Abstract: A light-weight transfer case is provided for implementation with a four-wheel drive vehicle. The light-weight transfer case includes a single-piece housing formed through either a lost-foam magnesium or die cast process. First and second output shafts are included which are formed from single-piece tubing through either a hydro-forming or swaging process. The first and second output shafts are lighter weight and maintain increased strength over traditional transfer case output shafts. A gear reduction unit is also included for establishing high, low and neutral speeds of the first and second output shafts. Furthermore, a mode selection device is included for selectively providing drive to either a single output shaft, in a two-wheel drive mode, or both the first and second output shafts, in a four-wheel drive mode.

Abstract: A power transfer system is provided and equipped with a torque transfer coupling which includes a stage 2 clutch and a clutch actuator. The clutch actuator includes stage 1 and stage 2 ball ramp actuators as well as a stage 1 clutch operably positioned between the ball ramp actuators to operatively engage the stage 2 clutch and vary the frictional engagement thereof.

Abstract: A torque transfer system is disclosed which is particularly well-suited for use in four-wheel drive transfer cases to establish distinct two-wheel and four-wheel drive modes as well as providing an automatic (“on-demand”) four-wheel drive mode. The torque through system includes a planetary gearset having a first component driven by an input member, a second component driving an output member, and a third component driven by a worm gearset. The worm gearset includes a worm gear fixed for rotation with the third component and a worm meshed with the worm gear. A variable speed motor drives the worm for varying the speed ratio between the first and third components of the planetary gearset, thereby causing a corresponding variation in the drive torque transferred from the input member to the output member.

Abstract: A power transfer system is provided and equipped with a torque transfer coupling which includes a stage 2 clutch and a clutch actuator. The clutch actuator includes stage 1 and stage 2 ball ramp actuators as well as a stage 1 clutch operably positioned between the ball ramp actuators to operatively engage the stage 2 clutch and vary the frictional engagement thereof.

Abstract: A torque transfer system is disclosed which is particularly well-suited for use in four-wheel drive transfer cases to establish distinct two-wheel and four-wheel drive modes as well as providing an automatic (“on-demand”) four-wheel drive mode. The torque through system includes a planetary gearset having a first component driven by an input member, a second component driving an output member, and a third component driven by a worm gearset. The worm gearset includes a worm gear fixed for rotation with the third component and a worm meshed with the worm gear. A variable speed motor drives the worm for varying the speed ratio between the first and third components of the planetary gearset, thereby causing a corresponding variation in the drive torque transferred from the input member to the output member.

Abstract: A light-weight transfer case is provided for implementation with a four-wheel drive vehicle. The light-weight transfer case includes a single-piece housing formed through either a lost-foam magnesium or die cast process. First and second output shafts are included which are formed from single-piece tubing through either a hydro-forming or swaging process. The first and second output shafts are lighter weight and maintain increased strength over traditional transfer case output shafts. A gear reduction unit is also included for establishing high, low and neutral speeds of the first and second output shafts. Furthermore, a mode selection device is included for selectively providing drive to either a single output shaft, in a two-wheel drive mode, or both the first and second output shafts, in a four-wheel drive mode.

Abstract: A torque transfer system is disclosed which is particularly well-suited for use in four-wheel drive transfer cases to establish distinct two-wheel and four-wheel drive modes as well as providing an automatic (“on-demand”) four-wheel drive mode. The torque through system includes a planetary gearset having a first component driven by an input member, a second component driving an output member, and a third component driven by a worm gearset. The worm gearset includes a worm gear fixed for rotation with the third component and a worm meshed with the worm gear. A variable speed motor drives the worm for varying the speed ratio between the first and third components of the planetary gearset, thereby causing a corresponding variation in the drive torque transferred from the input member to the output member.

Abstract: A light-weight transfer case is provided for implementation with a four-wheel drive vehicle. The light-weight transfer case includes a single-piece housing formed through either a lost-foam magnesium or die cast process. First and second output shafts are included which are formed from single-piece tubing through either a hydro-forming or swaging process. The first and second output shafts are lighter weight and maintain increased strength over traditional transfer case output shafts. A gear reduction unit is also included for establishing high, low and neutral speeds of the first and second output shafts. Furthermore, a mode selection device is included for selectively providing drive to either a single output shaft, in a two-wheel drive mode, or both the first and second output shafts, in a four-wheel drive mode.

Abstract: A power transfer device for a motor vehicle having a modular housing assembly which supports a geartrain. A first embodiment of the modular housing assembly includes a case having unitary sidewall with terminal edges defining two opposed openings. The sidewall also defines an interior chamber and the openings are enclosed by a pair of cover plates. Pillow blocks are used to support the drive components of the geartrain within the chamber and are secured to shelves which extend from the sidewall. Loads created during operation are transmitted from the geartrain to the sidewall. The cover plates are secured to the terminal edges of the sidewall using a plurality of U-shaped spring clamps. A second embodiment of the modular housing assembly includes a box-like case having one open side. A cover plate is used to enclose the geartrain and lubrication fluid within the interior volume of the box-like case.

Abstract: A power transfer device for a motor vehicle having a modular housing assembly which supports a geartrain. A first embodiment of the modular housing assembly includes a case having unitary sidewall with terminal edges defining two opposed openings. The sidewall also defines an interior chamber and the openings are enclosed by a pair of cover plates. Pillow blocks are used to support the drive components of the geartrain within the chamber and are secured to shelves which extend from the sidewall. Loads created during operation are transmitted from the geartrain to the sidewall. The cover plates are secured to the terminal edges of the sidewall using a plurality of U-shaped spring clamps. A second embodiment of the modular housing assembly includes a box-like case having one open side. A cover plate is used to enclose the geartrain and lubrication fluid within the interior volume of the box-like case.

Abstract: A hydraulic shift system for a four-wheel drive transfer case is disclosed. The hydraulic shift system includes a pump, a pressure regulator, an accumulator, a control valve, a range shift assembly, a mode shift assembly, and a shift actuator. The pump supplies hydraulic pressure to the accumulator which is in communication with the control valve. The shift actuator controls the delivery of hydraulic pressure from the control valve to the range shift assembly and the mode shift assembly in response to actuation by the vehicle operator of a mode select mechanism.

Abstract: The present invention is directed to an improved power transfer system for use in four-wheel drive vehicles having a transfer case equipped with a torque transfer arrangement that is operable for automatically controlling the drive torque delivered to the front and rear drivelines of the vehicle and establishing an on-demand four-wheel drive mode.