Multi body dynamics of a slipper considering contact with retainer in swash plate type piston pumps coupled with hydrodynamic analysis of oil-film

Abstract

In order to understand motion mechanisms of slippers in swash plate type piston pumps, the analysis flow combining multi-body dynamics and the oil-film analysis was constructed. In the modeling, it is possible to consider the slipper deformation due to the oil film reaction force and the contact with the retainer. This analysis evaluated the effects of elastic deformation of the slipper, discharge pressure, and hydraulic oil temperature on the slipper behavior, and clarified the following. (1) When the slipper is located on the high-pressure side of the pump, the oil-film gap to swash becomes wider in the entrance direction of slipper’s sliding surface. As a result, the gap becomes wedge shape and dynamic pressure is generated. The slipper floats due to this dynamic pressure combined with the static pressure. (2) The slipper tilt angle becomes larger and the flying height is smaller in calculation by considering the elastic deformation of the slipper. This makes it possible to safety evaluate the gap. (3) Changes in discharge pressure and hydraulic oil temperature have a great influence on the behavior of slippers.

Keywords

• axial piston pump
• slippers
• hydraulics
• hydrostatic bearing
• simulation