Compact hydrokinetic coupling apparatus, especially for a motor vehicle

A hydrokinetic coupling apparatus (10) comprising:

• a casing (12, 20, 22) having a generally radially oriented wall (24) and a radially outer peripheral portion (26, 102), the casing being adapted to be coupled in rotation to a drive shaft;
• a hub (34) adapted to be coupled in rotation to a driven shaft, the hub (34) having a splined rear portion (52, 54);
• a turbine wheel (30) coupled in rotation to the hub (34);
• a piston (58), in the form of a generally radially oriented annular ring movable axially and coupled in rotation to the casing, the piston (58) having a radially outer periphery and means (100) at the radially outer periphery for meshing with the radially outer periphery (26, 102) of the casing (22), the piston (58) further comprising a sleeve (60) mounted along the hub (34) for sliding movement;
• and
• a generally radially oriented annular friction disc (74) having a radially inner periphery (94) and being adapted to be gripped axially by the piston (58) between, respectively, the piston and the facing inner surface (73) of the radial wall (24) of the casing, the friction disc (74) comprising a damper plate (84) and being coupled at the radially inner periphery (94) to the hub (34) of the turbine wheel (30), said damper plate (84) having a radially inner periphery configured as a splined guide sleeve (98) through which a splined rear portion (52, 54) of the hub (34), along which the sleeve (60) is mounted for sliding movement, extends,
• wherein the apparatus has a front and a rear, the turbine wheel (30), the piston (58), the friction disc (74) and the radial wall (24) of the casing being arranged in axial succession from the front to the rear, and
• wherein the piston (58) includes, considered radially outward from the inside, an internal peripheral portion (64) and a bent first intermediate portion (66) which substantially follows an external profile (32, 36) of the hub and the turbine wheel, then an intermediate second portion (68) in the form of a radially oriented flat ring, the intermediate second portion having a rear annular face in facing relationship with a friction ring (76), and an outer peripheral skirt portion (70) in the form of a generally axially oriented skirt, the outer peripheral skirt portion including means for meshing the outer peripheral skirt portion (70) with the radially outer peripheral portion (26, 27, 20, 22) of the casing.