Clutch with decremental torque function

Patent metadata

Field	Value
Publication number	US-10288128-B2
Application number	US-201615051010-A
Country	US
Kind code	B2
Filing date	Feb 23, 2016
Priority date	Feb 27, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A clutch assembly that is less prone to overheating is disclosed. The clutch assembly includes a clutch housing, a shaft, and a clutch pack. The clutch pack includes a backing plate, an applied plate, a plurality of friction plates, and a plurality of reaction plates. A primary actuator applies pressure to the applied plate to longitudinally compress the entire clutch pack and couple rotation of the clutch housing and the shaft. A secondary actuator applies pressure to at least one plate in the plurality of friction plates and the plurality of reaction plates to longitudinally move the at least one plates independently of the applied plate. This relieves some of the torque transmitted across the clutch pack adjacent the applied plate and reduces localized temperature spikes in the clutch pack adjacent to the applied plate.

First claim

What is claimed is:

1. A clutch assembly comprising:
a clutch housing having an internal surface that defines an inner cavity within said clutch housing;
a shaft disposed within said inner cavity of said clutch housing, said shaft extending along a longitudinal axis and having an outer surface;
a clutch pack disposed radially between said clutch housing and said shaft that selectively couples rotation of said clutch housing and said shaft;
said clutch pack including a first end and a second end opposite said first end such that said second end is longitudinally spaced from said first end;
said clutch pack including a backing plate disposed at said first end of said clutch pack, said backing plate being retained on one of said clutch housing and said shaft such that said backing plate cannot move longitudinally relative to said clutch housing and said shaft beyond a predetermined limit;
said clutch pack including an applied plate disposed at said second end of said clutch pack that is moveable along said longitudinal axis relative to said clutch housing and said shaft;
said clutch pack including a plurality of friction plates disposed between said backing plate and said applied plate, said plurality of friction plates being moveable along said longitudinal axis relative to said clutch housing and said shaft;
said clutch pack including a plurality of reaction plates disposed between said backing plate and said applied plate in an interleaving relationship with said plurality of friction plates, said plurality of reaction plates being moveable along said longitudinal axis relative to said clutch housing and said shaft;
a primary actuator that selectively applies a first pressure to said applied plate at said second end of said clutch pack to move said second end of said clutch pack toward said first end of said clutch pack, longitudinally compress all of said friction plates and reaction plates in said clutch pack, and couple rotation of said clutch housing and said shaft; and
a secondary actuator that selectively applies a second pressure to at least one plate in said plurality of friction plates and said plurality of reaction plates, in the same direction as said first pressure, to longitudinally move said at least one plate independently of said applied plate at said second end of said clutch pack, wherein the independent movement of said at least one plate provided by said secondary actuator only compresses a portion of said clutch pack disposed between said at least one plate and said backing plate.

2. The clutch assembly as set forth in claim 1 wherein said secondary actuator includes a driver that generates said second pressure and an actuation member that extends between said driver and said at least one plate, said actuation member transferring said second pressure from said driver to said at least one plate during actuation of said secondary actuator.

3. The clutch assembly as set forth in claim 2 wherein said driver of said secondary actuator includes an actuator cavity configured to receive fluid.

4. The clutch assembly as set forth in claim 3 wherein said actuation member includes a bridging portion that extends longitudinally and a first leg that is transverse to said bridging portion and that is received in said actuator cavity such that said fluid within said actuator cavity applies pressure on said first leg and displaces said actuation member during actuation of said secondary actuator.

5. The clutch assembly as set forth in claim 4 wherein said actuation member includes a second leg that is transverse to said bridging portion, said second leg being positioned adjacent to said at least one plate, and said second leg being longitudinally spaced from said first leg.

6. The clutch assembly as set forth in claim 5 wherein said actuation member includes a third leg that is transverse to said bridging portion and that is positioned longitudinally between said first leg and said second leg, said at least one plate being received between said third leg and said second leg.

7. The clutch assembly as set forth in claim 2 wherein said actuation member includes a bridging portion that extends longitudinally and that is disposed radially between said clutch pack and said internal surface of said clutch housing.

8. The clutch assembly as set forth in claim 2 wherein said actuation member and said at least one plate are disposed in an abutting relationship such that said actuation member contacts said at least one plate and pushes said at least one plate toward said first end of said clutch pack in response to actuation of said secondary actuator.

9. The clutch assembly as set forth in claim 2 wherein said actuation member is coupled to said at least one plate such that said at least one plate moves longitudinally with said actuation member in a first direction toward said backing plate and in a second direction toward said applied plate.

10. The clutch assembly as set forth in claim 1 further comprising:
a controller operably connected to said secondary actuator that actuates said secondary actuator to longitudinally move said at least one plate toward said first end of said clutch pack by applying said second pressure to said at least one plate in response to every other longitudinal compression of said clutch pack by said primary actuator.

11. The clutch assembly as set forth in claim 1 further comprising:
a controller operably connected to said primary actuator and said secondary actuator wherein said controller actuates said secondary actuator to longitudinally move said at least one plate toward said first end of said clutch pack by applying said second pressure to said at least one plate before said controller actuates said primary actuator to longitudinally compress said clutch pack by applying said first pressure to said second end of said clutch pack.

12. The clutch assembly as set forth in claim 1 wherein said secondary actuator selectively applies said second pressure to at least one friction plate in said plurality of friction plates.

13. The clutch assembly as set forth in claim 1 wherein said secondary actuator selectively applies said second pressure to at least one reaction plate in said plurality of reaction plates.

14. A clutch assembly comprising:
a clutch housing having an internal surface that defines an inner cavity within said clutch housing;
a shaft disposed within said inner cavity of said clutch housing, said shaft extending along a longitudinal axis and having an outer surface;
a clutch pack disposed radially between said clutch housing and said shaft that selectively couples rotation of said clutch housing and said shaft;
said clutch pack including a backing plate retained on one of said clutch housing and said shaft such that said backing plate cannot move longitudinally relative to said clutch housing and said shaft beyond a predetermined limit;
said clutch pack including an applied plate slidably retained on one of said clutch housing and said shaft such that said applied plate is moveable along said longitudinal axis relative to said clutch housing and said shaft;
said clutch pack including a plurality of friction plates disposed between said backing plate and said applied plate, said plurality of friction plates being slidably retained on one of said clutch housing and said shaft such that each friction plate of said plurality of friction plates is moveable along said longitudinal axis relative to said clutch housing and said shaft;
said clutch pack including a plurality of reaction plates disposed between said backing plate and said applied plate in an interleaving relationship with

Assignees

• Avl Powertrain Engineering Inc

Inventors

• Mordukhovich Gregory

Classifications

• F16D25/0638

  with more than two discs, e.g. multiple lamellae · CPC title

• F16D13/648

  for clutches with multiple lamellae · CPC title

• F16D13/52 Primary

  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

• F16D2300/021

  Cooling features not provided for in group F16D13/72 or F16D25/123, e.g. heat transfer details · CPC title