| 摘要 |
A hydraulic actuator for a wet clutch (14, figs 1 & 2) comprising a cylinder (30, figs 1 & 2), a piston (26, figs 1 & 2) slidably disposed within the cylinder and serving as the movable wall of a variable volume working chamber filled with hydraulic fluid, and a sealing ring 44 for sealing between mating walls of the piston and the cylinder, characterised in that the sealing ring 44 comprises a circumferentially discontinuous piston ring 46 and/or 48 received within an annular groove in one of the mating walls and in sealing sliding contact with the other mating wall. The clutch may be a twin clutch assembly in an automatic gearbox. The seal is preferably made of steel, and is preferably formed of two parts 46 & 48 each consisting of a split ring having a gap 50, 52.The mating surface that slides relative to the piston ring 44 may be polished. |
