The half shaft is a shaft that transmits power between the main reducer (differential) and the driving wheels, and is mostly solid. The inner end is connected to the half-shaft gear of the differential, and the outer end is connected to the driving wheel hub. The axle shaft of the steering axle needs to be segmented and connected by constant velocity universal joints; the axle shaft with the swing axle axle needs not only to be segmented and equipped with a universal joint, but also needs to be equipped with a telescopic spline or a telescopic constant velocity. Universal joint.
According to the different types of support at the outer end, the half shaft is divided into three types: half floating shaft, 3/4 floating shaft and full floating shaft.
Semi-floating half shaft The journal near the outer end is directly supported on the bearing placed in the inner hole of the outer end of the axle housing. The brake drums are connected. Therefore, in addition to transmitting torque, the semi-floating half shaft also bears the bending moment caused by the vertical force, longitudinal force (driving force or braking force) and lateral force transmitted from the wheel, and the load is complicated. However, the structure is simple, the quality is small, the size is compact, and the construction cost is low, so it is used by passenger cars, minibuses, trucks, etc., which are of low quality, good use conditions, and low load.
3/4 floating axle The mounting relationship of the outer end of the 3/4 floating half shaft is similar to that of the full floating type, as shown in Figure 5. When the center of the wheel and the center of the bearing coincide, the longitudinal and vertical forces are transmitted directly from the wheel to the axle housing half shaft bushing, and the bending moment generated by the lateral force is partially transmitted to the half shaft. At this time, the half shaft only bears torque However, due to the use of a single cylindrical roller bearing, its bearing stiffness is poor. If the center of the wheel and the bearing are not coincident, although the longitudinal and vertical forces are transmitted to the axle housing bushing through the bearing, the bending moment formed by the longitudinal, vertical and lateral forces still needs to be determined by the axle and The axle shaft bushings of the axle housing are used to bear it together, that is, the 3/4 floating axle shaft also bears part of the bending moment in addition to the torque. The proportion of the bending moment is determined by factors such as the stiffness of the semi-axle, the structural type of the bearing, its support stiffness, and installation dimensions. Compared with the semi-floating half shaft, the load conditions are improved, but its structure is more complicated. Because its structure is relatively simple and lightweight, and can use a simple conical surface and key and hub connection method, it can be used in passenger cars and mini, light passenger cars, trucks.
Full floating axle The full-floating half-shaft outer end is connected to the hub supported on the axle shaft sleeve by two bearings (almost all using tapered roller bearings). Because the vertical, longitudinal and lateral forces on the wheel, and the bending moments caused by these forces are transmitted to the axle sleeve of the axle housing via the hub and bearing, the full floating axle only bears the torque and not the bending Moment. The size and quality of the hub are large, the structure is more complicated, and the cost is higher, but the work is reliable, and it is widely used in passenger cars, trucks and off-road vehicles of light weight and above.