The axial piston pump with rotating swashplate.
In hydraulic systems with a workingpressure above aprox. 250 bar the most used pumptype is the pistonpump. The pistons move parallel to the axis of the drive shaft. The swashplate is driven by the shaft and the angle of the swashplate determines the stroke of the piston.
The valves are necessary to direct the flow in the right direction. This type of pump can be driven in both directions but cannot be used as a hydromotor.