Downhole tool bearing system containing diamond enhanced materials

Abstract

Downhole tool bearings are provided with diamond enhanced materials. The diamond enhanced materials comprise diamond grains in a matrix of tungsten or silicon carbide. A brazed diamond grit or diamond particles coated with a reactive braze may be utilized for bearing applications. Bearing rings formed at least in part with diamond enhanced material are installed on at least one of the bearing pin journal, the nose and the cone cavity. The bearing rings may be continuous rings or partial rings and attached to the journal pin or cone cavity. These may include thrust bearings, rollers, roller race, balls and ball races made of diamond enhanced material. These bearing surfaces also are formed at least in part with diamond enhanced material and attached to portions of the journal or cone bearing surfaces.

Description

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61 / 029,719, which was filed on Feb. 19, 2008, and is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION

[0002] 1. Technical Field

[0003] The present invention relates in general to bearing systems for downhole tools and, in particular, to an improved system, method, and apparatus for a downhole tool bearing system containing diamond enhanced materials.

[0004] 2. Description of the Related Art

[0005] Diamond is a unique bearing material with superior wear resistance compared to traditional bearing materials, such as steel. Downhole tools with diamond enhanced bearings have been investigated in an effort to take advantage of diamond's wear resistant properties. Some diamond bearing systems in rolling cone drill bits and mud motor bearings have been proposed with polycrystalline diamond compacts (PDC), chemical vapor deposition (CVD) diamond, and diamond-like carbon (D...

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