Considering that when the car body has a high reduction ratio, the speed of the car body is low, at this time the car body transmission shaft can obtain a large torsion moment.According to the car body parameters, it can be known that the engine can obtain a large reduction ratio in the fourth gear.The transmission efficiency of the engine is now 0.96.
According to the results of the above calculations, the smaller torque value is selected as the small torque of the drive shaft.The reason why a larger value is not selected here is that the design principle of light weight of the transmission shaft is taken into consideration.In addition, for the car body, it is necessary to protect the engine from damage and other safety parts under heavy impact loads, so the drive shaft needs to be selected with a smaller value.