The present disclosure relates generally to four-wheel drive motor vehicles and, more particularly, to a transfer case equipped with a dual spiral bevel gear arrangement.
In view of increased demand for four-wheel drive vehicles, many different power transfer systems are currently being incorporated into vehicular drivetrain applications for transferring drive torque to all four wheels. In some vehicles, a transfer case is interconnected between primary and secondary drivelines. The transfer case may be equipped with a dog-type mode clutch that can be selectively engaged for rigidly coupling the secondary driveline to the primary driveline to establish a part-time, four-wheel drive mode. When the mode clutch is disengaged, all drive torque is delivered to the primary driveline for establishing a two-wheel drive mode.
Many existing transfer cases are equipped with a rear output shaft extending parallel to a front output shaft. A first sprocket may be coupled to the rear output shaft while a second sprocket is coupled to the front output shaft. A chain drivingly interconnects the first and second sprockets to transfer power between the front and rear output shafts. While the sprocket and chain arrangements have functioned generally satisfactorily in the past, it may be desirable to provide an alternate power transfer mechanism that may be stronger, lighter and smaller than existing designs.
The present disclosure relates to a transfer case for use in motor vehicles for transferring drive torque from a powertrain to first and second drivelines. The transfer case includes a first output shaft adapted to transmit drive torque from the powertrain to the first driveline. The second output shaft is adapted to transmit drive torque to a second driveline. The transfer case includes a first spiral bevel gear set driven by the first output shaft and a second spiral bevel gear set driven by the first spiral bevel gear set and driving the second output shaft.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
With particular reference to
Drivetrain 10 is shown to further include an electronically-controlled power transfer system for permitting a vehicle operator to select between a two-wheel drive mode, a part-time four-wheel drive mode, and an on-demand four-wheel drive mode. In this regard, transfer case 22 is equipped with a transfer clutch 50 that is operable for transferring drive torque from rear output shaft 32 to front output shaft 42 for establishing the part-time and on-demand four-wheel drive modes. The power transfer system further includes a power-operated actuator assembly 52 for actuating transfer clutch 50, vehicle sensors 54 for detecting certain dynamic and operational characteristics of the motor vehicle, a mode selector 56 for permitting the vehicle operator to select one of the available drive modes, and a controller 58 for controlling actuation of actuator assembly 52 in response to input signals from vehicle sensors 54 and mode selector 56.
Transfer clutch 50 may be operated to selectively transfer torque between rear output shaft 32 and front driveline 14. When mode selector 56 signals selection of the two-wheel drive mode, transfer clutch 50 does not transfer torque from rear output shaft 32 and all of the drive torque is delivered by powertrain 16 to rear driveline 12. In contrast, when either of the part-time or on-demand four-wheel modes is selected, transfer clutch 50 is operable to transfer drive torque from rear output shaft 32 to front output shaft 42 and front driveline 14.
Transfer case 22 may also be optionally equipped with a gear reduction unit 59 as shown in
Referring primarily to
Second hypoid gear set 64 includes a second pinion gear 72 fixed for rotation with pinion shaft 70. It should be appreciated that first pinion gear 68, pinion shaft 70 and second pinion gear 72 may be formed as a one-piece member or may alternatively be constructed from two or more sections. If two or more sections are interconnected to one another, it is contemplated that bearings (not shown) may be positioned about pinion shaft 70 prior to one of first pinion gear 68 and second pinion gear 72 being fixed to pinion shaft 70. In another alternate arrangement, pinion shaft 70 may be initially separated into two or more pieces and subsequently coupled to the others to facilitate assembly. Second pinion gear 72 is in driving engagement with a second ring gear 74. Second ring gear 74 is fixed for rotation with front output shaft 42.
Transfer clutch 50 may be a mechanically-actuated, multi-plate clutch assembly having a drum 76 fixed for rotation with first ring gear 66. A plurality of outer clutch plates (not shown) are drivingly engaged with drum 76. A hub 78 is fixed for rotation with rear output shaft 32. A plurality of inner clutch plates (not shown) are placed in splined engagement with hub 78 and interleaved with the outer clutch plates. Actuator assembly 52 is operable to selectively apply a force to engage the inner and outer plates to cause torque to transfer between rear output shaft 32 and first ring gear 66. The quantity of torque transferred to first hypoid gear set 62 may be varied by controlling the magnitude of force applied by actuator assembly 52. Actuator assembly 52 may also control a range clutch 79 operable to shift reduction gear set 59 between the high and low range modes of operation. A separate actuator may be used if desired.
In the arrangement depicted in
The relative arrangement of gears that allows the convex side of the ring gears to be contacted is shown in
Differential 82 is operable to provide speed differentiation between a first output member and a second output member. In
It should be appreciated that differential 82 may be constructed using bevel gears, helical gears, planetary gears or any number of power transmitting elements operable to provide speed differentiation between the first output member and the second output member.
Second pinion gear 72a is formed with a right-hand spiral and positioned in driving engagement with a second ring gear 74a having a left-hand spiral. Second ring gear 74a is positioned forward of second pinion gear 72a. In the driveline depicted in
It should be noted that the gears within transfer case 100 are handed and positioned relative to one another to assure that power is transferred through the convex side of each ring gear during forward vehicle travel.
Furthermore, the foregoing discussion discloses and describes merely exemplary embodiments of the present disclosure. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations may be made therein without departing from the spirit and scope of the disclosure as defined in the following claims.
This application claims the benefit of U.S. Provisional Application No. 61/038,181, filed on Mar. 20, 2008. The entire disclosure of the above application is incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
838604 | Bard | Dec 1906 | A |
1210754 | Beatty | Jan 1917 | A |
2262710 | Lang | Nov 1941 | A |
3580350 | Arkus-Duntov | May 1971 | A |
3939936 | Vinton | Feb 1976 | A |
4405029 | Hunt | Sep 1983 | A |
4605087 | Ashauer et al. | Aug 1986 | A |
4618022 | Hayashi | Oct 1986 | A |
4650202 | Tsuzuki | Mar 1987 | A |
4693334 | Hiraiwa | Sep 1987 | A |
4765433 | Fujii et al. | Aug 1988 | A |
4865396 | Sato | Sep 1989 | A |
5078229 | Kikuchi et al. | Jan 1992 | A |
5107951 | Kawamura | Apr 1992 | A |
5143167 | Moriyama et al. | Sep 1992 | A |
5146801 | Oda | Sep 1992 | A |
5348516 | Shibata | Sep 1994 | A |
5351782 | Kameda | Oct 1994 | A |
5966999 | Showalter et al. | Oct 1999 | A |
6135229 | Arimatsu | Oct 2000 | A |
6158303 | Shiraishi et al. | Dec 2000 | A |
6244126 | Brooks | Jun 2001 | B1 |
6655488 | Braud | Dec 2003 | B2 |
6719656 | Bowen | Apr 2004 | B2 |
6834738 | Kobayashi | Dec 2004 | B2 |
20030060321 | Greil | Mar 2003 | A1 |
20060113125 | Ima | Jun 2006 | A1 |
20060199697 | Kirkwood et al. | Sep 2006 | A1 |
20060243512 | Grabmaier et al. | Nov 2006 | A1 |
20110087410 | Cimatti et al. | Apr 2011 | A1 |
Number | Date | Country | |
---|---|---|---|
20090235780 A1 | Sep 2009 | US |
Number | Date | Country | |
---|---|---|---|
61038181 | Mar 2008 | US |