Abstract: A vehicle has a multi-gap magnetorheological fluid (MRF) clutch connecting rotatable input and output members, and includes a drum connected to the output member and a rotor connected to the input member. The drum contains a magnetically-permeable stator and a magnetic core, while the rotor has a magnetically-permeable member extending axially into the drum to define an outer working gap in conjunction with the stator and an inner working gap in conjunction with the magnetic core. MR fluid fills the working gaps, and a magnetic field generator or electromagnet induces a magnetic field when electrical current is passed through a field coil therein to change an apparent viscosity of the MR fluid. The inner and outer working gaps have a predetermined inner to outer gap thickness ratio balancing the slip power dissipation per unit volume in each of the working gaps.

Abstract: The present invention provides an accessory drive system for a vehicle. The accessory drive system includes a planetary gear set having a first, second, and third planetary member. A torque transfer device operatively connects an engine with the first planetary member. A motor/generator is operatively connected to the second planetary member, and a plurality of accessories are operatively connected to the third planetary member. Engine output is transferable through the planetary gear set to drive the accessories, and the speed at which the accessories are driven is selectable by controlling the speed of the motor/generator.

Abstract: A powertrain includes an engine, a multi-speed transmission connected to a final drive, and a selectively engageable magnetorheological fluid clutch drivingly connected between the engine and multi-speed transmission. A motor/generator is operatively connected to the engine and the magnetorheological fluid clutch for selectively exchanging power with the engine and/or the magnetorheological fluid clutch such that the motor/generator may be used to start the engine, to drive the multi-speed transmission, and to receive energy from the magnetorheological fluid clutch for regenerative braking.

Abstract: The present invention provides an accessory drive system for a vehicle. The accessory drive system includes a planetary gear set having a first, second, and third planetary member. A torque transfer device operatively connects an engine with the first planetary member. A motor/generator is operatively connected to the second planetary member, and a plurality of accessories are operatively connected to the third planetary member. Engine output is transferable through the planetary gear set to drive the accessories, and the speed at which the accessories are driven is selectable by controlling the speed of the motor/generator.

Abstract: A magnetorheological (MR) fluid coupling for vectoring torque with respect to a shaft capable of rotary motion is disclosed. The coupling includes a stator, a rotor having a rotational degree of freedom with respect to the stator and configured for physical communication with the shaft, and a magnetic field generator. The stator and rotor define an annular space therebetween and are coupled via a MR fluid disposed within the annular space. The magnetic field generator is in field communication with the MR fluid and is disposed to produce a substantially radially directed magnetic field across the annular space. The rotor is rotationally responsive to the application of a magnetic field at the MR fluid.

Abstract: The present invention provides a method of controlling thermal energy within a fan drive. The fan drive includes an input member rotating at an input speed, and an output member attached to the fan and rotating at a fan speed, with a viscous fluid disposed therebetween. The fluid selectively transmits torque between the input member and the output member such that the fan speed is a function of a controllable parameter of the fluid. The parameter is continually controlled by a programmed controller. The method includes the steps of pre-determining a threshold temperature for the fan drive, with the threshold temperature approaching a maximum desirable temperature for the fan drive, and adjusting the fan speed as necessary to maintain a fan drive temperature below the threshold temperature. The controller may regulate fluid volume or fluid viscosity, or any other controllable parameter of the fluid.

Abstract: A device employing a magneto rheological (MR) fluid in combination with a stator and a rotor is disclosed, where the stator includes a magnetic field generator. The rotor has a rotational axis and a rotational degree of freedom with respect to the stator. The stator and rotor define an annular space therebetween and are coupled via the MR fluid disposed within the annular space, and the magnetic field generator is in field communication with the MR fluid at the annular space. The device includes a means for promoting the formation of stationary stripes of MR fluid within the annular space in response to rotation of the rotor.

Abstract: A method is presented for controlling process delay times between a) thin film deposition and lubricant application, and b) lubricant application and abrasive polishing. Applicants have discovered that for certain lubricants, a minimum delay time after the overcoat has been deposited before the lubricant is applied increases the number of disks passing the glide test after abrasive polishing. In addition, applicants have discovered that for certain lubricants, the abrasive polishing should take place within a maximum time window following the application of the lubricant. A computerized work-in-progress tracking system is preferably used to implement the method of the invention.

Abstract: A starting clutch control includes an engine control state and a slip control state. The engine and slip control states include feedforward and driveline damping control terms. The engine state control may further include an engine speed control term. The slip control state further includes a clutch slip control term. Changes to clutch engagement commands are frozen upon throttle tip-in events.

Abstract: One embodiment of the invention includes an MR fluid of improved durability. The MR fluid is particularly useful in devices that subject the fluid to substantial centrifugal forces, such as large fan clutches. A particular embodiment includes a magnetorheological fluid including 10 to 14 wt % of a hydrocarbon-based liquid, 86 to 90 wt % of bimodal magnetizable particles, and 0.05 to 0.5 wt % fumed silica.

Abstract: One embodiment of the invention includes an MR fluid of improved durability. The MR fluid is particularly useful in devices that subject the fluid to substantial centrifugal forces, such as large fan clutches. A particular embodiment includes a magnetorheological fluid including a liquid, magnetizable particles, a stearate and a thiophosphate.

Abstract: A disk spring assembly including a flat disk between two angled plates is used in an automatic transmission clutch application. The inner peripheral edge and the outer peripheral edge of the disk are deflected in opposite directions relative to each other by the angled plates. The maximum deflection of the disk is defined by the angled plates. The stiffness of the disk increases monotonically with the deflection of the disk resulting in smooth clutch application.

Abstract: One embodiment of the invention includes an MR fluid of improved durability. The MR fluid is particularly useful in devices that subject the fluid to substantial centrifugal forces, such as large fan clutches. A particular embodiment includes a magnetorheological fluid including 10 to 14 wt % of a hydrocarbon-based liquid, 86 to 90 wt % of bimodal magnetizable particles, 0.05 to 0.5 wt % fumed silica, and an additive package including a paraffin oil, a phenol and a sulfide.

Abstract: One embodiment of the invention includes an MR fluid of improved durability. The MR fluid is particularly useful in devices that subject the fluid to substantial centrifugal forces, such as large fan clutches. A particular embodiment includes a magnetorheological fluid including 10 to 14 wt % of a hydrocarbon-based liquid, 86 to 90 wt % of bimodal magnetizable particles, and 0.05 to 0.5 wt % fumed silica.

Abstract: A disk spring assembly including a flat disk between two angled plates is used in an automatic transmission clutch application. The inner peripheral edge and the outer peripheral edge of the disk are deflected in opposite directions relative to each other by the angled plates. The maximum deflection of the disk is defined by the angled plates. The stiffness of the disk increases monotonically with the deflection of the disk resulting in smooth clutch application.

Abstract: A method for reducing oscillation in an automotive transmission system includes detecting a tip-out of an accelerator pedal position. Responsive to the detected tip-out, a pressure command is adjusted for a selected range clutch within the transmission system so as to reduce the pressure of the selected range clutch from a normal pressure level to a low pressure level, thereby producing a desired gear train slip in the transmission system. Then, the pressure command of the selected range clutch is re-adjusted after a determined period of time at the low pressure level so as to increase the pressure of the selected range clutch from the low pressure level, and thereby eliminating the gear train slip.

Abstract: A method for reducing oscillation in an automotive transmission system includes detecting a tip-out of an accelerator pedal position. Responsive to the detected tip-out, a pressure command is adjusted for a selected range clutch within the transmission system so as to reduce the pressure of the selected range clutch from a normal pressure level to a low pressure level, thereby producing a desired gear train slip in the transmission system. Then, the pressure command of the selected range clutch is re-adjusted after a determined period of time at the low pressure level so as to increase the pressure of the selected range clutch from the low pressure level, and thereby eliminating the gear train slip.

Abstract: One embodiment of the invention includes an MR fluid of improved durability. The MR fluid is particularly useful in devices that subject the fluid to substantial centrifugal forces, such as large fan clutches. A particular embodiment includes a magnetorheological fluid including a liquid, magnetizable particles, a stearate and a thiophosphate.

Abstract: One embodiment of the invention includes an MR fluid of improved durability. The MR fluid is particularly useful in devices that subject the fluid to substantial centrifugal forces, such as large fan clutches. A particular embodiment includes a magnetorheological fluid including a liquid, magnetizable particles, a stearate and a thiophosphate.

Abstract: A method is disclosed for controlling the slip power of a viscous fluid fan drive clutch, especially of a cooling fan drive for an automotive vehicle. Data is prepared correlating slip power generation with clutch input and output speeds for the clutch and fan design. A maximum slip power for the operation of the cooling fan is specified by considering, for one, fan drive durability requirements. During operation of a computer based, fan speed control module, a desired fan drive speed is continually determined for the cooling requirements of the vehicle and the desired fan speed is compared, and adjusted, if appropriate, to avoid excessive slip power.