Locking transfer case

Patent metadata

Field	Value
Publication number	US-10563704-B2
Application number	US-201715438814-A
Country	US
Kind code	B2
Filing date	Feb 22, 2017
Priority date	Feb 22, 2016
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

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.

First claim

What is claimed is:

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, the plate clutch including:
an apply plate coupled to and rotating with the primary output shaft;
a housing coupled to and rotating with the primary 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 transfer torque between the primary output shaft and the secondary output shaft; and

a locking sleeve for selectively transferring torque between the apply plate and the housing, 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 transfer torque between the apply plate and the housing.

2. The transfer case according to claim 1 , wherein the plate clutch transfers torque between the primary output shaft and the secondary output shaft in a first mode.

3. The transfer case according to claim 2 , wherein the locking sleeve transfers torque between the apply plate and the housing in a second mode but not in the first mode.

4. The transfer case according to claim 3 , wherein the plate clutch transfers torque between the primary output shaft and the secondary output shaft 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 other of the housing or the apply plate in the first position, and the locking sleeve is engaged with the other of the housing or the apply plate in the second position.

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.

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 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.

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

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

12. The transfer case according to claim 10 , wherein the actuation system includes a first face cam for operating the plate clutch, and a second face cam for operating the locking sleeve.

13. The transfer case according to claim 1 , further comprising an actuation system, wherein the actuation system operates the plate clutch and operates the locking sleeve in different stages of rotation;
wherein the plate clutch transfers torque between the primary output shaft and the secondary output shaft in a first mode, and the locking sleeve transfers torque between the apply plate and the housing 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 other of the housing or the apply plate in the first position, and the locking sleeve is engaged with the other of the housing or the apply plate in the second position; 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.

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 primary 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 16 , 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 including a housing and an apply plate to transfer torque between the primary shaft and the secondary shaft, the locking mechanism comprising:
a locking sleeve coupled to the apply plate of the plate clutch and selectively engageable with the housing of the plate clutch to positively couple the housing to the apply plate to transfer torque therebetween, the locking sleeve defining an inner diameter larger than an outer diameter defined by the apply plate such that the locking sleeve is axially slidable in relation to the apply plate between disengaged and engaged positions.

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.

Assignees

• Borgwarner Inc

Inventors

• Pritchard Larry A
• Kopp Jr Thaddeus R
• Reeves Branden L

Classifications

• F16D11/14

  with clutching members movable only axially (F16D11/02, F16D11/08 take precedence) · CPC title

• F16D23/12

  Mechanical clutch-actuating mechanisms arranged outside the clutch as such (specific for combined clutches F16D21/00; mechanisms specific for synchronisation F16D23/02) · CPC title

• F16D2023/123

  Clutch actuation by cams, ramps or ball-screw mechanisms · CPC title

• F16D13/52

  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 title

• B60K17/35

  including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches · CPC title