Locking Transfer Case

• US 20170241486A1
• Filed: 02/22/2017
• Published: 08/24/2017
• Est. Priority Date: 02/22/2016
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Pritchard, Larry A., Kopp, Jr., Thaddeus R., Reeves, Branden L.
• Granted Patent: US 10,563,704 B2
• Time in Patent Office: Days
• CPC Class Codes: B60K 17/02 characterised by arrangement, location, or kind of clutch
• CPC Class Codes: B60K 17/344 having a transfer gear
• CPC Class Codes: B60K 17/3467 combined with a change speed gearing, e.g. range gear
• CPC Class Codes: B60K 17/35 including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches differential gearing with locking devices F16H48/20
• CPC Class Codes: B60K 23/08 for changing number of driven wheels , for switching from driving one axle to driving two or more axles B60K17/3515 takes precedence
• CPC Class Codes: F16D 11/10 with clutching members movable only axially
• CPC Class Codes: F16D 11/14 with clutching members movable only axially F16D11/02, F16D11/08 take precedence
• CPC Class Codes: F16D 13/52 Clutches with multiple lamellae ; Clutches in which three or more axially moveable members are fixed alternately to the shafts to be coupled and are pressed from one side towards an axially-located member F16D13/385 takes precedence
• CPC Class Codes: F16D 2011/008 characterised by the form of the teeth forming the inter-engaging parts; Details of shape or structure of these teeth
• CPC Class Codes: F16D 2023/123 Clutch actuation by cams, ramps or ball-screw mechanisms
• CPC Class Codes: F16D 2023/141 characterised by using a fork; Details of forks
• CPC Class Codes: F16D 23/12 Mechanical clutch-actuating mechanisms arranged outside the clutch as such specific for combined clutches F16D21/00; mechanisms specific for synchronisation F16D23/02
• CPC Class Codes: F16D 23/14 Clutch-actuating sleeves or bearings; Actuating members directly connected to clutch-actuating sleeves or bearings

Abstract

A transfer case includes a primary output shaft, and a secondary output selectively coupleable to the primary output shaft with a secondary torque transfer mechanism. The secondary torque transfer mechanism comprises a plate clutch and a locking sleeve. The plate clutch includes a housing coupled to the secondary output shaft, a plurality of interleaved plates alternatingly coupled to the primary output shaft and the housing, and an apply plate coupled to the primary output shaft and being configured to compress the interleaved plates to selectively form a friction coupling between the primary output shaft and the secondary output shaft. The locking sleeve is non-selectively coupled to one of the housing or the apply plate to rotate therewith, and is selectively coupleable to the other of the housing or the apply plate to form a positive coupling between the primary output shaft and the secondary output shaft.

Claims

1. A transfer case comprising:

a primary output shaft

a secondary output shaft; and

a torque transfer mechanism comprising;

a plate clutch for selectively transferring torque between the primary output shaft and the secondary output shaft with a friction coupling, the plate clutch including an apply plate coupled to and rotating with the primary output shaft, a housing coupled to and rotating with the secondary output shaft, and interleaved plates that are alternatingly coupled to the primary output shaft and the housing to rotate therewith, the interleaved plates being compressible by the apply plate to form the friction coupling; and

a locking sleeve for selectively transferring torque between the apply plate and the housing with a positive coupling, wherein the locking sleeve is non-selectively coupled to one of the housing or the apply plate and is selectively coupleable to the other of the housing or the apply plate to form the positive coupling.

2. The transfer case according to claim 1, wherein the friction coupling is formed in a first mode.

3. The transfer case according to claim 2, wherein the positive coupling is formed in a second mode but not in the first mode.

4. The transfer case according to claim 3, wherein the friction coupling is formed in the second mode.

5. The transfer case according to claim 1, wherein the locking sleeve is configured to slide axially between a first position and a second position, wherein the locking sleeve is disengaged from the apply plate in the first position to not form the positive coupling, and the locking sleeve is engaged with the apply plate in the second position to form the positive coupling.

6. The transfer case according to claim 5, wherein the locking sleeve includes splines that non-selectively couple the locking sleeve to the one of the housing or the apply plate and that selectively couple the locking sleeve to the other of the housing or the apply plate to form the positive coupling.

7. The transfer case according to claim 6, wherein the locking sleeve slides axially along an outer surface of the housing, the splines protrude radially inward through slots of the housing, and the splines slide within the slots into engagement with the apply plate as the locking sleeve is moved axially from the first position to the second position to selectively couple the locking sleeve to the apply plate.

8. The transfer case according to claim 6, wherein the locking sleeve slides axially along an outer surface of the apply plate, and the splines include inner splines that non-selectively couple the locking sleeve to the apply plate and outer splines that selectively couple the locking sleeve to the housing.

9. The transfer case according to claim 5, further comprising an actuation system, wherein the actuation system operates the plate clutch to form the friction coupling and operates the locking sleeve to form the positive coupling in different stages of rotation.

10. The transfer case according to claim 9, further comprising a gear reduction mechanism that is operated by the actuation system in another stage of rotation.

11. The transfer case according to claim 9, wherein the actuation system includes a first face cam for operating the plate clutch, and a second face cam for operating the locking sleeve.

12. The transfer case according to claim 6, further comprising an actuation mechanism that includes a face cam, a shaft that is biased toward the second position by the face cam, a fork that couples the locking sleeve to the shaft to move therewith, and a spring that biases that shaft toward the first position.

13. The transfer case according to claim 1, further comprising an actuation system, wherein the actuation system operates the plate clutch to form the friction coupling and operates the locking sleeve to form the positive coupling in different stages of rotation;

wherein the friction coupling is formed in a first mode, and the positive coupling is formed in a second mode but not the first mode;

wherein the locking sleeve is configured to slide axially between a first position and a second position, wherein the locking sleeve is disengaged from the apply plate in the first position to not form the positive coupling, and the locking sleeve is engaged with the apply plate in the second position to form the positive coupling; and

wherein the locking sleeve includes splines that non-selectively couple the locking sleeve to the one of the housing or the apply plate and that selectively couple the locking sleeve to the other of the housing or the apply plate to form the positive coupling.

14. A transfer case comprising:

a primary shaft;

a secondary shaft; and

a torque transfer mechanism for selectively coupling the primary shaft to the secondary shaft to transfer torque therebetween, the torque transfer mechanism comprising;

a plate clutch including an apply plate coupled to the primary shaft to rotate therewith, a housing coupled to the secondary shaft to rotate therewith, and interleaved plates that are alternatingly coupled to the primary shaft and the housing to rotate therewith and that are compressible by the apply plate to selectively couple the primary shaft to the secondary shaft; and

a locking mechanism that selectively couples the apply plate to the housing to lock the primary shaft to the secondary shaft.

15. The transfer case according to claim 14, wherein the locking mechanism includes a locking sleeve is coupled to one of the housing or the apply plate to rotate therewith, and moves between an engaged position in which the locking sleeve is positively coupled with the other of the housing or the apply plate to lock the primary shaft to the secondary shaft and a disengaged position in which the locking sleeve is not positively coupled with the other of the housing or the apply plate.

16. The transfer case according to claim 15, wherein the locking sleeve slides axially on an outer surface of the one of the housing or the apply plate.

17. The transfer case according to claim 16, wherein the locking sleeve is non-selectively coupled to the housing in the engaged position and the disengaged position.

18. The transfer case according to claim 17, wherein the locking sleeve is non-selectively coupled to the apply plate in the engaged position and the disengaged position.

19. A locking mechanism for a transfer case of a type having a primary shaft and a secondary shaft that are selectively frictionally coupled with a plate clutch to transfer therebetween, the locking mechanism comprising:

a locking sleeve coupled to one of a housing or an apply plate of the clutch and selectively engageable with the other of the housing or the apply plate to selectively positively couple the primary shaft to the secondary shaft to transfer torque therebetween.

20. The locking mechanism according to claim 19, further comprising an actuation mechanism that operates the plate clutch and the locking sleeve in different stages of rotation.