Interfacing surfaces of adjacent tiles in a downhole tool may combine to form a tortuous path therebetween. In various embodiments, this tortuous path may run generally parallel and/or perpendicular to a top surface of the tiles. One example of such a tortuous path may be created by a protrusion extending from an interfacing surface of one of the tiles that may fit snugly within a cavity receding into an interfacing surface of another of the tiles.

Interfacing surfaces of adjacent tiles in a downhole tool may combine to form a tortuous path therebetween. In various embodiments, this tortuous path may run generally parallel and/or perpendicular to a top surface of the tiles. One example of such a tortuous path may be created by a protrusion extending from an interfacing surface of one of the tiles that may fit snugly within a cavity receding into an interfacing surface of another of the tiles.

A fixed cutting structure-composite cone drill bit includes a drill bit body, a fixed cutting structure, and at least one cone. The cone and the fixed cutting structure are disposed on the drill bit body. The cone is rotatably connected to the drill bit body by means of a bearing structure. The distance from the outermost tooth or back cone of the at least one cone to the front side surface of the fixed cutting structure La≤πR/3, and the distance from the outermost tooth or back cone of the at least one cone to the rear side surface of the fixed cutting structure Lb≤πR/3. In the composite drill bit, the distance from the cone to the front/rear side surface of the fixed cutting structure is short, the gap between the cone and the fixed cutting structure is small, transition between cutting structure is smooth.

Bearing assemblies that include a plurality of polycrystalline diamond (“PCD”) bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating and fabricating such bearing assemblies and apparatuses are disclosed. In an embodiment, the plurality of PCD bearing elements of one or more of the bearing assemblies disclosed herein include at least one first PCD bearing element. At least a portion of the first PCD bearing element exhibits a coercivity of about 125 Oersteds or more and a specific magnetic saturation of about 14 Gauss.Math.cm3/gram or less. The first PCD bearing element includes a bearing surface with at least one groove formed therein. In an embodiment, the plurality of PCD bearing elements also include at least one second PCD bearing element. The second PCD bearing element exhibits a coercivity that is less than and a specific magnetic saturation that is greater than the first PCD bearing element.

Bearing assemblies that include a plurality of polycrystalline diamond (“PCD”) bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating and fabricating such bearing assemblies and apparatuses are disclosed. In an embodiment, the plurality of PCD bearing elements of one or more of the bearing assemblies disclosed herein include at least one first PCD bearing element. At least a portion of the first PCD bearing element exhibits a coercivity of about 125 Oersteds or more and a specific magnetic saturation of about 14 Gauss.Math.cm3/gram or less. The first PCD bearing element includes a bearing surface with at least one groove formed therein. In an embodiment, the plurality of PCD bearing elements also include at least one second PCD bearing element. The second PCD bearing element exhibits a coercivity that is less than and a specific magnetic saturation that is greater than the first PCD bearing element.

Embodiments disclosed herein are directed to bearing assemblies that include integrated lubrication, bearing apparatuses including such bearing assemblies, and related methods. For example, a lubricated bearing assembly may include a lubricant that may lubricate the bearing surface thereof during operation of the lubricated bearing assembly and/or bearing apparatus including the lubricated bearing assembly.

Embodiments disclosed herein are directed to bearing assemblies that include integrated lubrication, bearing apparatuses including such bearing assemblies, and related methods. For example, a lubricated bearing assembly may include a lubricant that may lubricate the bearing surface thereof during operation of the lubricated bearing assembly and/or bearing apparatus including the lubricated bearing assembly.

A bearing providing a plurality of rolling elements and at least one raceway for the rolling elements. The at least one raceway or the rolling elements include a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating. In some embodiments, the at least one raceway or the rolling elements may comprise a steel substrate covered with the tungsten carbide coating. Embodiments also relate to a method for producing a bearing. The method includes coating a plurality of rolling elements or at least one raceway for the rolling elements with a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating.

A bearing providing a plurality of rolling elements and at least one raceway for the rolling elements. The at least one raceway or the rolling elements include a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating. In some embodiments, the at least one raceway or the rolling elements may comprise a steel substrate covered with the tungsten carbide coating. Embodiments also relate to a method for producing a bearing. The method includes coating a plurality of rolling elements or at least one raceway for the rolling elements with a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating.

A radial bearing having a wear surface with improved wear characteristics comprises a steel support, to which is bonded a metal carbide composite wear surface made by first arranging, within a cavity defined between a steel mold and the steel support, tiles made of microwave sintered, cemented metal carbide, closely packing the voids between the tiles with metal carbide powder, and infiltrating the mold cavity with a metal brazing alloy by subjecting the filled mold to rapid heating. The brazing alloy fills voids between the metal carbide particles, the microwave sintered metal carbide tiles, and the metal support, thereby relatively rapidly consolidating the carbide into a wear layer bonded with the steel support without substantially damaging the properties of the microwave-sintered metal carbide tiles.