A clutch device for a clutch system has an input member that rotates at a first speed. A friction drive system is disposed between the input member and an output member. The clutch device is selectively movable by a fluid actuator assembly, between an engaged position in which the friction drive system drives the output member to rotate at the first speed, and a disengaged position in which a viscous drive system rotates the output member at a second speed slower than the first speed. A variable viscous fluid supply assembly includes a viscous fluid storage chamber, a valve, and a valve actuator that selectively drives the valve to move between an open position and a closed position to control an amount of viscous fluid available to the viscous drive system, thereby varying the second speed.

A temperature-sensitive fluid fan clutch device includes an oil reservoir chamber in a case supported by a rotating shaft that has a drive disk fixed thereto. Plural dams are provided outward of the drive disk, and oil circulating flow passages contiguously to the dams extend between a torque transmission chamber and the oil reservoir chamber. A valve opens and closes an oil circulation flow hole of the oil reservoir chamber due to a change in temperature of a temperature-sensitive body. An oil effective contact area in a torque transmission gap between a drive side and a driven side is varied to control rotation torque transmission from the drive side to the driven side. An oil collection valve member independently opens and closes at least one of the oil circulating flow passages. The temperature-sensitive fluid fan clutch device inhibits a cold “drag” phenomenon and reduces fan power loss and fuel consumption.

A viscous fluid shear device having a housing, a rotor, which is rotatable in the housing, and a wiper that is coupled to the housing. The housing defines a scavenge conduit and a nozzle. Viscous fluid that clings to the circumference of the rotor during operation of the viscous fluid shear device is driven through the nozzle and directed by the wiper into the scavenge conduit.

A clutch device for a clutch system has an input member that rotates at a first speed. A friction drive system is disposed between the input member and an output member. The clutch device is selectively movable by a fluid actuator assembly, between an engaged position in which the friction drive system drives the output member to rotate at the first speed, and a disengaged position in which a viscous drive system rotates the output member at a second speed slower than the first speed. A variable viscous fluid supply assembly includes a viscous fluid storage chamber, a valve, and a valve actuator that selectively drives the valve to move between an open position and a closed position to control an amount of viscous fluid available to the viscous drive system, thereby varying the second speed.

A viscous fluid shear device having a housing, a rotor, which is rotatable in the housing, and a wiper that is coupled to the housing. The housing defines a scavenge conduit and a nozzle. Viscous fluid that clings to the circumference of the rotor during operation of the viscous fluid shear device is driven through the nozzle and directed by the wiper into the scavenge conduit.

A temperature-sensitive fluid fan clutch device includes an oil reservoir chamber in a case supported by a rotating shaft that has a drive disk fixed thereto. Plural dams are provided outward of the drive disk, and oil circulating flow passages contiguously to the dams extend between a torque transmission chamber and the oil reservoir chamber. A valve opens and closes an oil circulation flow hole of the oil reservoir chamber due to a change in temperature of a temperature-sensitive body. An oil effective contact area in a torque transmission gap between a drive side and a driven side is varied to control rotation torque transmission from the drive side to the driven side. An oil collection valve member independently opens and closes at least one of the oil circulating flow passages. The temperature-sensitive fluid fan clutch device inhibits a cold drag phenomenon and reduces fan power loss and fuel consumption.

A clutch device for a clutch system has an input member that rotates at a first speed. A friction drive system is disposed between the input member and an output member. The clutch device is selectively movable by a fluid actuator assembly, between an engaged position in which the friction drive system drives the output member to rotate at the first speed, and a disengaged position in which a viscous drive system rotates the output member at a second speed slower than the first speed. A variable viscous fluid supply assembly includes a viscous fluid storage chamber, a valve, and a valve actuator that selectively drives the valve to move between an open position and a closed position to control an amount of viscous fluid available to the viscous drive system, thereby varying the second speed.

A system and method of anchoring a bimetal coil member on a viscous clutch fan drive. An adjustable channeled retainer member together with a silicone or silicone-type material is used to anchor the free end of the bimetal coil member.

Viscous fan drive systems with wiper members positioned on the OD of the clutch disks, and which rotate at high speed. The fluid reservoir also rotates at input speed. The wiper member directs viscous fluid radially back to the fluid reservoir. The valves in the viscous fan drive systems can be activated by a bimetal mechanism.