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1、离合器外文翻译 Transmission SystemA Basic Parts of the transmission systemThe transmission system applies to the components needed to transfer the drive from the engine to the road wheels The main components and their purposes are 1 Clutch - to disengage the drive - to provide a smooth take-up of the drive
2、 2 Gearbox - to increase the torque applied to the driving road wheels - to enable the engine to operate within a given range of speed irrespective of the vehicle speed - to give reverse motion of the vehicle - to provide a neutral position so that the engine can run without moving the vehicle 3 Fin
3、al drive - to turn the drive through 90 - to reduce the speed of the drive by a set amount to match the engine to the vehicle 4 Differential - to allow the inner driving road wheel to rotate slower than the outer wheel when the vehicle is cornering whilst it ensures that a drive is applied equally t
4、o both wheels B Clutch and Clutch ServiceIn order to transmit the power of the engine to the road wheels of a car a friction clutch and a change-speed gearbox are normally employed The former is necessary in order to enable the drive to be taken up gradually and smoothly while the latter provides di
5、fferent ratios of speed reduction from the engine to the wheels to suit the particular conditions of runningA clutch performs two tasks 1 it disengages the engine from the gearbox to allow for gear changing 2 it is a means for gradually engaging the engine to the driving wheels when a vehicle is to
6、be moved from rest the clutch must engage a stationary gearbox shaft with the engine this must be rotating at a high speed to provide sufficient power or else the load will be too great and the engine will start come to test C Clutch Action To start the engine the driver must depress the clutch peda
7、l This disengages the gearbox from the engine To move the car the driver must reengage the gearbox to the engine However the engagement of the parts must be gradual An engine at idle develops little power If the two parts were connected too quickly the engine would stall The load must be applied gra
8、dually to operate the car smoothlyA driver depresses the clutch pedal to shift the gears inside the gearbox After the driver releases the clutch pedal the clutch must act as solid coupling device It must transmit all engine power to the gearbox without slippingThe clutch mechanism include three basi
9、c parts driving member driven member operating membersThe driving memberThe driving member consists of two parts the flywheel and the pressure plate The flywheel is bolted directly to the engine crankshaft and rotates when the crankshaft turns The pressure plate is bolted to the flywheel The result
10、is that both flywheel and pressure plate rotate togetherThe driven member The driven member or clutch disc is located between the flywheel and pressure plate The disc has a splined hub that locks to the splined input shaft on the gearbox Any rotation of the clutch disc turns the input shaft Likewise
11、 any motion of the input shaft moves the clutch disc The splines allow the clutch disc to move forward and backward on the shaft as it engages and disengagesThe inner part of the clutch disc called the hub flange has a number of small coil springs These springs are called torsional springs They let
12、the middle part of the clutch disc turn slightly on the hub Thus the springs absorb the torsional vibrations of the crankshaft When the springs have compressed completely the clutch moves back until the springs relax In other words the clutch absorbs these engine vibrations preventing the vibrations
13、 from going through the drive trainOperating MembersThese are the parts that release pressure from the clutch disc The operating members consist of the clutch pedal clutch return spring clutch linkage clutch fork and throwout bearing The clutch linkage includes the clutch pedal and a mechanical or h
14、ydraulic system to move the other operating membersWhen the clutch pedal is depressed the clutch linkage operates the clutch fork The clutch fork or release fork moves the throwout bearing against the pressure plate release levers These levers then compress springs that normally hold the clutch disc
15、 tightly against the flywheelAt this point the torque of the engine cannot turn the gearbox input shaft The gears in the gearbox may be shifted or the vehicle can be brought to a full stopWhen the clutch pedal is released the pressure plate forces the clutch disc against the flywheel The clutch retu
16、rn spring helps raise the pedalD Clutch Service The major parts of the clutch assembly need no maintenance or lubrication during normal service However all linkage parts need lubrication at points of contact The linkage itself must be adjusted to prevent wear of the clutch discFree-play AdjustmentYo
17、u can make only one adjustment on the clutch linkage 梩he free-play adjustment Free play is the allowable space between the throwout bearing and the pressure plate release levers This space is important because it prevents pressure on the levers that coduld keep the clutch from engaging fully In othe
18、r words the throwout bearing must be slightly away from the pressure plate levers so that the bearing applies no pressure on the levers On the other hand there must not be too much free play between the bearing and the levers With too much clearance the clutch cannot fully disengaged when the driver
19、 press the clutch pedal to the floor In most cases you measure the free play at the clutch pedal rather than at the bell housingThe free play allows some motion at the beginning of the clutch pedal travel before the pedal meets resistance Since the distance varies with the type of pressure plate che
20、ck the service manual Usually free play should be about 20 to 25mm Free play can be adjusted at some point where the clutch linkage consists of threaded rods with locknuts The rod closest to the clutch fork is the most common adjustment point Begin by locating the rod and locknut beneath the vehicle
21、 Then determine which way to turn the adjustment nuts to get the correct free play at the pedal You can get a rough estimate of free play by moving the clutch fork to see if it still has some movement The best way to make the adjustment is to loosen the locknut and move the adjustment nut a few turn
22、s Then check the free play at the pedal Continue making adjustments until you have the correct free play When the free-play adjustment meets the manufacturers specification tighten the locknut Check the free-play adjustment every six months and make any adjustment Clutches need adjustment that often
23、 since free play decreases slightly as the clutch disc wears However the need for frequent adjustments means a problem in the clutch mechanism itself There must be free play between the throwout bearing and pressure plate release levers Problems can result from riding the clutch A driver who rests o
24、ne foot on the clutch pedal causes the throwout bearing to rub against the clutch release levers As a result the throwout bearing becomes worn quickly Also the clutch disc may wear out due to slippage because the parts are not fully engagedClutch FaultsThe following are the main faultsSlip failure o
25、f the surface to grip resulting in the driven plate revolving slower than the engine flywheel tClutch gets hot and emits an odorSpin or drag failure of the plates to separate resulting in noise from the gearbox when selecting a lgear most noticeable when the vehicle is stationaryJudder a vibration w
26、hich occurs when the clutch is being engaged ie when the vehicle is stationaryeFierceness sudden departure of the vehicle even though the pedal is being released graduallyE The Clutch essupplementary contractA clutch is a friction device used to connect and disconnect a driving force from a driven m
27、ember In automotive applications it is used in conjunction with an engine flywheel to provide smooth engagement and disengagement of the engine and manual transmissionSince an internal combustion engine develops little power or torque at low rpm it must gain speed before it will move the vehicle How
28、ever if a rapidly rotating engine is suddenly connected to the drive line of a stationary vehicle a violent shock will resultSo gradual application of load along with some slowing of engine speed is needed to provide reasonable and comfortable starts In vehicles equipped with a manual transmission t
29、his is accomplished by means of a mechanical clutchThe clutch utilizes friction for its operation The main parts of the clutch are a pressure plate and a driven disk The pressure plate is coupled with the flywheel while the driven disk is fitted to the disk by the springs so that the torque is trans
30、mitted owing to friction forces from the engine to the input shaft of the transmission Smooth engagement is ensured by slipping of the disk before a full pressure is appliedThe automobiles are equipped with a dry spring-loaded clutch The clutch is termed dry because the surfaces of the pressure plat
31、e and driven disks are dry in contrast to oil-bath clutches in which the plate and disks operate in a bath of oil It is called springloaded because the pressure plate and the driven disk are always pressed to each other by springs and are released only for a time to shift gears or to brake the autom
32、obileIn addition to the plate and disk the clutch includes a cover release levers a release yoke pressure springs and a control linkage The clutch cover is a steel stamping bolted to the flywheel The release levers are secured inside the cover on the supporting bolts The outer ends of the release le
33、vers are articulated to the pressure plate Such a construction allows the pressure plate to approach the cover or move away from it all the time rotating with the cover or move away from it all the time rotating with the flywheel The springs spaced around the circumference between the pressure plate
34、 and the clutch cover clamp the driven disk between the pressure plate and the flywheelThe springs are installed with the aid of projections and sockets provided on the cover and pressure plate The pressure plate sockets have thermal-insulation gaskets for protecting the springs against overheatingT
35、he clutch release mechanism can be operated either mechanically or hydraulically The mechanically-operated release mechanism consists of a pedal a return spring a shaft with lever a rod m release yoke lever a release yoke a release ball bearing with support and a clutch release spring When the clutc
36、h pedal is depressed the rod and shaft with yoke shift the release bearing and support assembly The release bearing presses the inner ends of the release levers the pressure plate is moved away from the driven disk and the clutch is disengaged To engage the clutch the pedal is released the release b
37、earing and support assembly is shifted back by the return spring thus releasing the release levers so that the pressure plate is forced by its springs towards the flywheel to clamp the driven disk and engage the clutchThe clutch hydraulically-operated release mechanism consists of a clutch pedal clu
38、tch release spring a main cylinder a pneumatic booster pipelines and hoses and a lever of the clutch release yoke shaft Time main cylinder accommodates a piston with a cup The pneumatic booster serves to decrease the pedal force required disengage the clutch The booster includes two housings with th
39、e servo diaphragm clamped in between The housing accommodates pneumatic hydraulic and servo plungers When the clutch pedal is pushed the fluid pressure from the main cylinder is transmitted through the pipelines and hoses to the hydraulic and servo plungers of the pneumatic boosterThe servo arrangem
40、ent is intended for automatic change of the air pressure in the pneumatic cylinder proportionally to the force applied to the pedal The plunger moves with the diaphragm the outlet valve closes and the inlet valve opens thus admitting the compressed air to the pneumatic plunger piston The forces crea
41、ted by the pneumatic and hydraulic plungers are added together and are applied through the push rod to the release yoke shaft lever the lever turns the shaft and the release yoke thus disengaging the clutch After the clutch pedal is released the outlet valve opens and the air from the cylinder is le
42、t out to the atmosphereAutomatic clutches were used in certain US and European cars American Motors E-Stick clutch eliminated the need for physical operation of the clutch system called Hydrak which consisted of a fluid flywheel connected to a single dry disk clutchIn the E-Stick set up the pressure
43、 plate levers engage the clutch disk rather than release them Also the clutch remains disengaged until a servo unit is applied by oil pressure when the shift lever is placed in gear with the engine runningThe Hydrak unit also begins operation when the lever is in gear This activates a booster unit w
44、hich disengages the clutch disk The hydraulic clutch parts are bridged over by a free-wheel unit which goes into action when the speed of the rear wheel is higher than the speed of the engine A special device controls engagement of the mechanical clutch depending on whether the rear axle is in tract
45、ion or is pushed by car momentumA more-or-les unusual clutch pressure plate set-up is used on late model Chrysler and American Motors cars Called a semi-centrifugal clutch the pressure plate has six cylindrical rollers which move outward under centrifugal force until they contact the cover As engine
46、 speed increases the rollers wedge themselves between the pressure plate and cover so that the faster the clutch rotates the greater the pressure exerted on the pressure plate and disk传动系统A 基本传动系统的组成部份传动系统是将发动机动力转移到驱动轮的结构主要的结构和目的是 1 离合器 - 分离驱动 - 平顺的接合驱动 2 变速器 - 增加提供给驱动轮的转矩 - 使发动机能够在给定的速度范围里面运转而不考虑的车
47、速 - 使车辆的作倒退运动 - 提供一个齿轮的空档以便发动机能不需要移动车辆就运转 3 减速器 - 使驱动转向90 - 减少一定的驱动转速并增大输入转矩 4 差速器 - 当车辆转弯行驶时允许内侧驱动轮比外侧驱动轮慢同时驱动相等地作用于两轮 B 离合器和离合器功用为了要将发动机动力传递到汽车驱动轮通常使用磨擦离合器和变速器的组合前者是为了要逐渐地而且平顺地接合并传递驱动 这是必需的同时后者按不同比率减少两轮转速以适合特殊驾驶情况离合器运行的二个作用 1 它将发动机与变速器分离使其换档 2 它可以解释为逐渐的接合驱动车轮与发动机 离合器必须以高速的转动来产生足够的动力否则会因负荷过大导致发动机熄火
48、 进入静止状态 C 离合器工作原理为了启动发动机驾驶员首先得踩下离合器踏板使发动机与变速器分离 为了使汽车能够行驶驾驶员必须再接合发动机与变速器然而这种接合得是逐渐进行的发动机在不工作状态时只能产生极小的动力如果二个部份连接太快发动机将会熄火同时负荷必须被逐渐地加载才可以平顺地驾驶汽车驾驶员踩下离合器踏板并挂档变速器在驾驶员松开离合器踏板之后离合器成为一个结合装置将所有的发动机力量传递到变速器而不会打滑离合器机构包括三个基本的部份主动部分从动部分操纵机构主动部分主动部分分为两个部份 飞轮和压力盘飞轮直接地被闩在发动机的传动轴上并且随之一起转动压力盘被闩在飞轮端面上与飞轮一起转动从动部分从动部分或离合器盘位于飞轮和压力盘之间离合器盘上有一个花键毂用来扣在变速器上与从动轴连接离合器盘的任何转动都将带动从动轴转动同样地从动轴的任何运动都将传递到离合器盘从动盘在从动轴上的前后移动分离啮合通过滑动花键得以实现离合器盘的内部叫做法兰盘毂有若干的小螺旋弹簧这些弹簧叫做扭力弹簧它们让离合器盘的中央部份在毂上些微地转动因此弹簧吸收传动轴的扭转振
