Studies on the Mixed Lubrication of Piston Rings

A great deal of attention has been focused on decreasing the piston assembly friction in piston engines, since this friction accounts for the majority of total mechanical power loss in these type of engines. The tribology of the sliding surfaces between piston rings and cylinder liner includes extremely complicated phenomena which will become even more severe with an increase in the engine power. In the present study, the theoretical analysis on the mixed lubrication of piston rings is made. The friction characteristics of piston rings for both monograde and multi-grade oils are investigated.