Alternative pack designs for multidisk clutches

1. A transmission clutch including a rotating hub mounted for rotation relative to a rotating clutch housing in the transmission; the clutch comprising:

an alternative clutch pack having a plurality of annular plates including a first set of plates interleaved with a second set of friction plates having at least one layer of friction material on at least one side of each said friction plate, and

a clutch pack actuator including a plurality of axially elongated fingers aligned with said plates;

wherein said first set of plates is secured for rotation with the hub, wherein said second set is rotatably fixed to the rotating clutch housing and said actuator is axially displaceable but rotatably restrained relative to the rotating clutch housing.

2. The invention as defined in claim 1 wherein said second set of friction plates includes at least one plate having a friction layer applied to both sides of the plate, and each said side facing a bare surface of an adjacent plate.

3. The invention as defined in claim 2 wherein each said friction plate has a friction layer on both sides of the plate, and said first set of plates are reaction plates.

4. The invention as defined in claim 1 wherein each said friction plate has a single side carrying a friction lining.

5. The invention as defined in claim 1 wherein said clutch includes at least one of an end plate and an apply plate secured for rotation with said rotating clutch housing.

6. The invention as defined in claim 5 wherein said at least one of an end plate and an apply plate faces an unlined surface of said friction plate.

7. The invention as defined in claim 5 wherein said at least one of an end plate and an apply plate includes a friction lining.

8. The invention as defined in claim 7 wherein said one plate faces a reaction plate secured for rotation with said hub.

9. The invention as defined in claim 1 wherein said first set of plates includes at least one reaction plate.

10. The invention as defined in claim 1 wherein said first set and said second set are single-sided friction plates.

11. A method for reducing thermo-elastic instability hot spotting in a transmission clutch including a clutch pack of a plurality interleaved plates with annular surfaces engageable by axial displacement of an actuator having axially extended fingers in alignment with said annular surfaces in a transmission having a hub rotating relative to a rotating clutch housing, the method comprising:

including a friction plate with at least one layer of friction material on at least one side to form a first set of friction plates;

securing said first set of said friction plates to the clutch housing for rotation with said rotating clutch housing; and

securing a second set of said plurality of plates to a hub for rotation with said hub, each plate of said second set having at least one unlined plate surface in alignment with said fingers and subjected to circumferentially non-uniform axial forces generating frictional torque.

12. The invention as defined in claim 11 wherein said including step comprises including at least one plate with at least one friction layer on each of two sides.

13. The invention as defined in claim 11 wherein said including step comprises including at least one single-sided plate.

14. The invention as defined in claim 13 wherein said including step comprises facing a lined surface of each said single-sided plate in a single direction.

15. The invention as defined in claim 14 wherein said facing comprises positioning said lined surface adjacent to a reaction plate.

16. The invention as defined in claim 11 and further comprising positioning at least one of an end plate and an apply plate.

17. The invention as defined in claim 16 and including a friction lining on said at least one of said end plate and said apply plate.

18. The invention as defined in claim 17 and further comprising locating one of said plates of said second set adjacent to said at least one of an end plate and an apply plate.

19. A transmission clutch including a rotating hub mounted for rotation relative to a rotating clutch housing of the transmission; the clutch comprising:

an alternative clutch pack having a plurality of annular plates including a first set of plates interleaved with a second set of friction plates having at least one layer of friction material on at least one side of each said friction plate, and

a clutch pack actuator including a plurality of axially elongated fingers aligned with said plates;

wherein said first set of plates is secured for rotation with the hub, wherein said second set is rotatably fixed to the rotating clutch housing of the transmission and said actuator is axially displaceable but rotatably restrained relative to the rotating clutch housing,

wherein said clutch includes at least one of an end plate and an apply plate secured for rotation with said rotating clutch housing, and

wherein said at least one of an end plate and an apply plate faces a friction lining on an adjacent said friction plate.

20. A transmission clutch including a rotating hub mounted for rotation relative to a rotating clutch housing operating above 1000 rpm and further including a fingered piston aligned for circumferentially non-uniform, engagement of aligned clutch plates in the transmission, the clutch comprising:

an alternative clutch pack having a plurality of annular plates including a first set of plates interleaved with a second set of friction plates having at least one layer of friction material on at least one side of each said friction plate, and

a clutch pack actuator including a plurality of axially elongated fingers aligned with said plates;

wherein said first set of plates is secured for rotation with the hub, wherein said second set is rotatably fixed to the rotating clutch housing and said actuator is axially displaceable but rotatably restrained relative to the rotating clutch housing.