The drive gear of the excavator is at the power transmission end. Its basic function is to increase the torque transmitted by the drive shaft or transmission, and to distribute the power reasonably to the four swing arm drive wheels. In addition, it also bears the action on the road surface and the frame or body. The design of the drive axle between the vertical force and the lateral force should meet the following basic requirements: 1. The selected final reduction ratio should be able to ensure the power and fuel economy of the excavator. 2. The size of the machine should be small to ensure the necessary ground clearance. 3. Gears and other transmission parts work smoothly with low noise. 4. High transmission efficiency under various speeds and loads. 5. Under the condition of ensuring sufficient strength and rigidity, the drive teeth of the excavator should have a low mass, especially the unsprung mass should be as small as possible to improve the smoothness of the excavator. 6. The drive gear of the excavator is simple in structure, good in processing technology, easy to manufacture, easy to disassemble and adjust.