车辆工程外文翻译--差速器和后车轴.docx

附 录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.transaxle 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.the 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.差速器和后车轴差速器是后车轴体系的一部分，此体系包括差速器，后车轴，轮子和轴承。如果直线行车而不转弯，则不需要差速器。然而，车转弯时，外面轮子的速度必须比里面的轮子快。差速器保证车转弯时外面轮子的旋转比里面轮子快，同时给两个后车轮提供动力。后车轴和轮子相连，并且在内部的终端有倾斜齿轮。差速器在左车轴，但是能在车轴的轴承上独立旋转。差速器能使差速副齿轮作用于一个柄上，齿轮和两个斜齿轮互相咬合。环行齿轮和差速装置相连，从而使这个装置在副齿轮旋转时和环行齿轮一起旋转。通过驱动力作用于副齿轮的柄上，驱动力进入差速器。驱动副齿轮和大的环行齿轮互相咬合，从而使环行齿轮和副齿轮一起旋转。环行齿轮上（穿过差速装置）是一个差速副齿轮柄，柄上是两个差速副齿轮。每个后车轮上各有一个车轴，两个车轮的内侧边缘都有两个齿轮夹板。这两个差速副齿轮和两个边缘齿轮互相咬合。当车在公路上直线行驶时，两个差速副齿轮不在副齿轮柄上旋转，但是它们施力于两个边缘齿轮，从而使边缘齿轮和环行齿轮速度相当，使两个后车轮在转弯时速度相同。差速装置由两个滚动的副轴承支持。这个装置可以从一边到另一边进行调节用以在环行齿轮，副齿轮和副轴承之间提供反撞。通过螺丝轴承的调节和每一边垫片的代替，这种调节得以实现。横轴最后让齿轮提供传输，传输使转矩和传输车轴的差速部分相连。传输车轴的差速部分和rwd车轴的差速齿轮有相同的组成部分，基本上以相同的方式运转。这种力使火车和轮子在同一直线上，因此差速部分不需要以90度角转弯。当车曲线行驶时，外轮要比内轮转得快。为了保证这一点，两个副齿轮在其柄上旋转，