【正文】 heels . These parts include the clutch , the transmission ,the drive shaft ,and the final drive assembly . The clutch which includes the flywheel ,clutch disc , pressure plate , springs , pressure plate cover and the linkage necessary to operate the clutch is a rotating mechanism between the engine and the transmission . It operates through friction which es from contact between the parts . That is the reason why the clutch is called a friction mechanism . After engagement, the clutch must continue to transmit all engine torque to transmission depending on the friction without slippage . The clutch is also used to disengage the engine from the drive train whenever the gears in the transmission are being shifted from gear ratio to another . To start the engine or shift the gears , the driver has to depress the clutch pedal with the purpose of disengagement the transmission from the engine . At that time , the driven members connected to the transmission input shaft are either stationary or rotating at a speed that is slower of faster than the driving members connected to engine crankshaft . There is no spring pressure on the clutch assembly parts . So there is no friction between the driving members and driven members . As the driver lets loose the clutch pedal , spring pressure increase on the clutch parts . Friction between the parts also increases . The pressure exerted by the springs on the driven members is controlled by the driver through the clutch pedal and linkage. The positive engagement of the driving and driven members is made possible the friction between the surfaces of the members . When full spring pressure is applied , the speed of the driving and driven members should be the same . At the moment , the clutch must act as a coupling device and transmit all engine power to the transmission , without slipping . However , the transmission should be engaged to the engine gradually in order to operate the car smoothly and minimize torsional shock on the drive train because an engine at idle just develop little power . Otherwise , the driving members are connected with the driven members too quickly and the engine would be stalled . The flywheel is a major part of the clutch . The flywheel mounts to the engine crankshaft and transmits engine torque to the clutch assembly . The flywheel , when coupled with the clutch disc and pressure plate makes and breaks the flow of power the engine to the transmission . The flywheel provides a mounting location for the clutch assembly as well . When the clutch is applied , the flywheel transfers engine torque to the clutch disc . Because of its weight , the flywheel helps to smooth engine operation . The flywheel also has a large ring gear at its outer edge , which engages with a pinion gear on the starter motor during engine cranking . The clutch disc fits between the flywheel and the pressure plate . The clutch disc has a splined hub that fits over splines on the transmission input shaft . A splined hub has grooves that match splines on the shaft . These splines fit in the grooves . Thus , the two parts held together . However , back 168。C hence the differential is sometimes called a torque equalizer .4 Brake System The breaking system is the most important system in cars . If the brakes fail , the result can be disastrous . Brakes are actually energy conversion devices , which convert the kinetic energy ( momentum ) of the vehicle into thermal ( heat ) . When stepping on the brakes , the driver mands a stopping force ten times as powerful as the force that puts the car in motion . The braking system can exert thousands of pounds of pressure on each of the four brakes . The brake system is posed of the following basic ponents : the master cylinder161。177。這就是為什么將離合器稱之為摩擦機制。主動元件與從動元件機密結(jié)合就有可能在元件表面產(chǎn)生摩擦力。離合器工作時，飛輪將發(fā)動機扭矩傳給離合器盤。汽車離合器壓盤通常是由鐵鑄造而成，圓形外觀 ，其直徑大約與離合器盤相同。轉(zhuǎn)動杠桿使之一端與驅(qū)動器相連，擠壓彈簧使另一端與壓盤背面相連，這樣就可以釋放從動盤的壓力，切斷發(fā)動機上的變速器。隔膜式壓盤總成的優(yōu)越性在于，緊湊性，低重量，運動部件少，連接少，通過壓盤周圍提供的一平衡力和減少離合器打滑可能性來減少旋轉(zhuǎn)不平衡性。貝爾涵蓋固定在其底部。驅(qū)動軸將變速器連接到最終驅(qū)動——位于后軸向后輪傳遞動力。新的科威特轎車使用了這一系統(tǒng)。這段時間內(nèi)，每個驅(qū)動用來維持各自的駕駛都是合乎情理的。剎車失敗會帶來災(zāi)難性的后果。典型的制動系統(tǒng)由前面的磁盤制動器和后面的磁盤或鼓式制動器組成。這就是每個輪子上都有螺絲鉗和卡尺的目的所在。制動液煮至沸騰會造成海綿踏板情況，車就很難停下來。膠管僅僅用在那些靈活運轉(zhuǎn)的地方，如前輪，方向盤的上下移動。方向盤軸在方向盤頂部，轉(zhuǎn)向檔下部另一軸與臂桿相連。因此，轉(zhuǎn)向節(jié)、主軸、車輪和輪胎轉(zhuǎn)到一邊，使車子轉(zhuǎn)彎。因此前輪必須朝著正確的方向移動，從而使汽車沿著馬路向前行駛。在該系統(tǒng)中，每個輪子單獨安置于框架上并各自擁有彈簧和減震器。重型商用車使用的梁軸，其兩端軸都安有主連接，這種連接點使得車輪轉(zhuǎn)變方向。車輪和輪胎安裝在轉(zhuǎn)向節(jié)上，如圖所示，轉(zhuǎn)向節(jié)在頂部和底部轉(zhuǎn)動。如果需要修補鋼線，最好是代替完整的鋼線。如今大多數(shù)汽車都有一透明水庫，不用開蓋就可以看到里面的情況。巖釘向內(nèi)旋轉(zhuǎn)擠壓輪上依附的剎車墊，使之減慢或停下來。實際上，踩剎車踏板時，柱塞推擠主缸，液壓油（制動液）通過一系列的管子和軟管流至每個輪子的剎車元件。司機剎車時產(chǎn)生的制動力是汽車運行時動力的10倍。如果將此元件視為由一杠桿