计入柱塞套弹性变形的柱塞副摩擦与密封特性分析

Analyses of Friction and Sealing Characteristics of Piston/Bushing Interfaces Considering Elastic Deformations

综合考虑径向柱塞泵柱塞副粗糙表面接触和弹性变形,建立混合润滑状态下柱塞副弹流润滑理论分析模型,并结合有限差分法与有限单元法,基于MATLAB和ANSYS开展联合仿真,分析不同入口压力及凸轮转速下柱塞副弹性变形及表面形貌对摩擦与密封特性的影响。结果表明:柱塞套弹性变形对柱塞副微凸体接触影响显著,且影响程度与入口压力及凸轮转速有直接关系;弹性变形及表面形貌均在一定程度上影响摩擦功耗及泄漏量且弹性变形的影响更大;柱塞副摩擦与密封特性对工作条件较为敏感,随着入口压力或凸轮转速的增大,摩擦功耗、压差流量与剪切流量均有不同程度的增加。

Considering the rough surface contacts and elastic deformations of the piston bushing in the radial piston pumps,the theoretical model was established for the piston/bushing interfaces under the mixed-elastohydrodynamic lubrication conditions.The effects of elastic deformations and surface morphology caused by different inlet pressures and cam speeds on the friction and sealing characteristics were analyzed,through the co-simulation of MATLAB and ANSYS,and the combination between the finite-differential method and finite-element method.The results show that the elastic deformations of piston bushing have significant influences on the contacts of micro-convex bodies in the piston/bushing interfaces,which is related to the inlet pressures and cam speeds.The elastic deformations and surface morphology may affect the friction power losses and leakage as well,and the former is the greater one.Besides,the friction and sealing characteristics of the piston/bushing interfaces are sensitive to the working conditions,and the friction power losses,the couette flows and the poiseuille flows raise in varying degrees with the increases of inlet pressures or cam speeds.