A gear shaft is a mechanical part that supports and rotates with a rotating part to transmit motion, torque, or bending moment. It is generally a metal rod-shaped circle, with different diameters for each segment. The rotating parts of the machine are mounted on the shaft.
According to the different shape of the axis, the axis can be divided into two categories: crankshaft and straight shaft. According to the bearing capacity of the shaft, and can be divided into: 1. (2) mandrel, used to support the rotating parts only bear bending moment and not transfer torque, some mandrel rotation, such as the railway vehicle shaft, some mandrel is not rotating, such as the shaft supporting pulley. (3) the transmission shaft, mainly used to transfer torque and not bear bending moment, such as the long optical shaft in the mobile mechanism of the crane, the driving shaft of the car and so on.