Comprehensive performance and optimization of micro textured slipper pair of axial piston pumps

The present study aims to fully exploit the potential of micro-texturing to increase the operational efficiency of piston pump slipper pairs and expand the repertoire of discretely distributed pit micro-textures. Four micro-textures, each featuring unique opening and pit configurations, have been proposed. These micro-textures are applied to the working surface of the axial piston pump slipper to optimize friction and wear characteristics, mitigate heat generation during operation, and decrease leakage within the slipper pair. The influence of micro-texturing on the lubricant oil film of the slipper surface was evaluated using computational fluid dynamics (CFD) and experimental methodologies. The research employed response surface methodology to examine the impact of the position distribution and shape size parameters of the micro-textures on the bearing pressure, friction coefficient, temperature, and oil film leakage between slipper pairs, followed by multi-objective and multi-parameter optimization. The results indicate that the implementation of micro-textures substantially enhances the operational performance of the slipper surface. A texture design that integrates an elliptical opening with an elliptical offset parabolic pit body situated at the innermost two-ring support band of the slipper is recommended. Compared with the original prototype, this optimized design yields a 19.69% increase in the bearing pressure and a 21.08% reduction in the friction coefficient, coupled with a 14.20% decrease in the average temperature and a 14.03% reduction in oil film leakage. This research provides a valuable reference for the design of a wider array of pit micro-texture geometries and offers theoretical support for the performance enhancement of axial piston pumps.