Development of Piston Friction Force Measurement System

This paper presents a novel piston friction force measurement system that has characteristics of relieving the pressure force acting on the upper surface of the liner; the system uses general rubber O-rings for combustion chamber sealing, and does not need special changes to the piston top land. The lower supporter of the floating liner increases stiffness in the liner axial direction, and results in the increase of the natural frequency. The upper supporter has multi-layer structure designed for low axial stiffness and high radial stiffness. With the use of the present system, the effects of variation in clearance and piston ring tension on friction were studied.