1、 Fig 1 Drive axle Rear-wheel driveRear-wheel-drive vehicles are mostly trucks, very large sedans and many sports car and coupe models. The typical rear wheel drive vehicle uses a front mounted engine and transmission assemblies with a driveshaft coupling the transmission to the rear drive axle. Driv
2、e in through the layout of the bridge, the bridge drive shaft arranged vertically in the same vertical plane, and not the drive axle shaft, respectively, in their own sub-actuator with a direct connection, but the actuator is located at the front or the back of the adjacent shaft of the two bridges
3、is arranged in series. Vehicle before and after the two ends of the driving force of the drive axle, is the sub-actuator and the transmission through the middle of the bridge. The advantage is not only a reduction of the number of drive shaft, and raise the driving axle of the common parts of each o
4、ther, and to simplify the structure, reduces the volume and quality.Fig 2 Rear-wheel-drive axleSome vehicles do not follow this typical example. Such as the older Porsche or Volkswagen vehicles which were rear engine, rear drive. These vehicles use a rear mounted transaxle with halfshafts connected
5、to the drive wheels. Also, some vehicles were produced with a front engine, rear transaxle setup with a driveshaft connecting the engine to the transaxle, and halfshafts linking the transaxle to the drive wheels.Differential operationIn order to remove the wheel around in the kinematics due to the l
6、ack of co-ordination about the wheel diameter arising from a different or the same rolling radius of wheel travel required, inter-wheel motor vehicles are equipped with about differential, the latter to ensure that the car driver Bridge on both sides of the wheel when in range with a trip to the cha
7、racteristics of rotating at different speeds to meet the requirements of the vehicle kinematics.Fig 3 Principle of differentialThe accompanying illustration has been provided to help understand how this occurs. 1.The drive pinion, which is turned by the driveshaft, turns the ring gear.2.The ring gea
8、r, which is attached to the differential case, turns the case.3.The pinion shaft, located in a bore in the differential case, is at right angles to the axle shafts and turns with the case.4.The differential pinion (drive) gears are mounted on the pinion shaft and rotate with the shaft .5.Differentia
9、l side gears (driven gears) are meshed with the pinion gears and turn with the differential housing and ring gear as a unit.6.The side gears are splined to the inner ends of the axle shafts and rotate the shafts as the housing turns.7.When both wheels have equal traction, the pinion gears do not rot
10、ate on the pinion shaft, since the input force of the pinion gears is divided equally between the two side gears.8.When it is necessary to turn a corner, the differential gearing becomes effective and allows the axle shafts to rotate at different speeds .Open-wheel differential on each general use t
11、he same amount of torque. To determine the size of the wheel torque to bear two factors: equipment and friction. In dry conditions, when a lot of friction, the wheel bearing torque by engine size and gear restrictions are hours in the friction (such as driving on ice), is restricted to a maximum tor
12、que, so that vehicles will not spin round. So even if the car can produce more torque, but also need to have sufficient traction to transfer torque to the ground. If you increase the throttle after the wheels slip, it will only make the wheels spin faster.Fig 4 Conventional differentialLimited-slip
13、and locking differential operation Fig 5 Limited-slip differentialDifferential settlement of a car in the uneven road surface and steering wheel-driven speed at about the different requirements; but is followed by the existence of differential in the side car wheel skid can not be effective when the
14、 power transmission, that is, the wheel slip can not produce the driving force, rather than spin the wheel and does not have enough torque. Good non-slip differential settlement of the car wheels skid on the side of the power transmission when the issue, that is, locking differential, so that no lon
15、ger serve a useful differential right and left sides of the wheel can be the same torque.Limited-slip and locking differential operation can be divided into two major categories:(1) mandatory locking type in ordinary differential locking enforcement agencies to increase, when the side of the wheel s
16、kid occurs, the driver can be electric, pneumatic or mechanical means to manipulate the locking body meshing sets of DIP Shell will be with the axle differential lock into one, thus the temporary loss of differential role. Relatively simple structure in this way, but it must be operated by the drive
17、r, and good roads to stop locking and restore the role of differential. (2) self-locking differential installed in the oil viscosity or friction clutch coupling, when the side of the wheel skid occurs when both sides of the axle speed difference there, coupling or clutch friction resistance on the a
18、utomatic, to make certain the other side of the wheel drive torque and the car continued to travel. When there is no speed difference on both sides of the wheel, the frictional resistance disappeared, the role of automatic restoration of differentials. More complicated structure in this way, but do
19、not require drivers to operate. Has been increasingly applied in the car. About non-slip differential, not only used for the differential between the wheels, but also for all-wheel drive vehicle inter-axle differential/.Gear ratio The drive axle of a vehicle is said to have a certain axle ratio. Thi
20、s number (usually a whole number and a decimal fraction) is actually a comparison of the number of gear teeth on the ring gear and the pinion gear. For example, a 4.11 rear means that theoretically, there are 4.11 teeth on the ring gear for each tooth on the pinion gear or, put another way, the driv
21、eshaft must turn 4.11 times to turn the wheels once. The role of the final drive is to reduce the speed from the drive shaft, thereby increasing the torque. Lord of the reduction ratio reducer, a driving force for car performance and fuel economy have a greater impact. In general, the more reduction
22、 ratio the greater the acceleration and climbing ability, and relatively poor fuel economy. However, if it is too large, it can not play the full power of the engine to achieve the proper speed. The main reduction ratio is more Smaller ,the speed is higher, fuel economy is better, but the accelerati
23、on and climbing ability will be poor. 翻译:驱动桥和差速器所有的汽车都装有不同类型的驱动桥和差速器来驱动汽车行驶。无论是前驱汽车,后驱汽车还是四轮驱动的汽车,对于将发动机的动力转化到车轮上差速器都是不可缺少的部件。动力的传递驱动桥必须把发动机的动力转一个直角后传递出去,但人对于前轮驱动汽车发动机输出的转矩与主减速器是在同一直线上的,但是发动机前置的后轮驱动的汽车发动机的动力必须以正确的角度传递出去,来驱动车轮。图中所示是齿轮驱动的过程,即由一个相对小的齿轮驱动一个大齿轮(主动齿轮和从动齿轮),从动锥齿轮和差速器壳连接在一起,在半轴的根部有一对带有内花键的半
24、轴齿轮,半轴齿轮和半轴通过花键来连接在一起。当差速器壳旋转时,就驱动内部的半齿轮转动从而使半轴转动,将转矩传给车轮。后驱动桥后轮驱动的车辆大多是卡车,大型轿车和大部分跑车。典型的后轮驱动的车辆使用前置发动机和变速箱总成将转矩传输到后轮驱动桥。多驱动桥汽车中,在贯通式驱动桥的布置中,各桥的传动轴布置在同一纵向铅垂平面内,并且各驱动桥不是分别用自己的传动轴与分动器直接联接,而是位于分动器前面的或后面的各相邻两桥的传动轴,是串联布置的。汽车前后两端的驱动桥的动力,是经分动器并贯通中间桥而传递的。其优点是,不仅减少了传动轴的数量,而且提高了各驱动桥零件的相互通用性,并且简化了结构、减小了体积和质量。一
25、些车辆不是这个典型的例子。如老式的保时捷或大众汽车引擎在汽车后面,是后轮驱动。这些车辆使用的后方安装驱动桥与半轴来驱动车轮。另外,一些车辆是前置引擎,后桥与传动轴连接发动机来驱动车轮。差速器为了消除由于左右车轮在运动学上的不协调而产生左右车轮外径不同或滚动半径不相等而要求车轮行程,汽车左右驱动轮间都装有差速器,后者保证了汽车驱动桥两侧车轮在行程不等时具有以不同速度旋转的特性,从而满足了汽车行驶运动学要求。如图所示说明了其工作情况1. 主动齿轮转动,从而驱动从动齿轮。2. 从动齿轮将转矩作用于差速器壳,使其转动。3. 位于差速器壳中的行星齿轮以适当的角度和半轴齿轮接触,并随的差速器壳转动。4.
26、行星齿轮(驱动齿轮)和十字轴连接,和十字轴一起转动。5. 半轴齿轮(被驱动齿轮)和行星齿轮啮合并且和从动齿轮及差速器壳作为一个整体一起转动。6. 半轴齿轮的内花键和半轴端部饿花键接在一起随着差速壳一起转动。7. 当两侧车轮转速相同时,行星齿轮和半轴齿轮无相对运动,左右齿轮力矩平均分配。8. 当汽车转弯时差速器开始起作用,是两侧的半轴以不同的转速旋转。开式差速器对每个车轮一般使用相同量的扭矩。确定车轮承受的扭矩大小的因素有两个:设备和摩擦力。在干燥的条件下,当摩擦力很大时,车轮承受的扭矩大小受发动机和挡位的限制,在摩擦力很小时(如在冰上行驶),限制为最大扭矩,从而使车轮不会打滑。所以,即使汽车可
27、以产生较大扭矩,也需要足够的牵引力将扭矩传输到地面。如果在车轮打滑之后加大油门,只会使车轮更快地旋转。 如果曾在冰上驾驶过,您可能知道加速的窍门:如果启动时挂在二挡或三挡而不是一挡,则由于变速器中的齿轮传动,车轮的扭矩会较小。这样更容易在不旋转车轮的情况下加速。如果其中一个驱动轮具有很好的摩擦力,而另一个却在冰上时,这是开式差速器存在的问题。防滑差速器差速器很好的解决了汽车在不平路面及转向时左右驱动车轮转速不同的要求;但随之而来的是差速器的存在使得汽车在一侧驱动轮打滑时动力无法有效传输,也就是打滑的车轮不能产生驱动力,而不打滑的车轮又没有得到足够的扭矩。防滑差速器很好的解决了汽车在一侧车轮打滑
28、时出现的动力传输的问题,也就是锁止差速器,让差速器不再起作用,左右两侧的驱动轮均可得到相同的扭矩。防滑差速器主要可分为两大类:(1)强制锁止式在普通差速器上增加强制锁止机构,当发生一侧车轮打滑时,驾驶员可通过电动、气动或机械的方式来操纵锁止机构,拨动啮合套将差速器壳与半轴锁成一体,从而暂时失去差速的作用。这种方式结构比较简单,但必须由驾驶员进行操作,并在良好路面上停止锁止,恢复差速器的作用。(2)自锁式在差速器中安装粘性硅油联轴节或摩擦离合器,当发生一侧车轮打滑时,两侧半轴出现转速差,联轴节或离合器就自动发生摩擦阻力,使另一侧车轮得到一定的扭矩而驱动汽车继续行驶。当两侧车轮没有转速差时,摩擦阻
29、力消失,自动恢复差速器的作用。这种方式结构比较复杂,但不需要驾驶员进行操作。目前已越来越多地在汽车上得到应用。 防滑差速器不仅用于左右车轮间的差速器,也用于全轮驱动汽车的轴间差速器中。主减速比驱动桥都有一定得主减速比,这个数字(通常是一个整数和一个小数)实际上是主减速器主动齿轮与从动齿轮的关系。例如,如果主减速比为4.11则说明从动齿轮的齿数是主动齿轮齿数的4.11倍,换句话说就是主动齿轮轴转动4圈车轮才转动1圈。主减速器的作用是降低从传动轴传来的转速,从而增大扭矩。主减速器的减速比,对汽车的动力性能和燃料经济性有较大的影响。一般来说,主减速比越大,加速性能和爬坡能力较强,而燃料经济性比较差。但如果过大,则不能发挥发动机的全部功率而达到应有的车速。主减速比越小,燃料经济性较好,但加速性和爬坡能力较差。谢谢下载,祝您生活愉快!
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