Research on the Profile Design of Surface Texture in Piston Ring of Internal Combustion Engine

In this paper, a profile design of surface texture was applied for improving the tribological performance of piston ring–cylinder pair. The design of texture pattern was implemented by numerous textures of different depths in sliding speed direction to imitate the outline of barrel-shaped ring. The thickness and pressure distribution of oil film were obtained through a joint solution of modified Reynolds equation and other governing equations for textured surface. The results indicate that the novel texture pattern has the best overall performance in oil film thickness and friction force compared with normal surface textures, and the average friction power is 10.04% and 16.85% less than normal surface textures and barrel-shaped ring in the whole working cycle. Extra microhydrodynamic lubrication can be observed in the middle region of textured piston ring through the pressure distribution of oil film. At last, the experiment was conducted in a motored test rig and exhibited up to 3% reduction in friction power.