Transmission clutch assembly

Patent metadata

Field	Value
Publication number	US-2020096069-A1
Application number	US-201816137605-A
Country	US
Kind code	A1
Filing date	Sep 21, 2018
Priority date	Sep 21, 2018
Publication date	Mar 26, 2020
Grant date	—

Abstract

The present disclosure provides a transmission clutch assembly having a drum, a brake band, a smart material band and an electrical circuit. The brake band substantially encircles the drum and includes first and second ends, a high friction inner surface, and a low friction outer surface. The smart material band includes a beginning end and a terminating end wherein the beginning end of the smart material band is coupled to the second end of the brake band while the terminating end of the smart material band is coupled to the first end of the brake band. The electrical circuit transfers an electrical current to the smart material band. The smart material band contracts when the electrical current is applied to the smart material band thereby drawing the first and second ends of the brake band closer and contracting the brake hand against the drum to restrict drum movement.

First claim

What is claimed is:

1 . A clutch assembly for an automatic transmission comprising:
a drum; a brake band at least substantially encircling the drum, the brake band having a high friction inner surface, a low friction outer surface, a first end and a second end; a smart material band having a beginning end and a terminating end, the beginning end of the smart material band being coupled to the second end of the brake band while the terminating end of the smart material band being coupled to the first end of the brake band; an electrical circuit configured to transfer an electrical current to the smart material band; wherein the smart material band is configured to react when the electrical current is applied to the smart material band so as to change the distance between the first and second ends of the brake band and to change the engagement of the brake band against the drum to restrict rotational movement of the drum.

2 . The clutch assembly as defined in claim 1 further comprising a first pin and a second pin in electrical communication with the electrical circuit wherein the first pin is configured to mechanically and electrically couple the beginning end of the smart material band to the second end of the brake band while the second pin is configured to mechanically and electrically couple the terminating end of the smart material band to the first end of the brake band.

3 . The clutch assembly as defined in claim 2 wherein the smart material band is a wire.

4 . The clutch assembly as defined in claim 2 wherein the smart material band defines a smart material width which is less than a brake band width of the brake band.

5 . The clutch assembly as defined in claim 2 wherein the first and the second pins each define slots configured to receive and retain an end portion of each of the smart material band and the brake band.

6 . The clutch assembly as defined in claim 3 wherein the first and the second pins each define slots configured to receive and retain an end portion of each of the smart material band and the brake band.

7 . The clutch assembly as defined in claim 6 wherein the drum is a clutch brake drum.

8 . The clutch assembly as defined in claim 7 wherein the clutch brake drum is configured to at least partially house a plurality of gears.

9 . The clutch assembly as defined in claim 8 wherein the plurality of gears is a sun gear and at least one planet gear.

10 . The clutch assembly as defined in claim 9 wherein the clutch brake drum is coupled to at least one of the plurality of gears.

11 . A clutch assembly for a vehicle comprising:
a housing; a first smart material wire affixed to a first side of the housing; a second smart material wire affixed to a second side of the housing, the second side being disposed opposite from the first side of the housing and each of the first and second smart material wires include a housing end and an anchor end; and a rotational member rotating about a shaft within the housing; wherein the anchor end for each of the first and second smart material wires is affixed to the rotation member while the housing end of the first smart material wire is affixed to the first side of the housing and the housing end of the second smart material wire is affixed to the second side of the housing, and each of the first and second smart material wires are in communication with an electrical circuit.

12 . The clutch assembly as defined in claim 11 wherein the first smart material wire is configured to contract when the electrical circuit applies a current to the first smart material wire, and the second smart material wire is configured to contract when the electrical circuit applies a current to the second smart material wire.

13 . The clutch assembly as defined in claim 12 wherein the rotational member is configured to rotate about the shaft in a first direction when the first smart material wire contracts.

14 . The clutch assembly as defined in claim 12 wherein the rotational member is configured to rotate about the shaft in a second direction when the second smart material wire contracts.

15 . The clutch assembly as defined in claim 12 wherein the rotational member is a ball-ramp structure.

16 . The clutch assembly as defined in claim 12 wherein the rotational member is a window plate disposed between a pocket plate and a strut plate.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Holmes Alan G

Classifications

• F16D65/16

  arranged in or on the brake · CPC title

• F16D49/08 Primary

  shaped as an encircling band extending over approximately 360 degrees · CPC title

• F16D2121/28

  using electrostrictive or magnetostrictive elements, e.g. piezoelectric elements · CPC title

• F16D65/067

  with means for mounting, e.g. end connection members · CPC title

• F16D2121/32

  using shape memory {or other thermo-mechanical} elements · CPC title