What is the displacement and flow of a hydraulic pump?

The hydraulic pump displacement refers to the volume of oil discharged by the pump shaft for one revolution, expressed in V, and the unit is mL/r. The displacement of the hydraulic pump depends on the geometric size of the hydraulic pump seal chamber. Different pumps have different displacements due to different structural parameters.

The displacement is determined by the pump itself. The displacement of the quantitative pump is constant, and the flow rate is related to the speed of the driving pump; the displacement of the variable pump can be adjusted, and the flow rate is related to the speed of the motor driving the pump. The pressure is related to the driven load. The greater the load, The greater the pressure (of course within the rated range), the greater the flow rate, and the movement speed of the oil cylinder will definitely increase.

Hydraulic pump flow:
During the oil discharge process of the hydraulic pump, the instantaneous flow rate is uneven and changes with time. However, when the hydraulic pump rotates continuously, the instantaneous flow in each revolution changes repeatedly according to the same law. This phenomenon is called the flow pulsation of the hydraulic pump.

The flow pulsation of the hydraulic pump will cause pressure pulsation, which will cause vibration and noise in pipes, valves, and other components. Moreover, due to flow pulsation, the output flow of the pump is unstable, which affects the stability of the movement of the working parts, especially for the hydraulic transmission system of precision machine tools.

Generally, the flow pulsation of the screw pump is the smallest, followed by the vane pump, and the flow pulsation of the gear pump and the plunger pump is relatively large.