Abstract: In this paper, a certain type water hydraulic axial piston pump was taken as a prototype, and the original smooth surface swash plate was replaced with a biomimetic non-smooth surface one. The flow-pressure, volumetric efficiency-pressure and mechanical efficiency-pressure of the test pump at three different pressures of 7 MPa, 10 MPa, and 12 MPa were tested, and the worn surface of the swash plate was observed using laser confocal microscope and scanning electron microscope. The results show that the slipper pair with non-smooth surface can produce hydrodynamic lubrication effect and have chip holding capacity due to pits. Self-lubrication can be realized during the friction process, achieving the effect of reducing drag and wear. With the increase of working pressure, friction marks in the half-circle high pressure area of the non-smooth surface swash plate are gradually obvious, grooves on the worn surface become wider and deeper, and adhesion wear and oxidation wear are aggravated. That is the friction and wear are aggravated. The volumetric efficiency, mechanical efficiency and total efficiency of the non-smooth surface slipper pair test pump are increased by 0.2%-0.6%, 0.1%-1.7% and 0.1%-2.3% respectively, compared with those of the smooth surface slipper pair test pump.

Key words: water hydraulic axial piston pump, biomimetic non-smooth surface, slipper pair, friction and wear, efficiency of pump