Disc brake

Patent metadata

Field	Value
Publication number	US-11261928-B2
Application number	US-201916376012-A
Country	US
Kind code	B2
Filing date	Apr 5, 2019
Priority date	Apr 30, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

An actuation mechanism for a disc brake. The actuation mechanism may include a yoke, a piston, a wear adjustment mechanism, and a rolling element bearing. The piston may have a rotatable portion. The wear adjustment mechanism may have a driving portion. The rolling element bearing may be located between the driving portion and the yoke.

First claim

What is claimed is:

1. An actuation mechanism for a disc brake, the actuation mechanism comprising:
a non-rotatable yoke to transmit an actuating force from an operating shaft;
a piston configured to be driven by the yoke to transmit the actuating force to a brake pad, the piston including a rotatable portion that is rotatable with respect to the yoke to cause the piston to extend;
a wear adjustment mechanism for adjusting extension of the piston to account for wear of the brake pad, the wear adjustment mechanism including a driving portion configured to be driven by the operating shaft to transfer torque from the operating shaft to the rotatable portion of the piston to cause the rotatable portion to rotate and extend the piston, wherein the driving portion is a drive drum that is directly engaged by a link member that is connected to, or integral with, the operating shaft; and
a rolling element bearing located between the drive drum of the wear adjustment mechanism and the yoke, wherein an outer race of the rolling element bearing is rotationally fixed to the yoke, and an inner race of the rolling element bearing is rotationally fixed to the drive drum.

2. The actuation mechanism of claim 1 wherein the yoke comprises a generally inboard facing surface that opposes a generally outboard facing surface of the driving portion to define an annulus that locates the rolling element bearing.

3. The actuation mechanism of claim 1 wherein the rolling element bearing is a deep-groove ball bearing.

4. The actuation mechanism of claim 1 wherein the yoke comprises an inclined surface and the rolling element bearing is an angular contact ball bearing with a corresponding inclined surface that engages the inclined surface of the yoke.

5. The actuation mechanism of claim 1 wherein an inboard facing surface of the rotatable portion of the piston engages an opposing outboard facing surface of the yoke such that friction is created between the inboard facing surface of the rotatable portion of the piston and the opposing outboard facing surface of the yoke to resist relative rotation of the yoke and the rotatable portion of the piston.

6. The actuation mechanism of claim 5 wherein a resilient element is arranged to provide a load acting to urge the outboard facing surface of the yoke and inboard facing surface of the piston into contact.

7. The actuation mechanism of claim 6 wherein the driving portion is part of a one-way clutch, the one-way clutch further comprising a driven portion.

8. The actuation mechanism of claim 7 wherein rotation of the yoke in relation to the rotatable portion of the piston is frictionally resisted with a torque greater than a torque required to cause the one-way clutch to slip, when the actuating force is released at an end of a braking operation.

9. The actuation mechanism of claim 7 wherein one of the driven or driving portions of the one-way clutch comprises an axially extending projecting portion.

10. The actuation mechanism of claim 9 wherein the other of the driven or driving portions is rotatably mounted with respect to the axially extending projecting portion.

11. The actuation mechanism of claim 9 wherein the resilient element is arranged to apply a load to the axially extending projecting portion, the load being transmitted to the yoke via the rolling element bearing.

12. The actuation mechanism of claim 11 wherein the resilient element is further arranged to apply a load to a torque limiting clutch of the wear adjustment mechanism.

13. The actuation mechanism of claim 12 wherein the resilient element is further arranged to apply a load to the piston in an opposite direction to the load on the yoke.

14. The actuation mechanism of claim 13 wherein the wear adjustment mechanism further comprises a second rolling element bearing mounted at an outboard end of the axially extending projecting portion to take the load from the resilient element.

15. The actuation mechanism of claim 14 wherein an axial location of the second rolling element bearing determines an amount of load applied by the resilient element.

16. The actuation mechanism of claim 14 wherein the second rolling element bearing is axially fixed relative to the axially extending projecting portion and located on a force transmission path between the resilient element and the axially extending projecting portion.

17. The actuation mechanism of claim 16 wherein the first and second rolling element bearings are substantially identical.

18. A method of assembling a disc brake comprising the steps of:
installing an actuation mechanism within the disc brake, the actuation mechanism comprising:
a non-rotatable yoke to transmit an actuating force from an operating shaft;
a piston configured to be driven by the yoke to transmit the actuating force to a brake pad, the piston including a rotatable portion that is rotatable with respect to the yoke to cause the piston to extend; and
a wear adjustment mechanism for adjusting extension of the piston to account for wear of the brake pad, the wear adjustment mechanism including a driving portion configured to be driven by the operating shaft to transfer force from the operating shaft to the rotatable portion of the piston to cause the rotatable portion to rotate and extend the piston, wherein the driving portion is a drive drum that is directly engaged by a link member that is connected to, or integral with, the operating shaft; and

locating a rolling element bearing between the drive drum of the wear adjustment mechanism and the yoke, wherein an outer race of the rolling element is rotationally fixed to the yoke, and an inner race of the rolling element bearing is rotationally fixed to the drive drum.

19. A disc brake comprising:
an actuation mechanism that includes:
a non-rotatable yoke to transmit an actuating force from an operating shaft;
a piston configured to be driven by the yoke to transmit the actuating force to a brake pad, the piston including a rotatable portion that is rotatable with respect to the yoke to cause the piston to extend; and
a wear adjustment mechanism for adjusting extension of the piston to account for wear of the brake pad, the wear adjustment mechanism including a driving portion configured to be driven by the operating shaft to transfer torque from the operating shaft to the rotatable portion of the piston to cause the rotatable portion to rotate and extend the piston, wherein the driving portion is a drive drum that is directly engaged by a link member that is connected to, or integral with, the operating shaft; and

a rolling element bearing is located between the drive drum of the wear adjustment mechanism and the yoke, wherein an outer race of the rolling element bearing is rotationally fixed to the yoke, and an inner race of the rolling element bearing is rotationally fixed to the drive drum.

Assignees

• Meritor Heavy Vehicle Braking Systems Uk Ltd

Inventors

• Taylor Martin P
• Holtham Gareth

Classifications

• F16D65/40

  mechanical · CPC title

• F16D55/2255

  in which the common actuating member is pivoted · CPC title

• F16D2065/022

  Rollers · CPC title

• F16D65/18

  adapted for drawing members together {, e.g. for disc brakes} · CPC title

• F16D65/124

  adapted for mounting on the wheel of a railway vehicle · CPC title