1. Accept the power of the drive shaft, and generate traction through the action of the driving wheel and the road, so that the car can drive normally;
2. Withstand the total weight of the car and the reaction force of the ground;
3. Alleviate the impact of uneven roads on the body, attenuate the vibration of the car in driving, and maintain the smoothness of driving;
4. Cooperate with the steering system to ensure the steering stability of the car.