MXPA00009199A - Rotary cone drill bit with improved bearing system - Google Patents

Abstract

A rotary cone drill bit for forming a borehole having a bit body with an upper portion adapted for connection to a drill string. A number of support arms extending from the bit body with each support arm having an exterior surface with an opening extending therethrough. A number of cutter cone assemblies equal to the number of support arms with each cutter cone assembly rotatably mounted on a respective spindle projecting generally downwardly and inwardly from each support arm. A ball retainer passageway extending from the opening in the exterior surface of each support arm to allow installing ball bearings through the opening and the ball retainer passageway to rotatably mount each cutter cone assembly on its respective spindle. A ball race formed in the exterior of each spindle between a first outside diameter portion and a second outside diameter portion. The ball retainer passageway intersecting the ball race. The first outside diameter portion and the second outside diameter portion providing portions of radial bearing for rotatably mounting each cutter cone assembly on its respective spindle. The first outside diameter portion and the second outside diameter portion having approximately the same diameter relative to an axis extending through the spindle.

Description

ROTATING CONE DRILL WITH IMPROVED BEARING SYSTEM TECHNICAL FIELD OF THE INVENTION The present invention generally relates to a rotating cone drill having multiple support arms with a spindle or core extending from each supporting arm and a ball retainer system for rotatably mounting or respective cutting cone assembly thereon and more particularly to an improved support system for increasing the operation of deep-hole drilling of the associated broc.

BACKGROUND OF THE INVENTION * Various types of drill bits or drill bits can be used to form a hole in the ground. Examples of such rock drill bits include roller drill bits or rotary cone drill bits used in the drilling of oil and gas wells. A typical rodant cone bit includes a drill body with a top adapted for connection to a drill string. A plurality of support arms, typically three, depends on the lower part of the drill body with each support arm having a trunnion axis projecting radially in and down co with respect to the projected axis of the rotation of the drill body.

Conventional rolling cone bits are typically constructed in three segments. The segments can be placed together longitudinally with a weld slot between each segment. The segments can then be welded together using conventional techniques to form the drill body. Each segment also includes an associated support arm that extends from the drill body. An enlarged cavity or conduit is typically formed in the drill body to receive the drilling fluids from the drilling pan. U.S. Patent No. 4,054,772 entitled Welding Placement System D Barrena Para Roca, shows a method and an apparatus for constructing a rotating drill with three cones of three individual segments A cutter cone assembly is generally rotatably mounted on the respective spindle or core. The cutter cone assembly typically has a cavity formed therein and is dimensioned to receive the respective spindle. Several types of bearings and / or bearing surfaces may be located or may be between the exterior between the outside of the spindle and the interior of the cavity. A typical bearing system used to rotationally mount a cutter cone assembly on a spindle will include one or more radial bearings or one or more thrust bearings. The radial bearings will generally be located between the outer diameter of the spindle and the inner surfaces of the cavity placed next to them. The thrust bearings and / or the thrust bearing surfaces will generally be located between the end of the opposite spindle between the associated support arm and the adjacent portions of the cavity formed in the cutter assembly. For some applications a shoulder can be formed on the outside of the spindle and a corresponding shoulder can be formed inside the cavity with a thrust bearing and / or thrust bearing surfaces placed between them The thrust bearings and / or The radial bearings may be formed as integral components of the spindle as shown in "U.S. Patent No. 3,823.03, entitled" Method for Manufacturing a Bearing System Having Attrition-Resistant Particles. "For some applications, Rolling-type bearings can be placed between the outside diameter of the spindle and the adjacent portions of the cavity to support the radial loads transmitted from the cutter-cone assembly to the spindle.An example of such roller-type bearings are shown in the patent of the United States of America No. 3,952,815 entitled Protection of Earth Erosion for a Rock Cutter. d the United States of America No. 5No. 513,713 entitled "Sealed and Lubricated Rotary Cone Drill Bit" having improved seal protection shows multiple sets of roller type bearings placed between a spindle and adjacent portions of a cavity. For other applications, a sleeve may be placed on the outside diameter of the spindle and the adjacent portions of the cavity to carry such radial loads. Examples such sleeves are shown in U.S. Patent No. 5,570,750 entitled "Rotary Drill C Enhanced Skirt Tail and Seal Protection" and in United States of America Patent No. 5,593,231 entitled "Cojinet Hydrodynamics". These patents also disclose examples push buttons or thrust bearings which may be placed between the end of the spindle and the adjacent portions of the cavity.

In a sealed rotating cone drill, lubricant under pressure is forced into a space between the outside of the spindle and the inside of the cavity to cool and protect the associated bearings and / or the bearing surfaces. A lubricant reservoir is usually provided to compensate for any partial loss of lubricant to balance the internal lubricant pressure with the external hydrostatic pressure during the deep hole drilling operation. The lubricant may comprise, for example, a calcium complex fat. Additionally, solids such as molybdenum disulfide can be added to lubricant to increase the bearing capacity of the bearings and / or the bearing surfaces.

Bearings and bearing surfaces in a typical rotary cone drill are heavily loaded during deep hole drilling operations. During such drilling operations, the drill is rotated in a deep hole which causes the associated cut cone assemblies to rotate on their respective spindles. The typical drill operates at a low speed with a very heavy weight applied to the drill which also produces a high load on the associated cushions. Rotary cone bits with sealed lubrication systems typically include one or more elastomeric seals which can be damaged by exposure to the high temperatures created by excessive friction due to such heavy loads. Also, the non-concentric rotation and / or swing of a cutter assembly on its respective spindle and ot cause possible seal damage. Failure of the seal by exposure to high temperatures or mechanical damage will eventually allow water, drilling fluids, and other debris from the drilling operation to penetrate the space between the cavity in the cutter cone assembly and associated spindle and Increase wear on the bearing and / or bearing surfaces to the point where the cutter assemblies may get lost in the deep hole.

U.S. Patent No. 4,056,153 entitled Rotating Rock Drill With Multiple Row Coverage For Very Hard Formations, and U.S. Patent No. 4,280,571 entitled Auger Rock, show examples of conventional rotary cone drills with cutter cone assemblies mounted on a spindle projecting from a support arm. Typically, the ball bearings are inserted through an opening in an outer surface of each support arm and a ball retaining conduit being therefrom to rotatably secure each cutter cone assembly on its respective hus. A ball retainer plug is then inserted into the ball retainer conduit. Finally a ball plug weld is generally formed in the opening to secure the ball retainer plug within the ball retainer.

Hard coating of meta surfaces and substrates is a well-known technique for minimizing erosion and abrasion of the surface of a metal substrate. The hard coating can generally be defined as applying a layer of a material resistant to Hard abrasion on a hard surface or substrate by coating, welding, spraying, or other known meta deposit techniques. Hard coating is frequently used to extend the service life of drill bits and other deep hole tools used in the gas and oil industry. Tungsten carbide and its various alloys are some of the hard coating materials most widely used to protect drill bits and other deep hole tools associated with drilling and production of oil and gas wells.

SYNTHESIS OF THE INVENTION In accordance with the teachings of the present invention, the disadvantages and problems associated with the previous rotary cone bits have been reduced or eliminated substantially. One aspect of the present invention includes a rotating cone drill having support arms and a spindle a journal extending from each support arm with a respective cutter cone assembly rotatably mounted thereon. The application of the mechanism which retains the cutter cone assembly on its respective spindle, such as ball bearings positioned between the outside of the spindle and inside a cavity formed in each set of cutter, is optimized to increase the effectiveness of both radial bearing components and the bearing components of the associated bearing system. . For example, an outer part of each spindle may have a generally uniform outer diameter with a first radial or surface bearing bearing and a second radial bearing or radial bearing surface placed thereon with a ball socket formed in the outside of the spindle between the first radial bearing and the second radial bearing. The dimensions of the first radial bearing relative to the second radial bearing can be selected in accordance with the teachings of the present invention to increase the carrying capacity of the associated bearing system and the ability of the bearing system to prevent non-concentric rotation and / or rolling cone assembly cutter in relation to its respective spindle. The teachings of the present invention can be used with a wide variety of mechanisms which retain a set of cutter cone on a spindle in addition to the ball bearingsd V.

The technical benefits of the present invention include providing a rotating cone bit having a bearing system with an increased carrying capacity which can be incorporated into a support arm in the cutter cone assemblies without essentially increasing without modifying the Overall configuration of the support arm and cutter cone. A bearing system incorporating the teachings of the present invention generally maintains more concentric alignment during the rotation of a cutter assembly on the respective spindle and minimizes any tendency of the cutter cone assembly to swing relative to the spindle. The present invention will prolong the life in the deep hole of a rotating cone cone by increasing the carrying capacity of both radial bearing components and the thrust bearing components of the associated cushion system. The present invention also provides a rotating cone drill in which the configuration and dimensions of the skirt portion of each support arm can be increased to prolong the life of the associated deep drill hole with rotating.

The technical teachings of the present invention include the ability to apply coating material on an amplified skirt portion on an amplified skirt portion of each support arm. Alternatively, the present invention allows increasing the number and / or size of inserts and compacts which can be installed within the skirt portion within each support arm. Increasing the size of the supporting arm skirt portion and covering the enlarged skirt portion with a hard wearing layer according to the teachings of the present invention can be particularly effective in increasing the life of the broc during perforations of the legs. horizontal and / or directional wellbores. Premature bit failure due to increased lateral loading of the associated perforation and increased abrasion, erosion and wear can occur under such conditions. The compact multiple inserts can also be installed more securely within the skirt portion of each support arm to a ball stop function to further increase resistance to abrasion, erosion and / or wear.

Other technical advantages will be readily apparent to one skilled in the art of the following figures, descriptions and claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and its advantages, reference will now be made to the following brief description, taken in conjunction with the accompanying drawings and the detailed description, in which the like reference numbers represent equal parts, in which Figure 1 is a schematic elevational drawing showing a type of rotating cone drill with support arms and cutter cone assemblies formed in accordance with the teachings in accordance with the present invention; Figure 2 is a schematic sectional drawing in elevation with the parts cut out showing another type of rotating cone bit placed in a deep hole with the drill having support arms sets of cutter cone formed according to the teaching of the present invention; Figure 3 is a schematic sectional drawing in elevation with the cut portions of a drill bit having a unit drill body with the support arms and l cutter cone assemblies similar to the drill shown in Figure 2, - Figure 4 is a schematic drawing amplified in section and in elevation with the parts cut away showing bearing system incorporating teachings of the present invention in combination with a cutter cone assembly rotatably mounted on a spindle projecting from a support arm; Figure 5 is a schematic drawing enlarged in section and in elevation with cut portions showing a bearing system incorporating the teachings in combination with a cutter cone assembly rotatably mounted on a spindle projecting from a support arm; Y Figure 6 is a schematic drawing enlarged in section and in elevation with cut parts showing conventional bearing system embodying the teachings of the present invention in combination with a co-cutter assembly rotatably mounted on a spindle projecting from a support arm .

DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention and its advantages will be better understood with reference now in greater detail to Figures 1-6 of the drawings, in which similar numbers refer to like parts.

Support arms and cutter assemblies incorporating the teachings of the present invention can be used with a wide variety of rotary drill bits. The rotary cone bits 20, 70 and 170 which will be discussed later in greater detail represent only a few examples of the many types of drill bits that a bearing system may have that embody the teachings of the present invention. The support arms and cutter assemblies which are shown in Figures 1-6 s will describe with respect to a sealed lubrication system. However, a bearing system incorporating the teachings of the present invention will be used successfully with air cooled drill bits and drills which do not have a lubrication system.

Figure 1 illustrates the various aspects of a rotating cone drill which is generally indicated with the number 20 of the type used in drilling a deep hole in the ground. The bit 20 can also be referred to as a "rotating cone rock auger" or "rotating dew auger". With the rotating cone bit 20, the cutting action occurs when the cutters are rotated, indicated generally with the number 2, around the bottom of a deep hole (expressly shown) by the rotation of a perforation (n expressly shown) attached to the bit 20. The sets of cutter 22 can also be referred to as "rotary cone cutters" or "rolling cone cutters". Each cutter cone assembly 22 is rotatably shown on a respective trunnion spindle (not expressly shown) with a bearing system embodying the teachings of the present invention placed therebetween. Examples of such bearing systems are shown in Figures 3, 4, 5 and 6.

The rotary cone bit 20 includes a drill body 28 having an externally threaded tapered upper portion 30 which is adapted to be secured to the lower end of a drill string. Depending on the body 28 there are three support arms 32. Only two support arms 32 are visible in FIG. 1. The support arm 3 preferably includes an integral formed spindle or trunnion with the respective support arm 32. Each cone assembly cutter 2 is rotatably mounted on a respective spindle. The spindles are preferably angled downwards and inwards co with respect to the drill body 28 and the outer surface of respective support arm 38. As the drill 20 is rotated, the cutter cone assemblies 22 engage the bottom of a deep orifice (not expressly shown). For some applications the spindles can also be inclined at an angle of 0 to 3 4 degrees in the direction of rotation of the bit 20.

Cutter cone assemblies 22 may include pressed surface inserts 36 on the respective marker surfaces and protruding inserts 38 or milled teeth (not expressly shown), which scrape and empty against the side and bottom. of the deep hole under the downward force of the hole applied through the associated hole. The formation of the orifice debris was created by the cutter cone assemblies 22 being carried out from the bottom of the deep hole by the drilling hole which flows from the nozzles 40 on one side to the lower part 4 of the drill body 28. The drilling fluid flows upwards towards the surface through a ring (not expressly shown) formed between the drill 20 and the side wall (n expressly shown) of the deep hole.

Each cutter cone assembly 22 is generally constructed and mounted on its stump or associated use in an essentially identical manner. The dotted circle 48 on the outer surface 34 of each support arm 32 represents an opening for an associated ball retainer conduit (not expressly shown). The function of the opening 48 and the associated ball retainer will be discussed later with respect to the rotating mounting cutter cone assemblies on their respective spindle. One of the benefits of the present invention includes increasing the distance or spacing between each opening 48 and the skirt 50 of the respective support arm 32. Figure 32 is an isometric drawing of a rotating con, generally indicated with the number 70 constructed according to the teachings of the present invention attached to a drill string 72 and placed in a deep hole 74 Examples of such drill bits and their associated drill body, d the support arms and the cutter cone assemblies is shown in U.S. Patent No. 5,439,067 entitled Rock Drill with Increased Fluid Return Area, and in U.S. Patent No. 5,439,068 entitled "Modular Rotary Drill". These patents provide additional information regarding the fabrication of assembly of unitary drill bodies, support arms and cutter cone assemblies which are satisfactory for use with the present invention.

The ring 76 is formed between the outside of the perforation string 72 and the bore hole wall or interior 78 of the rotating drill 70. Drill string 72 is frequently used to provide a conduit for communicating the drilling fluids. and other fluids from the surface of the well to the drill bit 70 at the bottom of the deep hole 74. Such drilling fluids can be directed to flow from the drill string 72 to the multiple nozzles 80 provided in the drill 70. The cuts formed by the drill drill bit 70 and any other debris at the bottom of deep hole 70 will mix with drilling fluids leaving nozzles 80 and return to the surface of the well through ring 86. Drill 70 includes a unitary piece or body 82 with the top 84 has a bolt or threaded connection 86 adapted to secure the drill 7 with the lower end of the drill string 72. Three support arms 88 are preferred. They are joined together and extend longitudinally from the opposite drill body 82 from the bolt 86. Only two bearing arms are shown in Figure 2. Each support arm 88 preferably includes a respective cutter cone assembly 90. The cutter cone assemblies 9 generally extend downwardly and inwardly from the respective support arms 88.

The drill body 82 includes a lower part 92 having a generally convex outer surface 9 formed thereon. The dimensions of the convex surface 94 and the location of the cutter cone assemblies 90 are selected to optimize fluid flow between the lower part 92 of the drill body 82 and the sets of cutter 90. The location of each cone assembly Cutter 90 in relation to the lower part 92 can be varied by adjusting the length of the support arms 88 and spacing of the support arms 88 on the outside of the drill body 82.

The cutter cone assemblies 90 may further include plurality of surface compacts 96 placed on the face surface 98 of each cutter cone assembly 90. Cad cutter cone assembly 90 may also include a number d inserts projecting 100. The compacts of surface 96 the inserts 100 can be formed of various types of hard materials depending on the anticipated deep hole and operating conditions. Alternatively, the milled teeth (not shown expressly) can be formed as an integral part of each cutter cone assembly 90. Each support bracket 88 also comprises the flow channel 102 for assisting the removal of cuts and other debris from the deep orifice 74. The flow channel 102 is placed on the outer surface 104 of the support arm 88. The flow channel 102 can be formed in each of the support arms 88 by a machining operation. The flow channel 102 can also be formed during the process of forging the respective support arm 88. After the support arm 88 has been forged., the flow channels 102 can also be machined to define their desired configuration.

Each support arm 88 includes a skirt 106 c a layer of selected hard coating materials that cover the skirt portion 108. Relatively, one or more compact or inserts (not expressly shown) can be placed within the skirt mark 108 as a combination result a bearing system incorporating the teachings of the present invention included with the support arms 88 and the cutter cone assemblies 90, the dimensions of the associated skirt portions 108 can be amplified to better accommodate the use of the compacts and / or of the inserts for weaving the skirt part 108 from abrasion, erosion and wear. The opening location 110 and the associated ball retainer conduit to be modified to increase the dimensions of the skirt portion 108 were discussed later in more detail. FIG. 3 is a schematic sectional drawing with cut-away portions showing the drill bit. rotary cone 170 c the support arms 88 and the cutter cone assemblies 90 q have the bearing systems incorporating various teachings the present invention. Various components of the associated bearing systems, which will be discussed later in detail in May, allow each cutter cone assembly 90 to be rotatably mounted on its respective journal with rotatable 170 includes a unit or piezo body 182. The drill body 182 is essentially similar to the previously described drill body 182 described by the lower part 192 which has a generally concave outer surface 194 formed thereon. The dimensions of the concave surface 194 and the location of the cutter cone components 90 can be selected to optimize the flow of fluid between the lower part 192 of the drill body 182 and the cutter cone assemblies 90 as previously described with respect to the body of drill bits 82.

The cutter cone assemblies 22 of the drill 20 can be mounted on a spindle or stump projecting from the respective arms 32 using essentially the same techniques associated with assembling the cutter cone assemblies 90 on a spindle or stump 116 that is It projects from the respective support arms 88. Also, a bearing system embodying the teachings of the present invention can be used successfully to rotatably mount the cutter cone assemblies 22 on the respective support arms 32 in essentially the same manner as is shown in FIG. used to rotatably mount the cutter cone assemblies 90 of the respective support arms 88. Thus, the various features and benefits of the present invention will be described primarily with respect to the support arms 88 and the cutter cone assemblies 90.

Each cutter cone assembly 90 preferably includes the cylindrical cavity 114 which has been sized to receive a stump or spindle 116 there. Each cutter cone assembly 90 and its respective spindle 116 has a common length 150 axis, which also represents the axis of rotation for cutter cone assembly 90 in relation to its associated spindle. 11 Various components of the respective bearing system include the machine surfaces. associated with the interior of the cavity 114 and the interior of the spindle 116. These machined surfaces will be described with respect to an axis 150.

The support arms and the cutter assemblies shown in Figures 3, 4, 5 and 6 preferably include a sealed lubrication system. As not previously, bearing systems incorporating the teachings of the present invention can be used satisfactorily with the support arms and cutter assemblies, which are air cooled or which include a lubrication system. For incorporations the present invention as shown in Figures 3, 4, 5 and a seal ring .118 is located in the mouth or opening 119 of the cavity 114 to establish a fluid barrier between the cavity 114 and the stump 116. The ring of sel 118 can be formed of various types of elastomeric material to provide an essentially fluid-proof seal.

For the embodiments shown in Figs. 3, 4, 5 and 6, each cutter cone assembly is retained on the respective trunnion for a plurality of ball bearings 132. However, a wide variety of cutter cone retention mechanisms, which are well known in the art, can also be used with a bearing system incorporating the teachings of the present invention. For example shown in Figure 3, the ball bearings 132 s inserted through the opening 110 in the outer surface 104 and the ball retainer conduit 112 of the associated sleep arm 188. The ball bushes 134 and 136 are formed by respectively inside the cavity 114 of the associated cutter assembly 90 and on the outside of the stump 116.

The ball retainer conduit 112 is connected to the ball bushes 134 and 136 so that the ball bearings 132 can be inserted therethrough to form an annular array within the ball bushes 134 and 136 to prevent disengagement of the cutter assembly 90 of its associated stump 116. The ball retainer conduit 112 is subsequently capped by inserting a ball stopper catch (not expressly shown therein). A ball plug weld (not expressly shown) is preferably formed from each aperture 110 to provide a fluid bar between a ball retainer 112 and an exterior of each support arm 88 to prevent contamination and / or loss of lubricant from the associated sealed lubrication system.

Each support arm 88 preferably includes the lubricant reservoir or the lubricant cavity 120 which has a generally cylindrical configuration. The lubricant cap 122 is positioned within one of the lubricant cavity 120 to prevent fluid communication placed between the lubricant cavity 120 and the exterior of the support arm 88. The lubricant cap 122 includes the elastic and flexible diaphragm 124 which closes the lubricant cavity 120. cap 122 covers diaphragm 124 and defines a chamber portion 1 facing diaphragm 124 to provide a volume in which diaphragm 124 can expand. The cover 122 and the diaphragm 1 are supported within the lubrication cavity 120 by means of the retainer 129.

A lubricant conduit 121 extends through the support arm 88 to place the lubricant cavity 1 in a fluid communication with the bore seal conduit 112. The ball detent conduit 112 provides fluid communication with the cavity. internal 114 of the associated cutter assembly 90 and the bearing system located between the exterior of the spindle 116 and the interior of the cavity 114. With assembly of the drill 170, the lubricating cavity 121 of the lubricant cavity 120, of any space available in the duct of ball detent 112 and any available space between the inner surface of the cavity 114 and the outside d spindle 116 are filled with lubricant through an opening (shown expressly) on each support arm 88. The aperture is subsequently sealed after the filling of lubricant.

The pressure of the external fluids out of the drill 170 can be transmitted to the lubricant (not expressly shown) contained in the lubricant cavity 120 by diaphragm 124. The flexure of the diaphragm 124 maintains lubricant at a pressure generally equal to the pressure of the external fluids. outside the drill 170. This pressure transmitted after the lubricating fluid 120, the ball retainer conduit 112 and the internal cavity 114 to expose the face inward of the seal ring 118 to have pressure generally equal to the pressure of the external fluids. .

Each spindle or stump 116 is formed on the inner surface 105 of each support arm 88. Each spindle 116 has a generally cylindrical configuration extending along the axis 150 from the support arm 88. The shaft 15 also corresponds to the spindle of rotation for the set d associated cutter cone 90. For the incorporation of the present invention as shown in figure 3, the spindle 116 includes the first outer diameter part 138, the second outer diameter part 140, and the third part of the outer diameter 142. The first outer diameter part 138 extends from the joint between the spindle 116 and the inner surfaces 105 of support arm 88 to the ball bushing 136. The second part d diameter 140 extends from the ball bushing 136 to the shoulder 144 formed by the change in diameter from the second part diameter 140 and the third part diameter 142. The first outer diameter part 138 and second outer diameter part 140 have approximately the same diameter measured relative to axis 150. The third outer diameter part 142 has a substantially reduced outer diameter compared to the first part of diameter 138 and the second outer diameter part 140. The cavity 114 of the cutter cone assembly 9 preferably includes the machine surfaces which corresponds preferably to n the first outer diameter part 138 with the second outer diameter part 140, with the third outer diameter part 142, with the shoulder portion 140 and the end 146 of the spindle 116.

As discussed below in greater detail, the first outer diameter portion 138, the second outer diameter portion 140 and the third outer diameter portion 14 and the corresponding machined surfaces formed in the cavity 141 provide one or more used bearing components. to rotatably hold the cut cone assembly 90 on the spindle 116. The shoulder 144 and the end 146 of the spindle 11 and the correspondingly machined surfaces formed in the cavity 114 provide one or more thrust bearing components used to rotatably hold the assembly with cutter 90 on the spindle 116. As discussed below in greater detail, various types of sleeves, roller bearings, thrust rollers and / or push buttons may be placed between the spindle exterior 116 and the corresponding associated surfaces. with the cavity 114. The radial bearing components can also be mentioned as a bearing component of stump.

As best shown in Figure 3, a ball detent conduit 112 extends from the opening 10 in outer surface 104 of the support arm 88 through the hu 116 and interacts with the ball bushing 136. The intersection between the conduit ball retainer 112 and bo-bushing 136 forms opening 148 on the outside of spindle 116. U important feature of the present invention includes l placement of ball bushing 136 and middle aperture 148 of the joint between spindle 116 and the inner surface 10 of the support arm 88 and the shoulder 144 formed on the exterior of the spindle 116. As shown in Figures 3, 4, 5 and 6 the selection of the location of the ball bushing 136 and the opening 148 of In accordance with the teachings of the present invention, the length of the second outer diameter part 140 is essentially increased as compared to the previous cutter and support arm assemblies.

Depending on the specific dimensions and configurations associated with the drill 170, the support arms 88 the spindles 116 and the cutter cone assemblies 90, the length of the second outer diameter part 140 may vary in approximately twenty-five percent (25%) of the first part length of outer diameter 138 and about the same length as the first outer diameter part 13 For large diameter bits, the spokes of the associated hus will also increase. For such applications, the length of the second outer diameter portion 140 may be greater than the length of the first outer diameter portion 138. By varying the length associated with the first outer diameter portion 138 and the second outer diameter portion 14 in accordance with The teachings of the present invention will increase both the radial load bearing capacity and the thrust load carrying capacity of the cushion system used for the rotationally mounted cutter cone assembly 9 on the spindle 116.

For the embodiment shown in Fig. 3, the dimensions associated with the first outer diameter part 138 and with the second outer diameter part 130 and the dimensions of the adjacent portions of the cavity 140 are selected to provide a bearing of radius. during the rotation of the cutter cone assembly 90 on and spindle 116. In a similar manner, the dimensions associated with the first outer diameter part 142 and the adjacent portions d the cavity 114 are selected to provide an additional radial bearing support during the rotation of the cutter cone assembly 90 on the spindle 116. The first outer diameter part 138 and the second outer diameter part cooperate with each other to form the primary journal bearing or the primary radial bearing associated with the cutter cone assembly rotating assembly 90 on spindle 116. Third part outer diameter 142 provides a secondary journal bearing or a cushion and secondary radial.

The combined effective length of the bearing surfaces represented by the first outer diameter portion 138 and the second outer diameter portion 140 is approximately the same as the length of the primary journal bearing associated with the prior cut spindle and cone assemblies. However, by placing the opening 148 of the ball retainer conduit 112 between the first outer diameter part 138 and the second outer diameter part 140, in the effective extension of the primary bearing journal of the radial bearing is substantially increased in comparison With the sets of spindles and pre-cutter cone having approximately the same dimensions, the increased extent of the second outer diameter part 140 provides robust and relatively strong shoulder 144 which essentially increased the thrust load bearing capacity compared to a pre-cutter / spindle cone bearing having only the end 146 to carry the thrust loads.

As shown in Figures 4, 5 and 6, this invention allows the rotatable mounting of a cutter cone assembly on a spindle having a bearing system with increased thrust and / or load carrying capacity without requiring an increase. substantial in the physical limits associated with a bearing system. The cutter assembly 190 shown in FIG. 4 and the cutter assembly 990 shown in FIG. 5 are essentially the same as the previously described cutter cone assembly 90 except for the modification of the selected machined surfaces formed in the respective cavities. 214 and 314. The spindle 21 shown in Figures 4, 5 and 6 is essentially the same as the previously described spindle 116 except for the selected modifications on the outside diameter of the spindle 216 to a side of the inner surface 105 of the support arm. 88 For the embodiments of the present invention shown in Figures 4, 5 and 6, the thrust sheave 152 is preferably positioned between the shoulder 144 on the spindle 216 the corresponding shoulder 144 on the spindle 216 and the corresponding shoulder 154 formed within the spindles. cavities 214 and 314. The location of the ball bushing 136 formed on the outside of spindle 216 is preferably selected such that the length of the second outer diameter portion 14 will provide a relatively strong sturdy support for the shoulder 144 and the thrust ring. 152. Increasing the length d of the second outer diameter portion 140 increases the cutting resistance associated with the shoulder 144, which allows the associated rotating cone bro 170 to better withstand the condition of abusive deep hole drilling such as I fell from the drill string 72 into the deep hole 74 Also increasing the length of the second outer diameter 14 reduces the possibility the thermal and / or mechanical cracking that can occur if shoulder 144 is supported by a relatively thin metal section.

For some applications, a push button (n expressly shown) may be positioned between the end 14 of the spindle 216 and the adjacent portions of the cavity 214 and 314. As a result of this, the location of the ball cap 136 on the outside of the spindle 216 according to the teachings of the present invention, the thrust cushion components associated with the rotatably mounted cutter cone assemblies 290 and 390 on the respective spindles 216 can be substantially increased compared to previous rotary drill bits in which the ball bushing is generally formed closer to the end of the associated arm of the respective spindle.

For some applications, the radial bearings and / or thrust bearings of a bearing system embodying the teachings of the present invention may be formed as integral components of the spindle and / or the cavity of the associated cutter cone assembly. The set of cutter 90 and spindle 116 shown in FIG. 3 is a schematic representation of such a bearing system used to rotatably mount the cutter cone assembly 290 on and spindle 216 as shown in FIG. 4 includes the thrust sheaves. 152 and radial sleeve 156. For this particular incorporation, the inner cavity 214 includes an enlarged inner diameter part which provides the recess 254 sized to receive the sleeve 256 there. The spindle 216 also includes an amplified outer diameter portion 238 formed on one side d of the inner surface 105 of the support arm 88 to form a fluid barrier with a seal ring 118. Aside d enlarged outer diameter 238 also forms the shoulder 240 which contacts the sleeve 256 to assist in properly positioning the cutter cone assembly 290 on the spindle 216. The first diameter portion 138 of the spindle 216 is sized to contact both the sleeve 156 and a portion of the cavity. 214 placed between the ball bushing 134 and the recess 254. The second outer diameter portion 140 of the spindle 216 is preferably dimensioned to make contact with a portion of the cavity 214 placed on one side thereof. For some applications, the bearing spaces or corrid spaces associated with the sleeve 156 and the first diameter part 138 are together slightly closer compared to the running spaces between the second outer diameter part 140 and the adjacent portions in the cavity 214.

For the embodiment of the present invention shown in Figure 5, the cutter cone assembly 390 includes an amplified inner diameter part 354 which extends from the seal ring 118 to the ball sleeve 134 for this embodiment of the present invention, the enlarged sleeve 356 may be positioned between the first part d outer diameter 138 and the inner diameter 254 of the cavity 314.

For the embodiment of the present invention shown in Figure 6, the cutter cone assembly 390 has been further modified by forming an enlarged inner diameter part 358 which extends from the ball bushing 354 to the shoulder 158. For Embodiment of the present invention, the sleeve 357 can be positioned between the second outer diameter part 14 of the spindle 216 and the inner diameter 358 of the cavity 314.

The comparison between the sleeves 356 and 357 com is shown in Figure 6, it will further increase the rotational stability of the cutter cone assembly 490 on the spindle 216. The skirt 216 can be defined as between the juncture between the outer surface 104 and the surface interior 105 of support arm 88. For incorporation of the present invention, as shown in Figures 2 and 3, the skirt 10 will preferably have a radius of curvature that corresponds approximately with the adjacent portions of the cutter assembly 90. skirt 50 of support arm 32 has a similar radius of curvatures.

For the purposes of the present patent application, the term "skirt portion" is used to describe the portion of the outer surface 104 of the support arm 80 which extends from the opening 110 to the skirt 106. For the drill 20, the The skirt portion is generally defined as the part of the outer surface 54 that extends from the opening 48 to the skirt 50.

For the purposes of the present application, the term "coating" is used to refer to a layer of material which has been applied to a substrate to protect the substrate from abrasion, erosion and / or wear. Several binders such as cobalt, nickel, copper, iron and alloys thereof must be used to form the matrix or the binder part of the deposit. Various metal alloys, ceramic alloys and cermets, such as metal borides, metal carbides, metal oxides and metal nitrides can be included as part of the matrix deposit according to the teachings of the present invention. Some of the most beneficial metal alloys, ceramic alloys and cermets will be discussed later in May detail. The hard coating can also be mentioned as a "matrix deposit".

For the purposes of the present application, the term "tungsten carbide" includes the carbide of monotungsten (WC), the carbide of ditungsten (W2C), the tungsten carbide macro crystalline and the sintered tungsten carbide is increased. The sintered tungsten carbide is typically made from a mixture of tungsten carbide and cobalt d powders by pressing the powder mixture to form a compact green. Various cobalt alloy powders can be included.

The hard coating layer 108 can be formed satisfactorily using the hard ceramic particles and / or the hard particles formed from the super abrasive and the hard materials commonly found as phases in the boron-carbon-nitrogen-siliceous family of the alloy compounds. .

Examples of materials that can be used successfully to form the hard coat layer 10 include diamonds, silicon nitride (Si3N4), silicon carbide (SiC), boron carbide, (B4C) in addition to the cubic boron nitride (CBN). The various materials include cobalt, copper, nickel, iron and alloys and these elements can also be used to form the hard coating layer 108 For example, metal borides, metal carbides, metal oxides and the nitrides of metal or other super-abrasive and super-hard materials can be used to form all or a part of the hard coating layer 108. Depending on the intended application for the hard coating layer 108, various types of carbides can be used. tungsten to form all or a part of them.

A wide variety of hardcoat materials have been used successfully on drill bits and other deep hole tools. A frequently used hard coating includes the sintered tungsten carbide particles in a steel alloy matrix reservoir. Other forms of tungsten carbide particles may include grains of monotungsten carbide, bitungsten carbide and macro crystalline tungsten carbide. Satisfactory binders may include materials such as cobalt d, iron, nickel, iron alloys and other metal alloys. For some applications, the loose hard coating material is generally placed in a hollow tube or welding rod and applied to the substrate using conventional welding techniques. As a result of the welding process, a matrix deposit including both the molten steel alloy of the substrate surface and the steel alloy provided by the welding rod or the hollow tube is formed with the hard coating. Several cobalt, nickel and / or steel alloys can be used as a couple of the binder for the matrix deposit. Other heavy metal nitride carbides, in addition to tungsten carbide, can be used to form the hard coating.

ADDITIONAL COMMENTS The basic embodiment of the invention consists of a rolling rotating cone drill bearing arrangement with exception of the notch and function of the arm bearing thrust flange and the relative position of the ball bearings.

The invention optimizes the axial location of the ball bearing bushes to provide a maximum thrust and radial capacity of the bearing system. This configuration provides sufficient radial surface area of the arm thrust flange to serve as a complementary contact surface of the primary journal bearing.

The invention can also be applied to alternating bearing configurations using a wide variety of devices other than ball bearings to retain a cutter cone assembly on a spindle.

Most rotary cone bits sized up to about 12 folds and 1/4 inch diameter typically have a "friction-ball-friction" bearing geometry. The cylindric friction surfaces support the radial loads imposed on the bit, while the ball bearings resist the thrust forces.

It has been conventionally normal to place the arm ball bushing at some minimum essence distance from the thrust flange to provide the greatest possible spreading between the ball bearing and the seal. This expansion defines the contact area of the primary journal bearing only since the cylindrical surface area of the relatively thin thrust flange is insufficient to act as a load bearing surface, the radial space being provided in this region.

The secondary stump bearing is provided to fit within the balance of the available envelope.

The separations that run from the primary trunnion hub are generally slightly closer than that of the secondary trunnion to ensure that the smaller member n is overloaded.

In the new invention it provides a better one by placing the ball bearing closer to the seal thereby sufficiently increasing the cylindrical area of the arm thrust flange to serve as a radial load bearing surface. This increases the total surface area of the primary journal bearing compared to prior art designs. In addition, the effective extension of the primary journal is appreciably increased to improve bearing stability while tumbling loads are encountered. This added rigidity decreases the angular misalignment while reducing the bending stresses in the secondary stump.

Although the present invention has been described through various embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications, all of which fall within the scope of the appended claims.

Claims (17)

R E I V I N D I C A C I O N S

1. A rotating cone bit having a drill body with an upper part adapted for connection to a drill string for the rotation of the bit to form a deep hole, comprising: a number of support arms attached to extending from the drill body opposite to the upper part, each of the support arms has an inner surface with the respective spindle connected thereto; each spindle is generally projected downward inward with respect to its associated support arm; a number of cutter cone assemblies equal to number of support arms with each cut cone assembly rotatably mounted on a respective spindle; a first outer diameter part and a second inner diameter part formed on the outside of each spindle with the first outer diameter part and the second outer diameter part formed generally concentric with the axis of the effective spindle; an opening formed in the surface of each support arm with a ball retaining conduit extending from the opening on the outside of the support arm a space between the first outer diameter part and the second outer diameter part of the associated spindle whereby the ball bearings can be inserted through the aperture and ball retainer conduit to rotatably secure each cutter cone assembly about its respective spindle; the first outer diameter portion of each hus provides at least one radial bearing component positioned between the spindle and the cavity; in the second outer diameter portion of the hus provides at least one component of a second radial cushion positioned between the outside of the spindle and the adjacent portions of the cavity; the first outer diameter part has approximately the same diameter as the second outer diameter part; Y an opening from the ball retainer conduit positioned between the first outer diameter portion of the spindle and the second outer diameter portion of the spindle.

2. The drill bit as claimed in clause 1 characterized in that it also comprises: the first outer diameter part of the hus positioned on one side of the inner surface of the associated supporting arm; Y the second part of external diameter of the hus placed on the side of the shoulder formed on the shoulder formed on the outside of this spindle.

3. The drill bit as claimed in clause 2 characterized by the shoulder comprises at least one component of the thrust bearing placed between the spindle and the adjacent parts of the cavity.

4. The drill as claimed in clause 1 further characterized because it comprises: the first outer diameter part of the spindle having a first length; the second part of the outer diameter of the hus having a second length; and the value of the second length has a range between approximately 25% of the first length and equal to greater than that of the first length.

5. The drill as claimed in clause 1 characterized in that each support arm also comprises: each of the support arms has a front edge, a tail edge and an outer surface placed between them; a ball plug weld positioned within the opening to form a fluid barrier between the ball retainer and the outer surface of the respective sounder arm; the outer surface of each supporting arm has a skirt portion; Y a layer of coating material placed on the skirt part.

6. The drill bit as claimed in clause 5 characterized in that each support arm further comprises a plurality of inserts placed on the outer surface of each support arm.

7. The drill bit as claimed in clause 5 characterized in that the coating material dur is selected from the group consisting of borides of metal, metal carbides, metal oxides and metal nitrides.

8. The drill bit as claimed in clause 5 characterized in that the coating layer dur is formed of at least in part of materials selected from the group consisting of boron, carbon, copper, nickel, cobalt iron, carbides, nitrides, borides , silicides and oxides of tungsten, niobium, vanadium, molybdenum, titanium, tantalum, yttrium hafnium, zirconium, chromium, and mixtures thereof.

9. The drill bit as claimed in clause 1 further characterized in that it comprises each hus having an axis extending therethrough, the quad corresponds generally to the axis of rotation for the set d associated cutter cone.

10. The drill bit as claimed in clause 1 further characterized in that it comprises: a third part of outer diameter formed on the outside of each spindle with the outer diameter part located on one side of one end of the opposite spindle from the supporting arm ,- Y a shoulder formed on the outside of the spindle between the second part of outer diameter and the third part d diameter.

11. The drill bit as claimed in clause 1 further characterized in that it comprises the man formed from the inside of each spindle providing at least one component of a thrust bearing placed between the spindle and the cavity.

12. The drill bit as claimed in clause 1 characterized in that it also comprises: each spindle having an opposite end from the respective support arm; Y the end of each spindle provides at least one component of a thrust bearing positioned between the spindle and the cavity.

13. The drill bit as claimed in clause 1, characterized in that it also comprises: the cavity of each cutter cone assembly q has an opening with a seal ring placed inside the respective cavity on one side of the opening, - and an enlarged outer diameter formed on the outside of each spindle between the first outer effective diameter part and the inner surface of the respective sounder arm, whereby the outer diameter enlarged part of the ring cooperate with each other to form a barrier to the flow between the cavity and the outside of the cutter cone assembly.

14. A rotating cone drill that includes: a trunnion having the first, second and third trunnion bearing surfaces, said first and second trunnion bearing surfaces having essentially equal diameters, said third trunnion bearing surface having a smaller diameter than said first trunnion bearing surfaces and second.

15. The rotating cone bit as claimed in clause 14 characterized in that the first and second die bearing surface are separated by a ball bushing for the ball bearings.

16. A rotating cone bit comprising A cone part, which rotates around bearing, said bearing comprises: a first diary bearing part of the adjacent sealing ring; a retaining portion adjacent said first trunnion bearing; a second bearing being on a retention portion side opposite said first trunnion bearing; the first and second die bearings have essentially equal diameters; said second die bearing has an axial length, which is at least 25% of the axial extension of the first die bearing.

17. The rotary cone bit as claimed in clause 16 characterized in that the first and second journal bearing surfaces are separated by a ball bushing for the ball bearings. SUMMARY A rotating cone drill to form a deep hole having a drill body with a top part adapted to connect to a drill string. A number of support arms extend from the broach body with each support arm having an outer surface with an opening extending therethrough. A number d cone sets cutters equal to the number of support arms with each cutter cone assembly rotatably mounted on a respective spindle that projects generally downward and inward from each support arm. A ball retention duct extending from the opening in the outer surface of each support arm to allow the installation of ball bearings through the ball retention duct to rotatably mount each cutter cone assembly on its respective spindle. A bolt bushing formed on the outside of each spindle between a first part d outer diameter and a second part outer diameter. The ball retainer conduit intersects the ball bushing. The first outer diameter portion and the second outer diameter portion provide radial bearing portions for rotatably mounting each cutter cone assembly on its respective hus. The first part of outer diameter and the second part of outer diameter have approximately the same diameter in relation to an axis extending through the spindle.