Research on the influence of the lubrication status at the inlet on the lubrication characteristics of engine piston ring

Abstract In current researches on the lubrication of engine piston ring, some were based on a hypothesis that the piston ring is on a flooded lubrication status. Although some others belong to the starved lubrication analysis, the one‐dimensional model, a certain form of starved lubrication status or simplified manner were used. In this paper, on the basis of the equations about the lubricating oil flow‐rate and control volume, a flow model of lubricating oil in the piston ring‐cylinder liner conjunction is established, and the influence of the situation of supplied lubricating oil film at the piston ring inlet on the two‐dimensional starved lubrication characteristics of piston ring for a four‐stroke engine is studied. The results indicate that the lubrication condition at the piston ring inlet has significant impact on the lubrication characteristics of piston ring. When the supplied lubricating oil at the piston ring inlet increases, the minimum film thickness of piston ring will increase, meanwhile the maximum film pressure, asperity contact force, friction force and power loss will decrease. If the film thickness at the piston ring inlet is smaller, the increase of the supplied film thickness can improve obviously the lubrication characteristics of piston ring.