CA1090775A - Rotary drill bit with rotary cutter - Google Patents
Rotary drill bit with rotary cutterInfo
- Publication number
- CA1090775A CA1090775A CA328,775A CA328775A CA1090775A CA 1090775 A CA1090775 A CA 1090775A CA 328775 A CA328775 A CA 328775A CA 1090775 A CA1090775 A CA 1090775A
- Authority
- CA
- Canada
- Prior art keywords
- drill bit
- trunnion
- rotary
- bit body
- rotary cutter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/08—Roller bits
- E21B10/20—Roller bits characterised by detachable or adjustable parts, e.g. legs or axles
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/08—Roller bits
- E21B10/22—Roller bits characterised by bearing, lubrication or sealing details
Abstract
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 pro-vided 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.
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 pro-vided 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.
Description
BACKGROUND OF THE INVENTION
:
The present invention relates to drilling apparatus used in the exploration of underground petroleum reserves and more specifically to a rotary drill bit having a plurality of rotary cutters supported for rotation - on the drill bit body by a plurality of rolling elements, the rolling elements being laterally guided at least at their axial ends facing the drill bit body in a radially disposed outer bearing race groove incorporated in the bore of the rotary cutter.
; Rotary drill bits having conically shaped rotary cutters are known wherein the rotary cutters are supported on a trunnion formed integrally with the drill bit body and a radial roller bearing. The rollers of this bearing are laterally guided in a bearing race groove in the bore of the rotary cut-' ter and supported in place at their axial ends facing away from the drill bit body by means of a flange bolt secured in the trunnion so that each rotary cutter is mounted in a manner preventing removal from the trunnion.
. , .
An arrangement of this type is shown in the British Patent No. 456,570. This kn~wn assembly has several disadvantages and drawbacks. For example, the ~ -construction requires that the flange bolt be shaped in the form of a race ,i element for the axial bearing of the rotary cutter and be made of an expensive bearing material. In order to mount the flange bolt in a precise manner in the trunnion, the bolt has to be machined with close tolerances.
Thus, the method of manufacturing is relatively costly. Additionally, a center bore with a relatively large diameter must be provided in the trunnion ` to receive the highly stressed flange bolt and accordingly, the trunnion of the drill bit body is somewhat weakened and consequently there is the risk of trunnion failure by breakage especially in heavy duty operations ` In accordance with another known rotary drill bit assembly, the rotary cutters are each supported on a trunnion connected in one piece with the drill bit body in a radial roller bearing with conical roller elements.
-: . .: . - -. .- . . -" ' ' ' . ' ' ' ' ' ''~ ' ' ' " ' ' :
... . .
,, ' ' .
-This arrangement is shown in United States Patent No. 2,076,000. This arrangement has the advantage of providing a trunnion which is relatively rigid and possesses good load bearing characteristics. However, a so-called edge ring is required which is located in the bore of the rotary cutter on the side of the roller elements facing the drill bit body which axially guides the roller elements to support the rotary cutter in place on the trunnion. It has been found that the fabrication of the rotary cutter is rather expensive because of the incorporation of the additional edge ring.
Furthermore, in heavy duty operations with high impact stresses, it has been observed that a loosening of the edge ring may result and accordingly, pre-sents the disadvantage that the rotary cutter is not adequately secured against being drawn off the trunnion.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is an object of the present inven-tion to provide an improved rotary drill bit which is characterized by novel features of construction and arrangement including a novel mounting arrange-ment for the cutting rollers which are held in place securely and in an impact resistant manner preventing withdrawal from the trunnion via the rolling elements of at least one of the roller bearings. This produces a comparative-ly simplified construction which is easily fabricated.
The invention provides a rotary drill blt having a drill bit body, at least one cantilevered trunnion projecting from thé drill bit body, and a rotary'cutter supported on at least one radial roller bearing on the trunnion, said radial roller bearing lncluding roller elements received between an outer race bearing groove in said rotary cutter and an inner race bearing groove on said trunnion, said roller elements having first axial ends which face the drill bit body and are engaged and guided by a continuous annular radially-inwardly projecting shoulder on the rotary cutter, and having second ~ -2--, .. . .
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.
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axial ends engaged and guided by a continuous annular shoulder on the trunnion, and means defining at least one filling opening for insertion of said roller elements, said filling opening extending essentially axially through the drill bit body and trunnion and having one terminal end adjacent the inner race bearing groove and at least one filler piece for sealing the opening.
A rotary drill bit constructed in accordance with the present invention assures that the rolling elements of the radial roller bearings guided between the edges of the inside bearing race groove, are firmly supported on the trunnion and are laterally held in place. In this manner there is no danger of seizing of the bearing race groove edges. The filling opening for insertion of the rolling elements is of comparatively small diameter and does not detract appreciably from the stength of the trunnion. The trunnion of each rotary cutter may be constructed in one piece with the drill bit body thus providing a further simplification of the fabrication and assembly of the roller bit since the assembly comprises relatively few parts. These parts are comparatively easy to machine so that the fabrication and assembly of the rotary drill bit is simple and economical.
` The outside bearing race groove in the rotary cutter as well as the inside bearing race groove on the trunnion of the radial roller bearings can have a relatively large groove depth providing a good lateral guidance of the rolling elements and strong impact resistant edges of the bearing race grooves.
The filling openlng for the rolling elements in the trunnion is of optimally small cross section and does not harmfully effect the good strength character-istics of the trunnion.
The filling opening disposed in the machined bearing race groove is preferably located in the unstressed zone of the radial roller bearing so that the load bearing ability of the radial roller bearing is not effected ~, ~ .:
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by this filling opening. Additionally, the filling opening is adjacent the ' inside heavy walled portion of a drill bit body so that a relatively strong break-proof connection is guaranteed between the trunnion and drill bit body.
he outside peripheral surf~ce of the trun=ion can be ~upplettnted ,.
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by the correspondingly shaped end surface of the filler piece in such a manner that harmful holes and discontinuities are not present in this outside surface.
The specific construction of the filler piece completely seals to complement the inside bearing race groove at the filling opening location ~ithout dis-turbing the rolling kinematics of the rolling elements.
Various features and details of the operation and construction of the present invention are hereinafter more fully set forth with reference to the accompanying drawings, wherein:
Figure 1 is a fragmentary, longitudinal sectional view through an embodiment of the rotary cutter supported on a trunnion of a rotary drill bit in accordance with the present invention;
J Figure 2 is an enlarged transverse fragmentar~ sectional view taken on lines A-A of Figure l;
DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the drawings and particularly to Figure 1 thereof, there is illustrated one of a plurality of conical rotary cutters of a rotary drill bit constructed in accordance with the present invention. As illus-trated, the rotary cutter which is generally designated by the numeral 1 is rotatably supported on the trunnion 3, which, in the present instance, is formed integrally with the drill bit body 2. The bearing support illustrated includes an outer roller bearing 4 with cylindrical rolling elements 7, an inner radial bearing 5 with cylindrical rolling elements and intermediate axial bearing 6 with conical rolling elements. The rollers 7 of the outer radial roller bearing 4 facing the drill bit body run in the base of the outer bearing race groove 8 formed radially in the rotary cutter 1. The axial end face of the Tollers 7 which face the drill bit body 2 are guided by a radially inwardly directed shoulder 9 of the bearing race groove 8 which as illustrated is formed integrally with the rotary cutter 1. The trunnion is formed with a bearing race groove 10 for the rollers 7 of the .' ' .
radial bearing 4 so that rollers 7 are guided and held in place on both sides in the bearing race groove 10. By this construction, the rotary cutter 1 is secured against being drawn off the trunnion 3 by the shoulder 9 and the rollers 7. The inner end of the rotary cutter is provided with a pocket opposite the shoulder 9 to receive an annular seal 11 which as illustrated ,~
engages and slides on the opposite confronting front surface of the drill bit body 2 to seal the entire bearing space of the rotary cutter against in-gress of foreign matter from the outside of the assembly.
J Means is provided for filling the outer radial bearing with the rollers via the trunnion. To this end~ an axially extending filling opening 12, in the present instance, of circular cross section is bored in the trunnion 3 and extends from the outer end face of the rotary cutter 1 to the c, bearing groove 10. This filler opening 12 is sealed with a filler piece 13. The filler piece 13 as illustrated in Figures 1 and 2 is of a predeter-mined cross section to fill the opening in the drill bit body and at its '.1' l inner end is of half moon cross section having a surface 14 which blends ;` smoothly with the bearing race groove 10 to effectively form a smooth continuous bearing race groove surface for the rollers 7. As is clear, dis-continuities and holes interrupting the bearing race groove are, therefore, not present.
The filler piece is locked in place in a predetermined position i so that the surface 14 confronting the rollers blends smoothly with the i~ bearing race groove 10 and to this end a cylindrical lock pin 15 is provided ~,~ between the filler piece 13 and the filling opening 12 uhich as illustrated ¦ fits tightly and runs in an axial direction between the filler piece 13 and the opening 12 in a manner preventing twisting or rotation of the filler ~ piece in the filling opening.
`~1 The shoulder 9 of the rotary cutter 1 extends radially inwardly ~~ closely adjacent the outer peripheral surface 16 of the trunnion adjacent . . - -,. - - . , ., .
1. .
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the drill bit body to form a bore on the sides of the rollers 7 facing the drill bit body and form a sealing slot between them. At the same time, the bearing race groove 8 in the rotary cutter 1 as well as the bearing race groove 10 in the trunnion 3 have a fairly large radial depth which is advan-tageous in that the rollers 7 are laterally guided and securely held in place by the relatively large or high faces of the shaulder 9 and the bearing race groove 10.
In order to accommodate the optimum guide and support or the rollers and also allow for ease of assembly, the radial distance 17 of the filling opening is preferably the same siæe or slightly larger than the diameter of the cylindrical rollers 7 so that the rollers 7 on assembly through the filling opening can be advanced under the shoulder 9 into the bearing race groove of the trunnion 3. In loading the assembly, the rollers 7 are advanced one after another from there, radially outward into the out-side bearing race groove 8 of the rotary cutter 1 and uniformly distributed at the periphery of the rotary cutter 1 simply by rotating it. After a full complement has been inserted into the bearing in the manner described, the filler piece 13 is inserted into the filling opening to seal the same and thereafter the lock pin 15 is pressed into place between the filler piece 13 and the filling opening 12 to prevent twisting of the filler piece as noted above ensure perfect alignment of the surface 14 with the race groove surface 10. To further lock the assembly, the filler 13 may be welded to the drill bit body at the filling end of the opening.
The rotary drill bit according to the invention has a distinct advantage that it is equipped with rotary cutters in a simple economic fabrica-tion, which are held in place securely and impact resistant against being drawn off their trunnion via the roller bodies of at least one radial roller bearing.
Moreover, the rotary drill bit according to the invention is not . . ~ . , .
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limited to the above described exemplified embodiment. It can rather be modified within the scope of the basic concept of the invention. The rolling elements of the radial roller bearing may have a convexly shaped or a tapered contour. The rolling elements of the individual roller bearings do not have to be constructed without a cage, in other words, rolls or spheres, they can rather be guided by conventional cages, segments or spacers.
Even though the filler piece of the illustrated embodiment o~ the invention is held in a fixed correct angular position in the filler opening by means of the lock pin 15, other arrangements are possible to locate the filler so that the surface 14 blends smoothly with the inner raceway surface 10 of the bearing 7. For example, the filler opening and the filler piece may be at least in part of a complementary non-circular cross section, for example, rectangular, thereby to hold the filler piece against rotation in the opening. Alternatively, the filler piece may have radial openings in which set screws or similar securing members engage and which are inserted through the roller bit body. Additionally, note that the inner axial end face of the filler piece remote from the rolling elements is biased or slanted relative to the filler piece axis in order to be flush with the plane of the drill bit body contour and in this position, the surface 14 of the filler piece defining apportion of the raceway 10 for the rolling elements of bearing 7 blend smoothly with the raceway. Accordingly, any angular displacement of the filler piece in the opening from this position would show itself on the surface of the drill bit body, i.e. the axial end face of the filler piece would then at least partly protrude out of the plane of the drill bit body.
This would, of course, be visual indicia of incorrect positioning of the filler piece in the opening and would indeed cause difficulty in providing the weldment holding the filler piece in place.
"
:
The present invention relates to drilling apparatus used in the exploration of underground petroleum reserves and more specifically to a rotary drill bit having a plurality of rotary cutters supported for rotation - on the drill bit body by a plurality of rolling elements, the rolling elements being laterally guided at least at their axial ends facing the drill bit body in a radially disposed outer bearing race groove incorporated in the bore of the rotary cutter.
; Rotary drill bits having conically shaped rotary cutters are known wherein the rotary cutters are supported on a trunnion formed integrally with the drill bit body and a radial roller bearing. The rollers of this bearing are laterally guided in a bearing race groove in the bore of the rotary cut-' ter and supported in place at their axial ends facing away from the drill bit body by means of a flange bolt secured in the trunnion so that each rotary cutter is mounted in a manner preventing removal from the trunnion.
. , .
An arrangement of this type is shown in the British Patent No. 456,570. This kn~wn assembly has several disadvantages and drawbacks. For example, the ~ -construction requires that the flange bolt be shaped in the form of a race ,i element for the axial bearing of the rotary cutter and be made of an expensive bearing material. In order to mount the flange bolt in a precise manner in the trunnion, the bolt has to be machined with close tolerances.
Thus, the method of manufacturing is relatively costly. Additionally, a center bore with a relatively large diameter must be provided in the trunnion ` to receive the highly stressed flange bolt and accordingly, the trunnion of the drill bit body is somewhat weakened and consequently there is the risk of trunnion failure by breakage especially in heavy duty operations ` In accordance with another known rotary drill bit assembly, the rotary cutters are each supported on a trunnion connected in one piece with the drill bit body in a radial roller bearing with conical roller elements.
-: . .: . - -. .- . . -" ' ' ' . ' ' ' ' ' ''~ ' ' ' " ' ' :
... . .
,, ' ' .
-This arrangement is shown in United States Patent No. 2,076,000. This arrangement has the advantage of providing a trunnion which is relatively rigid and possesses good load bearing characteristics. However, a so-called edge ring is required which is located in the bore of the rotary cutter on the side of the roller elements facing the drill bit body which axially guides the roller elements to support the rotary cutter in place on the trunnion. It has been found that the fabrication of the rotary cutter is rather expensive because of the incorporation of the additional edge ring.
Furthermore, in heavy duty operations with high impact stresses, it has been observed that a loosening of the edge ring may result and accordingly, pre-sents the disadvantage that the rotary cutter is not adequately secured against being drawn off the trunnion.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is an object of the present inven-tion to provide an improved rotary drill bit which is characterized by novel features of construction and arrangement including a novel mounting arrange-ment for the cutting rollers which are held in place securely and in an impact resistant manner preventing withdrawal from the trunnion via the rolling elements of at least one of the roller bearings. This produces a comparative-ly simplified construction which is easily fabricated.
The invention provides a rotary drill blt having a drill bit body, at least one cantilevered trunnion projecting from thé drill bit body, and a rotary'cutter supported on at least one radial roller bearing on the trunnion, said radial roller bearing lncluding roller elements received between an outer race bearing groove in said rotary cutter and an inner race bearing groove on said trunnion, said roller elements having first axial ends which face the drill bit body and are engaged and guided by a continuous annular radially-inwardly projecting shoulder on the rotary cutter, and having second ~ -2--, .. . .
:
.
7 ~
axial ends engaged and guided by a continuous annular shoulder on the trunnion, and means defining at least one filling opening for insertion of said roller elements, said filling opening extending essentially axially through the drill bit body and trunnion and having one terminal end adjacent the inner race bearing groove and at least one filler piece for sealing the opening.
A rotary drill bit constructed in accordance with the present invention assures that the rolling elements of the radial roller bearings guided between the edges of the inside bearing race groove, are firmly supported on the trunnion and are laterally held in place. In this manner there is no danger of seizing of the bearing race groove edges. The filling opening for insertion of the rolling elements is of comparatively small diameter and does not detract appreciably from the stength of the trunnion. The trunnion of each rotary cutter may be constructed in one piece with the drill bit body thus providing a further simplification of the fabrication and assembly of the roller bit since the assembly comprises relatively few parts. These parts are comparatively easy to machine so that the fabrication and assembly of the rotary drill bit is simple and economical.
` The outside bearing race groove in the rotary cutter as well as the inside bearing race groove on the trunnion of the radial roller bearings can have a relatively large groove depth providing a good lateral guidance of the rolling elements and strong impact resistant edges of the bearing race grooves.
The filling openlng for the rolling elements in the trunnion is of optimally small cross section and does not harmfully effect the good strength character-istics of the trunnion.
The filling opening disposed in the machined bearing race groove is preferably located in the unstressed zone of the radial roller bearing so that the load bearing ability of the radial roller bearing is not effected ~, ~ .:
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~' "' - ' ' ,' . . "' ' ' ''',"" . ' :
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V~7~
by this filling opening. Additionally, the filling opening is adjacent the ' inside heavy walled portion of a drill bit body so that a relatively strong break-proof connection is guaranteed between the trunnion and drill bit body.
he outside peripheral surf~ce of the trun=ion can be ~upplettnted ,.
' ' , . .
~ -3a-~ . . . .
. .
.. ,, ' ' , :
0~7~
by the correspondingly shaped end surface of the filler piece in such a manner that harmful holes and discontinuities are not present in this outside surface.
The specific construction of the filler piece completely seals to complement the inside bearing race groove at the filling opening location ~ithout dis-turbing the rolling kinematics of the rolling elements.
Various features and details of the operation and construction of the present invention are hereinafter more fully set forth with reference to the accompanying drawings, wherein:
Figure 1 is a fragmentary, longitudinal sectional view through an embodiment of the rotary cutter supported on a trunnion of a rotary drill bit in accordance with the present invention;
J Figure 2 is an enlarged transverse fragmentar~ sectional view taken on lines A-A of Figure l;
DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the drawings and particularly to Figure 1 thereof, there is illustrated one of a plurality of conical rotary cutters of a rotary drill bit constructed in accordance with the present invention. As illus-trated, the rotary cutter which is generally designated by the numeral 1 is rotatably supported on the trunnion 3, which, in the present instance, is formed integrally with the drill bit body 2. The bearing support illustrated includes an outer roller bearing 4 with cylindrical rolling elements 7, an inner radial bearing 5 with cylindrical rolling elements and intermediate axial bearing 6 with conical rolling elements. The rollers 7 of the outer radial roller bearing 4 facing the drill bit body run in the base of the outer bearing race groove 8 formed radially in the rotary cutter 1. The axial end face of the Tollers 7 which face the drill bit body 2 are guided by a radially inwardly directed shoulder 9 of the bearing race groove 8 which as illustrated is formed integrally with the rotary cutter 1. The trunnion is formed with a bearing race groove 10 for the rollers 7 of the .' ' .
radial bearing 4 so that rollers 7 are guided and held in place on both sides in the bearing race groove 10. By this construction, the rotary cutter 1 is secured against being drawn off the trunnion 3 by the shoulder 9 and the rollers 7. The inner end of the rotary cutter is provided with a pocket opposite the shoulder 9 to receive an annular seal 11 which as illustrated ,~
engages and slides on the opposite confronting front surface of the drill bit body 2 to seal the entire bearing space of the rotary cutter against in-gress of foreign matter from the outside of the assembly.
J Means is provided for filling the outer radial bearing with the rollers via the trunnion. To this end~ an axially extending filling opening 12, in the present instance, of circular cross section is bored in the trunnion 3 and extends from the outer end face of the rotary cutter 1 to the c, bearing groove 10. This filler opening 12 is sealed with a filler piece 13. The filler piece 13 as illustrated in Figures 1 and 2 is of a predeter-mined cross section to fill the opening in the drill bit body and at its '.1' l inner end is of half moon cross section having a surface 14 which blends ;` smoothly with the bearing race groove 10 to effectively form a smooth continuous bearing race groove surface for the rollers 7. As is clear, dis-continuities and holes interrupting the bearing race groove are, therefore, not present.
The filler piece is locked in place in a predetermined position i so that the surface 14 confronting the rollers blends smoothly with the i~ bearing race groove 10 and to this end a cylindrical lock pin 15 is provided ~,~ between the filler piece 13 and the filling opening 12 uhich as illustrated ¦ fits tightly and runs in an axial direction between the filler piece 13 and the opening 12 in a manner preventing twisting or rotation of the filler ~ piece in the filling opening.
`~1 The shoulder 9 of the rotary cutter 1 extends radially inwardly ~~ closely adjacent the outer peripheral surface 16 of the trunnion adjacent . . - -,. - - . , ., .
1. .
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the drill bit body to form a bore on the sides of the rollers 7 facing the drill bit body and form a sealing slot between them. At the same time, the bearing race groove 8 in the rotary cutter 1 as well as the bearing race groove 10 in the trunnion 3 have a fairly large radial depth which is advan-tageous in that the rollers 7 are laterally guided and securely held in place by the relatively large or high faces of the shaulder 9 and the bearing race groove 10.
In order to accommodate the optimum guide and support or the rollers and also allow for ease of assembly, the radial distance 17 of the filling opening is preferably the same siæe or slightly larger than the diameter of the cylindrical rollers 7 so that the rollers 7 on assembly through the filling opening can be advanced under the shoulder 9 into the bearing race groove of the trunnion 3. In loading the assembly, the rollers 7 are advanced one after another from there, radially outward into the out-side bearing race groove 8 of the rotary cutter 1 and uniformly distributed at the periphery of the rotary cutter 1 simply by rotating it. After a full complement has been inserted into the bearing in the manner described, the filler piece 13 is inserted into the filling opening to seal the same and thereafter the lock pin 15 is pressed into place between the filler piece 13 and the filling opening 12 to prevent twisting of the filler piece as noted above ensure perfect alignment of the surface 14 with the race groove surface 10. To further lock the assembly, the filler 13 may be welded to the drill bit body at the filling end of the opening.
The rotary drill bit according to the invention has a distinct advantage that it is equipped with rotary cutters in a simple economic fabrica-tion, which are held in place securely and impact resistant against being drawn off their trunnion via the roller bodies of at least one radial roller bearing.
Moreover, the rotary drill bit according to the invention is not . . ~ . , .
~0~307J 7~
limited to the above described exemplified embodiment. It can rather be modified within the scope of the basic concept of the invention. The rolling elements of the radial roller bearing may have a convexly shaped or a tapered contour. The rolling elements of the individual roller bearings do not have to be constructed without a cage, in other words, rolls or spheres, they can rather be guided by conventional cages, segments or spacers.
Even though the filler piece of the illustrated embodiment o~ the invention is held in a fixed correct angular position in the filler opening by means of the lock pin 15, other arrangements are possible to locate the filler so that the surface 14 blends smoothly with the inner raceway surface 10 of the bearing 7. For example, the filler opening and the filler piece may be at least in part of a complementary non-circular cross section, for example, rectangular, thereby to hold the filler piece against rotation in the opening. Alternatively, the filler piece may have radial openings in which set screws or similar securing members engage and which are inserted through the roller bit body. Additionally, note that the inner axial end face of the filler piece remote from the rolling elements is biased or slanted relative to the filler piece axis in order to be flush with the plane of the drill bit body contour and in this position, the surface 14 of the filler piece defining apportion of the raceway 10 for the rolling elements of bearing 7 blend smoothly with the raceway. Accordingly, any angular displacement of the filler piece in the opening from this position would show itself on the surface of the drill bit body, i.e. the axial end face of the filler piece would then at least partly protrude out of the plane of the drill bit body.
This would, of course, be visual indicia of incorrect positioning of the filler piece in the opening and would indeed cause difficulty in providing the weldment holding the filler piece in place.
"
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A rotary drill bit having a drill bit body, at least one cantilevered trunnion projecting from the drill bit body, and a rotary cutter supported on at least one radial roller bearing on the trunnion, said radial roller bearing including roller elements received between an outer race bearing groove in said rotary cutter and an inner race bearing groove on said trunnion, said roller elements having first axial ends which face the drill bit body and are engaged and guided by a continuous annular radially-inwardly projecting shoulder on the rotary cutter, and having second axial ends engaged and guided by a continuous annular shoulder on the trunnion, and means defining at least one filling opening for insertion of said roller elements, said filling opening extending essentially axially through the drill bit body and trunnion and having one terminal end adjacent the inner race bearing groove and at least one filler piece for sealing the opening.
2. A rotary drill bit as claimed in Claim 1 wherein said annular shoulder defines a bore in the rotary cutter on the side thereof facing the drill bit body and disposed opposite a peripheral surface of the trunnion, the radial distance between the wall of the filling opening and the surface of this bore being at least as large as the maximum diameter of said roller elements.
3. A rotary drill bit as claimed in Claim 1 wherein the filling opening is disposed in an unstressed zone of the radial roller bearing.
4. A rotary drill bit as claimed in Claim 1, 2 or 3 wherein the filler piece has a contour conforming to the outside surface of the trunnion to blend smoothly therewith.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2823698.8 | 1978-05-31 | ||
| DE2823698A DE2823698C2 (en) | 1978-05-31 | 1978-05-31 | Roller bit with a filling hole for bearing rollers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1090775A true CA1090775A (en) | 1980-12-02 |
Family
ID=6040594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA328,775A Expired CA1090775A (en) | 1978-05-31 | 1979-05-31 | Rotary drill bit with rotary cutter |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4256193A (en) |
| CA (1) | CA1090775A (en) |
| DE (1) | DE2823698C2 (en) |
| ZA (1) | ZA792655B (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4478299A (en) * | 1982-03-26 | 1984-10-23 | Trend Rock Bit Alberta, Ltd. | Rock bit construction |
| US4445791A (en) * | 1982-09-30 | 1984-05-01 | Klima Frank J | Rotary drill bit ball plug |
| US4793719A (en) * | 1987-11-18 | 1988-12-27 | Smith International, Inc. | Precision roller bearing rock bits |
| US5441120A (en) * | 1994-08-31 | 1995-08-15 | Dresser Industries, Inc. | Roller cone rock bit having a sealing system with double elastomer seals |
| US5513715A (en) * | 1994-08-31 | 1996-05-07 | Dresser Industries, Inc. | Flat seal for a roller cone rock bit |
| US5513711A (en) * | 1994-08-31 | 1996-05-07 | Williams; Mark E. | Sealed and lubricated rotary cone drill bit having improved seal protection |
| US5636700A (en) * | 1995-01-03 | 1997-06-10 | Dresser Industries, Inc. | Roller cone rock bit having improved cutter gauge face surface compacts and a method of construction |
| US5709278A (en) * | 1996-01-22 | 1998-01-20 | Dresser Industries, Inc. | Rotary cone drill bit with contoured inserts and compacts |
| US5722497A (en) * | 1996-03-21 | 1998-03-03 | Dresser Industries, Inc. | Roller cone gage surface cutting elements with multiple ultra hard cutting surfaces |
| SE516079C2 (en) | 1998-12-18 | 2001-11-12 | Sandvik Ab | Rotary drill bit |
| GB2380500A (en) * | 2001-10-05 | 2003-04-09 | Varel International Inc | Rotary cone bit with thrust bearing |
| US7798254B2 (en) * | 2008-01-03 | 2010-09-21 | Atlas Copco Secoroc Llc | Earth bit with hub and thrust units |
| US8353369B2 (en) * | 2008-08-06 | 2013-01-15 | Atlas Copco Secoroc, LLC | Percussion assisted rotary earth bit and method of operating the same |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2104819A (en) * | 1935-03-09 | 1938-01-11 | Hughes Tool Co | Roller boring drill |
| GB456570A (en) * | 1935-06-25 | 1936-11-11 | Clarence Edward Reed | An improved roller cutter and bearing assembly for earth boring drills |
| DE671458C (en) * | 1935-06-25 | 1939-02-07 | Clarence Edward Reed | Cutting roller bearing for rotary drill bits |
| US2020625A (en) * | 1935-07-11 | 1935-11-12 | Guiberson Corp | Drill bit |
| US2060354A (en) * | 1935-08-01 | 1936-11-10 | Guiberson Corp | Drill bit |
| US2075999A (en) * | 1935-08-02 | 1937-04-06 | Chicago Pneumatic Tool Co | Roller cutter and antifriction bearing assembly for earth boring drills |
| US2076000A (en) * | 1935-08-06 | 1937-04-06 | Chicago Pneumatic Tool Co | Roller cutter and antifriction bearing assembly for earth boring drills |
| US2076001A (en) * | 1935-08-07 | 1937-04-06 | Chicago Pneumatic Tool Co | Roller cutter spindle and antifriction assembly |
| US2194675A (en) * | 1937-04-05 | 1940-03-26 | David C Vance | Drill bit |
| US2470695A (en) * | 1947-11-17 | 1949-05-17 | Globe Oil Tools Co | Cone type well drilling bit |
| US2595904A (en) * | 1948-05-06 | 1952-05-06 | Security Engineering Co Inc | Tricone rock bit |
| US2676790A (en) * | 1948-11-10 | 1954-04-27 | Turner Bits Inc | Rock bit |
| US3765495A (en) * | 1972-08-02 | 1973-10-16 | G W Murphey Ind Inc | Drill bit seals |
| DE2345002C2 (en) * | 1973-09-06 | 1983-04-21 | Reed Tool Co., Houston, Tex. | Sealing arrangement for roller bits for rock drilling |
-
1978
- 1978-05-31 DE DE2823698A patent/DE2823698C2/en not_active Expired
-
1979
- 1979-05-29 ZA ZA792655A patent/ZA792655B/en unknown
- 1979-05-29 US US06/042,924 patent/US4256193A/en not_active Expired - Lifetime
- 1979-05-31 CA CA328,775A patent/CA1090775A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ZA792655B (en) | 1980-06-25 |
| DE2823698A1 (en) | 1979-12-06 |
| DE2823698C2 (en) | 1981-09-17 |
| US4256193A (en) | 1981-03-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |