Chapter 5 Drive axle(3.4-3.8)

1、Chapter 3 power trainReview 1: Whats the function of drive shaft and UJ? To transmit the drive from the transmission mainshaft to the final drive pinion;To have some allowance for motion between the final drive and transmission. Chapter 3 power train1) The suspension connects the final drive assembl

2、y to the car body. The final drive moves up and down in relation to the engine and transmission. A coupling is needed that permits movement between the final drive and transmission. The universal joints (U-joints) and sliding joints Fig.3-8 provide this coupling. 悬架连接着主减速器总成和车身。主减速器相对于悬架连接着主减速器总成和车身

3、。主减速器相对于发动机和变速器上下运动，这样在主减速器和变速发动机和变速器上下运动，这样在主减速器和变速器之间就需要万向节和滑动联轴节等连接装置来允器之间就需要万向节和滑动联轴节等连接装置来允许其相对运动。许其相对运动。Chapter 3 power trainReview 2: List the types of UJ (Universal joints). Non-constant Velocity Universal JointConstant Velocity Universal JointNear-constant Velocity Universal JointChapter 3

4、power trainCardan (Hookes) Universal Joint （十字轴式万向节）（十字轴式万向节）Double Cardan Universal Joint （双联式万向节）（双联式万向节）Rzeppa Universal Joint （球笼式万向节）（球笼式万向节）Tripod Universal Joint （三销轴式万向节）（三销轴式万向节）Weiss Universal Joint （球叉式万向节）（球叉式万向节）Flexible Universal Joint （挠性万向节）（挠性万向节）Chapter 3 power train2) Here two U-s

5、haped pieces are placed perpendicular to one another and joined with a simple cross Fig. 3-16. The U-shaped pieces are called yokes. The cross that connects them is called a spider. The arms that extend from the spider are called trunnions. The two yokes are at a 90 angle to one another. Most cars h

6、ave two universal joints, one at each end of the propeller shaft. 两个两个U形片垂直布置，通过十字叉连接在一起。形片垂直布置，通过十字叉连接在一起。U形形片称为万向节叉，连接万向节叉的十字叉叫作十字片称为万向节叉，连接万向节叉的十字叉叫作十字轴，从十字轴延伸出的臂叫作耳轴，两个万向节叉轴，从十字轴延伸出的臂叫作耳轴，两个万向节叉成成90布置。多数汽车采用两个万向节，在传动轴布置。多数汽车采用两个万向节，在传动轴的每一端各有一个万向节。的每一端各有一个万向节。Chapter 3 power train3) A shaft whic

7、h receives the drive from a cross type joint varies its speed during rotation; the greater the drive angle the greater the speed variation. A constant rotational speed can be restored by fitting a second joint in a way such that when the first joint increases its speed the second joint decreases its

8、 speed. 传动轴接收十字轴式万向节传来的动力，转动时其速传动轴接收十字轴式万向节传来的动力，转动时其速度发生变化。传动角越大，速度变化越大。要实现等度发生变化。传动角越大，速度变化越大。要实现等速，必须以某种方式安装第二个万向节，这样第一个速，必须以某种方式安装第二个万向节，这样第一个万向节使转速增大，第二个万向节就使转速减少。万向节使转速增大，第二个万向节就使转速减少。Chapter 3 power trainReview 3: List the main parts of driving axle. Chapter 3 power trainReview 3: Whats the f

9、unction of Final Drive? To reduce the speed of rotation To redirect the line of driveChapter 3 power trainSingle( reduction) final drive(单级主减速器单级主减速器)Drive pinionCrown gear( ring gear)主动轮主动轮从动轮从动轮Chapter 3 power trainReview 4: List the Gear Types of final drive. Spur Gear（直齿圆柱齿轮）（直齿圆柱齿轮）Helical Gear

10、（斜齿圆柱齿轮）（斜齿圆柱齿轮）Chapter 3 power trainBevel GearBevel Gear（直齿圆锥齿轮）（直齿圆锥齿轮）Spiral/Hypoid BevelSpiral/Hypoid Bevel GearGear（斜齿（斜齿/ /双曲面圆锥齿轮）双曲面圆锥齿轮）Chapter 3 power trainWorm GearWorm Gear（蜗轮蜗杆）（蜗轮蜗杆）Chapter 3 power train4) The hypoid gear is in common use today due mainly to the fact that the offset pi

11、nion allows the propeller shaft to be set below (for cars) , or above (for commercial vehicles) , the crown wheel center. This gives either a reduction in the propeller shaft tunnel, which causes a bump in the vehicle floor, or in the case of a commercial vehicle a reduction in the angle through whi

12、ch the universal joint has to operate. 现在的主减速器普遍使用准双曲面齿轮，这主要是因为主动现在的主减速器普遍使用准双曲面齿轮，这主要是因为主动锥齿轮的偏移允许轿车上传动轴布置得比从动锥齿轮低一些锥齿轮的偏移允许轿车上传动轴布置得比从动锥齿轮低一些，而商用车上又允许传动轴布置得比从动锥齿轮高一些。这，而商用车上又允许传动轴布置得比从动锥齿轮高一些。这就使得就使得轿车上轿车上传动轴通道传动轴通道(它会导致汽车车身地板形成凸起它会导致汽车车身地板形成凸起)位置降低，或者使得商用车上万向节工作角度减小。位置降低，或者使得商用车上万向节工作角度减小。Chapter

13、 3 power trainReview 5: List the types of Final Drive. Single reduction final driveDouble reduction final driveChapter 3 power train Thru-final Drivepenetrable final drive （贯通式主减速器）（贯通式主减速器）Two Speed double reduction Final Drive （双速主减速器）（双速主减速器）Chapter 3 power train Planetary Wheel Reductor （行星齿轮式轮边

14、减速器）（行星齿轮式轮边减速器）Chapter 3 power trainWheel (Hub) Reductor （轮边减速器）（轮边减速器） Spur Geared Wheel Reductor （圆柱齿轮式轮边减速器）（圆柱齿轮式轮边减速器）Chapter 3 power train5) Large crown wheels reduce the ground clearance under the differential. In the case of pinion axles and planetary-hub reduction axles, the differential a

15、nd the half-shafts can be made smaller by splitting the reduction. This makes it possible, even in the case of high power outputs, to achieve sufficient ground clearance of the vehicle.从动锥齿轮尺寸大，就降低了汽车的离地间隙。如果采从动锥齿轮尺寸大，就降低了汽车的离地间隙。如果采用行星齿轮式轮边减速器，通过分级减速的形式可极大用行星齿轮式轮边减速器，通过分级减速的形式可极大减小差速器和半轴的尺寸。这样，汽车即使

16、要求大功率减小差速器和半轴的尺寸。这样，汽车即使要求大功率输出也可以获得足够大的离地间隙。输出也可以获得足够大的离地间隙。Chapter 3 power train6)(选讲选讲)Planetary gears are used mainly in final drives, rear-mounted splitter boxes and, above all, in automatic transmissions. The simplest form of planetary gear (the planetary-gear train) consists of sun gear, ring

17、 gear and arm with planet gears. Each of the three elements may act as drive, output or may be at rest. Therefore, great variation is possible as regards the transmission ratio, ranging as far as a reversal of the direction of rotation. The parallel meshing of several gears under load permits a comp

18、act construction.行星齿轮系主要应用在主减速器、后置副变速器和自动变速器上行星齿轮系主要应用在主减速器、后置副变速器和自动变速器上。最简单的行星齿轮系统由太阳轮、齿圈、行星轮臂组成。三部。最简单的行星齿轮系统由太阳轮、齿圈、行星轮臂组成。三部件中任意一个都可作输入、输出或保持静止。这样，依照变速比件中任意一个都可作输入、输出或保持静止。这样，依照变速比的不同可得到较大的变速范围，汽车的倒行也能实现。承载齿轮的不同可得到较大的变速范围，汽车的倒行也能实现。承载齿轮的平行啮合使行星轮系结构较紧凑。的平行啮合使行星轮系结构较紧凑。Chapter 3 power trainReview

19、 6: Whats the function of Differential? To allow the driving wheels rotate in different speeds.side gear半轴齿轮半轴齿轮half shaft /axle shanfe 半轴半轴Case (carrieer) 差速器壳差速器壳pinion （spider）gear /planetary pinion 行星齿轮行星齿轮Pinion shaft 行星行星(主主)齿轮轴齿轮轴driven gearside gear 半轴齿轮半轴齿轮pinion gear行星齿轮行星齿轮Chapter 3 power

20、 trainChapter 3 power train7) When a vehicle is cornered the inner wheel moves through a shorter distance than the outer wheel. This means that the inner wheel must slow down and the outer wheel must speed up. During this period it is desirable that each driving wheel maintains its driving action. T

21、he differential performs these two tasks.当汽车转弯时，内侧车轮比外侧车轮行驶的距离要短当汽车转弯时，内侧车轮比外侧车轮行驶的距离要短，这说明内侧车轮比外侧车轮转得要慢。在此期间，这说明内侧车轮比外侧车轮转得要慢。在此期间，维持每个驱动车轮的行驶状态是很重要的。这两个任维持每个驱动车轮的行驶状态是很重要的。这两个任务由差速器来完成。务由差速器来完成。Chapter 3 power train8) When the vehicle is travelling straight, the lever will divide the driving force

22、 equally and both discs will move the same amount. When the vehicle corners, the driving force will still be divided equally but the inner disc will now move through a smaller distance; this will cause the lever to pivot about its center which will prize forward the outer disc to give it a greater m

23、ovement. This action shows that the torque applied to each driving wheel is always equal - hence the differential is sometimes called a torque equalizer.汽车直行时，杠杆平均分配驱动力，两个圆盘移动相同的汽车直行时，杠杆平均分配驱动力，两个圆盘移动相同的距离。汽车转弯时驱动力仍然会平均分配，但是内侧圆盘距离。汽车转弯时驱动力仍然会平均分配，但是内侧圆盘移动的距离要小一些，这使得杠杆绕中心转动，推动外侧移动的距离要小一些，这使得杠杆绕中心转动，推

24、动外侧圆盘使之移动更大的距离。这个过程表明扭矩总是平均分圆盘使之移动更大的距离。这个过程表明扭矩总是平均分配给每个驱动轮，因此差速器有时也叫做扭矩平衡装置。配给每个驱动轮，因此差速器有时也叫做扭矩平衡装置。Chapter 3 power trainLimited Slip Differential (LSD): （防滑式差速器）（防滑式差速器）Locking Differential （强制锁止式差速器）（强制锁止式差速器）Multi-disc Selflocking Differential （摩擦片式自锁差速器）（摩擦片式自锁差速器）Chapter 3 power trainReview

25、8: Whats the functions of Interaxial Differential? To allow the driving axles rotate in different speeds.Chapter 3 power trainTorsen DifferentialChapter 3 power train1、整体式桥壳、整体式桥壳Separable carrier type axle housing / banio axle housing 与主减速器壳分开制造而用螺栓连接在一起的桥壳。与主减速器壳分开制造而用螺栓连接在一起的桥壳。2、可分式桥壳、可分式桥壳Trumpet Type axle housing / split axle housing 与主减速器铸成一体，并在两个或多个铸件的接合处用螺与主减速器铸成一体，并在两个或多个铸件的接合处用螺栓