From the point of view of energy conversion, the hydraulic pump and the hydraulic motor are reversible hydraulic components. Inputting working fluid to any hydraulic pump can make it work as a hydraulic motor; on the contrary, when the main shaft of the hydraulic motor is driven from the outside When the torque is driven to rotate, it can also become a hydraulic pump working condition. However, due to the different working conditions of hydraulic motors and hydraulic pumps, their performance requirements are also different, so there are still many differences between hydraulic motors and hydraulic pumps of the same type. First of all, the hydraulic motor should be able to forward and reverse, so its internal structure is required to be symmetrical; the speed range of the hydraulic motor needs to be large enough, especially for its minimum stable speed. Therefore, it usually adopts rolling bearings or hydrostatic sliding bearings; secondly, the hydraulic motor does not need to have self-priming ability because it works under the condition of input pressure oil, but it needs a certain initial sealing to provide the necessary starting torque. Due to these differences, the hydraulic motor and the hydraulic pump are similar in structure and generally cannot work reversibly.