A pump is a device which converts mechanical energy into fluid energy. Always driven by a prime mover such as an
internal combustion engine or an electric motor, it is the component which generates pressure energy in a fluid power
When there is no resistance to flow in the circuit, the pump discharge is at zero pressure. When resistance to flow is
encountered due to loading of the circuit, a pressure build-up occurs instantly. When pressure build-up exceeds the
pressure resistance to flow, fluid energy in the circuit is available to perform work.
COMMERCIAL Model H gear pumps deliver a constant flow per revolution due to their internal fixed displacement
construction. Two matched spur gears, revolving inside a close fitting housing, trap oil between gear teeth as the teeth
move out of mesh. This volume of oil is carried from the pump inlet around the periphery and discharged to the outlet
side as the teeth move into mesh.
Pump delivery is measured in gallons per minute at specified pump revolutions per minute. Pump delivery volume for
any one size of gears can only be varied as the speed (rpm) of the pump is changed.