Abstract: The invention provides a hydromechanical system for limiting differential speed between first and second rotating members of a vehicle drivetrain subassembly. The hydromechanical system comprises a casing disposed within a housing of the subassembly which is rotatably coupled to the first rotating member of the drivetrain subassembly. Hydraulic fluid is supplied from a sump within the drivetrain subassembly housing to a reversible hydraulic pump disposed within the casing, wherein the reversible hydraulic pump pumps hydraulic fluid in response to relative rotation between the first and second rotating members. A piston assembly is disposed within the casing which includes a guide member, an actuating member and a chamber disposed therebetween, wherein the chamber receives the pumped hydraulic fluid.

Abstract: A reversible gerotor pump and a drivetrain subassembly including the reversible pump, wherein the pump includes inner and outer rotors located within an eccentric ring and also includes a drag spring mechanism, such as a band spring, positioned around and frictionally engaged with a portion of the outer rotor. Frictional engagement between the outer pump rotor and the band spring permits the outer pump rotor to apply a rotational force to the eccentric ring when the outer rotor reverses direction, thereby ensuring positive rotation of the eccentric ring 180.degree. upon reversal of the pump. The spring may be a split-band spring having a free diameter which is smaller than the outer diameter of the outer rotor, and the eccentric ring preferably includes an ear projecting radially inwardly and positioned between the ends of the band spring. In this manner, rotation of the outer rotor and spring causes rotation of the eccentric ring through force applied on the eccentric ring at the ear.

Abstract: The invention provides a hydromechanical system for limiting differential speed between first and second rotating members of a vehicle drivetrain subassembly. The hydromechanical system comprises a casing disposed within a housing of the subassembly which is rotatably coupled to the first rotating member of the drivetrain subassembly. Hydraulic fluid is supplied from a sump within the drivetrain subassembly housing to a reversible hydraulic pump disposed within the casing, wherein the reversible hydraulic pump pumps hydraulic fluid in response to relative rotation between the first and second rotating members. A piston assembly is disposed within the casing which includes a guide member, an actuating member and a chamber disposed therebetween, wherein the chamber receives the pumped hydraulic fluid.

Abstract: The present invention is directed to an electronic clutch control mechanism for use in a vehicle transmission such as a four wheel drive transfer case which is utilized to control engagement of a clutch between two wheel drive, automatic ("on demand" four wheel drive), and "part-time" four wheel drive operating modes.

Abstract: A clutch actuating device for use in a vehicle drivetrain subassembly having a clutch and a rotatable drive member, comprising a first rotating member which is coupled to the drive member and a second rotating member which is free to rotate relative to the drive member. The first and second rotating members are differentially driven by a gear device and may include first and second ramp surfaces which engage one another so as to permit axial translation of the members relative to one another or alternatively, may comprise threaded screw members which engage one another so as to permit axial translation relative to one another. First and second pilot clutches comprising at least one rotatable plate are provided, with at least one of the pilot clutches being connected to the gear device.

Abstract: The present invention relates to a differential gear assembly including a rotatable case having an annular gear formed therein with first and second axle shafts journalled in the case for rotation relative thereto. A sun gear is connected to the first axle shaft for rotation therewith, and a planetary carrier is connected to the second axle shaft for rotation therewith. A plurality of pairs of planetary gears is supported on the carrier, with a first gear of each of the pairs meshing with the annular gear and a second of each of the pairs meshing with the sun gear. Clutch means are provided for limiting relative rotation between the first axle shaft and the second axle shaft by clutching the sun gear to the planetary carrier, the clutch means including a clutch pack formed of a plurality of annular clutch disks.