Abstract: A hybrid drill bit includes both fixed cutting elements and an adjustable cutting structure thereon. An adjustment mechanism is provided to allow an axial position of cutting elements at a leading end of the adjustable cutting structure to be adjusted with respect to an axial position of the fixed cutting elements. The adjustable cutting structure may include counter rotational cutting members mounted obliquely with respect to a bit body rotational axis, and the adjustment mechanism may dynamically support the adjustable cutting structure such that the axial position of the cutting elements may be adjusted as the drill bit is in operation within a wellbore. The axial position may be adjusted by altering a weight applied to the drill bit within the wellbore.

Abstract: A roller bearing configured to be mounted on a balancing shaft. The rolling bearing having an outer ring, a cage axially protruding beyond at least one side of the outer ring, and rollers mounted in the cage and in rolling contact with the outer ring. The cage provides at least one boss on a side that axially protrudes beyond the outer ring, the boss being dedicated to come into abutment against the outer ring in case of relative axial displacement between the cage and outer ring.

Abstract: A roller cone drill bit assembly with a bearing shaft having an outer bearing surface and defining a rotational axis. The outer bearing surface includes a necked portion having a varying radius with respect to the rotational axis. A roller cone is coupled about the bearing shaft and includes an outer cutting structure and an inner bearing surface. The inner bearing surface includes a necked portion proximate to and closely conforming to the necked portion of the outer bearing surface.

Abstract: A downhole motor for drilling and servicing of wells has an elongated outer housing and an elongated mandrel rotatably disposed within the housing. A primary thrust bearing is disposed between the lower end of the housing and the mandrel, and transfers axial loads downward from the housing to the mandrel, and then to the drill bit or other tool mounted on the lowermost end of the mandrel. The placement of the primary thrust bearing permits it to extend radially to the outer diameter of the housing. One preferred embodiment of the primary thrust bearing comprises bearing surfaces of polycrystalline diamond compact (“PDC”) material.

Abstract: Bearings for downhole tools including a first bearing member and a second bearing member, at least one of the first and second bearing members having a channel formed therein. Methods of cooling bearings of downhole tools comprise flowing a fluid within a channel formed in at least one bearing member. Heat is transferred from at least the at least one bearing member to the fluid. The fluid is flowed away from the at least one bearing member.

Abstract: Bearing apparatuses including contacting bearing surfaces comprising superhard materials are disclosed. In one embodiment, the present invention relates to bearings including polycrystalline diamond inserts or compacts defining a plurality of surfaces that move relative to one another and contact one another. For example, apparatuses may include radial bearings, or other bearings including arcuate bearing surfaces that more in relation to one another, without limitation. In one embodiment, a superhard bearing element may comprise a superhard table (e.g., polycrystalline diamond) forming an arcuate bearing surface. Further, such a superhard bearing element may comprise a chamfer formed about at least a portion of a periphery of the arcuate bearing surface. Bearing apparatuses including such bearing elements and various mechanical systems are disclosed.

Abstract: A thrust bearing system for a roller cone rock bit includes at least one roller cone disposed on a leg having an air channel therethrough, the thrust bearing system including a primary thrust bearing surface on the leg configured to contact a corresponding primary bearing surface on the roller cone, wherein the primary thrust bearing surface on the leg includes at least one air circulation port in fluid communication with the air channel.

Abstract: In an embodiment, a bearing apparatus comprises a first bearing assembly including a plurality of circumferentially-spaced first bearing elements each of which includes a first bearing surface. The bearing apparatus further includes a second bearing assembly including a plurality of circumferentially-spaced second bearing elements each of which includes a second bearing surface oriented to engage the first bearing surfaces of the first bearing assembly during operation. At least one of the second bearing elements may be circumferentially spaced from an adjacent one of the second bearing elements by a lateral spacing greater than a lateral dimension of the at least one of the second bearing elements.

Abstract: Embodiments of present invention relate to a bearing assembly, and a bearing apparatus and motor assembly that employs such a bearing assembly. In one embodiment of the present invention, a bearing assembly comprises a support ring including a plurality of recesses and at least one opening. The bearing assembly further includes a plurality of bearing elements, each of which is positioned generally within a corresponding one of the recesses. At least one of the bearing elements includes at least one groove. At least one retention element may be positioned generally within the at least one opening and adjacent to the at least one groove. Further embodiments of the present invention are directed to a thrust-bearing apparatus, a radial bearing apparatus, and a downhole motor that may utilize any of the disclosed thrust-bearing assemblies and radial bearing assemblies.

Abstract: Embodiments of present invention relate to a bearing assembly, and a bearing apparatus and motor assembly that employs such a bearing assembly. In one embodiment of the present invention, a bearing assembly comprises a support ring including a plurality of recesses and at least one opening. The bearing assembly further includes a plurality of bearing elements, each of which is positioned generally within a corresponding one of the recesses. At least one of the bearing elements includes at least one groove. At least one retention element may be positioned generally within the at least one opening and adjacent to the at least one groove. Further embodiments of the present invention are directed to a thrust-bearing apparatus, a radial bearing apparatus, and a downhole motor that may utilize any of the disclosed thrust-bearing assemblies and radial bearing assemblies.

Abstract: A thrust bearing system for a roller cone rock bit includes at least one roller cone disposed on a leg having an air channel therethrough, the thrust bearing system including a primary thrust bearing surface on the leg configured to contact a corresponding primary bearing surface on the roller cone, wherein the primary thrust bearing surface on the leg includes at least one air circulation port in fluid communication with the air channel.

Abstract: A roller cone bit having a sealed lubricant reservoir between a roller cone and a head section. A journal sleeve is included on the head section that circumscribes the journal bearing surface of the head section. The sleeve can axially pivot on the head section, but does not rotate thereon. The reservoir is formed into a journal bearing surface of the head section body and may be sealed by placing a seal around its periphery that extends between the journal bearing surface and journal sleeve. Sealing the reservoir results in a hydrostatic condition therein and substantially equalized pressures.

Abstract: Methods and apparatus for maintaining lubrication of rolling cone cutters mounted on journal pins. Embodiments comprise a rotating cone disposed on a journal pin and forming a journal gap there between. A cylindrical journal sleeve is disposed in the journal gap. The journal sleeve has a longitudinal gap forming opposing end portions, which are continuously contoured. A lubrication port is disposed in the journal pin and in fluid communication with a lubrication supply. The lubrication port has an outlet located in a recess in the journal gap. Each end of the recess comprises a transitioning surface extending between the bottom of the recess and the outer surface of the journal pin to prevent sharp transitions. In certain embodiments, the journal pin may comprise two or more lubrication ports, each located in a recess with transitioning surfaces.

Abstract: A roller-cone drill bit in which a large groove is machined into the backface of each cone, near the crack where the cone meets the arm assembly. By making the outer lip of this crack more exposed to the open volume of turbulent flow, turbulence near the crack is increased, deposit of sediments near the crack is reduced, and infiltration of sediments through the crack is also reduced.

Abstract: A ball-bearing unit for a bearing of a deep-drilling apparatus having bearing races made from steel with balls disposed therebetween. Contaminated drilling medium passes into the space between the bearing races. Load-bearing balls made from ceramic alternate with separating balls of smaller diameter made from steel between the bearing races to extend significantly the service life of the ball-bearing unit.

Abstract: A rolling cutter drill bit comprises a body and three legs, each leg having a cantilevered bearing spindle, a roll cutter rotatably mounted on the bearing spindle, a lubricating system within the spindle, and a tubular bearing element located radially between the spindle and the rolling cutter. The tubular bearing element is formed of a wrought alloy material consisting primarily of chromium carbide and cobalt and having a yield strength of less than 120,000 psi and a ductility greater than 4%, both at room temperature, and is of low wall thickness.

Abstract: A drill bit for use in an earthen annulus that contains loose particles is connected to a fluid supply source and includes a bit body having at least one journal segment and at least one fluid conduit in fluid communication with the fluid supply source. A roller cone is rotatably mounted upon the journal segment and forms at least one bearing cavity therebetween. An annular primary seal is disposed between the roller cone and the bit body and between the bearing cavity and the earthen annulus, and an annular gap is disposed between the annular primary seal and the earthen annulus. The annular gap is in fluid communication with the fluid conduit and the earthen annulus. An annular secondary seal is disposed between the annular primary seal and the earthen annulus and is capable of substantially preventing the ingress of debris from the earthen annulus to the annular primary seal.

Abstract: A rotary drill bit includes a rotary cutter rotatably mounted on a leg. A radial bearing arrangement and an axial bearing arrangement are provided in an interface between the cutter and the leg. The leg includes a filling opening for enabling cylindrical rolling elements of the radial bearing arrangement to be installed. The cutter includes a radial flange which radially overlaps the radial bearing arrangement to secure the cutter on the leg. The flange, which is disposed axially behind the radial bearing arrangement and axially in front of the filling opening, includes a recess for accommodating the passage of the cylindrical rolling elements. A locking element is disposed in the filling opening for preventing dislodgement of the cylindrical rolling elements. The locking element includes a lip which projects axially forwardly of the radial bearing arrangement. The lip is disposed radially inwardly of the flange and terminates axially behind the radial bearing arrangement.

Abstract: A drill bit for use in an earthen annulus that contains loose particles is connected to a fluid supply source and includes a bit body having at least one journal segment and at least one fluid conduit in fluid communication with the fluid supply source. A roller cone is rotatably mounted upon the journal segment and forms at least one bearing cavity therebetween. An annular primary seal is disposed between the roller cone and the bit body and between the bearing cavity and the earthen annulus, and an annular gap is disposed between the annular primary seal and the earthen annulus. The annular gap is in fluid communication with the fluid conduit and the earthen annulus. An annular secondary seal is disposed between the annular primary seal and the earthen annulus and is capable of substantially preventing the ingress of debris from the earthen annulus to the annular primary seal.

Abstract: A rolling cutter drill bit comprises a body and three legs, each leg having a cantilevered bearing spindle, a rolling cutter rotatably mounted on the bearing spindle, lubricant delivering means within the beating spindle, and a floating thrust bearing element configured to carry onward thrust loads from the rolling cutter onto the bearing spindle. Each floating thrust bearing element is formed of a wrought alloy material consisting primarily of chromium carbide and cobalt and having a yield strength of less than 120,000 psi and a ductility of at least 4%, both at room temperature.

Abstract: A radially disposed thrust bearing assembly for air cooled and lubricated mining type rotary cone rock bits consists of a first non-rotating radially disposed steel thrust bearing disc and an apposed, non-rotating carbide thrust bearing disc. One of the thrust bearing discs is pressed into a disc retention socket formed in the end of a spindle bearing extending from the end of a main axially aligned bearing cantilevered from a leg of the bit and the other thrust bearing disc is pressed into a disc retention socket formed in the rotary cone. An edge of the carbide disc is formed with large valleys and peaks, the robust undulations resist cracking when the carbide thrust bearing disc is pressed into its respective socket. Unique air passages and channels are formed in the main and spindle bearings to direct cooling air to the apposed thrust bearing discs.

Abstract: An earth boring bit having a body and a cantilevered bearing shaft extending inwardly and downwardly from the body. A rotatable cutter with an open end is assembled over the shaft, which has a radial bearing surface formed around a longitudinal axis. The cutter has a radial bearing surface sized to permit assembly over the journal surface of the shaft. The shaft and cutter have opposed thrust bearing surfaces, one of which has a gradually tapered outer region and a planar inner region to gradually reduce peak stress from a maximum to a minimum and avoid abrupt changes in stress from a high to a low value.

Abstract: A roller cutter assembly for a roller reamer which can be attached to a drill string is formed of a cylindrical body having an integral tapered bearing pin at each end. A journal bearing block for each bearing pin can be secured to the roller reamer by welding so as to hold the cutter rotatably on the reamer. The bearing block has a diameter slightly larger than that of the bearing pin. The angle of taper of the bearing pins and bearing surfaces is greater than the arc tangent of the coefficient of static friction between the coacting bearing surfaces such that the bearing pins do not self-lock in the bearing blocks.

Abstract: A rotary rock cutter cone is rotatively supported while being axially located and retained on a cooperating cantilevered journal shaft depending from a rock bit body by plain friction bearing means.A primary stationary thrust face is provided by a radially extending surface of the journal shaft adjacent the distal end of the journal shaft.An annular ring, fitted about the journal shaft, forms a gland for housing a grease seal which impinges upon the journal shaft. A radially extending distal surface of the annular ring runs in cooperation with a radially extending stationary thrust face formed by a secondary thrust member. The secondary thrust member is axially secured to the journal shaft thus axially trapping the annular ring adjacent to the supported end of the journal shaft.A radial bearing bore centrally enters the base of the cone and extends to a radially extending primary thrust bearing surface within the cone.

Abstract: A method of providing a selected bearing couple in a journal bearing of a rotary rock bit is described, wherein differential thermal expansion is used to mate a thin walled bushing of a chosen bearing alloy to one of the steel structural members. A pre-finished and pre-heat treated thin walled bushing is formed of the desired bearing alloy. Very little valuable space is required by the thin walled bushing. The use of arc-deposited metal, press fitting, or of loose parts is avoided, and many potential bearing alloys are adaptable as candidates for use in such a bushing.

Abstract: A sealed bearing roller cone rock bit is disclosed having precision roller bearings with very close fits. The bearing package includes highly refined and hardened surface finishes, special roller bearing metal materials and lubricants with specific lube viscosities.

Abstract: A roller cutter drill bit detachably secured to a drill string for delivering drilling fluid under pressure to the bit, comprising a plurality of bearing journals at its lower end and passaging extending down in the bit body to each of the journals for flow of the drilling fluid from the drill string to the journals. The bit further comprises a plurality of roller cutters, each having a bore adapted to receive a respective journal, and bearings in the annular cavity between each roller cutter and the respective journal for rotatably mounting the roller cutter on the journal. The drilling fluid when supplied in sufficient quantity flowing through the passaging, past the bearing means and exiting the bit in the bore via the bearing cavity for cooling and cleaning the bearings, but when supplied in insufficient quantity boring cuttings being allowed to enter the bearing cavity and fouling the bearings.

Abstract: An earth boring bit of the "air cooled" type that includes an air passage access system, including a generally vertical passage with an opening on the exterior of the leg or in the shank cavity that forms part of the body of the bit. This vertical passage is accessible through the opening by removal of a core that expands or retracts by altering the pressure exerted against it by two plates and a threaded fastener.

Abstract: A plain bearing pair comprising a bearing surface in opposed mating engagement with a relatively moveable friction bearing surface wherein the material of at least one of the mating bearing surfaces is formed from an amorphous metal alloy having a predominant refractory metal component and a Vickers Hardness Number in excess of 1000.

Abstract: An improved drilling bit has a cone shaped cutter 22 rotatably mounted on a leg 16 by way of a central journal 18 and an annular journal 20. The annular journal is axially coextensive with the central journal. The cutter has outer collar 26 and inner collar 28 which interfit with the journals to provide a large surface area for roller bearings 30, 36 and 42. Additionally, the cutter may have a post 68 within cavity 70 on the terminal and of the central journal 18 so that roller bearings 74 can be provided to further increase the area of roller bearings handling radial loads. This increases the lifetime of the bit assembly. Ball bearings 50, 52, 66 and 72 are provided to handle axial loads, and ball bearings 54 are provided to retain the cutter on leg 16.

Abstract: A bearing construction for a rotary earth boring drill bit is constructed of a bearing journal and a cutter rotatively mounted on the bearing journal, the bearing journal having a generally cone-shaped bearing wall formed by a plurality of steps comprised of a pair of adjacent walls joined at an apex having an acute included angle, and the cutter having a bearing wall formed with a plurality of steps mating in bearing contact with the steps of the bearing journal.

Abstract: A roller reamer-stabilizer tool includes a tubular body having threaded pin and box connectors at each end adapted to be connected in a drill string and providing a fluid passage connecting the upper part of the drill string with the lower part. Rollers having integral pins at their ends are mounted in pockets in the sides of the body. The pins are journaled in holes in arcuate cross section bearing blocks received in correlative sockets in the body at the ends of the pockets. The blocks make an interference fit with the body. Release bar access passages allow a release bar to be inserted behind each block to drive, wedge or pry it out. The holes in the blocks extend only part way through the blocks, the hole in the block at one end of each roller being blind, and the wall at the end of the hole in the block at the other end of each roller being ported. Each bearing is sealed by an O ring at the mouth or open end of the hole in the block.