Sealing structure and mounting of piston ring for use in the sealing structure

摘要

The present invention provides a sealing structure employing a piston ring structural body (10) of a type wherein an outer ring (20) continuously formed of a resinous material is pressed radially outwards by a metal coil expander (40) via a metal inner ring (30) provided with an abutment. The piston ring structural body (10) has a construction wherein the outer ring (20) continuously formed of polyimide is pressed radially outwards by the coil expander (40) via the steel inner ring (30) provided with the abutment. A sliding face (24, 25) of the outer ring, which slides on a cylinder wall (200), is divided by a groove into upper and lower sliding faces, whose respective upper edge portions are provided with chamfers (26, 27).