Floating brush seal

• US 6,244,599 B1
• Filed: 04/28/1999
• Issued: 06/12/2001
• Est. Priority Date: 04/28/1999
• Status: Expired due to Fees

• Current Assignee: Flowserve Management Company (Flowserve Corporation)
• Original Assignee: Flowserve Management Company (Flowserve Corporation)
• Inventors: Braun, Minel J., Choy, Fred K.
• Primary Examiner(s): Melius, Terry Lee
• Assistant Examiner(s): Hewitt, James M
• Application Number:
  US09/301,398
• Time in Patent Office: 776 Days
• Field of Search: 277/352, 277/355, 277/362, 277/390, 277/400
• US Class Current: 277/352
• CPC Class Codes: F16J 15/3288 Filamentary structures, e.g. brush seals
• CPC Class Codes: F16J 15/441 with floating ring

Abstract

A seal assembly which cooperates between relatively rotatable members for creating a sealing relationship between areas of high and low pressures. The assembly includes a face seal arrangement nonrotatably associated with one of the relatively rotatable members, which face seal arrangement defines thereon a pair of annular sealing faces, and an annular brush having a plurality of bristles disposed in an annular array. The brush bristles are mounted on the holder such that free ends thereof are in sealing contact with the other member to form a first seal between the areas of high and low pressures, whereby the brush is rotatable along with the other member to minimize wear thereto. The brush defines thereon a pair of annular sealing faces which are disposed in axially adjacent and opposed face-to-face relation with the respective sealing faces of the face seal arrangement to form a second seal between the areas of high and low pressures.

Claims

1. A seal assembly in combination with a housing member and a shaft rotatable relative thereto for creating a sealing relationship between areas of high and low pressures, said assembly comprising:

a face seal structure nonrotatably associated with the housing member and defining thereon a first annular sealing face which surrounds the shaft and extends transversely with respect to a longitudinal axis of the shaft;

an annular brush surrounding the shaft for rotation therewith and having a plurality of bristles disposed in an annular array about the shaft;

said brush including an annular holder, said bristles being mounted on said holder such that free ends of said bristles are in sealing contact with the shaft to form a first seal between the areas of high and low pressures;

said holder defining thereon a second annular sealing face which extends transversely with respect to the shaft axis, said second annular sealing face being disposed in axially adjacent and opposed face-to-face relation with said first annular sealing face; and

said face seal structure including a passage therein in communication with a gas source for directing a flow of gas between said first and second annular sealing faces to form a non-contacting second seal between the areas of high and low pressures.

2. The seal assembly of claim 1 wherein said annular brush is rotatable along with the shaft solely through engagement of said free ends of said bristles with the shaft.

3. The seal assembly of claim 1 wherein said face seal structure includes a pair of annular plate-like members disposed axially spaced-apart from one another to define a radially extending cavity therebetween, said annular brush being disposed in a free-floating manner within said cavity and said passage communicating with said cavity, said first sealing face being defined on one of said plate-like members.

4. The seal assembly of claim 3 wherein said face seal structure includes a ring disposed between said plate-like members adjacent outer peripheries thereof, said passage extending generally radially through said ring.

5. The seal assembly of claim 3 wherein said holder includes first and second annular plates fixed to one another in axially adjacent relationship, said bristles being stationarily disposed between said first and second plates, said second annular sealing face being disposed on said first plate, the other said plate-like member defining thereon a third annular sealing face which extends transversely with respect to the shaft axis, said second plate defining thereon a fourth annular sealing face which extends transversely with respect to the shaft axis and is disposed in axially adjacent and opposed face-to-face relation with said third annular sealing face, said passage additionally directing a flow of gas between said third and fourth annular sealing faces to form said non-contacting second seal between the areas of high and low pressures.

6. The seal assembly of claim 5 wherein one of said first and second annular sealing faces and one of said third and fourth annular sealing faces includes grooves therein configured to form a gas cushion between said first and second annular sealing faces and between said third and fourth annular sealing faces during relative rotation of said first and second annular sealing faces and said third and fourth annular sealing faces.

7. The seal assembly of claim 1 wherein said face seal structure and said annular brush are disposed and configured to accommodate both radial and axial movements of the shaft.

8. A seal assembly in combination with relatively rotatable inner and outer members for creating a sealing relationship between areas of high and low pressures, said assembly comprising:

a face seal structure nonrotatably associated with one of the inner and outer members and defining thereon first and second annular sealing faces which extend transversely with respect to a longitudinal axis of the one member;

an annular brush disposed between the inner and outer members and including an annular array of bristles having free ends in sealing contact with the other member to form a first seal between the areas of high and low pressures and to cause rotation of said brush along with the other member; and

said brush including thereon third and fourth annular sealing faces which extend transversely with respect to the axis, said third and fourth annular sealing faces being disposed in axially adjacent and opposed face-to-face relation with the respective said first and second annular sealing faces to form a non-contacting second seal between the areas of high and low pressures.

9. The seal assembly of claim 8 wherein said brush is rotatable along with the other member solely through frictional engagement of the free ends of said bristles with the other member.

10. The seal assembly of claim 8 wherein said face seal structure includes a pair of annular plate-like members respectively defining thereon said first and second annular sealing faces, said plate-like members being disposed axially spaced-apart from one another to define a generally radially extending cavity therebetween, said brush being disposed in a free-floating manner within said cavity.

11. The seal assembly of claim 10 wherein said plate-like members each define a network of passages therein, said passages opening at the respective said first and second annular sealing faces for communication with said cavity, said passages additionally communicating with a feed passage disposed within the one member which feed passage communicates with the high pressure area.

12. The seal assembly of claim 11 wherein said passages of said plate-like members discharge high pressure gas from the high pressure area into said cavity and against the respective said third and fourth annular sealing faces to form a gas film between said first and third annular sealing faces and said second and fourth annular sealing faces.

13. The seal assembly of claim 11 wherein said passages of said plate-like members open at the respective said first and second annular sealing faces via pockets defined therewithin, and said passages communicate with the feed passage of the one member via respective feed channels disposed within the one member.

14. The seal assembly of claim 10 wherein one of said first and third annular sealing faces and one of said second and fourth annular sealing faces includes grooves therein configured to form a gas cushion between the opposed pairs of said sealing faces during relative rotation of said first and third annular sealing faces and said second and fourth annular sealing faces.

15. The seal assembly of claim 8 wherein one of said first and third annular sealing faces and one of said second and fourth annular sealing faces includes grooves therein configured to form a gas cushion between the opposed pairs of said sealing faces during relative rotation of said first and third annular sealing faces and said second and fourth annular sealing faces.

16. The seal assembly of claim 15 wherein said grooves are disposed to receive high pressure gas from the high pressure area.

17. A seal assembly for creating a sealing relationship between areas of high and low pressures, said assembly comprising:

an inner member;

an outer member disposed in surrounding relation with said inner member;

a face seal structure nonrotatably associated with one of said inner and outer members and defining thereon first and second annular sealing faces which extend transversely with respect to a longitudinal axis of said one member;

an annular brush including an annular array of bristles having free ends in sealing contact with the other member to form a first seal between the areas of high and low pressures, said brush being rotatable along with said other member to minimize wear of at least said other member; and

said brush including thereon third and fourth annular sealing faces which extend transversely with respect to the axis, said third and fourth annular sealing faces being disposed in axially adjacent and opposed face-to-face relation with the respective said first and second annular sealing faces to form a non-contacting second seal between the areas of high and low pressures.

18. The seal assembly of claim 17 wherein said brush is rotatable along with said other member solely through frictional engagement of the free ends of said bristles with said other member.

19. The seal assembly of claim 17 wherein said face seal structure includes a pair of annular plate-like members respectively defining thereon said first and second annular sealing faces, said plate-like members being disposed axially spaced-apart from one another to define a generally radially extending cavity therebetween, said one member includes a feed passage therein in communication with the high pressure area, said feed passage opening into said cavity for directing high pressure gas thereinto such that said brush is disposed in a free-floating manner within said cavity.

20. The seal assembly of claim 19 wherein said feed passage opens into said cavity adjacent an end of said brush opposite said free ends of said bristles to direct high pressure gas against said end of said brush and prevent contact of said brush with said one member.

21. The seal assembly of claim 19 wherein said plate-like members each define a network of passages therein, said passages opening at the respective said first and second annular sealing faces for communication with said cavity and for discharging high pressure gas from the high pressure area into said cavity and against the respective said third and fourth annular sealing faces to form a gas film between said first and third annular sealing faces and said second and fourth annular sealing faces.

22. The seal assembly of claim 19 wherein one of said first and third annular sealing faces and one of said second and fourth annular sealing faces includes grooves therein configured to form a gas cushion therebetween during relative rotation of said first and third annular sealing faces and said second and fourth annular sealing faces, said grooves being disposed to receive high pressure gas from the high pressure area.

23. A seal assembly in combination with first and second relatively rotatable members for creating a sealing relationship between areas of high and low pressures, said assembly comprising:

a face seal structure nonrotatably associated with one of the first and second members and defining thereon a first annular sealing face which extends transversely with respect to a longitudinal axis of the one member;

an annular brush including a plurality of bristles disposed in an annular array, said bristles having free ends in sealing contact with the other member to form a first seal between the areas of high and low pressures and to cause rotation of said brush along with the other member; and

said brush including thereon a second annular sealing face which extends transversely with respect to the axis, said first and second annular sealing faces being disposed in axially adjacent and opposed face-to-face relation with one another to form a non-contacting second seal between the areas of high and low pressures.

24. The seal assembly of claim 23, wherein said face seal structure includes a passage therein in communication with a gas source for directing a flow of gas between said first and second annular sealing faces to form the non-contacting second seal between the areas of high and low pressures.

25. The seal assembly of claim 23, wherein said annular brush is rotatable along with the other member solely through frictional engagement of said free ends of said bristles with the other member.

26. The seal assembly of claim 23, wherein said face seal structure includes a pair of annular plate-like members disposed axially spaced-apart from one another to define a radially extending cavity therebetween, said annular brush being disposed in a free-floating manner within said cavity and a passage communicating with said cavity, said first sealing face being defined on one of said plate-like members.

27. The seal assembly of claim 26, wherein said face seal structure includes a ring disposed between said plate-like members adjacent outer peripheries thereof, said passage extending generally radially through said ring.

28. The seal assembly of claim 23, wherein said face seal structure and said annular brush are disposed and configured to accommodate both radial and axial movements of the other member.

29. The seal assembly of claim 23, wherein said face seal structure includes a pair of annular plate-like members disposed axially spaced-apart from one another to define a radially extending cavity therebetween, said annular brush being disposed in a free-floating manner within said cavity.

30. The seal assembly according to claim 23, wherein said brush includes an annular holder, said holder defining said second annular sealing face.