The axial piston pump with rotating barrel

piston pump

The axial piston pump with rotating barrel.

This axial piston pump consists of a non rotating swashplate (green) and a rotating barrel (light blue). The advantage of this construction is that the pump can operate without valves because the rotating barrel has a determined suck and pressure zone. The animation shows the behaviour of only one piston; normally this pump has 5, 7, 9 or 11 pistons.
The rotating barrel shifts at the right side over a so called port plate (yellow) . This port plate is mounted and locked in the housing. View A-A shows the port plate.
When the angle of the swash plate is adjustable, the pump has a variable displacement and in that case the pump is often provided with a pressure or flow control or a combination of both ('Load Sensing' and pressure 'cut off') .

The pump in the animation can also be applied as a hydraulic motor.