Hydraulic control system for dual wet clutch

A dual wet clutch (1) intended to be disposed in a motor vehicle transmission drivetrain between an engine having a crankshaft and a gearbox comprising two coaxial input shafts (2, 3) extending along an axis (X), the dual wet clutch (1) having first and second clutches (4, 5) intended to be disposed between the engine having and the gearbox and capable of transmitting a torque from the crankshaft to one and the other of the two input shafts (2, 3) of the gearbox respectively, each of the first and second clutches (4, 5) displaceable between a disengaged position and an engaged position thereof, and comprising:

• an input disc carrier (8, 9) intended to be rotationally coupled to the crankshaft;
• an output disc carrier (15, 30) intended to be rotationally coupled to one or the other of the two input shafts (2, 3) of the gearbox;
• a multiple-disc assemblage (10, 11) having at least one friction disc rotationally integral with one of the input and output disc carriers (8, 9, 15, 30) and at least two plates disposed respectively on either side of each friction disc, rotationally integral with the other of the input and output disc carriers (8, 9, 15, 30) and axially movable to grip the friction disc between the plates so as to transmit the torque between the input disc carrier (8, 9) and the output disc carrier (15, 30);
• a movable force transmission member (25, 38) capable of displacing the multiple-disc assemblage (10, 11) from the disengaged position to the engaged position of one of the first and second clutches (4, 5);
• first and second axial bearings (32, 33);
• and
• a hydraulic control system (21) comprising:
• a housing (41) intended to be fastened onto the gearbox, the housing (41) having an internal tube (42) extending axially around the axis (X) and configuring an internal space intended for passage of the two input shafts (2, 3) of the gearbox, the housing (41) furthermore having first and second annular chambers (43, 44) concentric around the axis (X) and disposed radially around the internal tube (42), the first annular chamber (43) being arranged radially outside the second annular chamber (44);
• first and second annular pistons (45, 46) respectively axially slidingly mounted inside the first annular chamber (43) and the second annular chamber (44), each of the first and second annular pistons (45, 46) axially moveable between an inactive position and an active position, each of the first and second annular pistons (45, 46) carrying a rotating stop (49, 50) configured to interact respectively with first and second force transmission members (25, 38), the first and second force transmission members (25, 38) interacting respectively with one and the other of the two clutches (4, 5) of the dual wet clutch (1) in order to displace one and the other of the clutches (4, 5) between the disengaged position and the engaged position of each of the two clutches (4, 5), the inactive position and the active position of the first and second annular pistons (45, 46) corresponding respectively to the disengaged position and the engaged position of the respective clutches (4, 5);
• the internal tube (42) extending axially toward the two clutches (4, 5) beyond the first and second annular chambers (43, 44) and having at least one flow conduit (55) for a cooling fluid, intended to direct the cooling fluid to the clutches (4, 5), the at least one flow conduit (55) having an output orifice (57) opening axially beyond the rotating stop (49) of the second annular piston (46) regardless of the position of the second annular piston (46) between the inactive position and the active position of the second annular piston (46);
• the first axial bearing (32) interposed between the output disc carrier (15) of the first clutch (4) and the output disc carrier (30) of the second clutch (5), and the second axial bearing (33) interposed between the output disc carrier (30) of the second clutch (5) and the internal tube (42) of the hydraulic control system (21).