Effects of a Cylinder Liner Microstructure on Lubrication Condition of a Twin-Land Oil Control Ring and a Piston Skirt of an Internal Combustion Engine

It is hypothesized that structured sliding-surfaces improve the lubrication condition by forming an oil sump on the sliding surface, redistributing the oil, and trapping wear debris. For these reasons, structured sliding-surfaces have been used as a friction reduction method for a long time. In this work, effects of microstructure laid on the cylinder liner of an internal combustion engine on twin-land oil control ring (TLOCR) and piston skirt lubrication condition were investigated by comparing friction between a conventional fine-honed liner (CFL) and a micro-structured liner with the CFL. The measurements using a floating liner engine showed that the microstructure improved lubrication condition by reducing hydrodynamic friction. On the other hand, it was also observed that the microstructure could result in elevated friction under certain engine operating conditions.