EFFECTS OF SLIPPER SURFACE SHAPING AND SWASHPLATE VIBRATION ON SLIPPER-SWASHPLATE INTERFACE PERFORMANCE

This thesis investigates the effects of swashplate vibration and slipper surface geometry on the performance of the slipper-swashplate interface. The lubricating interfaces within a swashplate type axial piston machine are the most complicated part of the design process. These interfaces are supposed to provide support to the significant loads they experience during operation and to prevent continuous contact of the sliding surfaces. Therefore a proper slipper-swashplate interface design ensures full film lubrication during operation and provides sufficient load support while minimizing viscous and volumetric losses at the same time. The effects of two factors on the performance of the slipper-swashplate are examined during this work; swashplate vibration and slipper surface micro-geometry. An already existing model of the slipper-swashplate interface was used to carry out the results for this work however some modifications were made to the model to suit the needs of this research. Swashplate vibration is a phenomenon that has not been implemented in the model before, therefore its effects on the performance of the interface were analyzed. Thickness of the fluid film in the lubricating regime corresponds with its performance and is directly affected by the micro-geometry of the sliding interfaces. Therefore the effects of slipper surface micro-geometry is crucial to study in order to find the optimal slipper-swashplate interface design.