A semi-floating axle refers to an axle that bears not only torque but also bending moment. The inner side of this axle is connected to the differential axle gear via a spline, while the outer end is supported on the axle housing by a bearing. The wheel is fixedly mounted on the cantilever at the outer end of the axle. Thus, all forces acting on the wheel and the resulting bending moment are directly transmitted to the axle, and then through the bearing to the drive axle housing. During vehicle operation, the axle not only drives the wheels but also supports the entire weight of the vehicle. Because the inner end of this axle only bears torque, while the outer end bears both torque and bending moment, it is called "semi-floating." Its structural feature is that the outer end is fixed to the hub by a conical surface and key, supported by a tapered roller bearing. Outward axial force is borne by the tapered roller bearing, while inward axial force is transmitted to the tapered roller bearing on the other axle via a slider.
While the semi-floating axle support structure is compact and lightweight, the axle experiences complex stresses and is difficult to disassemble and assemble. If the axle is removed, the vehicle cannot be supported on the ground. It is generally only applicable to small vans and light vehicles with low vehicle load, small wheel diameter, and solid rear axle.