考虑润滑油供给条件的油环-缸套摩擦副润滑分析

Lubrication Analysis of Oil-control-ring and Cylinder Liner Frictional Pair Considering Oil Feeding Condition

内燃机油环-缸套摩擦副润滑分析,多采用富油条件或假定某种特殊边界条件,与油环-缸套摩擦副实际润滑油供给状况不相符。以某四行程内燃机为研究对象,研究油环-缸套间润滑油流动与供给,确定油环进口油膜厚度;在此基础上,根据流量平衡和压力平衡,确定油环上、下轨各段工作面边界条件,并分别对各段求解Reynolds方程,分析油环-缸套摩擦副在计及润滑油供给条件下的润滑性能,并与富油状况对比。研究结果表明,计及供油状况下,油环-缸套摩擦副在上、下行程的润滑性能不对称,最小油膜厚度、最大油膜压力、摩擦力及摩擦功耗与富油状况均有一定差异,特别是在上行程差别显著。可见,考虑进口润滑油供给条件分析内燃机油环润滑性能,将对活塞环-缸套摩擦副的设计信赖性产生积极影响。

Most investigations on the lubrication of tribological interface between the oil-control-ring and the cylinder are based on the boundary condition of full lubrication condition or some certain one assumed. It does not meet well with the actuality of lubricant oil feeding. A 4-stroke IC engine is investigated to study the lubricant oil flowing and inlet feeding between the oil-control-ring and the cylinder. The oil film thickness of the inlet is determined. Based on this investigation, the flow equilibrium and the oil pressure equilibrium being guaranteed, boundary conditions are checked for each working surface. Lubrication parameters are analyzed for respective interface by resolving the Reynolds equation under the condition of actual inlet oil feeding. Research shows that, in the up-stroke, the lubrication performance of the frictional pair is asymmetrical with that in the down-stroke. As well as the maximum oil-film-pressure and the friction force and the friction power, the minimum oil-film-thickness has much difference with the one under full lubrication condition, especially in the up-stroke. Analysis of lubrication between the oil-control-ring and the cylinder, considering oil feeding condition, will benefit the reliability of design for the piston-cylinder frictional pair.