Hydraulic Power Units

Hydraulic power units provide pressurized flow to hydraulic cylinders, motors, and other hydraulically-powered mechanisms. Hydraulic power units differ from regular pumps in that they regulate fluid temperature and have multiple stages. They are an integral part of machines that rely on hydraulic power for operation.

The hydraulic power unit is comprised of several key parts and components. The three main components of a hydraulic power unit are the motor pump, accumulator and reservoir tank. The power unit’s pump is responsible for pulling the working fluid out of the reservoir tank and moving it into the accumulator. The accumulator is a container which collects the hydraulic fluid and helps build and maintain pressure in the system.

Once the pressure within the accumulator has reached a pre-set level, the fluid is released and circulated in the hydraulic system. The fluid moves the components of the motor, which in turn rotates the shaft that supplies mechanical power. The fluid is then discharged into the reservoir, where it will work its way back into the pump and continue the cycle.

Axial Vane Motor
Hydraulic Power Units – Von Ruden Manufacturing, Inc.

In hydraulic cylinders, the hydraulic power unit pumps hydraulic fluid into the bottom chamber of the cylinder and pushes the piston rod up, which pushes the fluid in the other chamber back into the reservoir. The movement of this fluid pressurizes the chamber and extends the piston to its full length, giving the hydraulic cylinder its ability to push. Since these systems can require high pressures, it is important that these power units be equipped with temperature regulation equipment.

Coolers and heaters are used to ensure that the hydraulic fluid remains within operational parameters and to make sure that the hydraulic equipment does not sustain any damage. Power units can be used for a huge range of applications, including in aerospace test equipment, automation equipment, heavy machinery, marine equipment, and machine tools.