Viscous fluid coupling and improved fluxring for use therein

A fluid coupling device of the type including a first rotatable coupling assembly defining an axis of rotation (A), said first coupling assembly including a first coupling member and a cover member cooperating to define a fluid chamber therebetween;

• valve means associated with said first coupling assembly and disposed to separate said fluid chamber into a fluid operating chamber and a fluid reservoir chamber;
• a second rotatable coupling member disposed in said fluid operating chamber and being rotatable relative to said first coupling member, said first coupling assembly cooperating with said second coupling member to define a viscous shear space therebetween;
• said valve means being operable to control the flow of fluid between said reservoir chamber and said operating chamber, and means operable to pump fluid from said operating chamber into said reservoir chamber;
• said valve means defining a fluid inlet port and a valve member being moveable between an open position permitting fluid flow through said inlet port, and a closed position substantially blocking fluid flow through said inlet port;
• and an actuator assembly operably associated with said first coupling assembly and with said valve means, and operable to move said valve member toward one of said open and closed positions in response to an input;
• said cover member comprising a nonferromagnetic member, and including an annular ferromagnetic member disposed within said cover member and being generally concentric about said axis of rotation (a), and operable to transmit said input from said actuator assembly to said valve means;
• characterized by:
• (a) said annular ferromagnetic member defines a radially inner surface, and extending radially inward therefrom, an annular dovetail portion;
• (b) said dovetail portion defining at least one radially outer surface;
• and
• (c) said cover member including a cast central portion disposed radially inwardly of said annular ferromagnetic member, said cast central portion being disposed in sealing engagement with said radially outer surface of said dovetail portion.