Brake assembly with brake pad position and wear sensor

• US 20060090968A1
• Filed: 11/01/2004
• Published: 05/04/2006
• Est. Priority Date: 11/01/2004
• Status: Abandoned Application

• Current Assignee: Meritor Heavy Vehicle Braking Systems UK Ltd. (Meritor, Inc. (Nevada))
• Original Assignee: Meritor Heavy Vehicle Braking Systems UK Ltd. (Meritor, Inc. (Nevada))
• Inventors: Taylor, Martin, Clarke, Lester, Norman, Mark, Thomas, Jeffrey, Morris, Royston
• Application Number:
  US10/978,737
• Publication Number:
  US 20060090968A1
• Time in Patent Office: Days
• US Class Current: 188/1.11L
• CPC Class Codes: F16D 2065/386 driven electrically
• CPC Class Codes: F16D 2121/14 Mechanical
• CPC Class Codes: F16D 55/2255 in which the common actuating member is pivoted
• CPC Class Codes: F16D 65/183 with force-transmitting members arranged side by side acting on a spot type force-applying member
• CPC Class Codes: F16D 66/02 Apparatus for indicating wear

Abstract

A brake assembly includes a sensor mounted to a brake component, and which is in communication with a transceiver. The sensor provides position information of the brake component, which is combined with known mechanical relationships between various brake components, to determine a wear state of a brake pad and a clearance between the brake pad and a rotor. The clearance is then adjusted based on signals from the sensor and the known mechanical relationship between the various brake components to maintain the clearance within desired limits.

Claims

1. A brake assembly comprising:

a friction member to be engageable with a rotatable member;

a first sensor mounted relative to a first transceiver, said first sensor sending a position signal indicative of a relative position between said friction member and the rotatable member to said first transceiver in response to said first transceiver sending a prompt signal.

2. The assembly of claim 1, wherein said first sensor comprises an inductive resonance device that transmits information in response to receiving said prompt signal.

3. The assembly of claim 1, including a motor for driving an adjustable member to adjust a clearance between said friction member and the rotatable member.

4. The assembly of claim 3, wherein said first transceiver is mounted to a housing fixed relative to said adjustable member.

5. The assembly of claim 3, wherein said first sensor is mounted to said adjustable member and produces a signal indicative of a current position of said adjustable member.

6. The assembly of claim 3, including an idler gear rotatable in response to movement of said adjustable member, said first sensor mounted for rotation with said idler gear.

7. The assembly of claim 6, wherein said first sensor communicates an angular position of said idler gear to said first transceiver.

8. The assembly of claim 1, including an operating shaft rotatable about an axis for moving said friction member into engagement with the rotatable member, a second sensor mounted for rotation with said operating shaft, and a second transceiver fixed relative to said operating shaft, said second sensor producing a signal indicative of an angular position of said operating shaft to said second transceiver.

9. The assembly of claim 1, wherein said friction member comprises a backing plate and friction material, wherein said first sensor is mounted on said backing plate for communicating information indicative of a position of said backing plate to said first transceiver.

10. The assembly of claim 9, including a movable housing, a fixed housing, and a housing sensor mounted to said movable housing, said housing sensor communicating information indicative of a position of said movable housing to a housing transceiver mounted to said fixed housing.

11. The assembly of claim 1O, wherein said housing sensor communicates information indicative of a relative position between said movable housing and said fixed housing.

12. A method of determining clearance between a friction member and a rotatable member, said method comprising the steps of:

a) communicating a first position signal between a first sensor and a first transceiver indicative of a position of a movable brake component;

b) determining contact between the friction member and the rotatable member in response to a predetermined force measurement; and

c) determining a position of the friction member relative to the rotatable member based on the first position signal, the predetermined force measurement and a known relationship between the movable brake component and the friction member.

13. The method of claim 12, wherein the first sensor is an inductive resonance device and said step a) comprises transmitting the first position signal from the inductive resonance device in response to a prompt signal transmitted by the first transceiver.

14. The method of claim 13, further comprising the step of transmitting a second position signal from a second sensor indicative of a position of an adjustable member.

15. The method of claim 14, comprising the step of determining a relative displacement between the adjustable member and the movable brake component based on the first and second position signals.

16. The method of claim 12, wherein said step a) comprises communicating an angular displacement of the movable brake component.

17. The method of claim 16, including determining a speed of an adjustable member based on the first position signal from the first sensor.

18. A method of determining a thickness of friction material of a brake pad, said method comprising the steps of:

a) sensing engagement of the friction material with a rotatable brake member;

b) communicating a first position between a first sensor and a first transceiver indicative of a position of a backing plate supporting the friction material relative to the rotatable brake member; and

c) determining a thickness of the friction material based on the first position signal during engagement with the rotatable brake member.

19. The method of claim 18, wherein the first sensor is an inductive resonance device and said step b) comprises transmitting the first signal in response to a signal transmitted by the first transceiver.

20. The method of claim 19, wherein the first transceiver is mounted to a component fixed relative to the rotatable brake member, and said step c) comprises determining a thickness of the friction material utilizing a known mechanical relationship between the rotatable brake member and the backing plate.