Effect of DLC coating on the friction power loss between apex seal and housing in small Wankel rotary engine

Abstract

Abstract The aim of this paper is to study effect of DLC coating on the friction power loss caused by apex seal in small Wankel rotary engine. A numerical model which is capable of evaluating the lubrication state under mixed lubrication is built. The involved parameters of DLC coating are obtained through experiment. Then, the effect of DLC coating is numerically investigated and validated by experimental result. Results show that the friction power loss for DLC coated surface is about 55% of that for uncoated surface. It is partly attributed to the low friction coefficient of DLC coating. Besides, the normal force of asperity is decreased by DLC coating. It is also conducive to the reduction of the power loss.