Rotary piston engine piston having an internal seal

Abstract From the Canadian patent

Internal seal for the piston of a rotary piston engine. The seal includes a slide ring with an annular scraping edge of L-shaped cross-section with an axial flange and a flange extending radially outward. The slide ring includes an axially extending ring with one face together with its inner periphery forming the scraping edge. The slide ring includes a radially extending ring with its inner periphery shrunk onto the outer periphery of the axial ring near the one face. The axial ring consists of a material having a smaller coefficient of heat expansion than the radial ring.