A diamond thrust bearing and method for manufacturing the diamond thrust bearing wherein diamond bearing pads are interference fitted at ambient temperatures into a plurality of equidistantly spaced bearing pad recesses located in a circle in a receiving surface of a bearing pad retainer. The bearing faces of the diamond bearing pads are located coplanar with a predetermined common bearing plane by pressing the bearing faces into the bearing pad retainer with a ram and inflexible pressing plate until the pressing face of the pressing plate is stopped by a press stop block. The diamond thrust bearing manufactured using the method will be free from heat induced stresses that cause bearing face misalignment.

Diamond thrust bearing and method for manufacturing same

A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table between about 0.070 inch and 0.150 inch thickness, mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a rake land extending forwardly and inwardly from the cutting edge at an angle of between about 10° and 80° to the longitudinal axis of the cutting element for a width, measured along the surface of the rake land, of not less than about 0.050 inch. The interface between the superabrasive volume and the substrate, taken to the rear of the cutting edge, is located no less than about 0.015 inch to the rear of the cutting edge.

Superabrasive cutting element with enhanced durability and increased wear life, and apparatus so equipped

The invention concerns a diamond bearing assembly for a downhole motor. The assembly (10) includes at least one set of opposing, relatively rotating thrust bearing rings (20, 22) each of which includes an annular support element (24, 30) and PCD compacts (26, 32) carried by the support elements. The PCD compacts of the bearing rings oppose one another at a thrust bearing interface (80). Shear limiting means (96, 110) are provided. These means are arranged to shear if frictional forces between the opposing PCD compacts at the thrust bearing interface exceed a critical level. This eliminates relative rotation between the bearing rings and avoids possible overheating and thermal degradation of the PCD. The shear limiting means can also serve as an alignment means to ensure correct axial alignment of the bearing components. The bearing assembly may also include a compact radial bearing capability.

Diamond bearing assembly

An optical device includes a transparent material layer having a desired curved surface configuration, a layer including a variable refractive index material having a dielectric constant anisotropy and having a property in which a sign of a difference Δe in dielectric constant due to the anisotropy is reversed at driving frequencies f1 and f2, at least two transparent electrodes arranged to sandwich the transparent material layer and the layer including the variable refractive index material, and a driving device supplying a voltage including the driving frequencies f1 and f2 between the transparent electrodes.

Optical device and three-dimensional display device

Hardfacing to protect wear surfaces of drill bits and other downhole tools having coated diamond particles (44) dispersed within and bonded to a metallic matrix deposit (20). The coating (42) on the diamond particles (44) may be formed from materials and alloys such as particles of tungsten carbide, and tungsten carbide/cobalt and cermets such as metal carbides and metal nitrides. The coated diamond particles (40) are preferably sintered and have a generally spherical shape. The coated diamond particles (40) are pre-mixed with selected materials such that welding and cooling will form both a metallurgical bond and a mechanical bond within the solidified metallic matrix deposit (20). A welding rod (70) is prepared by placing a mixture of coated diamond particles (40), hard particles such as tungsten carbide/cobalt (30), and loose filler material (74) into a steel tube (72). A substrate (24) is hardfaced by progressively melting the welding rod into a selected surface of the substrate (24) and allowing the melted material to solidify, forming the desired hardfacing with coated diamond particles (40) dispersed therein on the substrate surface (22).

Hardfacing with coated diamond particles

An earth boring apparatus is disclosed having bearing members comprised of transition layer polycrystalline diamond. The transition layer polycrystalline diamond bearings include a polycrystalline diamond layer interfaced with a composite transition layer comprising a mixture of diamond crystals and precemented carbide pieces subjected to high temperature/high pressure conditions so as to form polycrystalline diamond material bonded to the precemented carbide pieces. The polycrystalline diamond layer acts as the bearing surface. The transition layer bearings are preferably supported by a cemented tungsten carbide substrate interfaced with the transition layer.

David R. Hall

Papers

Transistion layer polycrystalline diamond bearing