From the point of view of energy conversion, hydraulic pump and hydraulic motor is reversible work of hydraulic components, to any kind of hydraulic pump input working liquid, can make it into a hydraulic motor working condition; Conversely, when the spindle of the hydraulic motor is driven by external torque, it can also become a hydraulic pump working condition.
Because they have the same basic structural elements-confined and can cycle change volume and the corresponding oil distribution mechanism. However, due to the different operating conditions of the hydraulic motor and hydraulic pump, the performance requirements are not the same, so there are still many differences between the same type of hydraulic motor and hydraulic pump. First, the hydraulic motor should be able to be positive, reverse, which requires the symmetry of its internal structure; the speed range of the hydraulic motor needs to be large enough, especially for its minimum stable speed has certain requirements. Therefore, it is usually used in rolling bearings or hydrostatic plain bearings, the second hydraulic motor because of the input pressure oil conditions, it does not have to have the ability to self-priming, but requires a certain initial sealing, to provide the necessary starting torque. Because of these differences, the hydraulic motor and hydraulic pump are similar in structure, but can not work reversible.