Among the four types of steering gear, the recirculation ball type and recirculation ball type have higher forward efficiency, while the worm gear finger pin type, especially the fixed pin type and worm gear steering gear have lower forward efficiency.The same type of steering gear due to different structure, different efficiency.. For example, the bearings between the rollers of a worm wheel steering gear and the supporting shaft may be needle bearings, tapered roller bearings, and ball bearings. When needle roller bearing is selected, there is not only friction loss between the roller and the needle, but also sliding friction loss between the side of the roller and the gasket, so the efficiency of the axial device is only 54%. The efficiency of the other two structures is 70% and 75% respectively.In the bearing of the steering rocker shaft, the needle roller bearing can improve the forward or reverse efficiency by about 10% compared with the plain bearing.