Frictional modes of barrel shaped piston rings under flooded lubrication

A friction force measurement system using the floating liner method was dev eloped to study the frictional behavior of piston rings. The measurement sy stem was designed to control the effect of the secondary piston motion and to control temperatures of the cylinder wall and oil. The friction force be tween the barrel shaped piston ring and the cylinder liner was measured und er flooded oil supply conditions. The measured friction forces were classif ied into five frictional modes with regard to the combination of predominan t lubrication regimes (boundary, mixed and hydrodynamic lubrication) and st roke regions (mid-stroke and dead centers). The modes were identified on a Stribeck diagram, where the friction coefficients were evaluated both at mi d-stroke and at the dead centers. (C) 2000 Published by Elsevier Science Lt d.