Swash Plate Oscillations due to Piston Forces in Variable In-line Pumps

This study investigates the oscillations of swash plates caused by piston forces acting on the swash plate. Earlier investigations of variable axial piston pumps assume a fixed swash plate angle, i.e. the swash plate is fixed at different displacement angles. Under normal operating conditions, the swash plate is controlled by a hydraulic actuator which affects the swash plate. The presented models are able to separate different losses caused by the swash plate oscillations and the controller. The results show oscillations on the swash plate which affect both efficiency and flow pulsation and hence the noise level.