System for monitoring bearing wear

• US 7,551,288 B1
• Filed: 07/25/2000
• Issued: 06/23/2009
• Est. Priority Date: 10/28/1997
• Status: Expired due to Fees

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Discenzo, Frederick M.
• Primary Examiner(s): Lee (Andrew); Hwa S
• Application Number:
  US09/625,094
• Time in Patent Office: 3,255 Days
• Field of Search: 356/450, 356/479, 356/482
• US Class Current: 356/477
• CPC Class Codes: B60C 11/24 Wear-indicating arrangements
• CPC Class Codes: B60C 11/246 Tread wear monitoring systems
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: F16J 15/3296 Arrangements for monitoring the condition or operation of elastic sealings F16J15/326 takes precedence; Arrangements for control of elastic sealings, e.g. of their geometry or stiffness
• CPC Class Codes: F16J 15/3492 with monitoring or measuring means associated with the seal
• CPC Class Codes: G01B 11/06 for measuring thickness ; e.g. of sheet material thickness measurement by thermal means G01B21/085
• CPC Class Codes: G01B 9/02023 Indirect probing of object, e.g. via influence on cavity or fibre
• CPC Class Codes: G01B 9/02027 Two or more interferometric channels or interferometers
• CPC Class Codes: G01D 5/35325 using interferometer with two arms in reflection, e.g. Mickelson interferometer
• CPC Class Codes: G01M 13/04 Bearings
• CPC Class Codes: H01R 39/26 Solid sliding contacts, e.g. carbon brush
• CPC Class Codes: H01R 39/36 Connections of cable or wire to brush
• CPC Class Codes: H02K 11/25 Devices for sensing temperature, or actuated thereby
• CPC Class Codes: H02K 11/35 Devices for recording or transmitting machine parameters, e.g. memory chips or radio transmitters for diagnosis
• CPC Class Codes: H02K 5/14 Means for supporting or protecting brushes or brush holders

Abstract

A system for determining at least one condition of a bearing including an optical fiber for transmitting light from a light source. The optical fiber is embedded in the bearing and operatively coupled to an interferometric system. The interferometric system is operatively coupled to a processor. The interferometric system provides the processor with information relating to wear of the optical fiber, and the processor determines wear of the bearing, rate of wear and remaining useful life of the bearing based on the information relating to wear of the optical fiber.

Claims

1. A system for determining at least one condition of a bearing, comprising:

at least one optical fiber embedded in a bearing, the at least one optical fiber having first and second ends, the first end receiving a beam of light from a light source and transmitting the light to the second end, the second end being flush with a contacting surface of the bearing; and

an interferometric system operatively coupled to the optical fiber and a processor;

wherein the interferometric system provides the processor with information relating to at least one condition of the bearing, and the processor determines a state of the at least one condition of the bearing based on the information.

2. The system of claim 1, wherein the processor determines rate of wear of the bearing based on the information.

3. The system of claim 1, wherein a length direction of the optical fiber is substantially parallel to a direction of wear of the bearing.

4. The system of claim 1, wherein the interferometric system generates a reference beam and a measuring beam from the light source, the measuring beam being transmitted through the optical fiber.

5. The system of claim 4, wherein the interferometric system generates an interference beam from a reflected reference beam and a reflected measuring beam.

6. The system of claim 5, wherein the interference beam includes at least one fringe, the at least one fringe corresponding to a change in length of the optical fiber.

7. The system of claim 6, further including a counter for counting the at least one fringe.

8. The system of claim 1, wherein the bearing is a ball bearing and includes at least one optical fiber in an inner race of the bearing and at least one optical fiber in an outer race of the bearing.

9. The system of claim 1, wherein the bearing includes a plurality of optical fibers in the inner race of the bearing and a plurality of optical fibers in the outer race of the bearing.

10. The system of claim 1, wherein the at least one condition is wear of the bearing.

11. The system of claim 1, wherein at least one optical fiber is grated and coupled to a temperature sensor and the at least one condition is temperature environment of the bearing.

12. The system of claim 1, wherein at least one optical fiber includes microbends and is coupled to a pressure sensor and the at least one condition is the pressure environment of the bearing.

13. The system of claim 1, further comprising an actuator coupled to the processor and coupled to the interferometric system, the processor and the actuator cooperating to maintain a fixed fringe pattern based on readings the processor receives from the interferometric system.

14. The system of claim 1, wherein the bearing is one of a sleeve bearing, a hydrodynamic bearing, a double row ball bearing and a thrust bearing.

15. The system of claim 1, wherein the at least one optical fiber comprises a plurality of optical fibers sharing the interferometric system and the processor.

16. A system for determining at least one condition of a bearing, comprising:

a light source for generating a beam of light;

at least one optical fiber at least part of which is embedded in a bearing, the at least one optical fiber having first and second ends, the first end receiving the beam of light, the second end being flush with a contacting surface of the bearing; and

a measuring system operatively coupled to the optical fiber;

wherein the optical fiber provides the measuring system with information relating to the at least one condition of the bearing.

17. The system of claim 16, the measuring system includes an interferometric system and a processor.

18. The system of claim 16, wherein a length direction of the at least one optical fiber is substantially parallel to a direction of wear of the article.

19. The system of claim 16, wherein the at least one condition is wear of the bearing.

20. The system of claim 16, wherein at least one optical fiber is grated and coupled to a temperature sensor and the at least one condition is temperature environment of the bearing.

21. The system of claim 16, wherein at least one optical fiber includes microbends and is coupled to a pressure sensor and the at least one condition is pressure environment of the bearing.

22. A method for determining at least one condition of a bearing, comprising the steps of:

providing a bearing having an optical fiber embedded therein, the optical fiber having first and second ends, the first end receiving the beam of light, the second end being flush with a contacting surface of the bearing;

using a measuring system operatively connected to the optical fiber to collect information relating to the optical fiber; and

using a processor operatively coupled to the measuring system to determine the at least one condition of the bearing based on the information.

23. The method of claim 22, the at least one condition being bearing wear rate.

24. The method of claim 22, the at least one condition being bearing temperature environment.

25. The method of claim 22, the at least one condition being bearing pressure environment.

26. A system for determining at least one condition of a bearing, comprising:

at least one optical fiber embedded in a bearing, the at least one optical fiber having first and second ends, the first end receiving a beam of light from a light source and transmitting the light to the second end, the second end being flush with a contacting surface of the bearing;

an interferometric system operatively coupled to the optical fiber and a processor, the interferometric system comprising optics and a detector, the light source transmitting light from the light source to the at least one fiber which is reflected from the optics to the detector;

an actuator coupled to the processor and the optics wherein the processor controls the actuator to adjust the optics based on at least one condition of the bearing.

27. The system of claim 26, the processor further providing at least one of diagnostics and prognostics information.

28. The system of claim 26, further comprising a plurality of interferometric systems each coupled to a processor wherein each of the plurality of interferometric systems employ the light source utilizing an optical coupler to split the light from the light source to the plurality of interferometric systems.

29. The system of claim 26, the at least one optical fiber comprising a plurality of optical fibers embedded in a plurality of devices, the plurality of optical fibers sharing the light source, the interferometric system and the processor.

30. The system of claim 26, the at least one optical fiber comprising a plurality of optical fibers measuring a plurality of condition of the bearing, the plurality of conditions being combined using sensor fusion to provide an output of at least one of health state, fault condition, control action, warning and recommendation action.

31. The system of claim 26, the at least one optical fiber, the light source, the interferometric system, the processor, the detector, the actuator being integrated into the bearing to form a smart bearing.

32. The system of claim 26, wherein the bearing is a babbitt and the processor predicts when the babbitt needs to be replaced.