Abstract: The slipper ball-socket pair is the key friction pair for connecting the plunger and slipper in a water hydraulic plunger pump, and its closing quality directly affects the reliability and life of the pump. Aiming at the problem of loosening at the closing part of the slipper ball-socket pair,which was composed of a metal matrix coated with a plastic material Carbon Fiber Reinforced Polyether Ether Ketone(CFRPEEK), two kinds of molding processes were proposed: molded closure and direct injection closure. The closing effect of sliding shoe ball and socket pairs with different molding processes was analyzed. Firstly, the finite element model of the slipper ball-socket pair was established. Then the simulation software ANSYS was used to simulate the closing and pull-off process of the plunger and slipper, the changes of the equivalent stress and strain in the closure part of the slipper boots were investigated, and the influence of two kinds of base materials of the slipper 316L and 17-4PH and the two kinds of closing forming processes on the pull-off stress of slipper was compared and analyzed. Finally, the plunger and slipper assembly of two kinds of closing molding process was installed in the water hydraulic pump respectively to run the test, the simulation results were verified in conjunction with test results. The research results show that comparing with the molded closure molding process, the slipper ball-socket pair with direct injection molding is fundamentally eliminated, the pulling force of the same structure is increased by 20.29%, and the closure effect is good after a long period of operation, there is no obvious axial clearance.
Key words:  positive displacement pump; slipper ball-socket pair; Carbon Fiber Reinforced Polyether Ether Ketone (CFRPEEK); molding and necking forming process; direct injection molding process; pull-off force; residual stress