When high operating pressures are required, piston pumps tend to be used. Piston pumps will traditionally withstand higher pressures than gear pumps with comparable displacements; however, there exists a higher initial cost associated with piston pumps as well as a lower resistance to contamination and improved complexity. This complexity falls to the gear designer and service technician to understand in order to make certain the piston pump is working correctly with its extra moving parts, stricter filtration requirements and closer tolerances. Piston pumps are often used in combination with truck-installed cranes, but are also discovered within other applications such as snow and ice control where it could be desirable to alter system stream without varying engine velocity.

A cylinder prevent containing pistons that move around in and out is housed within a piston pump. It’s the movement of the pistons that draw essential oil from the supply interface and then pressure it through the wall plug. The angle of the swash plate, which the slipper end of the piston rides against, determines the length of the piston’s stroke. As the swash plate remains stationary, the cylinder block, encompassing the pistons, rotates with the pump’s insight shaft. The pump displacement is then determined by the total volume of the pump’s cylinders. Fixed and variable displacement designs are both available.