Feature on hydraulic pumps of piston and vane design that changes the delivery flow in accordance with an input variable. On the pump this is a distance s that can be specified in various ways (Figure F 29).
This process takes place in the function in a control, i.e. disturbance variables such as leakage losses or rotation speed fluctuations are not compensated, but instead affect the output variable. For this purpose different adjustment systems are used that are also suitable for the adjustment of hydraulic motors given appropriate modification (adjustment of hydrostatic displacement machines).
Figure F 29: Schematic diagram of the function of a variable delivery flow