Numerical Simulation and Experimental Testing of the Strength of the Piston-Returning Spherical Joint Pair in a High-Speed Axial Piston Pump

The piston-returning spherical joint pair in an axial piston pump continuously bears alternating loads generated by conversions between high and low pressure. If its strength fails, then the axial piston pump cannot function normally. Therefore, we performed numerical simulations and laboratory experiments to investigate the strength properties of the piston-returning spherical joint pair components of an axial piston pump. The results show that when the piston is in the transition area from oil suction to oil discharge, the maximum deformation and stress of the slipper are located on the inner surface of the slipper spherical socket, and the maximum deformation value is 2.523 μm. When the piston is in the transition area from oil discharge to oil suction, the maximum deformation and stress of the slipper are located at the closing part of the slipper, and the maximum deformation value is 1.959 μm. The maximum deformation of the piston at both positions is located at the bottom of the piston, with values of 11.622 μm and 3.8512 μm, respectively. The maximum stress of the piston is located in the neck of the piston. The deformation at the spherical socket closure of the slipper increases with the increase in the pushing–pulling force, and this relationship is nonlinear. The maximum deformation at the spherical socket closure is smallest for the manganese brass slipper, is larger for the tin bronze slipper, and is largest for the ordinary brass slipper. The maximum deformation at the spherical socket closure of the slipper obtained by the strength test is greater than the simulation result. These research conclusions can serve as a reference for the design of piston-returning spherical joint pairs in axial piston pumps.