Dana Corporation

Joseph A Dick

Wesley M Dick

David C Reuter

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. The system further includes a clutch having first and second sets of plates which are rotatably coupled to the first and second rotating members, respectively, wherein individual plates of the first and second sets are disposed in axially alternating relationship with one another. At least one restricted vent passage extends through the actuating member of the piston for venting the hydraulic fluid from the piston chamber to the housing sump when the pressure of the hydraulic flow is below a predetermined pressure. A spring element resiliently separates the actuating member and the clutch until the pressure of the hydraulic fluid reaches the predetermined pressure whereby the actuating member is urged against the clutch which closes the vent passage causing the actuating member to compress the clutch so as to rotatably couple the first and second rotating members of the drivetrain subassembly to one another.

Hydromechanical system for limiting differential speed between

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. A stop pin is provided to limit rotation of the eccentric ring to 180.degree. in either direction and, once the ring is restrained from further rotation by the stop pin, the pressure of the spring end on the ear causes the spring's diameter to slightly increase, thereby reducing wear on the outer diameter of the outer rotor.

Reversible gerotor pump

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.

Electronic clutch control mechanism for a vehicle transmission

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. Pilot clutch activating devices are provided for selectively activating, and thereby selectively grounding, the first and second pilot clutches, wherein activating one of the first and second pilot clutches causes the second rotating member to translate axially relative to the first rotating member so as to load the drivetrain subassembly clutch, and wherein activating the other of the first and second pilot clutches causes the second rotating member to translate axially relative to the first rotating member so as to unload the drivetrain subassembly clutch.

Clutch actuating device for use in a vehicle drivetrain subassembly

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. The assembly also incorporates means for selectively compressing the clutch pack, including an actuator plate spaced by an air gap an effective distance from an electromagnet disposed between the actuator plate and the clutch pack. A pressure plate is disposed adjacent the clutch pack, the pressure plate being connected to the actuator plate by means of a plurality of legs. Upon actuation of the electromagnet, the actuator plate is drawn towards the electromagnet, moving the plurality of legs axially and urging the pressure plate against the clutch pack.

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Fort Wayne, IN, United States of America

Joseph A Dick