Power loss of slipper/swashplate based on elastohydrodynamic Lubrication model in axial piston pump

Abstract

Energy saving of the hydraulic system is significantly realized by improving the efficiency of the pump. The slipper/swashplate lubricating surface is one of the main energy consumption parts in axial piston pump which is always used in the hydraulic system. Being a hydraulic bearing in axial piston pump, the slipper/swashplate pair exerts both the bearing function and the sealing function under the oscillating working condition. Because of viscous friction and leakage flow, power loss of slipper/swashplate is also one of the main power loss sources in axial piston pump. A precise model of lubricating surfaces, which includes oil film thickness, dynamic pressure field, load carrying ability and energy dissipation, is indispensable to develop more effective lubricating surface morphology. An elastohydrodynamic lubricating oil film model has been established for the sliding surfaces between slipper/swashplate interfaces. The model includes an isothermal fluid model, micro-motion of slipper and pressure deformation of the bounding solid bodies using a partitioned solution scheme. The power loss model between the slipper and swashplate has been developed and solved by numerical analysis method. Numerical results demonstrate that the diameter of the fixed damping orifice in the slipper has an important role in power loss of slipper/swashplate except the axial rotational velocity and operating pressure. Finally, the accuracy of numerical results of power loss is verified by experiments.