Sealed bearing drill bit with dual-seal configuration and fluid-cleaning capability

• US 6,254,275 B1
• Filed: 12/01/1997
• Issued: 07/03/2001
• Est. Priority Date: 12/19/1995
• Status: Expired due to Term

• Current Assignee: Sandvik Intellectual Property AB (Sandvik AB)
• Original Assignee: Smith International Incorporated (SLB)
• Inventors: Cariveau, Peter, Didericksen, Roger, Slaughter, Robert H. Jr.
• Primary Examiner(s): RIVERA, WILLIAM ARAUZ
• Application Number:
  US08/980,935
• Time in Patent Office: 1,310 Days
• Field of Search: 384/92, 384/94, 384/95, 384/96, 175/367, 175/368, 175/369, 175/371, 175/372
• US Class Current: 384/92
• CPC Class Codes: E21B 10/25 characterised by sealing details
• CPC Class Codes: F16C 19/49 Bearings with both balls and rollers
• CPC Class Codes: F16C 19/54 Systems consisting of a plurality of bearings with rolling friction spindle bearings F16C35/08
• CPC Class Codes: F16C 2352/00 Apparatus for drilling
• CPC Class Codes: F16C 33/78 with a diaphragm, disc, or ring, with or without resilient members F16C33/761 takes precedence

Abstract

A drill bit for use in an earthen annulus that contains loose particles is connected to a fluid supply source and includes a bit body having at least one journal segment and at least one fluid conduit in fluid communication with the fluid supply source. A roller cone is rotatably mounted upon the journal segment and forms at least one bearing cavity therebetween. An annular primary seal is disposed between the roller cone and the bit body and between the bearing cavity and the earthen annulus, and an annular gap is disposed between the annular primary seal and the earthen annulus. The annular gap is in fluid communication with the fluid conduit and the earthen annulus. An annular secondary seal is disposed between the annular primary seal and the earthen annulus and is capable of substantially preventing the ingress of debris from the earthen annulus to the annular primary seal.

Claims

1. A drill bit for use in an earthen annulus that contains loose particles, the drill bit connected to a fluid supply source comprising:

a bit body having at least one journal segment, said bit body further having at least one fluid conduit in fluid communication with the fluid supply source;

a roller cone rotatably mounted upon said journal segment and forming at least one bearing cavity therebetween;

an annular primary seal disposed between said roller cone and said bit body and between said bearing cavity and the earthen annulus;

an annular gap disposed between said roller cone and said bit body and between said annular primary seal and the earthen annulus, said annular gap in fluid communication with said fluid conduit and the earthen annulus; and

an annular secondary seal disposed between said annular primary seal and the earthen annulus, said annular secondary seal being primarily radially energized.

2. The drill bit of claim 1 wherein said annular secondary seal includes a sealing lip having a dynamic sealing surface constructed at least partially of elastomeric material.

3. The drill bit of claim 2 wherein said annular secondary seal is capable of providing a substantially absolute seal.

4. The drill bit of claim 1 wherein said annular secondary seal is disposed between said fluid conduit and said annular primary seal.

5. The drill bit of claim 1 wherein said annular secondary seal is capable of permitting fluid flow from said fluid conduit into said annular gap and substantially preventing the passage of debris from said annular gap to said annular primary seal.

6. The drill bit of claim 5 wherein said annular secondary seal includes a one-way valve.

7. The drill bit of claim 1 wherein said bit body further includes an annular groove disposed between said cone and said bit body and between said annular primary seal and the earthen annulus, wherein said annular groove is in fluid communication with said fluid conduit and said annular gap.

8. The drill bit of claim 7 wherein said annular secondary seal is disposed between said fluid conduit and said annular primary seal.

9. The drill bit of claim 8 wherein said annular secondary seal is disposed at least partially within said annular groove.

10. The drill bit of claim 9 wherein said annular secondary seal includes a sealing lip having a dynamic sealing surface constructed at least partially of elastomeric material.

11. The drill bit of claim 9 wherein said annular secondary seal is capable of permitting fluid flow from said annular groove into said annular gap and substantially preventing the passage of debris from said annular gap to said annular primary seal.

12. The drill bit of claim 1 wherein said bit body further includes an annular interstice disposed between said cone and said bit body and between said annular primary seal and the earthen annulus, wherein said annular interstice is in fluid communication with said fluid conduit and said annular gap.

13. The drill bit of claim 12 wherein said annular secondary seal is disposed at least partially within said annular interstice.

14. The drill bit of claim 13 wherein said annular secondary seal is capable of permitting fluid flow from said annular interstice into said annular gap and substantially preventing the passage of debris from said annular gap to said annular primary seal.

15. A drill bit for use in an earthen annulus that contains loose particles, the drill bit connected to a circulation fluid supply source comprising:

a bit body having at least one journal segment and at least one fluid conduit in fluid communication with the fluid supply source;

at least one roller cone rotatably mounted upon said journal segment and forming at least one bearing cavity therebetween;

an annular primary seal disposed between said roller cone and said bit body and between said bearing cavity and the earthen annulus;

an annular gap disposed between said roller cone and said bit body and between said annular primary seal and the earthen annulus, said annular gap in fluid communication with said fluid conduit and the earthen annulus; and

an annular non-perforated secondary seal disposed between said annular primary seal and the earthen annulus, said annular non-perforated secondary seal having a dynamic sealing surface constructed at least partially of elastomeric material.

16. A drill bit for use in an earthen annulus that contains loose particles, the drill bit associated with a circulation fluid supply source, comprising:

a bit body having at least one conduit in fluid communication with the fluid supply source;

at least one roller cone rotatably mounted upon said bit body and forming at least one bearing cavity therebetween;

an annular primary seal disposed between said roller cone and said bit body;

an annular gap disposed between said cone and said bit body and between said annular primary seal and the earthen annulus, said annular gap in fluid communication with the earthen annulus;

an annular interstice disposed between said roller cone and said bit body and between said annular gap and said annular primary seal, said annular interstice in fluid communication with said conduit and said annular gap; and

an annular secondary seal disposed at least partially within said annular interstice, said annular secondary seal capable of substantially preventing the ingress of particles from said annular gap to said annular primary seal throughout disposition of the drill bit in the earthen annulus.

17. A rotary cone drill bit for use in an earthen annulus that contains loose particles, the drill bit associated with a circulation fluid supply source, comprising:

a bit body having at least one conduit in fluid communication with the fluid supply source;

at least one roller cone rotatably mounted upon said bit body and forming at least one bearing cavity therebetween;

an annular primary seal disposed between said cone and said bit body, said annular primary seal capable of sealing said bearing cavity;

an annular gap disposed between said cone and said bit body and between said annular primary seal and the earthen annulus, said annular gap in fluid communication with the earthen annulus;

an annular space disposed between said cone and said bit body and between said annular primary seal and the earthen annulus, said annular space in fluid communication with said annular gap and having at least one port in fluid communication with said conduit, said port capable of allowing the flow of fluid into said annular space from said conduit; and

an annular secondary seal disposed between said port and said annular gap, said secondary seal including a one-way valve capable of permitting the flow of fluid from said annular space into said annular gap and substantially inhibiting the ingress of particles from said annular gap to said annular primary seal.

18. A drill bit for use in an earthen annulus that contains loose particles, the drill bit associated with a circulation fluid supply source, comprising:

a bit body having at least one conduit in fluid communication with the fluid supply source;

at least one roller cone rotatably mounted upon said bit body and forming at least one bearing cavity therebetween;

an annular primary seal disposed between said roller cone and said bit body, said annular primary seal capable of sealing said bearing cavity;

an annular gap formed between said roller cone and said bit body and in fluid communication with the earthen annulus;

an annular space disposed between said annular primary seal and the earthen annulus, said annular space in fluid communication with said annular gap and said conduit; and

an annular non-perforated secondary seal disposed between said annular space and the earthen annulus, said annular non-perforated secondary seal capable of substantially sealing said annular space from the earthen annulus.