(1) The type of final reducer gear Spiral bevel gear can bear large load and work stably, even when running at high speed, its noise and vibration are very small. This design adopts spiral bevel gear [4].(2) Selection of the support form and installation mode of the driving bevel gear of the main reducerThis design selects: driving bevel gear: cantilever support (tapered roller bearing)Driven bevel gear: riding support (tapered roller bearing)(3) the choice of the supporting mode and installation mode of the driven bevel gearThe two ends of driven bevel gears are supported by tapered roller bearings, and their tapered rollers should be installed with their big ends facing inward and their small ends facing outward. In order to prevent the driven bevel gear from shifting under axial load, the tapered roller bearing should be adjusted by adjusting nuts at both ends. The driven bevel gear of the main reducer adopts a non-spoke structure and is fixed on the flange of the differential case with fine-tooth screws with high precision