Electronically controlled magnetorheological fluid based cooling fan drive assembly

An electronically controlled magnetorheological fluid based fan drive assembly 60, the assembly 60 being coupled to a fan to cool a closely coupled radiator, the assembly comprising:

• a cover 82 having a rotating portion;
• a plurality of fins 100a coupled to said rotating portion, said fins 100a used to cool the electronically controlled magnetorheological fluid based fan drive assembly 60 when said rotating portion is rotating;
• an input shaft 68 rotatably mounted to said rotating portion;
• a drive ring 74 coupled to said input shaft 68;
• a plurality of drive ring partial concentric hoops 76 coupled to said drive ring 74;
• an upper steel ring 70 coupled to said rotating portion;
• a lower steel ring 72;
• a driven ring 84 coupled to said upper steel ring 70 and said lower steel ring 72;
• a plurality of driven ring partial concentric hoops 90 coupled to said driven ring 84;
• a working chamber 99 between said drive ring 74 and said driven ring 84;
• a non-rotating coil 62 located between said upper steel ring 70 and said lower steel ring 72;
• an electronic control unit coupled to said non-rotating coil, wherein said electronic control unit controls an amount of electrical current flowing through said non-rotating coil 62;
• and
• a quantity of magnetorheological fluid contained within said working chamber 99, wherein the rotation of said drive ring 74 causes a portion of said quantity of magnetorheological fluid to shear within said working chamber 99 to rotate said driven ring 84.