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US 4,802,539 AGranted
Polycrystalline diamond bearing system for a roller cone rock bit
AssigneeSmith International, Inc.
InventorsDavid R. Hall, Donald G. Cross
Life of this patent
Estimating the term…
Abstract
A roller cone rock bit is disclosed with an improved bearing system. The improvement comprises a main journal bearing which is substantially frustoconically shaped and a main roller cone bearing which is reverse shaped to mate with the journal bearing. The journal and roller cone bearings comprise polycrystalline diamond. The invention also includes a member for retaining the roller cone on the journal.
Claims20
A roller cone rock bit comprising:
- a main bit body with at least one downwardly extending leg, said leg having a journal thereon, said journal having a frusto-conically shaped main journal bearing surface which comprises polycrystalline diamond;
- a roller cone rotatively mounted on each journal, said roller cone having a main roller cone bearing surface which mates with the main journal bearing surface and which comprises polycrystalline diamond;
- and
- means for maintaining the two bearing surfaces in a state of compression against each other.
1 more element
A roller cone rock bit comprising:
- a main bit body with at least one downwardly extending leg, each leg having a journal thereon, said journal having a journal bearing with a substantially frusto-conically bearing surface comprising polycrystalline diamond;
- a roller cone rotatably mounted on the journal, the roller cone having a roller cone bearing with a surface comprised of polycrystalline diamond which mates with the substantially frusto-conically shaped bearing surface of the journal bearing;
- said journal defining a hole which includes the axis of rotation of the roller cone;
- a bolt which passes &through said hole in the journal and has a first end which is threadably attached to the roller cone, and has a second enlarged end positioned outside of said hole;
- a first thrust bearing which is adjacent to said enlarged end and through which said bolt passes said first thrust bearing having a first thrust bearing surface;
- a second thrust bearing which is adjacent to said leg and through which said bolt passes, said second thrust bearing having a second thrust bearing surface which mates with said first thrust bearing surface;
- and
- said bolt being maintained in tension so as to place said journal bearing and roller cone bearing in compression against each other, and to place said first and second thrust bearing surfaces in compression against each other.
5 more elements
A roller cone rock but comprising:
- a main bit body with at least one downwardly extending leg, each leg having a journal thereon, said journal having a journal bearing with a substantially frusto-conically shaped bearing surface comprising polycrystalline diamond;
- a roller cone rotatably mounted on the journal, the roller cone having a roller cone bearing with a bearing surface comprised of polycrystalline diamond which mates with the substantially frusto-conically shaped bearing surface of the journal bearing, said roller cone defining a hole which includes the axis of rotation of the roller cone;
- a bolt which passes through said hole in the roller cone and has a first end which is threadably attached to the journal, and has a second enlarged end positioned outside of said hold;
- a first thrust bearing which is adjacent to said enlarged end and through which said bolt passes said first thrust bearing having a first thrust bearing surface;
- a second thrust bearing which is adjacent to said roller cone and through which said bolt passes, said second thrust bearing having a second thrust bearing surface which mates with said first thrust bearing surface;
- and
- said bolt being maintained in tension so as to place said journal bearing and roller cone bearing in compression against each other, and to place said first and second thrust bearing surfaces in compression against each other.
4 more elements
A roller cone rock bit comprising:
- a main bit body with at least one downwardly extending leg, each leg having a journal thereon, said journal having a journal bearing with a substantially frusto-conically shaped bearing surface comprising polycrystalline diamond;
- a roller cone rotatably mounted on the journal, the roller cone having a roller cone bearing with a bearing surface comprised of polycrystalline diamond which mates with the substantially frusto-conically shaped bearing surface of the journal bearing, said roller cone defining a hole which includes the axis of rotation of the roller cone;
- said journal defining a hole which includes the axis of rotation of the roller cone;
- a bolt which passes through said hole in the journal and said hole in the roller cone, said bolt having a first end with a first nut threaded thereon and a second end with a second nut threaded thereon;
- a first set of thrust bearings through which the first end of the bolt passes and which are positioned between said first nut and the leg;
- a second set of thrust bearings through which the second end of the bolt passes and which are positioned between the second nut and the roller cone;
- and
- said first and second nuts being sufficiently tightened to place said bolt in tension, thereby placing said journal bearing and roller cone bearing in compression against each other
5 more elements
Dependencies are inferred from the claim text.