Abstract: A gantry assembly includes a rotor, a stator and a bearing for coupling the rotor and the stator. The bearing includes an inner ring connected with the rotor or stator, an outer ring connected with the other one of the rotor and the stator and rolling elements between the two rings. The ring connected with the stator, preferably the outer ring, includes one or more damping washers disposed between the ring and the stator, each washer being disposed about one threaded fastener connecting the ring with the stator. Also, one or more damping cylinders are each disposed within a mounting hole of the ring connected with the stator and about a threaded fastener disposed within the hole. The bearing ring connected with the rotor may also include damping washers between the ring and the rotor or/and damping cylinders disposed within mounting holes receiving fasteners connecting the ring with the rotor.

Abstract: A gantry assembly includes a rotor rotatable about a central axis, a stator fixed with respect to the axis and a bearing inner ring connected with the rotor and having an outer circumferential surface providing a least one inner raceway and two opposing axial end. A bearing outer ring is disposed about the inner ring and has an inner circumferential surface providing at least one outer raceway, first and second axial ends, an annular recess extending axially inwardly from the first axial end, and a plurality of threaded mounting holes extending axially-inwardly from the recess and spaced circumferentially about the central axis. An annular damper is disposed within the recess and a plurality of threaded fasteners each extend from the stator, through the damper and into a separate one of the plurality of threaded mounting holes to connect the bearing outer ring with the stator.

Abstract: A gantry assembly includes a rotor rotatable about a central axis, a stator fixed with respect to the axis and a bearing inner ring connected with the rotor and having an outer circumferential surface providing a least one inner raceway and two opposing axial end. A bearing outer ring is disposed about the inner ring and has an inner circumferential surface providing at least one outer raceway, first and second axial ends, an annular recess extending axially inwardly from the first axial end, and a plurality of threaded mounting holes extending axially-inwardly from the recess and spaced circumferentially about the central axis. An annular damper is disposed within the recess and a plurality of threaded fasteners each extend from the stator, through the damper and into a separate one of the plurality of threaded mounting holes to connect the bearing outer ring with the stator.

Abstract: A gantry assembly includes a rotor, a stator and a bearing for coupling the rotor and the stator. The bearing includes an inner ring connected with the rotor or stator, an outer ring connected with the other one of the rotor and the stator and rolling elements between the two rings. The ring connected with the stator, preferably the outer ring, includes one or more damping washers disposed between the ring and the stator, each washer being disposed about one threaded fastener connecting the ring with the stator. Also, one or more damping cylinders are each disposed within a mounting hole of the ring connected with the stator and about a threaded fastener disposed within the hole. The bearing ring connected with the rotor may also include damping washers between the ring and the rotor or/and damping cylinders disposed within mounting holes receiving fasteners connecting the ring with the rotor.

Abstract: 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.

Abstract: 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.

Abstract: A roller cone drill bit for drilling earth formation includes rows arranged on each of the cones such that, when viewed in routed profile, cutting element profiles partially overlap other cutting element profiles. The roller cone drill bit having at least a first three interior rows adjacent a gage row, each have a cutting element count selected from the group of 16, 18, 21 and 26 cutting elements.

Abstract: A drill bit for drilling through earthen formations and forming a borehole. In an embodiment, the bit comprises a bit body having a bit axis. In addition, the bit comprises a plurality of cone cutters, each of the cone cutters being mounted on the bit body and adapted for rotation about a different cone axis. Further, at least one cone cutter on the bit comprises an array of cutter elements mounted in a band. Still further, the cutter elements in the array are mounted in a plurality of differing radial positions relative to the bit axis.

Abstract: A roller cone drill bit for drilling earth formation may include rows arranged on each of the cones such that when viewed in routed profile, cutting element profiles partially overlap with other cutting element profiles and at least the first three interior rows adjacent a gage row each have a cutting element count selected from the group of 16, 18, 21 and 26 cutting elements.

Abstract: A drill bit includes a plurality of cutting elements are positioned on the at least two roller cones, wherein cutting elements contributing to an operative gage row of the drill bit comprise less than 31 percent of a total cutting elements of the drill bit that contact the bottom of the borehole. A method to design a roller cone drill bit includes designing an initial bit, testing the initial bit; and adjusting the bit design to optimize at least one of rate of penetration and wear resistance, wherein cutting elements contributing to an operative gage row of the adjusted bit design comprise less than 31 percent of a total of cutting elements on the adjusted bit design that contact a bottom of a borehole.