Pump, Variable Displacement
A mechanical device that creates a flow of fluid when its shaft is rotated in the proper direction and when its inlet is connected to a chamber filled with fluid (a reservoir or tank).
The outlet port may be connected to a passage leading to a fluid power system or exhausted into another chamber that is at a higher pressure, The higher pressure chamber must be equipped with a pressure limiting device.
The output flow rate is fixed by the pump displacement per revolution but variable by the operator in a manual or servo controlled system, depending on the design.