1附 錄 1Differential and Rear AxlesThe differential is part of the rear-axle-housing assembly, which includes the differential, rear axles, wheels, and bearings. If the car were to be driven in a straight line without having to make turns, then no differential would be necessary. However, when the car rounds a turn, the outer wheel must travel farther than the inner wheel. The differential permits the two rear wheels to rotate different amounts when the car goes around a turn, while still delivering power to both rear wheels.The rear axles are attached to the wheels and have bevel side gears on their inner ends. The differential case is assembled on the left axle but can rotate on a bearing independently of the axle.The differential case supports the differential-pinion gear on a shaft, and this gear meshes with the two bevel gears. The ring gear is attached to the differential case so that the case rotates with the ring gear when the later is driven by the drive pinion.The driving power enters the differential through the drive pinion on the end of the propeller shaft. The drive pinion is meshed with a large ring gear so that the ring gear revolves with the pinion.Attached to the ring gear (through the differential case) is a differential-pinion shaft on which are assembled two differential-pinion gears. Each rear car wheel has a separate axle, and there are two side gears splined to the inner ends of the two wheel axles. The two differential-pinion gears mesh with these two side gears. When the car is on a straight road, the two differential-pinion gears do not rotate on the pinion shaft, but they do exert pressure on the two side gears so that the side gears turn at the same speed as the ring gear, causing both rear wheels to turn at the same speed, also.The differential case is supported in the carrier by two tapered-roller side bearings. This assembly can be adjusted from side to side to provide the proper backlash between the ring gear and pinion and the required side bearing preload. This adjustment is achieved by threaded bearing adjusters on some units and the placement of selective shims and spacers on others.The differential case is supported in the carrier by two tapered-roller side bearings. This assembly can be adjusted from side to side to provide the proper backlash between the ring gear and pinion and the required side bearing preload. This adjustment is achieved by threaded bearing adjusters on some units and the placement of selective shims and spacers on others.2Transaxle final drive gears provide the means for transmitting transmission output torque to the differential section of the transaxle. The differential section of the transaxle has the same components as the differential gears in a RWD axle and basically operate in the same way. The power flow in transversely mounted power trains is in line with the wheels and therefore the differential unit does not need to turn the power 90 degrees.When the car rounds a curve, the outer wheel must turn faster than the inner wheel. To permit this, the two pinion gears rotate on their pinion shaft, transmitting more turning movement to the outer side gear than to the inner side gear. Thus, the side gear on the outer-wheel axle turns more rapidly than the side gear on the inner-wheel axle. This permits the outer wheel to turn more rapidly while the car is rounding the curve.There are two basic types of axle: dead axles and live axle. The dead axle does not rotate; the wheel rotates on it. A common example is the axle on a horse- drawn wagon. Live axles are attached to the wheel so that both the wheel and the axle rotate together. Live axles are classified according to the manner in which they are supported: semi-floating, three-quarter-floating, and full-floating.Propeller Shaft and Universal JointThe propeller shaft is a drive shaft to carry the power from the transmission to the rear-wheel axles. It connects the transmission main, shaft carries through the propeller shaft to the differential at the rear axles. Rotary motion of the transmission main shaft carries through the propeller shaft to the differential, causing the rear wheels to rotate.The propeller-shaft design must take two facts into consideration. First, the engine and transmission are more or less rigidly attached to the car frame. Second, the rear-axle housing (with wheels and differential) is attached to the frame by springs. As the rear wheels encounter irregularities in the road, the springs compress or expand. This changes the angle of drive and the distance between the transmission and the differential, and the propeller shaft may take care of these two changes. That is to say, as the rear axle housing, with differential and wheels, moves up and down, the angel between the transmission output shaft changes. The reason the propeller shaft shortens as the angel increases is that the rear axle and differential move in a shorter arc than the propeller shaft. The center point of the axle-housing arc is the rear-spring or control-arm attachment to the frame. In order that the propeller shaft may take care of these two changes, it must incorporate two separate types of device. There must be one or more universal joints to permit variations in the angel of drive. There must also be a slip joint that permits the effective length of the propeller shaft to change.3The propeller shaft may be solid or hollow, protected by an outer tube or exposed. Some applications include bearings at or near the propeller shaft center to support the shaft. The two-section propeller is supported by a center bearing and coupled together by universal joints. A universal joint is essentially a double- hinged joint consisting of two Y-shaped yokes, one on the driving shaft and the other on the driven shaft, and across-shaped member called the spider. The four arms of the spider, known as trunnions, are assembled into bearings in the ends of the two shaft yokes. The driving shaft causes the spider to rotate, and the other two trunnions of the spider cause the driven shaft to rotate. When the two shafts are at an angel to each other, the bearings in the yokes permit the yokes to swing around on the trunnions with each revolution. A variety of universal joints have been used on auto mobiles, but the types now in most common use are the spider and two-yoke, the constant-velocity, and the ball-and-trunnion joints.A slip joint consists of outside splines on one shaft and matching internal splines in the mating hollow shaft, the splines cause the two shafts to rotate together but permit the two to move endwise with each other. This accommodates any effective change of length of the propeller shaft as the rear axles move toward or away from the car frame.4差速器和后車軸差速器是后車軸體系的一部分，此體系包括差速器，后車軸，輪子和軸承。如果直線行車而不轉(zhuǎn)彎，則不需要差速器。然而，車轉(zhuǎn)彎時，外面輪子的速度必須比里面的輪子快。差速器保證車轉(zhuǎn)彎時外面輪子的旋轉(zhuǎn)比里面輪子快，同時給兩個后車輪提供動力。后車軸和輪子相連，并且在內(nèi)部的終端有傾斜齒輪。差速器在左車軸，但是能在車軸的軸承上獨立旋轉(zhuǎn)。差速器能使差速副齒輪作用于一個柄上，齒輪和兩個斜齒輪互相咬合。環(huán)行齒輪和差速裝置相連，從而使這個裝置在副齒輪旋轉(zhuǎn)時和環(huán)行齒輪一起旋轉(zhuǎn)。通過驅(qū)動力作用于副齒輪的柄上，驅(qū)動力進入差速器。驅(qū)動副齒輪和大的環(huán)行齒輪互相咬合，從而使環(huán)行齒輪和副齒輪一起旋轉(zhuǎn)。環(huán)行齒輪上（穿過差速裝置）是一個差速副齒輪柄，柄上是兩個差速副齒輪。每個后車輪上各有一個車軸，兩個車輪的內(nèi)側(cè)邊緣都有兩個齒輪夾板。這兩個差速副齒輪和兩個邊緣齒輪互相咬合。當車在公路上直線行駛時，兩個差速副齒輪不在副齒輪柄上旋轉(zhuǎn)，但是它們施力于兩個邊緣齒輪，從而使邊緣齒輪和環(huán)行齒輪速度相當，使兩個后車輪在轉(zhuǎn)彎時速度相同。差速裝置由兩個滾動的副軸承支持。這個裝置可以從一邊到另一邊進行調(diào)節(jié)用以在環(huán)行齒輪，副齒輪和副軸承之間提供反撞。通過螺絲軸承的調(diào)節(jié)和每一邊墊片的代替，這種調(diào)節(jié)得以實現(xiàn)。橫軸最后讓齒輪提供傳輸，傳輸使轉(zhuǎn)矩和傳輸車軸的差速部分相連。傳輸車軸的差速部分和 RWD 車軸的差速齒輪有相同的組成部分，基本上以相同的方式運轉(zhuǎn)。這種力使火車和輪子在同一直線上，因此差速部分不需要以 90 度角轉(zhuǎn)彎。當車曲線行駛時，外輪要比內(nèi)輪轉(zhuǎn)得快。為了保證這一點，兩個副齒輪在其柄上旋轉(zhuǎn)，向外輪提供比內(nèi)輪更多的動力。但是，外輪車軸的邊緣齒輪比內(nèi)輪邊緣齒輪轉(zhuǎn)得快。這就保證了車轉(zhuǎn)彎時外輪比內(nèi)輪轉(zhuǎn)得快。車軸有兩種基本類型：固定車軸和活動車軸。固定車軸不能旋轉(zhuǎn)；輪子在上面旋轉(zhuǎn)。以馬車為例。活動車軸和輪子在一起，從而使兩個輪子和車軸一起旋轉(zhuǎn)?；顒榆囕S根據(jù)他們支持的方式分類；半活動，四分之三活動和全活動。推進器柄和聯(lián)軸節(jié)推進器柄是一種驅(qū)動柄，能使力傳輸?shù)胶筝嗆囕S。它連接傳輸主柄，通過推進器柄帶動到后車軸的差速裝置。主柄的傳輸旋轉(zhuǎn)通過推進器柄到差速裝置，使后車輪旋轉(zhuǎn)。推進器的設(shè)計必須將以下兩個因素考慮在內(nèi)。首先，發(fā)動機和傳輸裝置的堅硬度要和車框差不多。其次，后車軸裝置（包括車輪和差速裝置）通過發(fā)條連接5到車框。當后車輪在公路上違規(guī)，發(fā)條擠壓或膨脹。這就改變了驅(qū)動以傳輸和差速裝置之間的距離，并且推進器柄會照應這兩種變化。這就是說，后車軸裝置，差速裝置和輪子，上下移動，傳輸柄之間改變。推進器柄縮短的原因是后車軸和差速移動的弧比推進器柄的小。車軸裝置弧的中心點是連接到框架后發(fā)條或控制臂。為了使推進器柄適應這兩個變化，必須有兩個獨立的裝置。這必須有一個或更多的聯(lián)軸節(jié)以保證裝置的多樣化。必須有一個滑動節(jié)保證推進器柄改變長度時的效率。推進器柄可以是實的也可以是空的，由一個管子維持著。一些施用包括推進器中心或附近那些支持柄的軸承。這個兩部分推進器由中心軸承和聯(lián)軸節(jié)一起支持。在雙鉸鏈中聯(lián)軸節(jié)是必不可少的，它包含兩個 Y 型軛，一個在驅(qū)動柄上，另一個在被驅(qū)動柄上，還有個十字形裝置叫星形輪。星形輪的四臂叫耳軸，集中在兩個柄軛的終端。驅(qū)動柄使星形輪旋轉(zhuǎn)，星形輪上的另兩個耳軸使驅(qū)動柄轉(zhuǎn)動。當兩個柄互相疊壓時，軛的軸承保證軛在每個耳軸上旋轉(zhuǎn)。多種聯(lián)軸節(jié)已經(jīng)用于汽車中，但是通用的種類只有星形輪和雙軛輪，速效輪，和球耳軸聯(lián)節(jié)?；瑒勇?lián)節(jié)包括一個柄上的外部板條和一個空心柄上的內(nèi)部板條，它使兩個柄一起旋轉(zhuǎn)，并向前移動。這使后車輪向前移動時，推進器柄的長度發(fā)生改變。