Fluid coupling device

Claim 1

A fLuid coupling device comprising relatively rotatable first and second coupling members, said second coupling member defining a working chamber having at least a portion of said first coupling member disposed therein, said working chamber being adapted to contain a quantity of viscous fluid to enable torque to be transmitted between said first and second coupling members, wall means for defining a fluid reservoir, said wall means including an inner wall mounted on said second coupling member and separating said working chamber from said fluid reservoir and an outer wall mounted on said second coupling member spaced apart from and cooperating with said inner wall to at least partially define the fluid reservoir, said inner wall having a first opening formed therein for providing fluid communication between said working chamber and said fluid reservoir, said outer wall having a second opening formed therein, and flow control means for regulating fluid flow through said first opening to at least partially control the quantity of fluid in said working chamber, said flow control means comprising a rotatable shaft member extending through said second opening in said outer wall, a valve member comprising a single valve arm mounted on an inner end portion of said shaft and located in said reservoir adjacent to said inner wall, said valve member being movable relative to said inner wall between a closed position in which an outer end portion of said valve arm covers said first opening to block fluid flow through said first opening and an open position in which the outer end portion of said valve arm at least partially uncovers said first opening to enable fluid to flow through said first opening, seal means disposed in said second opening between said shaft and said outer wall for preventing leakage of fluid from said reservoir through said second opening, for axially positioning said shaft during assembly to locate said valve member adjacent to said inner wall and for thereafter retaining said shaft against axial movement to maintain said valve member adjacent to said inner wall during movement of said valve member between the open and closed positions, said seal means including an outer rim portion disposed in engagement with opposite sides of said outer wall to retain said seal means against axial movement relative to said outer wall, said shaft member having opposing surfaces disposed in abutting engagement with inner and outer surface areas of said seal means to retain said shaft member in a predetermined axial position relative to said outer wall and to retain said valve member against movement toward and away from said inner wall, and temperature-responsive means operatively connected to said outer wall and an outer end portion of said shaft member for effecting rotational movement to said shaft and valve member in response to variations in temperature to thereby effect movement of said valve member between the open and closed positions with variations in temperature.