As the fixed shaft of the gear, the gear shaft plays a supporting role in the gear. The strength and stiffness requirements of the gear shaft are high to ensure the structural stability and normal operation of the gear. The gear shaft is usually combined with gears in a reducer for transmission and plays a role in balancing torque.
The gear shaft achieves a decrease in speed and an increase in torque through the meshing between different gears. This enables new energy vehicles to provide more stable output and higher efficiency when greater driving force is required.

The gear shaft of the reducer is usually designed in a hollow shape, with an internal spline in the middle hollow part of the gear shaft. The external spline of the reducer input shaft is inserted into the spline hole of the middle gear shaft. The torque output from the motor output end is transmitted to the input shaft of the transmission, and then transmitted to the gears of the intermediate gear shaft. The torque is then transmitted to the output shaft through the large gear that meshes with it, driving the wheels to work.
The middle gear shaft is designed to be hollow, which not only reduces the weight of the gear shaft, saves materials, but also reduces the volume of the reducer, making the hardness of the gears on the gear shaft and the splines inside the shaft more uniform during heat treatment, which can reduce the occurrence of deformation, internal cracks and other adverse situations during the heat treatment of the middle gear shaft.