HYDROKINETIC COUPLING APPARATUS, PARTICULARLY FOR A MOTOR VEHICLE

摘要

A hydrokinetic coupling device has a generally transversally extending wall (2) on which is centrally mounted a guide ring (6), wherein a piston (9) is axially displaceable along the guide ring (6) and defines therewith and with the transversal wall (2) a variable volume chamber (30) outwardly defined by a disc (10) and by friction seals (11, 111) arranged to be clamped between the piston (9) and the disc (10) and between the disc (10) and the transversal wall (2) respectively, each friction seal (11, 111) having at least one so-called cooling groove (80, 180) and the one or more grooves (80, 180) extending from the outer periphery to the inner periphery of each fiction seal (11, 111) in a spiral following the direction of rotation of the disc (10) and being alternately distributed from one friction seal to the other. The invention is useful for motor vehicles.