Fiber-on-tip contact design brush assemblies

Patent metadata

Field	Value
Publication number	US-9362697-B2
Application number	US-201214113632-A
Country	US
Kind code	B2
Filing date	Mar 13, 2012
Priority date	Mar 13, 2012
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

The present invention broadly provides improvements in a slip-ring adapted to provide electrical contact between a stator and a rotor. The improved slip-ring includes a brush assembly having a brush tube mounted on the stator and having a fiber bundle composed of a number of individual fibers. The upper marginal end portions of the fibers are received in the brush tube. The lower marginal end portions of the fibers extend beyond the brush tube toward the rotor. The improvements broadly comprise: a central portion of the fibers having been removed below the brush tube such that the fibers extending below the brush tube toward the rotor are in the form of an annulus; and wherein the tangential compliance of the fiber bundle at its point of contact with the rotor is more than twice the tangential compliance of the fiber bundle if the central portion had not been removed.

First claim

The invention claimed is:

1. In a slip-ring for providing electrical contact between a stator and a rotor, said slip-ring including a brush assembly having a brush tube mounted on one of said rotor and stator and having a fiber bundle composed of a number of individual fibers, one marginal end portion of said fibers being received in said brush tube, other marginal end portion of said fibers extending beyond said brush tube toward the other of said rotor and stator, an improvement comprising:
a central portion of said fibers having been removed below said brush tube such that the fibers extending below said brush tube toward said other of said rotor and stator are in a form of an annulus; and
wherein a tangential compliance of said fiber bundle at its point of contact with said rotor is more than twice a tangential compliance of said fiber bundle if said central portion had not been removed.

2. The improvement as set forth in claim 1 wherein the tangential compliance of said fiber bundle may be varied as a function of diameters of said fibers, a free length of said fibers from the end of said brush tube toward tips of said fibers, and an area of said central portion.

3. The improvement as set forth in claim 1 wherein a portion of said brush tube is crimped or swaged to hold said one marginal end portion of said fibers therein.

4. The improvement as set forth in claim 1 wherein the tangential compliance of the fiber bundle at its point of contact with said rotor is more than 2½ times the tangential compliance of said fiber bundle if said central portion had not been removed.

5. The improvement as set forth in claim 1 wherein said fiber bundle has about 2000 individual fibers.

6. The improvement as set forth in claim 5 wherein said central portion includes about 1000 fibers.

7. The improvement as set forth in claim 1 wherein said central portion contains about half of a number of fibers in said fiber bundle.

8. The improvement as set forth in claim 1 wherein said annulus has a substantially-constant radial thickness.

9. The improvement as set forth in claim 1 wherein said fibers have diameters in the range of 0.002-0.005 inches.

10. The improvement as set forth in claim 9 wherein each fiber has a diameter of about 0.003 inches.

11. The improvement as set forth in claim 1 wherein a length of said fibers extending beyond said tube and toward said rotor is in the range of 0.3-0.7 inches.

12. The improvement as set forth in claim 11 wherein the length of said fibers extending beyond said tube and toward said rotor is about 0.40 inches.

13. The improvement as set forth in claim 1 wherein a transverse cross-sectional area of said central portion is more than ⅔ of the transverse cross-sectional area of said fiber bundle.

14. The improvement as set forth in claim 1 wherein the tangential compliance of said fiber bundle at its point of contact with said rotor is about 0.006350 inches/gram.

15. The improvement as set forth in claim 14 wherein the tangential compliance of a fiber bundle from which said central portion had not been removed at its point of contact with said rotor is about 0.00139 inches/gram.

16. The improvement as set forth in claim 1 wherein the tangential compliance of the fiber bundle at its point of contact with said rotor is more than 4.5 times the tangential compliance of said fiber bundle at its point of contact with said rotor if said central portion had not been removed.

17. The improvement as set forth in claim 1 , and further comprising: a reservoir above said brush tube, said reservoir being in fluid communication with said fiber bundle; and a lubricant in said reservoir.

18. The improvement as set forth in claim 17 wherein said lubricant includes at least one of a diester, a fluorocarbon, a halocarbon, a hydrocarbon, and a polyphenyl ester.

19. The improvement as set forth in claim 17 wherein said reservoir is in fluid communication with said fiber bundle through the spaces between said fibers.

20. The improvement as set forth in claim 19 wherein the flow of lubricant through said spaces is a function of the sizes of said spaces.

21. The improvement as set forth in claim 1 , and further comprising: resilient means for urging said fiber bundle to move toward said rotor.

22. The improvement as set forth in claim 21 wherein said fiber bundle is urged to move toward said rotor with substantially-constant force.

23. The improvement as set forth in claim 21 wherein said resilient means includes a negator spring.

24. The improvement as set forth in claim 21 wherein said resilient means includes a cantilever spring.

25. The improvement as set forth in claim 1 wherein said other of said rotor and stator does not have an electrodeposited material.

26. The improvement as set forth in claim 1 wherein said fibers are formed of at least one of a silver alloy, a gold alloy and a copper alloy.

Assignees

• Lewis Norris E
• Perdue Jerry T
• Moog Inc

Inventors

• Lewis Norris E
• Perdue Jerry T

Classifications

• H01R39/22 Primary

  incorporating lubricating or polishing ingredient · CPC title

• H01R39/24 Primary

  Laminated contacts; Wire contacts, e.g. metallic brush, carbon fibres · CPC title

• H01R13/2442

  with a single cantilevered beam · CPC title