Positive Displacement Hydraulic Pumps and Motors

Hydraulic pumps and motors, like cylinders, belong to the category of hydraulic components that convert mechanical energy into hydraulic energy and vice versa. The pump typically draws fluid from a reservoir through its suction port and discharges it through its pressure port. The pressurized fluid is usually directed to a directional control valve, which, in its neutral position, returns the fluid to the reservoir and, in its working position, directs it to a load. Hydraulic motors convert the hydraulic energy produced by the pumps back into the mechanical energy required to drive a rotating load. Hydraulic motors generally have the same construction as hydraulic pumps of the same type. Pumps can often be used directly as motors provided they do not have spring-loaded check valves.