Remote sensing fan drive

A viscous fluid clutch rotatable about an axis of rotation and adapted to be controlled by a sensing element spaced apart from the fluid clutch comprising an axially extending shaft disposed on the axis of rotation, a first member secured to said shaft for rotation therewith, a second member rotatably disposed on said shaft relative to said first member, shear surfaces disposed on said first and second members and forming an operating chamber therebetween, a fluid storage chamber disposed adjacent to said operating chamber, valve means effecting selective communication between said storage chamber and said operating chamber including a valve member having a first and a second position, one of said positions providing for fluid communication between said storage chamber and said operating chamber and the other of said positions blocking said fluid communication, fluid means disposed within said storage chamber and being selectively displaced into said operating chamber when said valve member is in said one position to provide in said operating chamber a medium to transmit rotational movement from one of said members to the other of said members, pump means in said operating chamber to displace said fluid means from said operating chamber to said storage chamber, said shaft having a cavity therein disposed coaxial to said axis of rotation, an electromagnetic coil disposed in said cavity having an opening therein disposed coaxial to said axis of rotation and defined by an inner surface of said coil, and an elongate armature member disposed coaxial to said axis of rotation and having an outer surface located at least partially within said axial opening, said armature member being movable in an axial direction upon energization of said coil, said coil when energized establishing a flux field which sequentially passes from said coil, through said armature and back to said coil, said armature member being operatively connected to said valve member to effect movement of said valve member between said first and second positions in response to energization of said coil.

A cooling system for an internal combustion engine comprising a fan for directing a cooling medium, a viscous fluid clutch for driving said fan and adapted to be controlled by a sensing element spaced apart from the fluid clutch, said fluid clutch including an axially extending shaft adapted to rotate about an axis of rotation, a first member secured to said shaft for rotation, a second member rotatably disposed on said shaft relative to said first member, shear surfaces disposed on said first and second members and forming an operating chamber therebetween, a fluid storage chamber disposed adjacent to said operating chamber, valve means effecting selective communication between said storage chamber and said operating chamber and including a valve member having a first and a second position, one of said positions providing for fluid communication between said storage chamber and said operating chamber and the other of said positions blocking such fluid communication, fluid means disposed within said storage chamber and being selectively displaced into said operating chamber when said valve member is in said one position to provide in said operating chamber a medium to transmit rotational movement from one of said members to the other of said members, and pump means in said operating chamber to displace said fluid means from said operating chamber to said storage chamber, a water pump connected to said viscous fluid clutch for driving said shaft and said first member, said shaft including a cavity located therein coaxial to said axis of rotation, an electromagnetic coil having an axial opening therein defined by an inner surface of said coil, said coil being disposed in said cavity with said axial opening in said coil being disposed coaxial to said axis of rotation, and an armature member having an outer surface located at least partially within said axial opening with said outer surface of said armature member being disposed contiguous to said inner surface of said coil, said armature member being movable in an axial direction upon energization of said coil, said armature member being operatively connected to said valve member to effect movement of said valve member between said first and second positions in response to energization of said coil.