Split rotor cooling fan clutch

摘要

A split rotor cooling fan clutch includes an input member that is constantly driven at engine speed, or at some selected proportion thereof. An output member is journaled on the input member so as to be supported thereon in a substantially nonrotating state when decoupled and alternately, to be concentrically rotatable in concert therewith at a variety of speeds. A space presented between the input and output members contains a quantity of magnetorheological fluid. An engagement mechanism includes the split rotor and coil, with a ferromagnetic element positioned to define an operative gap between the rotor and the ferromagnetic element. The coil is selectively energized with a given current to result in a torque transfer between the input and output elements that provides a rotational speed of the fan tailored to the cooling requirements of the associated engine. Internal heat generation is managed electronically to prevent overheating.