American Motors Corporation

Chrysler Motors Corporation

Robert B Batchelor

Gerald P Hentschel

A transfer case for selectively providing four-wheel drive for a motor vehicle comprises a first clutch for shifting the input torque to and between a high speed power path, a low speed power path and a neutral position, as well as a second clutch for selectively engaging first and second output shafts for connection with the low and high speed power paths. Each clutch includes a slidable collar which is aligned with and slidable along the axis of the input shaft of the transfer case. Preferably, a single selector is used to shift the first and second clutch collars to provide the transfer case with four operating modes: a neutral position in which the input shaft is disengaged from the first and second output shafts, a two-wheel drive high speed output, a four-wheel drive high speed output and a four wheel drive low speed output.

Vehicle drive-train transfer case

The transfer case comprises differential gearing in the form of a single planetary gear set having an annulus, a first set of planet gears in engagement with the annulus, a second set of planet gears in engagement with corresponding planet gears of the first set and a sun gear in engagement with the planet gears of the second set. The input torque supplied by a transmission output member is applied to the annulus so that substantially any portion of the torque can be applied to the sun gear by appropriate sizing of the sun gear with respect to the size of the annulus. In one form of the invention, a planet carrier, upon which the planet gears are rotatably mounted, is connected to one output shaft for rotation therewith and a selectively engageable clutch permits actuation of the transfer case in a two-wheel drive mode, a full-time four-wheel drive with differential action between the front axle drive and the rear axle drive, and a four-wheel drive lock mode in which the second output shaft rotates with the first output shaft. In another form of the invention, a viscous clutch automatically drags the second output shaft for rotation with the first output shaft when the differential torque applied to one of the output shafts exceeds the traction torque load at the wheels driven by that output shaft, and thereby provides a fully automatic, full time, four-wheel drive.

Transfer case for multiple drive axle vehicle

A vehicle transfer case (10) includes first and second planetary gear sets (68,70) and a selector (146) for selectively positioning (a) the first planetary gear set (68) in an operating position and the second planetary gear set (70) in a locked position to provide low speed driving without any differential action between first and second outputs (36,38) or (b) the first planetary gear set (68) in a locked or nonoperating position and the second planetary gear set (70) in an operating position to provide high speed driving with differential action between the first and second outputs (36,38). The second planetary gear set (70) which selectively provides the differential action between the first and second outputs (36,38) has components (106,108,122) all of which are rotatable about a central axis A, and planet gears (126,128) of the planet carrier component (122) are rotatable about axes parallel to the central axis. This construction provides compact axial packaging of the transfer case while still having a differential action between the two outputs (36,38). Both planetary gear sets (68,70) are positioned along a central shaft (40) having one end constituting the first output (36) and are located between an input (28) and an output member (71) connected to the second output (38), to thereby provide compact packaging.

Growing community of inventors

Birmingham, MI, United States of America

Robert B Batchelor