SPACER RING FOR ELASTOMERIC SEAL

• US 20100089657A1
• Filed: 10/14/2008
• Published: 04/15/2010
• Est. Priority Date: 10/14/2008
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Lin, Chih
• Granted Patent: US 7,896,109 B2
• Time in Patent Office: Days
• US Class Current: 175/371
• CPC Class Codes: E21B 10/25 characterised by sealing details

Abstract

A roller cone bit is provided that includes a companion ring positioned adjacent to the seal, wherein the companion ring is formed of a porous material that is compatible with the fluid lubricating the interface between the roller cone and the bearing pin.

Claims

1. An earth boring bit, comprising:

a bit body having a depending bearing pin;

a cone having a plurality of cutting elements for engaging a bore hole, the cone having a cavity that rotatably engages the bearing pin, the cone and the bearing pin having a seal area defined by two annular surfaces, one of which rotates relative to the other;

a seal having a forward side surface, a rearward side surface and positioned between the bearing pin and the cone cavity in sealing engagement with the annular surfaces of the seal area; and

at least one companion ring abutting one of the side surfaces of the seal, the seal and positioned between the bearing pin and the cone cavity in non-sealing engagement with the annular surfaces of the seal area, wherein the companion ring is a permeable material.

2. The earth boring bit of claim 1, wherein the companion ring is impregnated with a fluid compatible with a lubricant lubricating the bearing pin.

3. The earth boring bit of claim 1, wherein companion ring is positioned between the forward side surface of the seal and a forward side of the seal area.

4. The earth boring bit of claim 1, wherein companion ring is positioned between the rearward side surface of the seal and a rearward side of the seal area.

5. The earth boring bit of claim 3, wherein said at least one companion ring comprises a second companion ring, wherein the second companion ring is positioned between the rearward side surface of the seal and a rearward side of the seal area.

6. The earth boring bit of claim 1, wherein companion ring includes an inner diameter that contacts, but does not seal the bearing pin, and an outer diameter that contacts, but does not seal the cone.

7. The earth boring bit of claim 1, wherein the companion ring includes an inner diameter and an outer diameter, said inner diameter having a non-contiguous contact pattern where said companion ring contacts the bearing pin.

8. The earth boring bit of claim 1, wherein the companion ring comprises a first material selected from the group consisting of polyethylene microfibers, polypropylene microfibers, fiberglass, polyester, and a polyethylene terephthalate/polypropylene composite material.

9. The earth boring bit of claim 1, wherein:

the companion ring has a forward side and a rearward side, and

the rearward side is formed of a second material, wherein the second material has a greater density than the first material.

10. The earth boring bit of claim 1, wherein the companion ring comprises a layered structure, said layered structure comprising an inner core, a forward side surface material and a rearward side surface material, said inner core having a density greater than the density of the forward and rearward side surface materials.

11. An earth boring bit, comprising:

a bit body having a depending bearing pin;

a cone having a plurality of cutting elements for engaging a bore hole, the cone having a cavity that rotatably engages the bearing pin; and

a groove formed in the cavity of the cone and having a forward side surface, a rearward side surface and a base;

a seal in the groove, having an outer diameter sealingly engaging the base of the groove and an inner diameter sealingly engaging the bearing pin, the seal having a forward side surface and a rearward side surface;

at least one companion ring adjacent to one of the side surfaces of the seal, said companion ring comprising a permeable material; and

wherein the height of the groove is greater than the combined height of the seal and companion ring.

12. The earth boring bit of claim 11 wherein companion ring is impregnated with a fluid compatible with a lubricant operable for lubricating the interface between the bearing pin and the cone cavity.

13. The earth boring bit of claim 11 wherein said companion ring is porous.

14. The earth boring bit of claim 11 wherein the companion ring is located between the forward side surface of the seal and the forward side surface of the seal groove.

15. The earth boring bit of claim 11 wherein the companion ring is located between the rearward side surface of the seal and the rearward side surface of the seal groove.

16. The earth boring bit of claim 12 wherein the at least one companion ring comprises a second companion ring, wherein the second companion ring is located between the rearward side surface of the seal and a rearward side of the seal groove.

17. The earth boring bit of claim 11 wherein the companion ring comprises a first material selected from the group consisting of polyethylene microfibers, polypropylene microfibers, fiberglass, polyester, and a polyethylene terephthalate/polypropylene composite material.

18. The earth boring bit of claim 11 wherein:

the companion ring has a forward side and a rearward side, and the rearward side is formed of a second material, wherein the second material has a greater density than the first material.

19. The earth boring bit of claim 11 wherein the inner diameter of the companion ring has a non-contiguous contact pattern where the companion ring contacts the bearing pin.

20. An earth boring bit, comprising:

a bit body having a depending bearing pin;

a cone having a plurality of cutting elements for engaging a bore hole, the cone having a cavity that rotatably engages the bearing pin, the cone and the bearing pin having a seal area defined by two annular surfaces, one of which rotates relative to the other;

an elastomeric seal having a forward side surface, a rearward side surface and positioned between the bearing pin and the cone cavity in sealing engagement with the annular surfaces of the seal area;

a first companion ring abutting the rearward side surface of the seal and positioned between the bearing pin and the cone cavity in non-sealing engagement with the annular surfaces of the seal area, wherein the first companion ring is felt material; and

a second companion ring abutting the forward side surface of the seal and positioned between the bearing pin and the cone cavity in non-sealing engagement with the annular surfaces of the seal area, wherein the second companion ring is foam material.