Abstract: A pump assembly includes a pump housing, a stator ring supported within the pump housing, and a pump ring also rotatably supported within the pump housing. The pump ring interfaces with the stator ring to define a plurality of variable volume pressure chambers. A cover plate covers the stator ring and pumping ring within the pump housing. The cover plate is axially displaceable relative to the pump housing and defines a wall of each of the pressure chambers. Pressure within the pressure chambers induces linear movement of the cover plate away from the stator ring and the pump ring.

Abstract: A hydraulic coupling having a multi-plate friction clutch assembly operably connecting a pair of rotary members and a hydramechanical clutch actuator for automatically controlling engagement of the friction clutch assembly. The clutch actuator includes a hydraulic fluid pump, a hydraulically-actuated rotary operator, and a ball ramp mechanism. The hydraulic fluid pump is operable to draw low pressure fluid from a sump and deliver 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 the angular movement of the second component relative to the first component. Translational movement of the second cam member results in a compressive clutch engagement force being exerted on the friction clutch assembly, thereby controlling the drive torque transferred from the first rotary member to the second rotary member.

Abstract: A drive axle assembly for an all-wheel drive vehicle includes an adaptively controlled first hydraulic coupling for providing front-to-rear torque transfer control to a first wheel and an adaptively controlled second hydraulic coupling for providing front-to-rear torque control to a second wheel. The drive axle assembly is contained with a common housing and communicates with a traction control system to actively control actuation of the first and second hydraulic couplings based on the operating characteristics of the vehicle as detected by suitable sensors.

Abstract: A transfer case is provided with a range unit, an interaxle differential, a clutch assembly and a power-operated actuation mechanism. The range unit includes a planetary gearset driven by an input shaft, and a synchronized dog clutch assembly for releasably coupling one of the input shaft or an output component of the planetary gearset to an input member of the interaxle differential. The interaxle differential further includes a first output member driving a first output shaft, a second output member operably driving a second output shaft. The clutch assembly is a multi-plate friction clutch operably disposed between the first and second output shafts. The power-operated actuation mechanism includes a range actuator assembly, a ball-ramp clutch actuator assembly and a motor assembly operable to control actuation of the range actuator assembly and the clutch actuator assembly.

Abstract: A drive axle assembly includes a pair of axleshafts connected to a pair of wheels, and a drive mechanism for selectively coupling a driven input shaft to one or both of the axleshafts. The drive mechanism includes first and second drive units that can be selectively engaged to control the magnitude of the drive torque transferred and the relative rotary speed between the input shaft and the axleshafts. Each drive unit includes a planetary gearset disposed between the input shaft and its corresponding axleshaft, and a pair of mode clutches that may be activated to cause the planetary gearset to establish different speed ratio drive connections between the input shaft and the axleshaft. A control system including an electronic control unit (ECU) and sensors are provided to control actuation of the clutches so as to control the side-to-side traction characteristics of the drive axle assembly.

Abstract: A drive axle assembly for use in an all-wheel drive vehicle having a first hydraulic coupling operable to automatically transfer drive torque to a secondary driveline in response to slip of the primary driveline and a second hydraulic coupling operable to bias torque and limit slip between the wheels of the secondary driveline. The first hydraulic coupling is electronically-controlled.

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.

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 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 a clutch actuator assembly for generating and applying a clutch engagement force on the clutch assembly. The clutch actuator assembly includes an electric motor/brake unit, a torque/force conversion mechanism, and a force amplification mechanism. The motor/brake unit can be operated in either of a motor mode or a brake mode to cause bi-directional linear movement of an output member of the torque/force conversion mechanism. The thrust force generated by the torque/force conversion mechanism is increased by the force amplification mechanism with the resultant clutch engagement force applied to the clutch assembly. The dual mode feature of the electric motor/brake unit significantly reduces the power requirements.

Abstract: A drive axle assembly for an all-wheel drive vehicle includes an adaptively controlled first hydraulic coupling for providing front-to-rear torque transfer control to a first wheel and an adaptively controlled second hydraulic coupling for providing front-to-rear torque control to a second wheel. The drive axle assembly is contained with a common housing and communicates with a traction control system to actively control actuation of the first and second hydraulic couplings based on the operating characteristics of the vehicle as detected by suitable sensors.

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 a clutch actuator for generating and applying a clutch engagement force on the clutch assembly. The clutch actuator includes a wedge fork having a gear rack segment and a tapered tang segment and a reaction block defining a tapered edge in sliding engagement with the tapered tang segment. An electric motor drives a pinion that is meshed with the gear rack to cause bi-directional linear movement of the wedge fork which causes corresponding sliding movement of the reaction block relative to the clutch assembly.

Abstract: The present invention discloses a preferred method for operating a adaptive clutch system of the type used in a motor vehicle power transfer assembly by employing a dithered control signal. One aspect of the present invention superimposes a dithering signal onto a control signal by nulling consecutive blocks of control signal pulses. Another aspect of the present invention provides a method for generating a dithered control signal by providing a wave function with which to systematically vary a duty cycle of the dithered control signal. A method for varying the output force of a clutch actuator assembly in response to the dithered control signal is also provided.

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 segment fixed for rotation with the first rotary member and a second segment having a screw thread formed thereon which is rotatably and slidably 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 actuator for engaging the multi-plate clutch assembly.

Abstract: A transfer case is provided and includes a first output shaft driven by a powertrain and operably interconnected with a first pair of wheels, a second output shaft selectively driven by the first output shaft and operably interconnected with a second pair of wheels and a transfer gear assembly operably disposed between the first output shaft and the second output shaft for transferring drive torque from the first output shaft to the second output shaft. The transfer gear assembly includes a first transfer gear in selective drive connection with the first output shaft, a second transfer gear in meshed engagement with the first transfer gear, a third transfer gear in drive connection with the second transfer gear and the second output shaft. A clutch pack is operably disposed between the first output shaft and the first transfer gear for selectively establishing drive connection therebetween.

Abstract: A transfer case includes a two-speed range unit, a friction clutch, an actuation mechanism, and a control system. The actuation mechanism includes an electric motor, a geartrain driven by the motor, a range actuator assembly and a mode actuator assembly. The range actuator assembly includes a driveshaft driven by the geartrain, a cam driven by the driveshaft, and a shift fork having a follower retained in a groove formed in the cam and a fork engaging a shift collar associated with the range unit. The mode actuator assembly has a cam member with ramp surfaces and a control gear with rollers engaging the ramp surfaces. The control gear is rotatively driven by the geartrain. The cam member is axially moveable for controlling engagement of the friction clutch. An anti-rotation mechanism limits rotation of the cam member in response to continued rotation of the control gear.

Abstract: A transfer case having an input shaft driven by a powertrain, a first output shaft adapted for connection to a first driveline, a second output shaft adapted for connection to a second driveline, an interaxle differential operably disposed between the input shaft and the first and second output shafts, and a torque transfer mechanism. The torque transfer mechanism includes a friction clutch assembly operably disposed between the first output shaft and the second output shaft, and a clutch actuator assembly for generating and applying a clutch engagement force to the friction clutch assembly. The clutch actuator assembly includes an electric motor, a geared reduction unit, and a clutch apply operator. A control system including vehicle sensors and a controller are provided to control actuation of the electric motor.

Abstract: A power transfer system is provided and equipped with a torque transfer coupling which includes a clutch and a ball-screw actuator. The ball-screw actuator functions to axially translate an apply plate via a closed hydraulic system to operatively engage the clutch and vary the frictional engagement thereof.

Abstract: A hybrid transfer case includes a mainshaft, front and rear output shafts, an electric motor/generator connected to the mainshaft, and an input clutch for selectively coupling the transmission to the mainshaft. The transfer case further includes a planetary gearset having a sun gear driven by the mainshaft, a ring gear, and planet gears supported from a carrier. A direct clutch is operable to selectively couple the rear output shaft for rotation with the input shaft. A low brake is operable to selectively brake rotation of the ring gear. A transfer clutch controls the amount of drive torque delivered through a transfer assembly to the front output shaft. A hybrid control system is provided for controlling actuation of the various clutch and brake assemblies and the electric motor/generator to establish various drive modes.

Abstract: An on-demand two-speed transfer case is equipped with a planetary gearset assembly and a range shift mechanism to provide high-range and low-range drive connections. The transfer case is also equipped with a dual-mode bi-directional overrunning clutch and a mode shift mechanism to establish on-demand and part-time four-wheel drive modes.