Hydraulic pumps are power-generating components in hydraulic systems. Their main function is to convert mechanical kinetic energy into hydraulic potential energy. Driven by a prime mover, often an internal combustion engine in mobile equipment, a hydraulic pump intakes the fluid at atmospheric pressure to fill an expanding volume of space inside the pump through an inlet port and discharges pressurized fluids by reducing the volume of space at an output chamber of the pump. Such a way of pumping fluid is often called positive-displacement pumping.