Abstract: A torque transfer mechanism having a multi-plate friction clutch connecting a pair of rotary members and a electrohydraulic clutch actuator for controlling engagement of the friction clutch. The clutch actuator includes a hydraulic pump, a hydraulically-actuated rotary operator, and a ball ramp mechanism. The hydraulic pump draws low pressure fluid from a sump and delivers high pressure fluid to a series of actuation chambers defined between coaxially aligned first and second components of the rotary operator. The magnitude of the fluid pressure delivered to the actuation chamber controls angular movement of the second component relative to the first component for energizing the ball ramp mechanism. The ball ramp mechanism applies a clutch engagement force on the friction clutch assembly, thereby transferring drive torque from the first rotary member to the second rotary member. A hydraulic control system adaptively regulates the fluid pressure delivered to the actuation chamber.

Abstract: A drive axle assembly includes first and second axleshafts connected to a pair of wheels and a drive mechanism operable to selectively couple a driven input shaft to one or both of the axleshafts. The drive mechanism includes a differential, first and speed changing units, and first and second mode clutches. The first mode clutch is operable in association with the first speed changing unit to increase the rotary speed of the first axleshaft which, in turn, causes a corresponding decrease in the rotary speed of the second axleshaft. The second mode clutch is operable in association with the second speed changing unit to increase the rotary speed of the second axleshaft so as to cause a decrease in the rotary speed of the first axleshaft. A control system controls actuation of both mode clutches.

Abstract: A hybrid drive system for a four-wheel drive system arranged to supply motive power to a primary output shaft of a transfer case from an internal combustion engine and to a secondary output shaft from an electric motor/generator. The transfer case is comprised of a planetary gearset having an input driven by the motor/generator and an output directing drive torque to the secondary drivelines. This hybrid drive arrangement permits use of a modified transfer case in place of a conventional transfer case in a traditional four-wheel drive driveline.

Abstract: A controllable, multi-mode, bi-directional overrunning mode clutch and a shift system adapted for use in a power transfer assembly for transferring drive torque from a primary driveline to a secondary driveline so as to establish a four-wheel drive mode. The mode clutch includes a first ring journalled on a first rotary member, a second ring fixed to a second rotary member, and a plurality of rollers disposed in opposed cam tracks formed between the first and second rings. The first ring is split to define an actuation channel between its end segments. A cam member is moveable between positions engaged with and released from one or both end segments of the split first ring. The shift system includes a mode fork which controls movement of the cam member for establishing a two-wheel drive mode in addition to on-demand and locked four-wheel drive modes.

Abstract: A torque transfer mechanism for controlling the magnitude of a clutch engagement force exerted on a clutch pack that is operably disposed between a first rotary member and a second rotary member includes a hydraulic clutch actuation system. The hydraulic clutch actuation system includes a primary fluid circuit coupled to a secondary fluid circuit by a pressure intensifier. The pressure intensifier provides magnified pressure to a piston for actuating the clutch pack.

Abstract: A gear coupler for a power transmission comprises an outer race having an cylindrical inner surface and an inner race having a cylindrical outer surface with spaced apart ramped surfaces. A plurality of rollers are seated between the inner and outer race. A controllable cage has a plurality of cage pins seated between adjacent pairs of rollers and engages the rollers with the ramped surfaces. A shifting ring is coupled to the cage for axial movement therealong for selectively aligning the rollers between the ramped surfaces to disengage the inner race from the outer race and allow relative rotation therebetween and for wedging the rollers against the ramped surface to engage the inner race with the outer race and prevent relative rotation therebetween in response to varying rotational speeds of the inner and outer race.

Abstract: A torque transfer mechanism having a multi-plate friction clutch connecting a pair of rotary members and a electrohydraulic clutch actuator for controlling engagement of the friction clutch. The clutch actuator includes a hydraulic pump, a hydraulically actuated rotary operator, and a thrust mechanism. The hydraulic pump draws low pressure fluid from a sump and selectively delivers high pressure fluid to a series of actuation chambers and return chambers defined between coaxially aligned first and second components of the rotary operator. The magnitude of the fluid pressure delivered to the actuation chamber controls angular movement of the second component relative to the first component for energizing the thrust mechanism. The thrust mechanism applies a clutch engagement force on the friction clutch, thereby transferring drive torque from the first rotary member to the second rotary member. An electrohydraulic control system regulates the fluid pressure delivered to the actuation and return chambers.

Abstract: A torque transfer mechanism having a transfer clutch connecting a pair of rotary members and a electrohydraulic clutch actuator for controlling engagement of the transfer clutch. The clutch actuator includes a hydraulic pump and a hydraulically-actuated rotary operator. The hydraulic pump draws low pressure fluid from a sump and delivers high pressure fluid to a series of actuation chambers defined between coaxially aligned first and second components of the rotary operator. The magnitude of the fluid pressure delivered to the actuation chamber controls angular movement of the second component relative to the first component for energizing a pilot ball ramp unit. The pilot ball ramp mechanism applies a clutch actuation force on a pilot friction clutch which energized a main ball ramp unit for applying a clutch engagement force to a main friction clutch. A hydraulic control system adaptively regulates the fluid pressure delivered to the actuation chamber.

Abstract: A torque transfer mechanism is provided for controlling the magnitude of a clutch engagement force exerted on a multi-plate clutch assembly that is operably disposed between a first rotary and a second rotary member. The torque transfer mechanism includes an actuator having a first cam fixed for rotation with the first rotary member and a second cam having a rotor which is rotatably disposed within a chamber filled with magnetorheological fluid. An electromagnetic coil is disposed in proximity to the chamber and is selectively energized for varying the viscosity of the magnetorheological fluid so as to induce axial movement of the first cam for engaging the multi-plate clutch assembly.