUtIay as far as the movable mounting Of the S eparate drive Shaft is COnCerned・Taking as departure POint the belt COnVeyOr known from DE 42 44 170 C2, the Obje Ct Of the invention is to SPeCify a belt COnVeyOr Of the type in question WhiCh Iargely r UleS OUt any adverse effect to the SUrfaCe Of the COCOnVeying belt Of the belt COnVeyOr by the force-transmission device・ ACCOrCling to a PartiCUIarIy Preferred COnfigUration, the belt COnVeyOr is intended to require just a IOvV IeVel Of stιβuctural OUtIay.The above ObjeCt is achieved by the features Of Patent CIaim 1. ACCOrding to the Iatt er, a belt COnVeyOr Of the type in question is COnfigUred SUCh that a Pair Of elements W hich interact With One another With a form fit is PrOVided for force-transmission PUrPO ses, and that One element is assigned to the force-transmission device and the Other ele ment is assigned to the COnVeying belt. ACCOrding to the invention, it has been found t hat the SUrfaCe Of the COnVeying belt is not adversely affected as a result Of the action Of the force-transmission device if a SeParate Pair Of elements is PrOVided in Order to r ealize force transmission. It has also been found that the USe Of a Pair Of nιoveιnent-co nverting elements WhiCh are known Per Se and interact With One another With a form fi t IargeIy eliminates the CliSadVantageS WhiCh are known in the CaSe Of friction-fitting movement COnVerSion, in PartiCUIar Wear and abrasion.ACCOrding to a Preferred exemplary embodiment Of the belt COnVeyOr according to t he invention, the Pair Of elements COUld be PreSent as toothed ring and toothed belt, th e tooth flanks Of the toothed ring and Of the toothed belt interacting With One another. It WOUId be POSSible for the toothed ring to be assigned to the force-transmission devic e and for the toothed belt to be assigned to the COnVeying belt.AS far as a PartiCUIarly IOW IeVel Of StnJCtUral OUtIay is concerned, a Preferred COnfi guration Of the abovementioned exemplary embodiment PrOVideS that the toothed ring is assigned to a Carrying roller, and the Iatter thus SimUltaneOUSIy assumes the role Of the force-transmission device・ Via a journal PrOjeCting from the Carrying roller, the dri Ve takes PlaCe by means Of a motor. The toothed ring COUId be PIUgged OntO the Carryi ng roller and fixed releasably—for example Via a ShaftzhUbCOnneCtiOn Or a feather key —to the Same・In the CaSe Of a PkIgged-On toothed ring, it isadvantageous that it is POSSible to USe Carrying rollers WhiCh are already present. It is PartiCUIarIy advantageous for each Carr ying roller to be assigned at IeaSt One toothed ring. OVer the entire ιβunning Path Of the COnVeying belt, it WOUId then be the CaSe that the toothed belt and the toothed rings int erengage and move the COnVeying belt in a CIimenSiOnany StabIe manner・ COrreSPOndi ng to the toothed ring Or rings WhiCh is/are arranged between the top and bottom Stran ds and belongs/belong to the Preferred COnfigUratiOn mentioned above, the toothed bel t is arranged On the UnderSide Of the COnVeying belt, and extends in the running CiireCti On Of the Same・ Arranging the toothed belt On the UnderSide Of the COnVeying belt OnC e again ensures that the top Side Of the COnVeying belt, WhiCh is Charged if appropriate With goods WhiCh are to be kept clean, is not SUbjeCt to any force transmission, media nical damage Or PrOdUCtiOn Of abrasion PartiCleS Or Other COntanIinantS・An expedient development Of the Preferred COnfigUratiOn Of the belt COnVeyOr acco rding to the invention makes PrOViSiOn for the toothed ring to be arranged at the end o f the Carrying roller. AS a result, On the One hand, Straightfoi e Ward maintenance Of the f orce-transmission device is Inade POSSibIe and, On the Other hand, this arrangement is also more cost-effective than a, for example, Central arrangement. DireCt force transmi SSiOn OVer a ShOrt distance is achieved by a journal for the COnneCtiOn Of the drive dev ice PrOjeCting from that end Of the Carrying roller WhiCh is PrOVided With the toothed r ing.It is PartiCUlarIy advantageous if the toothed belt extends in the region Of the Side bOrder Of the COnVeying belt. AS a result, On the One hand, StraightfOrWard PrOdUCtiOn o f the COnVeying belt With the toothed belt is made POSSible by the direct relationship to the border region and, On the Other hand, a role is also Played here by the accessibilit y to the Pair Of elements for maintenance PUrPOSeS and, Of course, by the COOrdinatiOn between the toothed belt and the arrangement Of the toothed ring.In addition to toothed belts and toothed rings With normal toothing, it WOUld also b e POSSible to realize Inultisplining. ThiS further reduces UndeSired Sliding and thus We ar, heating and noise development. In Order to absorb high tensile forces, it WOUId be POSSible for KeVlar filaments to be incorporated in the toothed belt, WhiCh USUalIy COn SiStS Of PlaStiC. It WOUId be POSSible for the COnVeying belt to be PrOdUCed With the too thed belt by welding, VUICaniZing Or adhesive bonding・ ACCOrding to a PartiCUIarIy Pre ferred COnfigUration, it WOUId be POSSibIe for the toothed belt to be a COnStitUent Part o f a toothed- belt COmPOnent WhiCh is Of essentially U-ShaPed design in the transverse direction Of the toothed belt・The U-ShaPe InakeS it POSSibIe for the toothed- belt COnIPOnent SilnPly to be Pklgge d OntO the border Of the COnVeying belt Until the border region has COme into COntaCt With the base Part between the U-Iegs. The inner SUrfaCe Of the toothed- belt COmPOne nt Inay have been PrOVided With adhesive beforehand・ AS a result Of its ShaPing and Of being PrOdUCed in this way,the toothed- belt COmPOnent engages around the side-bor der region Of the COnVeying belt・While the toothed belt Of the COnVeying belt is SUbjeCted to COmPreSSiVe force by th e toothed ring, and this Iargely rules OUt detachment Of the toothed- belt COmPOnent o n the UnderSide Of the COnVeying belt, a COUnterPreSSUre device COUld be PrOVided in o rder to SeCUre that region Of the toothed- belt COmPOnent WhiCh extends On the top Sid e Of the COnVeying belt. In design terms, the Ieg Of the COUnterPreSSUre device COUId b e PreSent in the form Of an arm WhiCh acts On the U-toothed- belt COInPOnent On the to P Side and thus COnStantIy PreSSeS the Same OntO the top Side Of the COnVeying belt.AS far as reliable guidance is concerned, it WOUId be POSSible for the toothed belt Or the toothed- belt COInPOnent COntaining the toothed belt to form a bead・ A bead ridge is thus PrOdUCed OVer the Iength Of the COnVeying belt. In the CaSe Of a U-ShaPed tooth ed- belt COmPOnent, the bead ridge extends in each CaSe at the free ends Of the U-Iegs, at a distance from the border Ofthe COnVeying belt, the distance depending essentially On the Width Of the toothed belt. AS an alternative to a bead ridge, it WOUId be POSSibIe for the toothed- belt COmPOnent Or for the StraightfOrWard toothed belt also to have at IeaSt One beveled free end・ The guidance measure taken On the toothed belt Or On the S PeCifiC toothed- belt COmPOnent is PrOVided in Order that a guide roller Or a Pair Of gui de rollers acts On the beveled SUrfaCe Or On the bead Or bead ridge ・ The guidance meas Ure explained above COUld be taken equally Well in the CaSe OfbeIt CUrVeS and Straight belt IineS and Of belt S・ShaPeS bridging Clifferent heights・In the CaSe Of belt curves, the force acting On the COnVeying belt is directed toward the inner radius Of the belt curve, With the result that the guide rollers, in an advantage OUS manner WhiCh is known Per se, COUIei have inclined running SUrfaCeS・ COrreSPOndi ngly angled retaining arms as a COnStitUent Part Of retaining StrUCtUreS for the guide ro IIerS COUld be arranged in each CaSe in the region Of a Carrying roller. The guide roller S COUld be arrangedin PairS On the top Strand and On the bottom Strand Of the COnVeyi ng belt.It ShOUld be emphasized at this POint that, With the abovementioned COnfigUratiOn o f thebelt COnVeyOr according to the invention having the bead Or beveled free ends, t WO functionsare COmbined in the Pair Of form-fitting elements. NOt OnIy the force tra nsmission, but alsothe guidance Of the COnVeying belt, takes PIaCe. The dimensional S tability Of the COnVeyingbelt isadvantageously increased by the Pair Of form-fitting el ements With the SPeCifiC COnfigUratiOn Of the toothed belt Or Of the toothed- belt COmP Onent for action Of the guide rollers thereon.In the CaSe Of the already Cited design Of the belt COnVeyOr in the form Of a belt CUrV e,the Carrying rollers are Of COniCal design and the toothed ring is arranged at the Iarg er-diameter end Of the respective Carrying roller, that is to Say On the OUter radius Of th e belt CUrVe・ The CiriVe device is PreSent as a motor and is assigned to the first Carrying roller Of the belt CUrVe. The form-fitting interengagement Of the toothed Wheel and to Otheel belt takes PIaCe in the region Of each Carrying roller, the form fit, in relation to t he first, motor-driven Carrying roller, SerVing for force-transmission PUrPOSeS and, in r elation to the rest Of the rollers, SerVing for guiding the COnVeying belt.The PreViOUSIy explained PrinCiPle Of force transmission Via a Pair Of elements W hich interact With One ano什Ier With a form fit COUld also be USed in the CaSe Of a Strai2 ht beltIine Or in the CaSe Of a height-changing belt S-ShaPe・Here, the Carrying rollers are Of a CylindriCal design and the force transmission takes PlaCe—as With the belt cur Ve—at a first Carrying roller, While the followingcarrying rollers, IikeWiSe equipped W ith the Pair Of form-fitting elements, SerVe for guiding the COnVeying belt. In COntraSt t 0 the belt curve, however, it WOUld be possible, in the CaSe Of the Straight belt Iine Or i n the CaSe Of the belt S-ShaPe, for the Pair Of elements to be arranged at the two free e nds Of the respective Carrying roller and On the two border regions Of the COnVeying b elt. It WOUld thus be POSSible SPeCifiCany for the two border regions Of the COnVeying belt to have a toothed belt Or a toothed- belt COInPOnent WhiCh interacts With the tooth ed rings at the two free ends Ofeac Carrying roller. FUrthermore, it WOUld also be possible, With these types Of COn StrUCtiOn Of the belt COnVeyOr according to the invention, to PrOVide guide rollers・ A further advantage Of the Preferred embodiment Of the belt COnVeyOr according to th e invention, the toothed ring and toothed belt interacting, COnSiStS in the improved CaP acity for COntrOning the belt SPeed in accordance With the CUrrent loading. It WOUId be POSSibIe to PrOVide a COntrOl device WhiCh SenSeS a Change in the SPeed by COrreSPOn ding measuring SenSOrS and adjusts the POWer Of the drive device in Iine With the Safet y regulations・In COmPariSOn With the force transmission realized by friction fitting, the belt COn VeyOr according to the invention not Only has the advantage Of better CaPaCity for COnt rol, but also has the advantage that the COnVeying belt has a high IeVel Of dimensional Stability as a result Of the guidance by means Of the Pair Of form-fitting elements and b y means Of the PairS Ofguide rollers and Can be SUbjeCted to higher torques・ OVeralL it is POSSibIe to achieve an increased IeVel Of CIriVe POWer during Start-UP .In the CaSe Of the belt COnVeyOr according to the invention being designed in the form Of a belt CUrV e With an inner radius Of 400 mm, the Carrying rollers rotate at 230 rpm at a maximum SPeed Of 1.5 n√sec ・There are VariOUS POSSibiIitieS then, Of advantageously COnfigUring and developin g the teaching Of the PreSent invention・ FOr this purpose, reference is made, On the One hand, to the CIaimS SUbOrdinate to Patent CIainl 1 and, On the Other hand, to the follow ing explanation Ofan exemplary embodiment Of the invention With reference to the dr awing. In COnjIInCtiOn Withthe explanation Of the Cited exemplary embodiment Of the invention, generally Preferred COnfigUratiOnS and developments Of the teaching are also explained・中文译文带式输送机是连续运动的无端输送带输送货物的机械。
中英文对照外文翻译A Comparison of Soft Start Mechanisms forMining Belt Conveyors1800 Washington Road Pittsburgh, PA 15241 Belt Conveyors are an important method for transportation of bulk materials in the mining industry. The control of the application of the starting torque from the belt drive system to the belt fabric affects the performance, life cost, and reliability of the conveyor. This paper examines applications of each starting method within the coal mining industry.INTRODUCTIONThe force required to move a belt conveyor must be transmitted by the drive pulley via friction between the drive pulley and the belt fabric. In order to transmit power there must be a difference in the belt tension as it approaches and leaves the drive pulley. These conditions are true for steady state running, starting, and stopping. Traditionally, belt designs are based on static calculations of running forces. Since starting and stopping are not examined in detail, safety factors are applied to static loadings (Harrison, 1987). This paper will primarily address the starting or acceleration duty of the conveyor. The belt designer must control starting acceleration to prevent excessive tension in the belt fabric and forces in the belt drive system (Suttees, 1986). High acceleration forces can adversely affect the belt fabric, belt splices, drive pulleys, idler pulleys, shafts, bearings, speed reducers, and couplings. Uncontrolled acceleration forces cancause belt conveyor system performance problems with vertical curves, excessive belt take-up movement, loss of drive pulley friction, spillage of materials, and festooning of the belt fabric. The belt designer is confronted with two problems, The belt drive system must produce a minimum torque powerful enough to start the conveyor, and controlled such that the acceleration forces are within safe limits. Smooth starting of the conveyor can be accomplished by the use of drive torque control equipment, either mechanical or electrical, or a combination of the two (CEM, 1979).SOFT START MECHANISM EVALUATION CRITERIONWhat is the best belt conveyor drive system? The answer depends on many variables. The best system is one that provides acceptable control for starting, running, and stopping at a reasonable cost and with high reliability (Lewdly and Sugarcane, 1978). Belt Drive System For the purposes of this paper we will assume that belt conveyors are almost always driven by electrical prime movers (Goodyear Tire and Rubber, 1982). The belt "drive system" shall consist of multiple components including the electrical prime mover, the electrical motor starter with control system, the motor coupling, the speed reducer, the low speed coupling, the belt drive pulley, and the pulley brake or hold back (Cur, 1986). It is important that the belt designer examine the applicability of each system component to the particular application. For the purpose of this paper, we will assume that all drive system components are located in the fresh air, non-permissible, areas of the mine, or in non-hazardous, National Electrical Code, Article 500 explosion-proof, areas of the surface of the mine.Belt Drive Component Attributes Size.Certain drive components are available and practical in different size ranges. For this discussion, we will assume that belt drive systems range from fractional horsepower to multiples of thousands of horsepower. Small drive systems are often below 50 horsepower. Medium systems range from 50 to 1000 horsepower. Large systems can be considered above 1000 horsepower. Divisionof sizes into these groups is entirely arbitrary. Care must be taken to resist the temptation to over motor or under motor a belt flight to enhance standardization. An over motored drive results in poor efficiency and the potential for high torques, while an under motored drive could result in destructive overspending on regeneration, or overheating with shortened motor life (Lords, et al., 1978). Torque Control.Belt designers try to limit the starting torque to no more than 150% of the running torque (CEMA, 1979; Goodyear, 1982). The limit on the applied starting torque is often the limit of rating of the belt carcass, belt splice, pulley lagging, or shaft deflections. On larger belts and belts with optimized sized components, torque limits of 110% through 125% are common (Elberton, 1986). In addition to a torque limit, the belt starter may be required to limit torque increments that would stretch belting and cause traveling waves. An ideal starting control system would apply a pretension torque to the belt at rest up to the point of breakaway, or movement of the entire belt, then a torque equal to the movement requirements of the belt with load plus a constant torque to accelerate the inertia of the system components from rest to final running speed. This would minimize system transient forces and belt stretch (Shultz, 1992). Different drive systems exhibit varying ability to control the application of torques to the belt at rest and at different speeds. Also, the conveyor itself exhibits two extremes of loading. An empty belt normally presents the smallest required torque for breakaway and acceleration, while a fully loaded belt presents the highest required torque. A mining drive system must be capable of scaling the applied torque from a 2/1 ratio for a horizontal simple belt arrangement, to a 10/1 ranges for an inclined or complex belt profile.Thermal Rating.During starting and running, each drive system may dissipate waste heat. The waste heat may be liberated in the electrical motor, the electrical controls,, the couplings, the speed reducer, or the belt braking system. The thermal load ofeach start Is dependent on the amount of belt load and the duration of the start. The designer must fulfill the application requirements for repeated starts after running the conveyor at full load. Typical mining belt starting duties vary from 3 to 10 starts per hour equally spaced, or 2 to 4 starts in succession. Repeated starting may require the dreading or over sizing of system components. There is a direct relationship between thermal rating for repeated starts and costs. Variable Speed. Some belt drive systems are suitable for controlling the starting torque and speed, but only run at constant speed. Some belt applications would require a drive system capable of running for extended periods at less than full speed. This is useful when the drive load must be shared with other drives, the belt is used as a process feeder for rate control of the conveyed material, the belt speed is optimized for the haulage rate, the belt is used at slower speeds to transport men or materials, or the belt is run a slow inspection or inching speed for maintenance purposes (Hager, 1991). The variable speed belt drive will require a control system based on some algorithm to regulate operating speed. Regeneration or Overhauling Load. Some belt profiles present the potential for overhauling loads where the belt system supplies energy to the drive system. Not all drive systems have the ability to accept regenerated energy from the load. Some drives can accept energy from the load and return it to the power line for use by other loads. Other drives accept energy from the load and dissipate it into designated dynamic or mechanical braking elements. Some belt profiles switch from motoring to regeneration during operation. Can the drive system accept regenerated energy of a certain magnitude for the application? Does the drive system have to control or modulate the amount of retarding force during overhauling? Does the overhauling occur when running and starting? Maintenance and Supporting Systems. Each drive system will require periodic preventative maintenance. Replaceable items would include motor brushes, bearings, brake pads, dissipation resistors, oils, and cooling water. If the drive system is conservatively engineered and operated, the lower stress onconsumables will result in lower maintenance costs. Some drives require supporting systems such as circulating oil for lubrication, cooling air or water, environmental dust filtering, or computer instrumentation. The maintenance of the supporting systems can affect the reliability of the drive system.Cost.The drive designer will examine the cost of each drive system. The total cost is the sum of the first capital cost to acquire the drive, the cost to install and commission the drive, the cost to operate the drive, and the cost to maintain the drive. The cost for power to operate the drive may vary widely with different locations. The designer strives to meet all system performance requirements at lowest total cost. Often more than one drive system may satisfy all system performance criterions at competitive costs.Complexity.The preferred drive arrangement is the simplest, such as a single motor driving through a single head pulley. However, mechanical, economic, and functional requirements often necessitate the use of complex drives. The belt designer must balance the need for sophistication against the problems that accompany complex systems. Complex systems require additional design engineering for successful deployment. An often-overlooked cost in a complex system is the cost of training onsite personnel, or the cost of downtime as a result of insufficient training.SOFT START DRIVE CONTROL LOGICEach drive system will require a control system to regulate the starting mechanism. The most common type of control used on smaller to medium sized drives with simple profiles is termed "Open Loop Acceleration Control". In open loop, the control system is previously configured to sequence the starting mechanism in a prescribed manner, usually based on time. In open loop control, drive-operating parameters such as current, torque, or speed do not influence sequence operation. This method presumes that the control designer hasadequately modeled drive system performance on the conveyor. For larger or more complex belts, "Closed Loop" or "Feedback" control may he utilized. In closed loop control, during starting, the control system monitors via sensors drive operating parameters such as current level of the motor, speed of the belt, or force on the belt, and modifies the starting sequence to control, limit, or optimize one or wore parameters. Closed loop control systems modify the starting applied force between an empty and fully loaded conveyor. The constants in the mathematical model related to the measured variable versus the system drive response are termed the tuning constants. These constants must be properly adjusted for successful application to each conveyor. The most common schemes for closed loop control of conveyor starts are tachometer feedback for speed control and load cell force or drive force feedback for torque control. On some complex systems, It is desirable to have the closed loop control system adjust itself for various encountered conveyor conditions. This is termed "Adaptive Control". These extremes can involve vast variations in loadings, temperature of the belting, location of the loading on the profile, or multiple drive options on the conveyor. There are three common adaptive methods. The first involves decisions made before the start, or 'Restart Conditioning'. If the control system could know that the belt is empty, it would reduce initial force and lengthen the application of acceleration force to full speed. If the belt is loaded, the control system would apply pretension forces under stall for less time and supply sufficient torque to adequately accelerate the belt in a timely manner. Since the belt only became loaded during previous running by loading the drive, the average drive current can be sampled when running and retained in a first-in-first-out buffer memory that reflects the belt conveyance time. Then at shutdown the FIFO average may be use4 to precondition some open loop and closed loop set points for the next start. The second method involves decisions that are based on drive observations that occur during initial starting or "Motion Proving'. This usually involves acomparison In time of the drive current or force versus the belt speed. if the drive current or force required early in the sequence is low and motion is initiated, the belt must be unloaded. If the drive current or force required is high and motion is slow in starting, the conveyor must be loaded. This decision can be divided in zones and used to modify the middle and finish of the starsequence control. The third method involves a comparison of the belt speed versus time for this start against historical limits of belt acceleration, or'Acceleration Envelope Monitoring'. At start, the belt speed is measured versus time. This is compared with two limiting belt speed curves that are retained in control system memory. The first curve profiles the empty belt when accelerated, and the second one the fully loaded belt. Thus, if the current speed versus time is lower than the loaded profile, it may indicate that the belt is overloaded, impeded, or drive malfunction. If the current speed versus time is higher than the empty profile, it may indicate a broken belt, coupling, or drive malfunction.In either case, the current start is aborted and an alarm issued. CONCLUSIONThe best belt starting system is one that provides acceptable performance under all belt load Conditions at a reasonable cost with high reliability. No one starting system meets all needs. The belt designer must define the starting system attributes that are required for each belt. In general, the AC induction motor with full voltage starting is confined to small belts with simple profiles. The AC induction motor with reduced voltage SCR starting is the base case mining starter for underground belts from small to medium sizes. With recent improvements, the AC motor with fixed fill fluid couplings is the base case for medium to large conveyors with simple profiles. The Wound Rotor Induction Motor drive is the traditional choice for medium to large belts with repeated starting duty or complex profiles that require precise torque control. The DC motor drive, Variable Fill Hydrokinetic drive, and the Variable Mechanical Transmission drive compete for application on belts with extreme profiles orvariable speed at running requirements. The choice is dependent on location environment, competitive price, operating energy losses, speed response, and user familiarity. AC Variable Frequency drive and Brush less DC applications are limited to small to medium sized belts that require precise speed control due to higher present costs and complexity. However, with continuing competitive and technical improvements, the use of synthesized waveform electronic drives will expand.煤矿业带式输送机几种软起动方式的比较1800 年华盛顿路匹兹堡, PA 15241带式运送机是采矿工业运输大批原料的重要方法。
中文3450字,2120单词,9600英文字符毕业设计(论文)参考文献译文学生姓名:系别:机械工程系专业:机械设计制造及其自动化班级:学号:译文出处:The South African Instituteof Materials HandlingFROM : The South African Institute of Materials HandlingBELT CONVEYOR DRIVES - A CONSIDERATION OFSOME DESIGN ASPECTSJ.H. Rall Pr.Eng., BSc Eng., MSAIME Hansen Transmissions(Pty) ltdP. Staples Pr.Eng BSc, MSAIMEManaging Director Conveyor Knowledge and InformationTechnology (Pty)Ltd (CKIT)Summary:This is a short review of part of the link between the electric power grid and flat rubber covered belts used for transporting large volumes of granular material. It is concerned with high volume material conveying and not with special cases such as feed or metering conveyors, steep inclined conveyors etc. It considers mainly the speed reducer between motor coupling and drive pulley, ratings, bearing life, service factors, stopping and anti-runback devices1.GeneralThe ever increasing rate of consumption of earth's raw materials has brought with it a need for faster movement of these material from the point of extraction to the point of process or usage and transporting these materials through the process plant and disposing of the waste in the shortest possible time. Many methods of material handlingare employed from wheel barrows to dump trucks or shuttle cars, to pneumatic ducts carrying pulverised particles in an air stream. In this line of movement, belt conveyors play a very important part in the reliable carrying of material over long distances at a competitive cost.Each method of material conveying has its advantages and disadvantages. One of the problems with belt conveyors is that soft friable material can be degraded, particularly inloading and unloading. If the maintenance of lump size is important, this can present difficulties on a complicated conveyor system.Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so.Bigger belts require more power and has brought the need for larger individual drives as well as multiple drives such as 4 drives of 1000 kW each on one belt. Shaft mounting of the complete drive unit is another change which has brought with it the requirement for more compact and lighter drive units. This tends to favor a right angle drive configuration with the motor next to the belt and hardened gears to reduce the dimensions and mass of the drive. 2. Drive Ratio and Belt speedsDepending on the quantity, size, distance and characteristics of the material to be conveyed, the absorbed power, width, tensile requirements and top cover thickness of the belt will be decided.Large volume conveyor belts run in the range of 2 to 6 metre/second and the allowable bend radius of the belt determines pulley diameters which for large belts is of the order of 0,8 to 1,5 m giving pulley speeds between 50 and 125 rpm.Assuming that 4 pole motors are used, this gives a reduction ratio required between 12:1 and 30:1.Most modern gear manufacturers do not use a higher ratio per stage than 5:1, which means that speed reducers will be either 2 or 3 stage reduction. (Except for small powers where worm reducers, or torque arms and V belt drives may be used).There is a misconception that one can reduce the cost of the gear-speed reducer by using a 6 or 8 pole motor, but even an 8 pole motor on the higher speeds would require a reduction above 6:1and a 2 stage unit would still be required. The bulk of the cost of a gearbox is relatedto the low speed shaft torque and therefore having determined this, there is generally no economic advantage at all in using anything but a 4 pole motor. The motor manufacturers, because of size and volume, generally supply 4 pole motors at the lowest price, and as a rule therefore, a 4 pole motor is the best choice with a gearbox of the appropriate ratio to arrive at the desired conveyor shaft speed.Where ball and roller bearings are used in the electric motors some manufacturers prefer 6 pole or even 8 pole speeds for motors over 1000 kW.3.1. Choice of Single or Multiple DriveHaving calculated the power required to drive the belt and having considered the belt tension and angle of contact, a decision can be taken on whether the belt should be fitted with single or multiple drive.This decision is often influenced by other equipment installed in a plant and multiples of other smaller drives are often used. Drive size may also be determined by the nearest standard motor available. Where a drive point is situated some considerable distance from the main power source, a long cable may be involved to supply electric power to the drive. In this case, the cable size and cost of transformers may play an important part in the selection of number and size of motors used. With direct on line starting, the peak current the motor will draw is likely to be of the order of 6 x full load current and the combination of running current of a motor or group of motors with the starting current of the last motor to start will have a strong influence on the drive choice.3.2. Method of Low Speed Shaft ConnectionsDrive from the reducer to the belt pulley shaft is either by "flexible" coupling from a drive pack mounted on a foundation next to the structure or by shaft mounted drive unit hanging on the pulley shaft. When shaft mounted, the drive unit can be either hollow shaft, driving through a friction locking element or solid shaft attached by a rigid coupling to the conveyor shaft.Some typical attachments are shown in the sketches. (See appendix A).4.1. Choice of Starting method, drive size and ProtectionDuring start up of conveyor belts, a considerable mass is usually involved which requires acceleration, and to reduce the length of time that the motor draws starting current, a "slip coupling" is fitted between the drive motor and speed reducer. Alternatively,slip ring motors are used to achieve a quick but gentle start up with control of the peak current. On small belts below 10kW direct on line starting directly coupled is quite normal and on belts, say below 100 kW D.O.L. starting with "slip" couplings is most common, and probably the simplest and most cost effective. On larger drives with power at its present continuously increasing cost, slip ring motors may be attractive, due to the prevention of the peak, particularly where maximum demand plays a part in the electricity tariff.There is a multitude of slip couplings on the market for use with D.O.L. start motors, but for larger belts the majority in use are liquid type couplings, either straight traction or traction with delayed fill or controllable fill (scoop type). A fluid coupling will always "slip" a small amount and will help multiple drives to share load, provided the coupling "fill" has been carefully adjusted. As a rule, each coupling has a slightly different characteristic and if adjusted to share load correctly under full load conditions will more than likely not share properly under light load conditions. Motor characteristics also vary a little and can also contribute to poor load sharing on multiple drives. Drive systems commonly go up to 4 motors per belt, but rarely more.4.2. Motor Starting: (D.O.L. with fluid coupling)On multiple drives accepted practice is to start the motor on the secondary drive first and say 3-5 seconds later one of the primary drive motors and then the next primary motor say 5-10 seconds later.In practice, however, the observed starting procedures and delay times vary a great deal. Avery common sight is to see the secondary drive motor running and due to conservative coupling selection, the starting current drops somewhat, but starts rising quickly again due to the delayed fill coupling increasing it's slip torque, while the belt remains stationary. If a primary drive is started at the correct time before the coupling torque has increased too far, the belt is brought into motion much quicker with a lower overall current. The relative slip of the coupling affects it's torque and so the motor current, and the sooner the belt can be moved, the sooner the current peaks will drop.In the case of scoop controlled fluid couplings all motors are started in quick succession and then all couplings filled slowly. A similar procedure is followed with slip ring motors and these two methods are undoubtedly the kindest to the belt, pulley and lagging etc.The choice of scoop type fluid couplings or slip ring motors is likely to lead to the use of smaller motors with safety and possible savings on switch gear maintenance.4.3. Other Drive MethodsWhere a variable conveying rate is required, D.C. drives can be used as well as squirrel cage motors with frequency control. Another method is by hydro-static drive; again idealfor variable speed, but overall running and maintenance costs on big powers are likely tobe higher than a fluid coupling drive, with S.C. motor or slip ring motor.4.4. Belt ProtectionBelt protection against overload and stalling is commonly done by a centrifugal switch driven by a roller on the underside of the belt. This, however, is not very sensitive and more sophisticated methods are now used.One method consists of fitting a pulse generator to the drive gearbox low speed shaft and similar pulse generator to a roller driven by the belt. A monitoring unit compares the pulse frequencies continuously and if they go outside set limits, an alarm is given or the beltstopped. On start up, belt slip can be kept to a minimum by using the monitoring unit to control the start up on slipring motors. The monitoring unit can control the rotor resistance and so the starting torque. Alternatively, the "fill" of a variable fill fluid coupling can be controlled by the comparitor.5. Stopping a Belt Conveyor5.1. Forward stoppingAs a general rule, friction will reduce the normal forward speed of the belt and load and bring it to rest in a relatively short time. The allowable time for stopping depends mainly on the discharge end conditions. Where one belt feeds onto another, tripping conditions, transfer bunker size and belt layout may indicate a need for a belt to be slowed down by other methods than normal friction.On a downhill section of a conveyor discharging onto a level or uphill belt is generally the place where braking is required. If one belt runs on longer than the rest of a system of conveyors, bunkers or transfer chutes can be overloaded and may even be a hazard, but this is generally a very rare condition.Considering a conveyor layout as per sketch (see appendix B) fitted with a brake on the gearbox high speed shaft, it can be seen that when stopped under load the inertia of the load would tend to pick up the gravity tensioner and release the tension in the belt between drive and head pulley and may even go slack by the time the load comes to rest. The load assisted by the gravity take up would then accelerate the belt in the return direction while the drives are stationery with brakes on. When the belt between drive and head pulley becomes tight it has to retard the load in a fraction of the distance in which it had been accelerated. Under this sudden stopping of the load the drive is subjected to heavy shock. In this case, a brake is not only unnecessary, but highly undesirable.A brake fitted on a downhill belt drive would again release tension between drive and headpulley and pick up the take up, but this would tend to release tension on the driving (or stopping) pulleys and allow the belt to slip. This can damage the belt and pulley lagging and can also be dangerous. The proper method of stopping a belt like this is on the tail pulley or other pulley on the return belt after it leaves the take up.Another application where brakes are sometimes used is on belts running through a mobile stacker, to reduce the risk of the belt snagging; should the stacker be moved while the belt is stationary. Here again a brake would be fitted to the tail pulley and a holdback to the drive or head.有关带式输送机驱动装置设计的一些研究J.H. Rall 理工学硕士1,P. Staples 理工学硕士 2(1汉森变速器(控股)有限公司董事;2输送机知识与信息科技(控股)有限公司)摘要:这是一篇关于探讨运送大量颗粒物质动力机构和平板橡胶输送带之间的驱动装置的综述。