Torque transmission system, in particular for a vehicle

A torque transmission system comprising:

• a gearbox housing (16) having a shaft opening (22);
• a gearbox input shaft (24) connected to a gearbox (14) within said gearbox housing (16);
• a wet clutch arrangement (12) including a housing arrangement (26) having an interior space (34) filled or fillable with fluid;
• a first friction surface formation (46) rotatable around an axis of rotation (A) with said housing arrangement (26);
• a second friction surface formation (54) rotatable around the axis of rotation (A) with a driven element (60) of a vibration damper;
• said housing arrangement (26) comprising a hub (40) enclosing said gearbox input shaft (24) and extending into said shaft opening (22) of said gearbox housing (16);
• a bearing/seal arrangement (42) for rotatably supporting said hub (40) so as to be substantially fluid-tight with respect to said gear box housing (16);
• said housing arrangement (26) further comprising in said hub (40) at least one first fluid port (97) in communication with said interior space (34) and an intermediate space (98) defined between said hub (40) and said gearbox housing (16);
• and
• at least one second fluid port (104) in communication with said intermediate space (98) and disposed in at least one of said gearbox housing (16) and said bearing/seal arrangement (42) so as to bypass said bearing/seal arrangement (42);
• wherein said friction surface formations (46, 54) have a radial extension;
• and said at least one second fluid port (104) is arranged radially outwardly of said radial extension of said friction surface formations (46, 54);
• said torque transmission system additionally comprising a closure arrangement (102, 128) at said gearbox housing (16) and wherein said intermediate space region (98) is bounded substantially by said gearbox housing (16) and said closure arrangement (102, 128);
• wherein said closure arrangement (102, 108) is rotatably connected in a fluid-tight manner with respect to said hub region (36);
• and
• additionally comprising a flow path (90) leading to said at least one first fluid port (97), said flow path at least partially defined in the housing arrangement (26) by said hub (40) and said driven element (60).