Arrangement type and structure of the drive shaft


Time:

2023-06-16

Since the drive axle and the frame are flexibly connected, the universal transmission consisting of cross shaft universal joints cannot guarantee equal speed transmission in any case, so the drive shaft is used.

Arrangement type and structure of the drive shaft

Since the drive axle and frame are elastically connected, the universal drive consisting of cross shaft universal joints cannot guarantee equal speed drive in any case, so the drive shaft is used.

Function of universal drive shaft

The engine is fixed to the frame (beam), the power output shaft is fixed relative to the frame, and the drive wheels of the car are fixed to the shaft. To reduce vibration, the axle is fixed to the frame (beam) by spring brackets. When the car is driven on an uneven ground, the drive axle constantly moves up and down relative to the frame due to inertia, enabling the car to drive horizontally and steadily.

When the frame position fixed engine power output axis drive axle frame position changes when the power transfer, need a transmission device - universal drive shaft to meet this requirement, in order to ensure that the drive axle position changes in the process, the engine power can effectively transfer power to the wheels, drive the vehicle forward and backward.

The arrangement of the driveshaft is as follows:

1) Single-section driveshaft

When the transmission distance is short, only one driveshaft is used! As shown in Figure 4.1(b) and (c), the two ends are connected to the transmission and drive axle respectively through common universal joints. When assembled, the universal joints at both ends of the driveshaft fork in the same plane, which can meet the conditions of full load equal speed transmission.

2) Double-joint driveshaft

When the transmission distance is far, two drive shafts and three universal joints are used. There are two arrangements: the car transmission output shaft and the intermediate drive shaft are not in a straight line. When the car is fully loaded, the two drive shafts are roughly in a straight line, equivalent to only one drive shaft. At this time, the middle universal joint is not able to change the angular speed. Therefore, in order to meet the conditions of full load equal speed transmission, two sections combined into a whole drive shaft, the two ends of the universal joint fork should be installed in the same plane. For this reason, some cars stipulate that the universal joint forks at both ends of the intermediate drive shaft are perpendicular to each other, and the universal joint forks at both ends of the main drive shaft are in the same plane, and if the intermediate drive shaft and the transmission output shaft are approximately in a straight line, the first universal joint cannot change the angular speed. At this point is equivalent to a drive shaft and two universal joints, so as long as the main drive shaft to meet the requirements of equal speed transmission.

3) Three-stage drive shaft

In some long wheelbase cars, the drive shaft is divided into three sections, the first two sections are intermediate drive shafts, which are supported by the intermediate support shaft on the frame, and the last section is the main drive shaft. When assembling, the universal joint forks at both ends of each drive shaft should be installed in the same plane to ensure equal speed transmission.

The drive shaft of the off-road vehicle is arranged between the transmission and the transfer case, and between the transfer case and each drive axle, as shown in Figure 4.20.

The transmission distances from the transmission to the transfer case 4 and from the transfer case to the front axle 1 and the middle axle 7 are such that one driveshaft and two universal joints are used. However, the distance from the transfer case to the rear driveshaft 10 is very long. The driveshaft is divided into three sections connected by four universal joints, but the middle section of the shaft is supported on the intermediate axle housing as an intermediate support shaft. In this way, when fully loaded, the output shaft of the transmission is roughly parallel to the axes of the distributor box, the intermediate shaft 7 and the input shaft of the rear axle 10, and the intermediate support 8, and the universal joints at the ends of each drive shaft are in the same plane, so that the front axle 1 is roughly arranged in an isosceles triangle, thus ensuring a roughly constant speed transmission when the car is fully loaded.