Relative motion relationship and collision mechanism of slipper-retainer assembly of axial piston machines

Abstract

Under high-speed rotation, the retainer-slipper assembly has serious collision interference, which affects the performance of the key friction pair of the piston pump. And abnormal wear of the retainer and slipper is observed in the faulty piston pump, even with fracture of the retainer and severe wear of the slipper neck. Based on the master-slave principle of the slipper and the retainer, a mathematical model of the relative motion relationship between the slipper-retainer is established. And the collision law between the slipper and the retainer is obtained by combining the relative motion velocity equation of the slipper. The effects of swashplate angle and pump shaft speed on the relative motion trajectory and collision strength of the slipper-retainer assembly are analyzed. The coordinates of all contact points between the slipper and the retainer during one piston cycle are calculated. These results clearly show the friction area of the retainer hole. Researches show that the rotation angle of the power slipper at the transition point is reduced with increasing swashplate angle. The increase of pump shaft speed has no influence on the contact law of the assembly. The collision strength of the assembly increases with the swashplate angle and pump shaft speed. A parametric investigation of the contact and collision between the slipper and the retainer is realized, providing a design method for analyzing the wearing character and mechanical properties of the axial piston pump.