US Patent 7364025 Magnetorheological fan coupling

A magnetorheological fan coupling (10) having an inverted construction with an input member (18) rotatably mounted to an output member (20). The input member (18) defines a fluid chamber (50) with the output member (20) rotating therein and a magnetic medium (52) between the output member (20) and the input member (18). The coupling (10) further includes an electromagnet subassembly (14) actuated by a controller (82) for adjusting the shear stress of the magnetic medium (52) and regulating the amount of torque transferred from the input member (18) to the output member (20).