Patent ID: 7913826

Claim:
An electronically controlled viscous fluid coupling assembly for a fan comprising: (a) an output member configured for attachment to a fan; (b) an input member bearing mounted to said output member and rotatable around said output member and at input speed, said input member comprising a body member and a cover member; (c) a stationary mounting member bearing coupled to said input member; (d) a viscous fluid supply mechanism positioned within said input member and comprising a rotor member having a scavenge passageway, a reservoir plate member having a fluid aperature, a fluid reservoir, a fluid chamber, a working chamber and a quantity of viscous fluid; (e) an electromagnetic member mounted on said stationary mounting member; (f) an electromagnetically actuated valve mechanism for controlling viscous fluid engagement of said output member with said input member, said valve mechanism having a moveable member for opening, partially opening and covering said fluid aperature port responsive to a magnetic field generated by said electromagnetic member; and (g) a check valve mechanism in said body member for preventing drain back of viscous fluid; (h) said check valve mechanism positioned adjacent said working chamber and in fluid communication with said working chamber and said scavenge passageway; wherein controllability and response of the viscous fluid coupling assembly are improved; and wherein the operation and the speed of a fan member is controlled by said viscous fluid coupling assembly without a wire tether member.