Patent ID: 8789674

Claim:
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 ).