Patent ID: 6189669
Filing Date: 2001-02-20
Classification: F16D

Abstract:
A friction device comprising:a drive member and a driven member which are rotatable about a common axis and which define a clutch housing therebetween;a clutch pack interposed between said drive and driven members and operable to connect and disconnect said drive and driven members for transferring and interrupting torque therebetween;a piston assembly supported in said clutch housing and defining a first expandable chamber between said piston assembly and said clutch housing;a first source of pressurized fluid in communication with said first expandable chamber, said piston assembly being responsive to the pressure of fluid in said expandable chamber to move between disengaged and engaged positions thereby actuating said clutch pack to connect and disconnect said drive and driven members;said piston assembly including a main body, a housing extension having an outer ring slidably disposed therein;said housing extension and said outer ring forming a second expandable chamber;a seal for sealing between said housing extension and said main body;said outer ring including at least one orifice extending through said outer ring;a second source of pressurized fluid in communication with said second expandable chamber for supplying fluid to said outer ring;said outer ring being movable between a first position wherein said orifice is closed and said drive and driven members are disconnected and a second position wherein said orifice is opened by movement of said piston to allow flow of said second source of pressurized fluid through said orifice and into contact with said clutch pack thereby cooling same when said drive and driven members are operatively connected through said clutch pack.