缸套-活塞环三维润滑状态模拟分析

摘要

以发动机缸套‐活塞环摩擦副为对象，研究润滑表面粗糙度、润滑油的变黏度效应以及气缸套圆周方向的形变等因素对润滑状态的影响。运用三维瞬态平均Reynolds方程与微凸体接触模型，建立缸套‐活塞环三维瞬态动压润滑模型，并使用Fortran语言编制了润滑状态计算程序，得出行程内的最小油膜厚度、压力分布、摩擦力等曲线。结合实际工况对计算结果进行分析，表明在活塞环圆周方向上的油膜压力及油膜厚度分布都是不均匀的，有明显变化；在压缩冲程上止点附近，微凸体摩擦力数倍于流体摩擦力，是引起摩擦磨损的主要原因。%For the friction pair of cylinder liner and piston ring ,the effects of surface roughness ,variable viscosity effect and circumferential deformation on lubrication condition were researched .A three‐dimensional transient hydrodynamic lubrication model of cylinder liner‐piston ring was built based on the three‐dimensional transient average Reynolds equation and asperity contact model and the calculation program of lubrication condition was written with FORTRAN language .The minimum film thickness ,pressure distribution and friction curve were acquired with the program .By comparing the simulation results with those achieved under the actual working conditions ,the oil film pressure and thickness distribution in the circumferential direc‐tion of piston rings was found to be uneven .On the top end of compression stroke ,the asperity friction force was much larger than the fluid friction force ,which was the main cause for friction and wear .