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. Drill bit lifetime has been shown to be greatly extended by this change.

Abstract: Annular seals of this invention comprise an elastomeric seal body that is configured to fit within a seal gland of a rock bit. The seal comprises a first seal surface, for providing a seal along a dynamic rotary surface formed between the seal body and one portion of the rock bit, and a second seal surface, for providing a seal between the seal body and another portion of the rock bit. The annular seal further comprises an extrusion prevention member that is positioned adjacent a surface of the seal body between the first and second seal surfaces. The extrusion prevention member can be integral, partially-attached, or independent of the seal body. The extrusion prevention member is preferably formed from a material having a hardness that is greater than that of the seal body. The member is positioned along the seal body at a location adjacent a groove, formed between opposed members of the rock bit, to act as a physical barrier to prevent the seal from being extruded therethrough.

Abstract: A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions.

Abstract: An improved rotary cone bit includes a threaded end on a bit body for coupling to a drill string. The drill bit body includes two or more leg portions extending from one end thereof. From interval at each of the leg portions is a bearing pin that extends inwardly toward the longitudinal axis of the drill bit body. On each of the bearing pins, there is rotatably mounted a cutter cone having rows of cutting teeth as a part hereof. The bit shirttail comprises a plateau extending along the longitudinal axis of the bit body in substantially the same plane as the bearing pin surface area of the shirttail.

Abstract: A sealing structure for a rock drill bit includes an elastomeric diaphragm for installation in the drill bit so as to separate grease from drilling mud. The diaphragm has an aperture extending through it, and a plug is disposed in the aperture so as to form a mechanical seal with a wall of the aperture. The plug has a channel therethrough which is normally held sealed by a face of the aperture in the diaphragm. If the pressure of the grease exceeds pressure in mud on the other side of the diaphragm by more than a critical value, the diaphragm aperture deforms and allows grease to move through the plug channel and escape. The critical value can be varied by using, with the same diaphragm, plugs having different numbers, sizes and axial positions of plug channels.

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 drill bit for use in a borehole at least partially containing drilling fluid includes a bit body having at least two bit components, including at least one leg, the leg having a journal segment, and a roller cone rotatably mounted upon the journal segment and forming at least one bearing cavity therebetween. Also included is an annular primary seal disposed between the leg and the roller cone and an annular secondary seal disposed between the leg and the roller cone and between the annular primary seal and the borehole. An annular space is defined between the annular primary seal and the annular secondary seal, the annular space at least partially containing fluid and being in substantially absolute fluid isolation from the bearing cavity. The seals are configured to allow the passage of a fluid from the annular space to the borehole. The annular secondary seal may be primarily elastomeric and a passage for fluid from the borehole to the annular space can be included.

Abstract: A bearing seal for earth boring bits is disclosed. A supporting ring is located in a groove formed in the earth boring bit. An annular cavity between the outer circumference of the supporting ring and the bottom of the groove is connected with the outside. An O-ring made of rubber is provided in an annular space defined by the sidewalls of the groove, the inner circumference of the supporting ring and the cylindrical surface of the bearing shaft of the head section to form a seal comprising a radial and axial seal. Compressive deformation of the O-ring does not depend on the eccentric rotation of the cone. Therefore, the working life of the seal is increased and the compressive deformation is decreased, thus facilitating use at high rotating speeds.

Abstract: A heavy-duty lubricating grease is shown which includes a synthetic fluid base and a thickener system. The heavy-duty grease can be used in both rolling element and journal type rock bit bearings to drill in heavy-duty, high temperature applications, such as in the bearing structures of rock bits used to drill hot subterranean formations.

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 slide ring unit includes a slide ring having first and second opposite axial ends. The slide ring further has a sealing face at the first axial end and a conical circumferential surface for supporting an elastic rolling body thereon. The circumferential surface tapers from the sealing face toward the second axial end. The slide ring unit further has a stop for axially retaining the rolling body on the circumferential surface of the slide ring. The stop forms a component separate from the slide ring and adjoins the slide ring at the second axial end thereof. The stop has an outer circumferential surface terminating at and flush with the conical circumferential surface of the slide ring at the second axial end thereof. Further, a securing arrangement is provided for attaching the stop to the slide ring.

Abstract: A roller cutter assembly for use in hard rock tunneling machines comprises a rectangular saddle having a rectangular recess with V-shaped mounting surfaces. Support plates are secured against these mounting surfaces, and the support plates have a shaft extending between them with a non-rotatable head in one plate, and the circular nut in the other plate. The shaft mounts a pair of inner races for tapered roller bearings which run directly on the roller cutter inner surface which forms the outer race for the bearing assembly. Rotation of the circular nut in the recess and on the shaft sets the preload for these bearings. Between the nut and its recess on the adjacent support plate is an annular groove formed in both the support plate and the nut, and an elastomeric diaphragm fits across this groove.

Abstract: A shaft boring bit has a bit body with at least one saddle member secured to the bit body. The saddle receives and supports the ends of a journal member. A cutter is mounted for rotation on the journal member and an anti-friction bearing is disposed between the cutter and the journal and secures the cutter on the journal member. Seal means are provided between the cutter and the journal member to retain lubricant in the anti-friction bearing. A bearing loading passage is formed in the journal member for loading at least a portion of the anti-friction bearing between the cutter and the journal member. A lubricant compensator assembly is removably disposed in a lubricant compensator recess formed at one end of the journal. The lubricant compensator is in fluid communication with the anti-friction bearing and includes a rigid ball plug member, which obstructs the bearing loading passage and abuts the portion of the anti-friction bearing to retain the bearing between the cutter and journal.

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: An improved O-ring seal for rock bit bearings is formed from a resilient elastomeric composition comprising a multiplicity of low friction wear resistant particles distributed uniformly throughout the composition. The low friction wear resistant particles can have a rounded or non-rounded configuration. The low friction wear resistant particles located near the surface of the O-ring are exposed through wear of the elastomeric component to form wear pads that contact adjacent rotating rock bit sealing surfaces. The wear pads serve to reduce the break-off friction between the adjacent sealing surfaces and minimize the occurrence of stick-slip, thereby enhancing the service life of the O-ring seal and rock bit.

Abstract: A sealing assembly for relatively movable, e.g., rotating or reciprocating, members with a plurality of surfaces defining an annular space having a longitudinal axis, at temperatures up to about 1000.degree. F., comprises first and second annular rings of a hard, material having low frictional properties. Each of the annular rings has a radially extending wall and an axially extending wall defining an annular seal gland when fitted together and has external surfaces facing longitudinally outward relative to the longitudinal axis and external surfaces facing outward and inward radially of the longitudinal axis adapted to fit the surfaces of the annular space and of the relatively movable members. The annular rings have surfaces facing inwardly toward each other when assembled shaped to form an annular cavity.

Abstract: A rock bit for drilling subterranean formations has improved dynamic O-ring seals for retaining lubricant around the rock bit bearings during operation at more than 50 meters per minute surface speed on the O-rings. Such a bit has a plurality of journal pins, each having a bearing surface, and a cutter cone mounted on each journal pin and including a bearing surface. A pressure-compensated grease reservoir is in communication with such bearing surfaces for maintaining a grease adjacent to the bearing surfaces. The grease is sealed in with dynamic O-ring seals comprising a perfluorinated terpolymer of tetrafluoroethylene, perfluoro(methyl vinyl ether) and a cure site monomer for introducing crosslinking sites. Preferably the cure site monomer is selected from the group consisting of trifluoroethylene, vinyl perfluoroalkyls and monomers including a perfluoroalkyl ether group.

Abstract: An earth boring bit having a body, pressure compensating lubricating system and cantilevered bearing shaft with an annular seal surface and a radial seal surface. A cutter is rotatably secured to the bearing shaft, with an annular seal recess having radial and cylindrical seal surfaces to oppose the seal surfaces on the body and bearing shaft to define a seal gland. A resilient and annular packing ring is compressed between the cylindrical seal surfaces, but has a length less than the minimum length of the gland. A shroud extends inwardly near the outer backface a selected distance behind the packing ring to bias it inwardly. The shroud extends inwardly toward the bearing not more than about 30% of the cross-sectional thickness of the O-ring in the relaxed condition. The O-ring is compressed in a range of about 10 to 15 percent.

Abstract: A roller cutter earth boring bit having longer roller bearings recessed into surrounding bit structure for increased load carrying capacity. The elimination of thrust bearing shoulders from the bearing pin structure between sets of roller bearings enables the use of such longer roller bearings.

Abstract: An earth boring bit of the type having three rotary cone cutters carried on bearing pins depending from respective head sections is disclosed. Adjacent the rear face of a cutter is located a portion of the respective head section commonly known as the shirttail. The invention discourages the intrusion of cuttings into the bearing surfaces or seals and reduces the likelihood of fracture of the shirttail. This is achieved by forming the coacting faces as truncated conical surfaces instead of the usual configuration of the prior art which is arranged substantially perpendicular to the bearing pin axis.

Abstract: A sealing member for relatively movable, e.g., rotating or reciprocating, members comprises a pair of annular rings each with a radially extending wall and an axially extending wall defining an annular seal gland. An elastic spring member compression-loaded in the seal biases the exterior surfaces against the bearing surfaces. The ring members are preferably of TEFLON, or like polytetrafluoroethylene plastic, RYTON, polyphenylene sulfide, or a soft elastic metal capable of being compressed by the spring member against the walls of the surface being sealed. The spring is a rubber or elastomeric O-ring or the like. Other spring members, such as a Belleville spring assembly or the like, may be used. This seal is characterized by its operation at elevated temperatures, i.e., up, to 1000.degree. F.

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 improved mechanical face seal for rock bits using rigid rings and energizers placed in recesses or grooves in the cutter and bearing shaft. The minimum diameter of the shaft groove is substantially equal to the relaxed inside diameter of the shaft energizer and the maximum diameter of the cutter recess is substantially equal to the relaxed outside diameter of the cutter energizer. The radii at the inner end of the shaft groove and the outer end of the cone groove conform to the relaxed cross-section of their respective energizers. The mean diameter of the shaft energizer is substantially equal to the cone journal diameter and the product of the mean diameter and cross-sectional diameter is the same for both energizers.

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 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: In an earth boring bit of the type having a rotatable cone secured to a bearing shaft, an improved pressure compensating and relief system. A flexible diaphragm has an enlarge peripheral portion in an o-ring configuration sealingly secured in a compensator cavity to form a mud region and a lubricant region. A central portion of the diaphragm has a perforated and ridged protrusion extending into the mud region to form a self energizing area, exposed to the mud region, that seals the perforation when the pressure of the lubricant is less than or substantially equal that of the mud. A wall at the end of the compensator cavity surrounds the mud passage and engages an area around the protrusion when the diaphragm is fully extended by lubricant pressure build-up that exceeds the hydrostatic pressure. Thus, the resulting pressure differential opens the perforation, releases lubricant and relieves the build-up of lubricant pressure.

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 sealed rotary drill bit comprising at least one rotatably carried roller cutter (13) and provided with a seal between the cutter and a mounting head (22) for preventing lubricating medium from being discharged from the bearing (14, 15, 16, 17, 18) and impurities from entering the bearing. For purposes of decreasing the friction the seal (22) is provided with a low friction material on a portion of the seal which engages the head to promote rotation between the seal and the head. The portion of the seal which engages the roller cutter has a material of higher frictional coefficient to resist relative rotation between the seal and the roller cutter (25).

Abstract: A rotary drag drill bit is seen wherein cutter bodies are rotatively connected to a main body structure at a fully offset position. The fully offset position is defined by a rotational axis of each cutter body, a longitudinal axis of the drill bit and end support points or positions of the cutter bodies. The rotational axes of the cutter bodies are perpendicular to the longitudinal axis of the drill bit. The end supports of the cutter body are each equal distance from any point on the longitudinal axis of the drill bit. The cutter bodies of essentially ellipsoidal configuration, being slightly thicker at a mid-portion thereof. Cutting elements are connected to flutes projecting above an outer surface of each cutter body. In a primary rotational direction of the drill string and drill bit, the rows abrade the bottom and side walls of a well bore as the cutter body attacks the earth formation as the drill bit is rotated.

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. This is accomplished by 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.

Abstract: A rotary rock bit having the load bearing elements between the axle and the cone cutter encased in a permeable porous plastic material having lubricant in the pores thereof, with the material substantially filling a portion of the bearing cavity to seal the cavity and a lubricant reservoir in the bit with a lubricant flow passage therefrom to adjacent said material to replenish the lubricant lost from the pores during use.

Abstract: An earth boring bit has features to reduce stress concentration. The earth boring bit is of the type having three bit legs, each bit leg having a depending bearing pin for rotatably carrying a cutter. An annular fillet is formed at the junction of the bearing pin and the bit leg for receiving a seal ring. To relieve stress above the fillet and on the inside surface of the bit leg, a depression is formed. The depression is formed in the inside surface of the bit leg with a lower edge commencing at the top of the fillet. The depression is curved in vertical cross-section and is located behind the backface of the cutter.

Abstract: A chamfered intermediate thrust bearing is positioned between a rotating cutter and its bearing pin of an earth-boring rock bit. The chamfered intermediate bearing is so configured to be mechanically secured in place within the cone and to take outthrust loads, without rotation, that are directed axially against a radially disposed surface of the roller cone journal as the rock bit works in a borehole.

Abstract: A boring head for reaming a pre-drilled hole in raise boring or for similar earth cutting operations comprising a plurality of roller cutters (13, 14), each of which being rotatably journalled over a bearing system. The bearing system comprises a split roller bearing (60) having axially spaced rollers (62, 63) which are separated by a loose guide ring (69).

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: In a rotary drill bit assembly, comprising a drill bit body, at least one trunnion and a rotary cutter rotatably supported on the rotary cutter by bearing means including at least one inner roller bearing, the rollers of the inner roller bearings running in a deep radial bearing race groove in the trunnion and a deep radial bearing race groove formed in the bore of the rotary cutter and a filling opening extending generally axially in the trunnion between the inner bearing race grooves, characterized in that the outer bearing facing the drill bit body comprises a tapered roller bearing including a plurality of tapered rollers and wherein the filling opening for the rolling elements of the inner bearing is arranged radially inside the inner bearing race of the tapered rollers in the trunnion.

Abstract: A self compensating seal apparatus is provided for forming a seal between two rotary members such as the body and cutting head of a rotary drill bit to seal the space between the members from an external environment. The seal apparatus comprises a first sealing device mounted in a first of the members and a second sealing device mounted in the second of the members, the first and second sealing devices being positioned opposite to and in contact with each other along a contact plane and forming a seal therebetween. A Belleville spring is fixedly mounted in the first member for producing a force on the first sealing device in a direction perpendicular to the contact plane such that the first sealing device is biased and held in contact with the second sealing device. A third sealing device seals the Belleville spring and the space between the first and second members from the external environment.

Abstract: An earth boring bit particularly for use in drilling mining blast holes, has features for reducing the possibility of cutter drag and reducing wear on the bit legs. The bit is of the type having three bit legs, a bearing pin depending from each bit leg, and a cutter with a central cavity mounted on each bearing pin with roller bearings. The roller race for the roller bearings is formed in the central cavity of the cutter. The lower side of each bearing pin commences at the outer side of each bit leg, eliminating the shirttail flange. Clearances are provided between the central cavity and the bearing pin at the backface for the discharge of air in a direction parallel with the bearing pin axis.

Abstract: An earth boring drill bit, particularly for large diameter shafts, has a cutter assembly with improved bearing and seal arrangement and an improved cutting insert arrangement. A cutter assembly has an axle with an enlarged central portion and reduced portions on both sides. A cutter sleeve is carried on bearings by the central portion of the axle. An annular member with a central bore is secured to each side of the cutter sleeve. A metal face seal is secured between the reduced portion and the central bore on each side. The cutter contains rows of hard metal inserts secured in holes in the exterior. To reduce tracking, the inserts within a row are separable into groups with varied pitch within each group. The groups cycle with two groups having a gradual increase in pitch and two groups having decreasing pitch.

Abstract: A rotary roller bit comprising at least one rotatably carried roller cutter (12) and provided with sealing means (21) for preventing impurities from entering into the bearing system (14, 15, 16,) of the roller cutter. For purposes of preventing axial and wobbling movements of the roller cutter (12) relative to the bit head from creating high contact pressure at the contact surface between the sealing means (21) and the surface against which same seals the sealing means (21) is provided with an elastically yieldable tongue (25) which extends radially relative to the rotational axis of the roller cutter (12).

Abstract: A rotary drill bit assembly comprising a drill bit body, at least one trunnion formed integrally with the drill bit body and a rotary cutter rotatably supported on the trunnion by bearing means. The bearing means consist of at least two rows of balls which ride between an inner raceway groove formed integrally in the trunnion and an outer raceway groove formed in the interior peripheral surface of the rotary cutter. A filling hole or port is provided in the drill bit body which terminates at its inner end in each raceway so that the balls of the corresponding row may be assembled in the annular space between the trunnion and rotary cutter. A filler pin closes the corresponding filling hole or port and has a terminal end which complements the cross section of the raceway groove.

Abstract: An improved sealing system for a rotary rock bit retains lubricant inside the bearing area of the bit and acts as a barrier to the pulverized cuttings and other materials in the borehole to prevent the materials from entering the bearing area through the cone mouth opening of the rolling cone cutter. An annular seal member located in the cone mouth opening has a hollow core filled with a fluid. The fluid will flow thru the hollow core when pressure is applied. During drilling with a rotary rock bit the lower or loaded side of the bearing has less clearance than the upper or unloaded side. The pressure on the loaded side of the bearing will force the fluid to the unloaded side of the seal member and cause that side of the seal member to expand and fill the clearance to maintain a seal.

Abstract: A rotary drill bit having a drill bit body and at least one trunnion projecting from the drill bit body and a rotary cutter supported on at least one radial roller bearing on the trunnion. The rolling elements of the bearing are guided on at least one axial end facing the drill bit body in an outer bearing race groove incorporated in the bore of the rotary cutter. The inner bearing race groove is formed on the trunnion for the rolling elements of the radial roller bearing. At least one filling opening is provided which extends through the drill bit body and trunnion and is essentially axially oriented having one terminal end adjacent the inner bearing race groove and at least one pair of filler piece for sealing the opening. One of the filler pieces is made of an elastically compressible material.

Abstract: A rotary drill bit having a drill bit body and at least one trunnion projecting from the drill bit body and a rotary cutter supported on at least one pair of radial rolling bearings on the trunnion. The rolling elements of at least one bearing are guided on at last one axial end facing the drill bit body in an outer bearing race groove incorporated in the bore of the rotary cutter. The inner bearing groove is formed on the trunnion for the rolling elements of the radial roller bearing. A filling opening is provided for assembly of the rolling elements comprising a channel which extends through the drill bit body and trunnion and is essentially axially oriented having one terminal end adjacent the inner bearing race groove and at least one filler piece for sealing the opening. The filling opening is arranged to provide a common filling means for each radial bearing.

Abstract: A drill string reamer-stabilizer includes a main body adapted to be connected as an element of a rotary drill string. Individual bearing shafts are mounted axially along the exterior of the main body to support roller cutters that engage the wall of the borehole. Seal units are positioned around each bearing shaft between each roller cutter and bearing shaft to define a lubricant space. The seal units retain lubricant in the lubricant space and prevent contaminating fluid and materials in the borehole from entering the lubricant space. At least one seal unit comprises an annular cup-shaped elastomer seal member mounted in an annular seal gland in the roller cutter. The seal gland has an inner side adjacent the lubricant space and an outer side exposed to the fluid and materials in the borehole.

Abstract: A sealing system acts as a barrier to the drilling fluid, pulverized cuttings and other materials in the borehole preventing the materials from entering the bearing area of a rotary rock bit and retains lubricant inside the bearing area of the bit. At least one bearing pin extends from the body of the bit and a rolling cutter is mounted on the bearing pin. A seal assembly is located in the mouth of the cutter between the cutter and the bearing pin. The seal assembly includes a non-rotating element affixed to the bearing pin and a rotating element affixed to the rolling cutter. The rotating and non-rotating elements have intermeshing labyrinthine projections that may be constructed of heat resistant materials.

Abstract: A rotary drilling bit with conically shaped rotary cutters which are supported in bearings on the drilling bit body by a plurality of bearings. At least one seal is provided in each rotary cutter for separating the bearing cavities of the bearings.

Abstract: A rolling cone cutter earth boring bit is provided with a floating seal for sealing the bearings of the bit from the abrasive materials in the borehole and retaining lubricant within the bearing area. At least one cantilevered bearing pin extends from the arm of the bit. A cutter receiving surface is located on the arm. A first shallow annular groove is located in said cutter receiving surface. A rolling cone cutter is adapted to be rotatably mounted on the bearing pin with said rolling cone cutter having a cone mouth. A second shallow annular groove is located within said cone mouth. Bearing and cutter retaining means are located between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing pin between the cutter receiving surface and the rolling cone cutter.

Abstract: A sliding seal ring for a drill bit comprising at least one cutter rotatably mounted on a journal forming part of the drill bit body. The seal ring is made of elastic metallic strip material and is of spiral configuration with the spirals in overlapping relation. The seal ring is mounted under axial tension between the pocket in an edge ring and the drill bit body and rotates with the cutter. In one form of the invention, the spirals are in abutting relation to provide a complete seal. In another form the spirals are open to define gaps permitting flow of flushing liquid to cool and lubricate the bearings supporting the cutter on the trunnion.