Piston for clutch assembly

Patent metadata

Field	Value
Publication number	US-10794433-B2
Application number	US-201816033544-A
Country	US
Kind code	B2
Filing date	Jul 12, 2018
Priority date	Sep 20, 2017
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

Pistons and clutch assemblies including the pistons are disclosed. A clutch assembly may include at least one rotatable clutch plate, a reaction plate arranged to rotate with and apply a force to the at least one rotatable clutch plate, and a spring configured to urge the reaction plate away from the at least one rotatable clutch plate. A piston may be provided including a first segment formed as a plate and defining an internal space between the first segment and a housing and a second bulk segment that occupies at least a portion (e.g., 50% by volume) of the internal space. At least one bearing rolling element may be arranged between the reaction plate and the piston to permit relative rotational motion therebetween. The second bulk segment may be formed of plastic or a plastic composite and may reduce the amount of hydraulic fluid present in the internal space.

First claim

What is claimed is:

1. A clutch assembly comprising:
at least one rotatable clutch plate;
a reaction plate arranged to rotate with and apply a force to the at least one rotatable clutch plate;
a spring configured to urge the reaction plate away from the at least one rotatable clutch plate; and
a piston;
at least one bearing rolling element arranged between the reaction plate and the piston to permit relative rotational motion therebetween;
wherein the piston includes:
a first segment formed as a plate and defining an internal space between the first segment and a housing;
a second segment that occupies a portion of the internal space:
the second segment defines a cavity with the housing, the cavity configured to receive a hydraulic fluid;
at least one o-ring is disposed between the first segment and the second segment in an axial direction; and
the cavity does not axially overlap with the at least one o-ring.

2. The clutch assembly of claim 1 , wherein the second segment is formed of plastic or a plastic composite.

3. The clutch assembly of claim 1 , wherein the second segment occupies at least 50 % by volume of the internal space.

4. The clutch assembly of claim 1 , wherein the cavity extends radially along only a portion of an axial end face of the second bulk segment.

5. The clutch assembly of claim 1 , wherein the second segment is press-fit into the first segment.

6. The clutch assembly of claim 1 , wherein the first segment includes a bearing raceway configured to directly contact the at least one bearing rolling element.

7. A piston for a clutch assembly, comprising:
a first segment formed as a plate and defining an internal space between itself and a housing of the clutch assembly; a second segment formed as a bulk support piece; and
an inner o-ring disposed axially between the first segment and the second segment on a radially inner side of the piston;
wherein the second segment is formed of plastic or a plastic composite and occupies a portion of the internal space,
wherein the second segment defines a cavity with the housing and
wherein the cavity does not axially overlap with the inner o-ring.

8. The piston of claim 7 , wherein the second segment occupies at least 50% by volume of the internal space.

9. The piston of claim 7 , wherein the cavity extends radially along only a portion of an axial end face of the second segment.

10. The piston of claim 7 , wherein the second segment is press-fit into the first segment.

11. The piston of claim 7 , wherein the first segment includes a hardened bearing raceway configured to directly contact a bearing rolling element of the clutch assembly.

12. The piston of claim 7 further comprising an outer o-ring disposed axially between the first segment and the second segment on a radially outer side of the piston wherein the cavity does not axially overlap with the outer o-ring.

13. A clutch assembly comprising:
at least one rotatable clutch plate;
a reaction plate arranged to rotate with and apply a force to the at least one rotatable clutch plate;
a spring configured to urge the reaction plate away from the at least one rotatable clutch plate; and
a piston;
at least one bearing rolling element arranged between the reaction plate and the piston to permit relative rotational motion therebetween;
wherein the piston includes:
a first segment formed as a plate and defining an internal space between the first segment and a housing; and
a second segment that occupies at least 50% by volume of the internal space.

Assignees

• Schaeffler Technologies Ag

Inventors

• Barnes Jay

Classifications

• F16C19/30

  for axial load mainly · 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

• F15B15/1447

  Pistons; Piston to piston rod assemblies · CPC title

• F16D25/083

  Actuators therefor (F16D25/085 - F16D25/087 take precedence) · CPC title

• F16D25/12 Primary

  Details not specific to one of the before-mentioned types · CPC title