Abstract: A lubrication system for an earth boring drill bit having a pressure compensator for minimizing the pressure differential between the drill bit lubricant and the well bore fluid is improved in a manner to prevent sharp edges in the lubricant reservoir wall from damaging the flexible diaphragm and for enabling the lubricant space available in the lubricant reservoir to be maximized. In accordance with a preferred embodiment, the pressure compensator is positioned on a shoulder ring in the lubricant reservoir and the shoulder ring retains the open end of a pressure diaphragm within an interior recess of a compensator cap, the diaphragm sealing against a perimetric wall of the recess. Methods of filling the lubrication system with the pressure compensator installed or removed are provided which avoid stretching or damage to the diaphragm while still maximally filling of the lubrication system with lubricant.

Abstract: An earth boring (rock) bit having a flexible diaphragm located inside the bearing shaft in a cavity between a threaded lug and a mating bearing sleeve. The diaphragm has an enlarged periphery, shaped somewhat like an o-ring, that is confined and sealed between opposed annular surfaces on the lug and the sleeve. The circular periphery of the diaphragm and cavity provide good compensation volume, from which excessive lubricant pressure is relieved by an enlarged portion which is punctured and contoured to discharge lubricant under excessive pressure while excluding drilling fluid. Simplicity and reliability are achieved by the elimination of multiple and complex manufacture and assembly operations.

Abstract: A one-way pressure relief valve assembly is provided for venting the lubricant reservoir of a roller-type well drilling bit. The valve assembly is mounted in the cap of the lubricant reservoir, to open outwardly, and is adapted to provide hydrostatic loading of the valve element to its closed position.

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 adapted to drill bores in the earth comprising a bit body of steel having a plurality of bearing journals at its lower end, and a plurality of roller cutters, each having a recess therein receiving one of the journals. A radial bearing asembly for each roller cutter rotatably mounts the roller cutter on the journal, and an axial or thrust bearing assembly at the free end of each journal carries axial forces applied to the roller cutter during drilling, with the thrust bearing assembly thus being subject to rotary frictional forces and heating upon rotation of the drill bit during drilling. According to this invention, a heat dissipation member formed of material having higher thermal conductivity than steel is incorporated into the bit body. This material extends from the free end toward the attached end of the journal for conducting heat away from the thrust bearing assembly, thereby reducing bearing temperatures and providing longer bearing life.

Abstract: There is disclosed a drill bit which is connectable to the lower end of a rotary drill string for use in drilling oil and gas wells as drilling mud is circulated downward through the string, out the bit, and upwardly within the annulus between the string and well bore so as to remove cuttings therefrom. The bit has cones which are mounted for rotation about thrust bearings which extend inwardly from the lower ends of legs which depend from a shank at the upper end of the bit body which is attached to the drill string.

Abstract: A friction bearing is disclosed, intended for very heavy duty use, for example, as in rotary cone rock bits.In a pair of structural members having cooperating load bearing surfaces, one such cooperating surface is interrupted by a fine grid of small grooves formed therein to retain lubricant and to produce, over the total bearing surface, the turbulent hydraulic environment normally found only along the line of formation of a hydro-dynamic lubricant film. An extension of the useful life expectancy of the bearing is claimed by thus postponing degradation of the bearing surfaces by metal transfer therebetween due to failure of the hydro-dynamic lubricant film.

Abstract: A downhole drilling tool having a tubular stem connected to the drill string, and a tubular housing mounted concentrically and rotatably on the stem, forming an annular space between the housing and the stem. A plurality of bearings within the annular space support the housing against radial and longitudinal thrust loads. A plurality of seals within the annular space above and below the bearings form a lubricant chamber. The housing has a cylindrical lubricant passage extending between the lubricant chamber and the annular space outside of the lubricant chamber. A cylindrical piston is sealably slidable within the lubricant passage and responds to pressure of the drilling fluid entering the passage from the exterior of the housing to force lubricant out of the passage and into the lubricant chamber in order to replace lubricant which is lost therefrom. A downhole drilling motor is attached to the lower end of the housing.

Abstract: An earth boring bit with sealed and lubricated bearings and rotatable cutters, the seals being isolated from detritus in the borehole by a seal protector ring and groove. The ring, generally L shaped in cross-section, has radial and axial clearances from the registering groove to maintain a labyrinth path with selected values, irrespective of cone movement during drilling.

Abstract: A sealed, pressure-equalizing lubrication system for a rotary rock bit is shown. The system includes a lubricant-filled container having an outlet and a portion of the container includes a flexible diaphragm. The container is mounted in a chamber in the journal axle portion of the bit, immediately adjacent and open to the sealed bearing cavity of the bit cutter, with the outlet disposed adjacent the cavity. A bleed hole is provided from the back face of the bit to the chamber adjacent the diaphragm causing the diaphragm to be responsive to the pressure of the external downhole fluid. The adjacency of the reservoir to the sealed bearing cavity permits the pressure of the lubricant adjacent the seal to be immediately responsive to the pressure of the downhole fluid at the diaphragm to prevent pressure differentials between the lubricant and the fluid at the seal.

Abstract: A downhole bearing assembly includes concentric inner and outer tubes, with bearings mounted therebetween. A high pressure elastomeric cup seal assembly is mounted between the inner and outer tubes, and at least one metal-to-metal seal is mounted between the inner and outer tubes on each side of the high pressure seal assembly. A pair of pressure balancing systems are provided, each acting to minimize pressure differentials across a respective one of the metal-to-metal seals. The metal-to-metal seals protect the high pressure elastomeric seal assembly and the bearings from contamination by drilling mud, and the pressure balancing systems protect the metal-to-metal seals from excessive differential pressures.

Abstract: This invention discloses the utilization of a metal bellows in a grease reservoir cavity that is compressed during a rock bit grease filling process to create a positive pressure differential between the internal cavities in the bit and the outside atmosphere.

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: 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: 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 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: A lubrication system for a multiple segment rotary rock bit, with each segment having lubrication supply means to the cutter bearing structure associated therewith and whereby each supply means is in lubricant flow communication with the lubricant supply means of the remaining segments so that the internal pressure of the lubricant system is substantially equal in each segment.

Abstract: A compressible pressure compensating member is disposed within a sealed lubricant volume enclosing a bearing and seal system of an earth boring apparatus. Lubricant is maintained within the volume by metal face seals so that both the bearing and the seal structure are lubricated thereby. As the lubricant expands, due to thermal expansion under use, the increased pressure is accommodated by compression of the compressible member so that no lubricant is expelled through the seals. When the lubricant cools and contracts, the compensator expands to maintain the lubricant volume at the initially filled level.

Abstract: A positive displacement grease pump apparatus is disclosed to circulate a lubricating grease from a grease reservoir system, formed within a body of a sealed bearing rotary cone rock bit. The relatively viscous grease is positively circulated to and from the reservoir through bearings defined between a rotary cone and its respective journal bearing extending from the rock bit body.

Abstract: Disclosed herein is an earth boring bit of otherwise conventional construction except for the bearing and cutter retention. A snap ring is used to retain the cutter, the grooves that receive the ring and the ring construction being such that the ring is forced into the retainer groove when the cone is thrust inward. The ring cannot therefor accidentally return to its assembly position to permit cutter loss. This enables the use of exclusively frictional bearings and retainer means of exceptional strength and reliability.

Abstract: A sealed, internally lubricated rotary roller drill bit for drilling hard earth formations in which internally disposed axially, thrust and ball anti-friction bearings are used in combination and in which a first seal means is provided for preventing the introduction of drilling debris and a second seal means is provided to prevent the introduction of such debris and to maintain the lubricant inside of the bit under pressure. A pressure relief means is provided to allow excess lubricant to flow around one of the seals. A stream of air is directed through the bit, first in a direction to "clean" the bore hole and in further directions to allow ready access to a lubricant fitting and to effect a seal at the interface between rotating portions of the bit.

Abstract: A valve system is disclosed for use in the lubrication passages of a rolling cutter drill bit, which valve assembly utilizes one or more reed valves to maintain flow of lubricant in a desirable direction.

Abstract: A drilling bit for drilling earthen material such as an oilwell rotary cone drilling bit which includes means for centrifugally providing lubricant to the drill bit cone bearing from a storage cavity. A storage cavity is provided for lubricant for the drill bit bearings, means being provided for forcing the lubricant from this cavity through channels to such bearings in response to the centrifugal force generated with the rotation of the bit.

Abstract: This invention relates to rotary rock drilling apparatus, particularly roller cone rock bits used with dry drilling of rock formations. Mining bits are typically air-driven, air-lubricated roller cone rock bits having open bearings, the air being driven through the bearing system between the roller cones and their associated journals. A lubrication system is disclosed which drips a lubricant in liquid form into the air passages communicating with each of the bearings associated with, for example, the three roller cones of the rock bit. Oil is entrained, along with the compressed air, and is directed to the bearings for cooling and lubrication purposes.

Abstract: A rotary drill bit comprising a roller cutter (12) which is rotatably carried over a bearing system. The bearing system comprises at least one roller bearing (16). Fluid is supplied to the bearing system for flushing and lubricating and when needed cooling thereof. For purposes of ensuring suitable fluid flow through the roller bearing (16) and thus ensuring satisfactory lubrication thereof the rollers in the roller bearing (16) are provided with an axial bore (25).

Abstract: A rolling cutter drill bit with at least one downwardly extending leg which supports a cantilevered bearing shaft thereon is disclosed. A cutter cone is rotatably mounted on the bearing shaft by radial bearing means and by axial bearing means. A radially disposed thrust washer is positioned between the journal and the cone, the washer further defining a lubricant transferring means in each radially disposed side of the thrust washer to assure adequate lubrication of the roller cone on the journal bearing.

Abstract: A pressure compensator installed in the bit body of a rotary earth boring tool to lubricate the bearing surfaces of a rotary cutter and to effect a liquid seal. In order to reduce the number of component parts and to enhance durability, the pressure compensator includes a rubber diaphragm interposed between upper and lower capsule halves that form a spherical space.

Abstract: A device for lubricating rotary drill bits of the type comprising a roller cutter (14) which is rotatably carried by means of a bearing system (15, 16, 17, 18). Fluid is supplied to the bearing system for cooling and/or cleaning thereof through a passage (31, 32, 33; 51, 61), and a lubricant is delivered to said passage from a body (31; 39) of porous material, which is soaked in lubricating means. For purposes of controlling the supply of lubricating means the porous member forms a fraction of the inner wall of said passage.

Abstract: A roller reamer assembly for mounting in a longitudinally extending undercut groove in a reamer body and having longitudinally slidable bearing blocks with cooperating locking members for securing the bearing blocks in the groove upon longitudinal movement of the bearing blocks to prevent undesired longitudinal and radial movement of the bearing blocks and an automatic lubricating system for the bearing blocks.

Abstract: Discloses a lubricant circulating system for a rotary drilling bit including a lubricating space defined between a rotary cone cutter and a journal shaft extending from the bit body, the body defining a lubricant supply passageway connecting the lubricating space with a substantially cylindrical inlet chamber of a lubricant reservoir and with the centerline of the supply passageway being disposed substantially tangential with the cylindrical wall of said inlet chamber to form a restrictive vortex flow passage from the supply passageway into said reservoir and a nonrestrictive return flow passage, the body defining a lubricant exhaust passageway connecting the lubricating space through a substantially cylindrical outlet chamber into a discharge passageway forming part of the reservoir and with the centerline of the discharge passageway being disposed substantially tangential with the cylindrical wall of the outlet chamber to form a restrictive vortex flow passage from the reservoir into the outlet chamber and

Abstract: An earth boring drill bit has a lubricant pressure compensator that includes a plunger that moves slidingly in the reservoir to reduce pressure differential, and also allows lubricant to bleed past to relieve excess lubricant pressure. The plunger is carried slidingly in the reservoir. The plunger has a convex end in contact with the lubricant and a concave end in contact with the borehole fluid. The plunger has a rod that contacts a stop in the reservoir when the lubricant pressure is greater than the borehole pressure. Once stopped, the configuration of the plunger allows lubricant to bleed past the plunger to relieve excess lubricant pressure.

Abstract: A lubrication system is disclosed for a rolling cutter drill bit, which system utilizes solid or semi-solid sticks of lubricants located in internal channels and continuously biased against rotating surfaces in the bit.