| 摘要 |
PURPOSE:To improve a sealing effect and reliability by providing a seal piece having a front piece in conatact with a rear piece through a cylindrical surface and free to move in semi-circular motion. CONSTITUTION:A seal piece consisting of a front seal piece 211 having a convex cylindrical surface 203 with radius r at its rear side and a rear seal piece 205 having a concave cylindrical surface 204 with radius r at its front side which are fitted together with freedom of circular movement at said cylindrical surfaces 203 and 204 is contained in a groove 206 of a casing 8 reciprocatingly movable in the direction of X-X axis whereby said seal piece 211 is held at neutral position when the geometrical center 0 of a rotary piston 4 is at the center of rotation Y and circularly moves sliding on the cylindrical surface 203 when the piston 4 is moving to the upper dead center to constantly maintain the contact between a sealing surface 200 and an outer surface 7 of the piston 4, said contact of the sealing surface 200 with wide contact area reducing the surface pressure and forming good oil film between the outer surface 7 for smooth sealing. |
