A viscous friction clutch includes a rotor, a housing that is rotatable relative to the rotor, a working chamber located between the rotor and the housing such that a volume of shear fluid can be selectively introduced to the working chamber to contact both the rotor and the housing, an electromagnetic coil, a valve assembly that controls the volume of the shear fluid present in the working chamber, and a flux path that magnetically links the electromagnetic coil and the valve assembly. The flux path passes through a flux guide part made of a ferromagnetic material that extends through the rotor in an interior of the viscous friction clutch and across a flux gap that traverses both an air gap and a non-ferromagnetic portion of the housing.

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 fan clutch assembly includes several features. A first feature relates to a lubrication passage that runs through the clutch package and has a return collection passage that extends through the operating piston. As a result, pitot tubes employed behind the piston may not be necessitated. Additionally, an anti-tamper device may be installed on the lead screw body to prevent adjustment of the fan hub and unintentional adjustment of the load carried on various bearings contained within the fan clutch assembly. Additionally, to position the speed sensor appropriately, a transfer shaft is provided that extends from the fan hub and/or lead screw back to the backside where a sensor is provided. This transfer shaft can be adjusted to precisely locate the sensor target relative to the sensor.

A clutch assembly includes a journal bracket having a center shaft, a drive feature rotatably supported on the center shaft of the journal bracket and configured to accept a torque input to the clutch assembly, a clutch pack that is controllable to selectively transmit torque between an input and an output, a housing attached to the clutch pack that includes a stub shaft, a removable connection engaged between the drive feature and the stub shaft such that torque is transmittable through the removable connection during operation of the clutch assembly, and one or more perpendicular engagement features on the stub shaft configured to accept a tool to engage and disengage the removable connection. At least one of the perpendicular engagement features is exposed to line-of-sight access from a location substantially perpendicular to an axis of rotation of the clutch pack.

A clutch assembly includes a journal bracket having a center shaft, a drive feature rotatably supported on the center shaft of the journal bracket and configured to accept a torque input to the clutch assembly, a clutch pack that is controllable to selectively transmit torque between an input and an output, a housing attached to the clutch pack that includes a stub shaft, a removable connection engaged between the drive feature and the stub shaft such that torque is transmittable through the removable connection during operation of the clutch assembly, and one or more perpendicular engagement features on the stub shaft configured to accept a tool to engage and disengage the removable connection. At least one of the perpendicular engagement features is exposed to line-of-sight access from a location substantially perpendicular to an axis of rotation of the clutch pack.

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 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.