Abstract: An improved magnetorheological (MR) fluid fan drive design is disclosed. A critical area in the design of such fan drives is the gap for MR fluid between the rotor ring and the corresponding structure of the stator. The stator member must confine the MR fluid in the gap and the applied magnetic field for the fluid and the field coil close to it. In this disclosure a ferrous alloy stator insert is made as one piece and cast within a larger aluminum alloy stator body. A slot for the rotor ring is cut through stator insert separating it into two pieces that remain supported by the aluminum body. The magnetically permeable insert pieces confine the fluid and the magnetic field at the fluid gap around the rotor, and one of the stator insert pieces supports the field coil next to the gap.

Abstract: An improved magnetorheological (MR) fluid fan drive design is disclosed. A critical area in the design of such fan drives is the gap for MR fluid between the rotor ring and the corresponding structure of the stator. The stator member must confine the MR fluid in the gap and the applied magnetic field for the fluid and the field coil close to it. In this disclosure a ferrous alloy stator insert is made as one piece and cast within a larger aluminum alloy stator body. A slot for the rotor ring is cut through stator insert separating it into two pieces that remain supported by the aluminum body. The magnetically permeable insert pieces confine the fluid and the magnetic field at the fluid gap around the rotor, and one of the stator insert pieces supports the field coil next to the gap.

Abstract: A clutch includes an input element with an engaged input shaft and clutch plate rotatable in concert. The clutch plate has an annular portion with a clutch plate set of lands and grooves mating with a housing set of lands and grooves to define a shear zone space. A cover is included as part of the housing and engages the body and includes a reservoir. A pump plate is captured between the cover and the body separating out a working chamber generally within the body and includes a pump port. The pump port includes an outer extreme edge that is substantially in line with the outer surface of the clutch plate. A valve port in the pump plate is positioned near the radial outside of the reservoir. A control arm normally closes the valve port and is movable to open the valve port.

Abstract: A clutch includes an input shaft with a clutch plate engaged with the input shaft to rotate in concert therewith. The clutch plate has an annular disk portion with a clutch plate set of lands and grooves. A housing includes a body supported on the input shaft by a bearing with a body set of lands and grooves mating with the clutch plate set of lands and grooves. A cover is included as part of the housing and engages with the body. A pump plate is captured between the cover and the body separating out a working chamber. The pump plate includes an engage port and a pump-out port positioned further radially outward in the pump plate than the engage port. A control arm normally closes the engage port and is rotatable to open the engage port. A slide-block is carried in a pocket of the cover with a spring biasing the slide-block toward engagement with the control arm. The slide-block locks the control arm against rotation when the clutch is inactive.