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 bearing 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: Disclosed is a bit apparatus in which a cutter member having cutting teeth is axially supported on a shaft for rotation about the shaft, and a bearing mechanism is interposed between the cutter member and the shaft. The bearing mechanism includes at least a radial bearing for bearing a radially directed load and a thrust bearing for bearing an axially directed load. The radial bearing has a shaft-side split bearing member and a cutter-side split bearing member that are opposed to or in sliding contact with each other and capable of rotating relative to each other.

Abstract: The present invention allows the load carrying capability of a drill bit journal bearing or bushing to be increased. The present invention increases the length of the journal bushing by using the ball bearings to retain the journal bushing at a desired location between the journal and the cutter cone assembly. Normally, the journal bushing is retained by a flange formed on the interior surface of the cutter cone assembly. In the present invention, this flange is removed, and the ball bearings are used as a retention device for the journal bushing. With the flange removed, the length of the journal bushing may be increased.

Abstract: The present invention allows the load-bearing capabilities of a drill bit thrust flange to be increased. The invention utilizes a thrust flange that is larger than the inside diameter of an associated drill bit journal bushing. The thrust flange may extend past the inside diameter of the journal bushing up to a distance equal to two times the thickness of the journal bushing. The invention may also utilize a thrust washer that is disposed adjacent the thrust flange to assist in bearing loads applied to the thrust flange.

Abstract: A first embodiment of a radially disposed thrust bearing assembly for rotary cone rock bits consists of a first non-rotating radially disposed steel thrust bearing disc and an adjacent, 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 thrust bearing discs.

Abstract: A novel split threaded ring bearing member for rolling cutter drill bits with at least a portion of its threads having a different pitch than its mating threads is disclosed. The pitch difference is designed so that the threaded ring can be seated or otherwise located precisely with respect to the other bearing elements within the drill bit to effectively control the axial displacement of the rolling cutter on the bearing spindle within a given tolerance range. Upon assembly, the difference in thread pitch causes the opposite, opposing mating thread flanks to engage, effectively applying a tensile or compressive force to a portion of the threaded ring bearing member, which gradually increases as the assembly is tightened. The result is an improved rolling cutter drill bit with a threaded ring cutter bearing system with excellent resistance to back-off which will not allow significant radial movement between the engaged threads, even if some back-off of the threads occurs.

Abstract: A rotary rock bit is formed as a rock bit body, a bearing shaft supported by the rock bit body, a rotary cutter adapted to be rotatably mounted on the bearing shaft, and at least one bearing that promotes rotation between the rotary cutter and the bearing shaft. Each bearing includes a bearing element having a steel matrix with steel-free volumes distributed therethrough. The matrix is a hypoeutectoid steel having more than about 0.40 weight percent carbon. An anti-galling alloy resides within the steel-free volumes of the steel matrix. The anti-galling alloy is a silver-copper alloy having a composition of from about 60 weight percent to about 95 weight percent silver, balance copper.

Abstract: A rotary rock bit is formed as a rock bit body, a bearing shaft supported by the rock bit body, a rotary cutter adapted to be rotatably mounted on the bearing shaft, and at least one bearing that promotes rotation between the rotary cutter and the bearing shaft. Each bearing includes a bearing element having a steel matrix with steel-free volumes distributed therethrough. The matrix is a hypoeutectoid steel having more than about 0.40 weight percent carbon. An anti-galling alloy resides within the steel-free volumes of the steel matrix. The anti-galling alloy is a silver-copper alloy having a composition of from about 85 weight percent to about 95 weight percent silver, balance copper.

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: A rock cutting tool with a plurality of independently rotatable cutter units and with a shaft, a sleeve located around the shaft, and at least two rotatable hubs located around the sleeve. At least one cutter unit is located on each of the two rotatable hubs for rotation about an axis of rotation with respect to a rock-face. Bearings between the sleeve and each of the hubs rotatably support the hubs. The bearings comprise at least one cylindrical roller bearing set and at least one ball bearing set for each hub. Each roller bearing set is located substantially entirely under the cutter unit of its associated hub to absorb radial loads, and each ball bearing set is located remotely from the cutter unit of its associated hub to be isolated from radial loads. The shaft has first and second key receiving openings. The key is located on the interior surface of the sleeve.

Abstract: A hydrodynamic bearing (16) for a cutter cone assembly (12) that rotates around a journal (14). The bearing (16) comprises a plurality of grooves (88) on an outer surface (90) to produce undulations (82) on an inner surface (84) upon insertion of the bearing (16) into a bearing recess (94). Undulations (82) act as pockets to collect lubricant which is forced upon rotation of the bearing (16) between the outer journal surface (86) and the inner bearing surface (84) to produce a hydrodynamic film.

Abstract: A rotary cutter cone type drill bit having a body structure with a plurality of depending cutter support lugs each having a spindle integral therewith and defining a cylindrical bushing support surface and a spindle head. A cutter cone is positioned for rotation about each of the spindles and is supported for rotation and axial retention by a dual split bushing arrangement. The dual split bushing arrangement has an inner split bushing received in immovable relation about the cylindrical bushing support surface of the spindle and outer split bushing being received in rotatable bearing relation about a portion of the inner split bushing and functioning to retain the inner split bushing about the cylindrical bushing support surface. The inner split bushing also retains the outer split bushing so that the cutter cone is maintained in assembly with the spindle. The outer split bushing is secured in immovable relation within the cutter cone by a lock element or by threaded connection.

Abstract: A sliding part having a metallic main body which is formed with a silver plating layer over a surface thereof slidable in contact with other metallic part. The silver plating layer has a crystal structure so adapted that the intensity of diffraction X-rays diffracted by the (200) plane thereof is at least 1/3 of the intensity of diffraction X-rays diffracted by the (111) plane.

Abstract: A bearing includes a bearing component, such as a bearing race, having a bearing contact surface. A region at the bearing contact surface is made of titanium aluminide, preferably an alpha-2 or gamma titanium aluminide. A case-hardened layer present at the surface of the titanium aluminide region increases the hardness and wear resistance of the titanium aluminide at elevated temperature. The case-hardened layer is preferably formed by diffusing carbon into the surface of the titanium aluminide from a gaseous medium, at elevated temperature land at ambient or reduced pressure.

Abstract: The present disclosure sets forth various forms of inserts for operating as elements in bearing drill bits and similar devices. A single insert is formed with an external side face of cylindrical construction. One or more strips of hardened materials such as diamond or other hard material are provided along the side face. At the end face, the insert incorporates exposed tungsten carbide, diamond or other hard material. A PDC layer is optionally placed over the end face. The PDC layer has the form of a covering terminating at a radius of curvature.

Abstract: A mud motor bearing assembly is defined by and constructed with a support or base ring having an exposed upper or planar face. On the planar face, a number of PCD disc are attached to define a bearing surface at a common plane. The improved bearing assembly further includes a separate ring or an integral lip serving as a deflector ring brazed to the face of the support ring. The brazed deflector ring alters the fluid flow patterns of drilling fluid in the bearing assembly to reduce support ring erosion.

Abstract: A cone drill bit includes legs and attached to them trunnions with cones mounted thereon. A support unit for mounting the cones upon the trunnions includes a strengthened radial thrust ball bearing which transmits a load directed along a cone centerline. Strengthening the ball bearing in order to increase a bit wear resistance is attained by using the balls which diameter is appropriately related to the bit diameter as well as by strengthening a shoulder on the trunnion between the ball and peripheral roller bearings.

Abstract: A method of forming a bearing assembly is set forth. A PCD disk typically of circular construction is joined to a cylindrical plug formed of support metal. The plug is registered with respect to an internal shoulder in a passage formed in a ring for the bearing assembly. Multiple PCD disks are installed in the same fashion. In assembly, the disk is attached to the cylinder, the cylinder is wrapped in brazed material, then the cylinder with the brazed material wrapping is registered on an internal shoulder in a drilled passage in the bearing assembly. A brazing temperature which is too low to damage the material is applied to complete joinder. Then, multiple disk faces supported by individual disk in a circle around the bearing assembly can be lapped to assure that they are brought to a common height with respect to a reference plane.

Abstract: An improved sealing system for a sealed bearing assembly used in earth drilling. The bearing assembly has a first tubular member, and a second tubular member telescopically received in the first tubular member. The second tubular member has an interior passage through which drilling fluids pass under pressure from on surface pumps. A clearance space is provided between the first tubular and the second tubular member defining a lubricant filled bearing chamber. The improvement is in the seal at a pump end of the bearing chamber which consists of a first floating piston, a second floating piston spaced from the first floating piston, and a fixed seal intermediate the first floating piston and the second floating piston. A first chamber is provided between the first floating piston and the fixed seal. The first chamber is filled with lubricant. A second chamber is provided between the fixed seal and the second floating piston. The chamber has a passage to external of the first tubular member.

Abstract: A modular drill bit mounts legs within recesses in a body which are parallel to the central axis of the body using threaded studs with tapered outer portions, in conjuction with an attached pin having recesses therein receiving the upper ends of the legs. The lower ends of the legs terminate in spindles of open face configuration rotatably receiving cones thereon for rotation via a arrangement of bushings, roller bearings and thrust bearings, and a plurality of seals which slide and therefore rotate relative to both the leg spindle and the cone with the help of pressure compensating apparatus. A bushing disposed in the cone-leg spindle interface has oil-lubricated rubber rods disposed in apertures therein to prevent lock-up on an adjacent bearing surface. The cone is held on the leg spindle by a lock nut forming one end of a race for receiving rollers of a roller bearing, in conjunction with a ring-nut secured to an extended portion of the cone protecting the leg from wear and damage.

Abstract: A roller cutter drill bit (10) has separate bearing elements (82, 84, 86) positioned between a journal (20) and a roller cutter (60) mounted for rotation on the journal (20). The bearing elements (82, 84, 86) are formed of a superalloy material and the bearing surfaces of the bearing elements (82, 84, 86) have an aluminide coating applied thereon to form a bearing surface stable at operating temperatures over 500 F. and as high as 1000 F.

Abstract: A modular drill bit mounts legs within recesses in a body which are parallel to the central axis of the body using threaded studs with tapered outer portions, in conjunction with an attached pin having recesses therein receiving the upper ends of the legs. The lower ends of the legs terminate in spindles of open face configuration rotatably receiving cones thereon for rotation via a arrangement of bushings, roller bearings and thrust bearings, and a plurality of seals which slide and therefore rotate relative to both the leg spindle and the cone with the help of pressure compensating apparatus. A bushing disposed in the cone-leg spindle interface has oil-lubricated rubber rods disposed in apertures therein to prevent lock-up on an adjacent bearing surface. The cone is held in the leg spindle by a lock nut forming one end of a race for receiving rollers of a roller bearing, in conjunction with a ring-nut secured to an extended portion of the cone protecting the leg from wear and damage.

Abstract: A bearing assembly for a downhole motor comprising a pair of annular support rings, each having a plurality of polycrystalline diamond thrust bearing inserts mounted thereon. The rings are oriented to have the respective inserts face and bear against each other. In operation, drilling mud passes through the space between the inserts to cool the inserts. The rings are made of tungsten carbide to prevent erosion of the areas at the bases of the inserts, thereby improving the life of the thrust bearings.

Abstract: An improved drill bit seal arrangement, including a seal ring having a boronized outer annular surface which is fabricated separate and apart from the journal bearing structure of the drill bit arm. The seal ring boronized surface is polished to define a smooth non-abrading surface for the elastomeric seal. The seal arrangement enhances the wear resistance of the seal between the drill bit arm and the cutting cone, thereby increasing the life span of the drill bit.

Abstract: A roller cutter (28) of a drill bit (10) is retained on a journal (24) for rotation by a retainer ring (82) having external screw threads (88) which are threaded onto mating screw threads (108) on the roller cutter (28) for rotation therewith. The retainer ring (82) is mounted within a semicircular groove (68) on the journal (24) and has an inner periphery formed of a smooth arcuate surface contacting the annular groove at a position spaced at least 10.degree. from the entrance opening of the groove thereby to reduce bending stresses exerted against the root (74) of the groove (68).

Abstract: An earth boring bit having an improved two piece bearing and seal assembly containing a cantilevered bearing lug that is threaded to receive a mating bearing sleeve, the lug having a transverse shoulder intersected by a mouth on the sleeve to define a bearing shaft upon which is supported a rotatable cutter. A lubrication system includes a hydrostatic pressure compensator and seal means, the transverse shoulder being positioned inwardly of the seal means toward an inner end region of the lug to avoid exposure of the transverse shoulder of the lug and the mouth of the bearing sleeve to ambient drilling fluid. The seal means is a rigid face seal assembly which includes a rigid, sealing ring and a resilient energizer ring.

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 journal surface formed around a longitudinal axis. The cutter has a bearing surface sized to permit assembly over the journal surface of the shaft. At the open end of the cutter bearing surface is a seal recess which includes an intersecting wall that defines an annular, generally curved corner to oppose the journal surface of the shaft. The cutter bearing surface has a curved outer region that converges from the annular corner of the seal recess into an inner region to reduce the stress the corner induces upon the journal bearing surface of the shaft, including the stress induced by cutter cocking during drilling.

Abstract: A drill bit direct drive for deep well drilling tools includes a tubular casing, a rotary machine provided inside the casing and driven by oil well fluid flowing through it, a radially mounted shaft connected to a rotary drill bit and at least one friction bearing exposed to the oil well fluid for axial bearing of the shaft and having at least one trace ring supported on the shaft plus at least one bearing ring supported on the housing and working together with one trace ring. This bearing ring has a number of bearing segments distributed regularly around its periphery including a bearing body supported with respect to the bearing ring so it can be shifted axially and tilted to a limited extent against the action of a spring force.

Abstract: A rolling cutter earth drilling bit in which integral one-piece pilot bushings provide both radial and thrust load sliding surfaces which incorporate an anti-galling material. A roller cone bit has three downwardly extending arm members which terminate in cylindrical spindles for the rolling cutters. Each spindle has a stepped configuration providing an enlarged journal section which is stepped down to provide an annular thrust shoulder and a reduced pilot pin which projects from the thrust shoulder. The rolling cutter mounted on the spindle has an enlarged rearward bearing recess which receives the journal section of the spindle and a reduced forward bearing recess which receives the spindle pilot pin. An annular thrust face corresponding generally to the spindle shoulder is between the recesses.

Abstract: An improved apparatus and method for rotatably mounting and retaining a rock bit roller cone on a journal of a drill bit is disclosed. The bit body has at least one depending leg with an outer free end and an inner end continuous with the remainder of the bit body, and the cone surrounds the leg adjacent the outer end, forming an annular space between the leg and the cone. At least two retention bearing sleeves are disposed in the space: a first fixed to the leg and rotatable relative to the cone; and a second, disposed longitudinally inwardly of the first, fixed to the cone and rotatable relative to the leg. The retention bearing sleeves cooperate to prevent relative movement of the second sleeve longitudinally past the first.

Abstract: An underreamer including a body having a bore therethrough, an arm mounted at its upper end to the body, a sleeve member detachably secured to the lower end of each arm and adapted to receive the frictional wear caused by the rotation of the conical cutter mounted thereto. Bearings and seals disposed between the cutter and the sleeve member provide smooth rotation of the cutter. In addition, locking pins and bearings extending between the arm and the sleeve member secure the sleeve on the arm. The arms are pivotally mounted in slots in the body and mechanical structure is provided for moving the arms to their cutting position with their lower ends positioned radially outward from the body.

Abstract: A sealing relationship between a rotatable and stationary member is formed by a seal arrangement between the rotatable and stationary member wherein a first member engages the seals forming the sealing relationship and a second member is rotatable by the rotatable member to rotate the first member about the stationary member at a substantially reduced rotational speed relative to the rotational speed of the rotatable member to inhibit damage to the sealing relationship.

Abstract: A roller cone rock bit is disclosed with an improved bearing system. The improvement comprises a main journal bearing which is substantially frustoconically shaped and a main roller cone bearing which is reverse shaped to mate with the journal bearing. The journal and roller cone bearings comprise polycrystalline diamond. The invention also includes a member for retaining the roller cone on the journal.

Abstract: A bearing for a rotary cone for a rock bit is disclosed. The bearing consists of a multiplicity of small synthetic diamond particles nested within a matrix base, each with an exposed flattened surface to form the bearing. The diamond particles are strategically positioned on a bearing surface and secured within the matrix base. A substantially identical synthetic diamond bearing is concentrically positioned adjacent to the first bearing to form the bearing package.

Abstract: An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. The positioning and sizing of resilient energizer rings in relationship to the geometries of the mating grooves between the cutter and shaft and the rigid sealing rings of the face seal assembly minimize axial seal movement relative to cutter and shaft during drilling to enhance seal life. A threaded bearing lug receives an internally threaded bearing sleeve. The journal bearing surface is approximately midway between the shaft seal groove, a portion of which is on its bearing sleeve and another portion on the cutter seal groove.

Abstract: A downhole drive shaft and bearing structure having a unitary, generally cylindrical housing with a radial bearing surface affixed to its interior; a drive shaft having a radial bearing surface affixed to its exterior and thrust bearing inserts mounted at the bit end thereof; and a drive shaft cap affixed to the drive shaft and carrying thrust bearing inserts, the thrust bearing inserts of the cap and drive shaft interfacing with oppositely disposed inserts mounted in the housing.

Abstract: 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.

Abstract: An underreamer including a body having a bore therethrough, an arm mounted at its upper end to the body, a conical cutter mounted for rotation on the lower end of each arm, a cup-shaped thrust bearing between the cutter and the arm, means extending through the arm to secure the cutter on the arm including pin elements that extend into a groove in the cutter to prevent rotation movement between the arm and the thrust bearing to lock the thrust bearing to the arm. The arms are pivotally mounted in slots in the body and means are provided for moving the arms to their cutting position with their lower ends positioned radially outward from the body.

Abstract: A structure and method for attaching bearing inserts including a bearing ring having through holes therein into which said inserts are press fitted and an underlying brazing ring, which, when heated, attaches the bearing inserts to the bearing ring and the bearing ring and inserts to an adjoining structural member.

Abstract: Bearing surfaces or other selected areas of component parts of a rotary cone earth boring rockbit are carburized or otherwise surface enriched by the sequential steps of coating the selected surface area to be enriched with a non-water based composition capable of effecting a corrosive protective seal thereabout; covering the coated area with a predetermined applied thickness of a carbonaceous paste; drying the paste and thereafter, subjecting the component part to an elevated temperature below which the coating is pyrolyzed to fully austenize the part and achieve a desired case depth followed by quenching, tempering, and finished machining as required.

Abstract: This invention relates to the use of spinodal alloys consisting essentially of copper-nickel-tin for bearing surfaces formed between roller cutter cones of sealed bearing rock bits.

Abstract: A hardened bearing surface (36, 38, 42, 48, 50, 51 and 52) on a component (14, 16) of a rotary cutter drill bit (10) and the method of forming same. A composite mix (60) of alloy material (56) and base material (54) forms the hardened bearing surface (36, 38, 42, 48, 50, 51 and 52) with the alloy material (56) consisting of at least ten (10) percent of the adjacent base material (54) and of an optimum of around fifty (50) percent. The alloy material (56) of predetermined amounts of predetermined elements is positioned on the base material (54) and a precisely controlled high energy density source, such as a laser beam (58), melts the alloy material (56) and adjacent base material (56) to form the composite mix (60) defining the hardened bearing surface.

Abstract: A roller bit cutter comprises:(a) a tough, metallic generally conical and fracture resistant core having a hollow interior, the core defining an axis,(b) an annular metallic radial bearing layer carried by said core at the interior thereof to support the core for rotation, said bearing layer extending about said axis,(c) an impact and wear resistant metallic inner layer on the core, at the interior thereof, to provide an axial thrust bearing, and(d) hard metallic inserts having anchor portions carried by the core and partly embedded therein, the inserts protruding outwardly at the exterior of the core to define cutters, at least some of the inserts spaced about said axis,(e) and a wear resistant outer metallic layer on the exterior of said core.

Abstract: An earth boring drill bit having roller cutters which are rotatably supported on journals by bushings. At least one of the bushings is formed by a plurality of bushing segments which are positioned about a circular bearing surface having thrust shoulders at each end thereof. The roller cutter elements are assembled about the bushing segments in heated condition, by press-fitting to establish a firmly seated relationship between the cutter and bushing segments upon cooling of the cutter. The rotary cutter is then secured to the bushing segments by means of a locking element to prevent inadvertent disassembly during drilling operations. End portions of the bushing segments engage hardened bearing inserts of cutter support legs to minimize wear during drilling operations. A circular sealing element positioned about the bushing segments establishes sealing engagement with the cutter support legs to prevent ingress of contaminants and egress of lubricant during drilling activity.

Abstract: In accordance with an illustrative embodiment of the present invention, a thrust bearing member is positioned between the rolling cutter or cone and the bearing pin of a rock bit and comprises wound wire such as a closed spiral coil spring that provides spaced-apart bearing surfaces with open areas therebetween. The flexibility of the spiral spring tends to spread the load between several bearing areas to thereby reduce concentrations of stress and the occurrence of localized high temperatures and wear, and the spacing of the bearing surfaces provides wear and contamination particle traps as well as lubricant reservoirs, to significantly increase the useful life of the bearing.

Abstract: An earth boring bit has thrust surfaces with enhanced cooling features. The bit has a body with three depending bearing pins. A cutter having an axial cavity is mounted on each bearing pin. The bearing pin and the cavity have mating thrust shoulders. Hard metal inserts or buttons are spaced around each of the shoulders and secured interferingly in mating holes. The buttons in one of the shoulders protrude slightly from the shoulder to allow air to flow past.

Abstract: A friction bearing assembly for a roller cutter drill bit, comprising a first bearing member of cylindrical configuration and a second bearing member having an opening of generally circular section therein receiving the first member for enabling relative rotation of the members. A bushing is fitted between the bearing members, the bushing being of annular configuration and having an inner and an outer diameter so related to the diameter of the first bearing member and the diameter of the opening in the second bearing member as to enable the bushing to rotate relative to both members. The bushing is of width substantially greater than its thickness, and comprises a plurality of relatively thin, narrow elongate metal members, each metal member being of generally circular configuration and constituting a ring.

Abstract: In accordance with an illustrative embodiment of the present invention, a bearing positioned between the rolling cutter or cone and the bearing pin of a rock bit comprises wound wire such as a closed helical coil spring that provides spaced-apart bearing surfaces with open areas therebetween. The flexibility of the helical spring tends to spread the load between several bearing areas to thereby reduce concentrations of stress and the occurrence of localized high temperatures and wear, and the spacing of the bearing surfaces provides wear and contamination particle traps as well as lubricant reservoirs, to significantly increase the useful life of the bearing.

Abstract: A heavy-duty composite radial journal bearing and a method to produce it is described. A pattern of openings is formed through a bearing sleeve representing, for instance, axially aligned metal bars. The openings are subsequently filled wth a metal dissimilar to the sleeve. Filling may be done with the sleeve in place either on a journal or in a housing, in which case the bearing becomes integral to that member by fusion. Alternately, the sleeve may be filled upon a nonwettable mandrel and subsequently used as a floating ring or as a bushing. Final finish machining reveals a pattern which exists throughout the bearing of alternating areas of relatively hard metal and a softer antigalling metal.

Abstract: A heavy-duty composite radial journal bearing and a method to produce it is described. A pattern of openings is formed through a bearing sleeve representing, for instance, axially aligned metal bars. The openings are subsequently filled with a metal dissimilar to the sleeve. Filling may be done with the sleeve in place either on a journal or in a housing, in which case the bearing becomes integral to that member by fusion. Alternately, the sleeve may be filled upon a nonwettable mandrel and subsequently used as a floating ring or as a bushing. Final finish machining reveals a pattern which exists throughout the bearing of alternating areas of relatively hard metal and a softer antigalling metal.