A through hole is made in the center of the shaft body, and an internal key groove is formed in the through hole. The outer surface of the shaft body is processed with a stepped cylinder and an external key groove. The central through hole of the shaft is sleeved with the main shaft of the pressing chamber. The input power drives the shaft through a transmission gear mounted on a cylinder on the outer surface of the shaft and is directly transmitted to the main shaft of the press chamber.
Hollow shafts take up a lot of space but can reduce weight. According to the material mechanics analysis, when the shaft transmits torque, viewed from the radial section, the effect of transmitting effective torque is greater in the outer areas. When the shaft needs to transmit a large torque, a thicker shaft diameter is required. And because the effect of transmitting torque at the center of the shaft is small, hollow is generally used to reduce the weight of the shaft.