As shown in fig. 8, the steering drive axle has a main reducer 1, a differential 3 and half shafts 4 and 8, which are common drive axles. It also has a knuckle housing 1 1, a kingpin 12, a hub 9, etc. There are general steering axles. Different from the single drive axle and steering axle, due to the need of steering, the axle shaft is divided into two sections, namely, the inner axle shaft 4 (connected with the differential) and the outer axle shaft 8 (connected with the hub), which are connected through the constant velocity universal joint 6. At the same time, the kingpin is divided into upper and lower sections, which are respectively fixed on the spherical support 14 of the universal joint. The knuckle journal 7 is made hollow so that the outer half shaft can pass through it. The steering knuckle connecting fork is a spherical steering knuckle housing 1 1, which not only meets the steering needs, but also adapts to the steering knuckle force transmission. Steering drive axle is widely used in all-wheel drive off-road vehicles.
Take an off-road vehicle as an example to explain the internal structure of the steering drive axle, as shown in Figure 9. The steering knuckle consists of a steering knuckle journal 1 1 and a steering knuckle housing 9, which are connected into a whole by bolts. The steering knuckle journal is equipped with two hub bearings to support the hub13; Bushing is pressed into the inner hole wall of the knuckle journal to support the outer half shaft. The upper and lower ends of the knuckle housing 9 are respectively provided with thickened parts of the upper and lower kingpins 6, which are stopped by a stop pin 14; The upper end of the knuckle housing is also provided with a knuckle arm 8, and the lower end of the knuckle housing is provided with a lower cover 15. The knuckle arm and the lower cover are respectively connected with the knuckle housing 9 through bolts and tapered bushings 7, so that the upper and lower kingpins can be positioned in a sealed manner. The kingpin is equipped with a bronze kingpin bushing 17 with flanging, which is pressed into the upper and lower kingpin seat holes 4 respectively. The kingpin seat holes are press-fitted at the upper and lower ends of the spherical support 3, and the flanging of the bushing plays a role in promoting. After the grease is injected from the upper nozzle and the lower nozzle, it enters the central oil passage of the kingpin respectively, and then comes out from the holes on both sides and enters between the kingpin and the bushing to realize lubrication. When the car turns, the steering straight pull rod pulls the steering knuckle arm 8 to drive the steering knuckle to swing around the kingpin, and the steering wheel deflects accordingly, thus realizing the steering of the car.