Tribological performance evaluation and sensitivity analysis of piston ring lubricating film with deformed cylinder liner

摘要

The interface between piston ring and cylinder liner is lubricated with an oil film to improve wear resistance and operating life of the engine. The high combustion pressure, variable loadings, manufacturing errors, and thermal distortions in the engine cylinder deform the cylinder liner, thus making a significant effect on the lubricant performance. To investigate the effects of cylinder liner deformation on the piston ring lubrication, a 2D model of elastohydrodynamic lubrication under fully flooded conditions was considered. Various elliptically deformed profiles of the cylinder liner were tested to evaluate conformability, lubricating film thickness, friction, power loss, and lubrication flow rate for a complete four-stroke engine cycle. Comparative analysis of the simulation results was conducted to evaluate the dependency of engine performance on deformed bore shape. Results showed that the lubricating film thickness and engine performance parameters strongly depend on the cylinder liner shape and the degree of distortion.