Development of a New Measurement System for Piston Ring Friction Based on the Floating Liner Method.

A new friction measurement system was developed to investigate piston ring friction in detail based on the floating liner method. Unlike the conventional floating liner experiments, an extended piston was adopted for the conventional crank-piston system to minimize friction from a piston lateral motion. The interaction between piston skirt and liner caused by piston thrust force can be excluded with the new measurement system. Therefore, a parametric study for the only piston ring friction can be possible. In this study, the experiments were conducted under both motoring and firing conditions. The oil temperature was changed to observe the effect of the oil viscosity on the piston ring friction. The friction data showed good agreement with the Stribeck curve for the engine speed, in-cylinder pressure, and oil temperature changes. [ABSTRACT FROM AUTHOR]