Effects of the surface texture on the slipper pair for ultra-high-speed piston pumps in aerospace

Axial piston pumps are key power components in aerospace hydraulic systems. The slipper pair of piston pumps exhibits progressive degradation of load-bearing capacity under ultra-high-speed conditions (up to 20,000 r/min), significantly compromising system performance. This paper proposes a circular micro-dimple textured slipper pair to improve the output performance of ultra-high-speed piston pumps. A load-bearing model considering the piston-slipper coupled vibration and surface texture was established. Effects of the texture radius, depth, and distribution position on the frictional power loss, leakage power loss, and tilt angle were analyzed. Multi-objective optimization of these parameters was achieved. In addition, an experimental investigation on the ultra-high-speed piston pump with a specific circular micro-dimple textured slipper pair was conducted. Results showed that the texture can reduce the slipper pair's frictional power loss and tilt angle. The weighted comprehensive performance index of the slipper pair increases by 15.49% compared to the non-textured baseline with optimized texture. The mechanical efficiency of the test pump has increased by 9.60% at 20,000 r/min and 10 MPa. The proposed texture is effective for the slipper pair and can be used for the pumps’ other friction pairs.