U.S. patent application number 15/972537 was filed with the patent office on 2018-09-06 for earth-boring tools including bearing element assemblies, and related methods.
The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to Michael L. Doster, Kenneth R. Evans, Jason E. Hoines, Oliver Matthews, Brian E. Miller, Chaitanya K. Vempati.
Application Number | 20180252044 15/972537 |
Document ID | / |
Family ID | 54538084 |
Filed Date | 2018-09-06 |
United States Patent
Application |
20180252044 |
Kind Code |
A1 |
Miller; Brian E. ; et
al. |
September 6, 2018 |
EARTH-BORING TOOLS INCLUDING BEARING ELEMENT ASSEMBLIES, AND
RELATED METHODS
Abstract
An earth-boring tool includes a body comprising a pocket in a
leading end thereof for accepting at least a portion of a bearing
element assembly. A bearing element assembly may be disposed within
the pocket, and the bearing element assembly may include a
retaining element at least partially disposed in a groove in a
sidewall of the pocket and a bearing element. The bearing element
may include a distal end having a bearing surface, a proximal end,
and a side surface between the distal end and the proximal end, the
side surface comprising a feature configured to abut the retaining
element, wherein mechanical interference between the feature and
the retaining element axially retains the bearing element within
the pocket. Methods include disengaging a mechanical retention
device retaining a bearing element within a pocket in a body of the
earth-boring tool, and removing the bearing element from the
pocket.
Inventors: |
Miller; Brian E.; (The
Woodlands, TX) ; Doster; Michael L.; (Spring, TX)
; Evans; Kenneth R.; (Spring, TX) ; Hoines; Jason
E.; (Spring, TX) ; Matthews; Oliver; (Spring,
TX) ; Vempati; Chaitanya K.; (Conroe, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated |
Houston |
TX |
US |
|
|
Family ID: |
54538084 |
Appl. No.: |
15/972537 |
Filed: |
May 7, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14276587 |
May 13, 2014 |
|
|
|
15972537 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 10/55 20130101;
E21B 10/42 20130101; E21B 10/633 20130101; Y10T 29/49732
20150115 |
International
Class: |
E21B 10/42 20060101
E21B010/42; E21B 10/633 20060101 E21B010/633; E21B 10/55 20060101
E21B010/55 |
Claims
1. An earth-boring tool, comprising: a body comprising a threaded
receptacle in a leading end thereof for accepting at least a
portion of a bearing element assembly; and a bearing element
assembly located within the threaded receptacle, the bearing
element assembly comprising: a holder with a receptacle at a distal
end thereof for receiving a bearing element and a threaded outer
surface at a proximal end thereof for engagement with the threaded
receptacle in the body of the earth-boring tool; and at least one
feature proximate the distal end of the holder configured to
interface with a tool configured to apply torque to the holder.
2. The earth-boring tool of claim 1, wherein the threaded
receptacle comprises a sleeve with an at least partially threaded
inner diameter and a generally smooth outer diameter, and the
sleeve is affixed within a pocket of the body.
3. The earth-boring tool of claim 2, further comprising a slot
extending from an exterior surface of the body to a portion of an
outer surface of the sleeve.
4. The earth-boring tool of claim 1, wherein the threaded outer
surface of the holder is configured substantially identically to an
outer surface of a nozzle insert for insertion in a fluid outlet
port in the body of the earth-boring tool.
5. The earth-boring tool of claim 4, wherein the bearing element
assembly comprises an internal fluid passageway in communication
with a fluid port in the body of the earth-boring tool and in
communication with one or more fluid outlets in a side surface of
the bearing element.
6. The earth-boring tool of claim 2, wherein the holder comprises a
conical portion, and the sleeve comprises a corresponding conical
surface on an inner surface thereof.
7. The earth-boring tool of claim 1, wherein the body of the
earth-boring tool comprises: a plurality of generally radially
projecting and longitudinally extending blades rotationally
separated by fluid courses; and at least one cutting element
attached to one of the plurality of blades.
8. The earth-boring tool of claim 7, wherein the bearing element is
a non-cutting bearing element positioned and oriented on the body
as a rubbing surface configured to rub against a formation as the
body of the earth-boring tool is rotated within a wellbore, the
bearing element assembly located rotationally behind the at least
one cutting element on the one of the plurality of blades.
9. The earth-boring tool of claim 7, wherein the bearing element
assembly is located within one of the fluid courses between
adjacent blades of the plurality of blades.
10. The earth-boring tool of claim 1, wherein the threaded
receptacle in the leading end of the body comprises a removal
access hole configured to receive the tool.
11. The earth-boring tool of claim 1, wherein the body of the
earth-boring tool comprises a metal alloy, and the threaded
receptacle comprises threads machined directly into an inner
surface of a cavity of the body.
12. The earth-boring tool of claim 1, wherein the bearing element
and the holder comprise an integral unitary body.
13. The earth-boring tool of claim 1, wherein the at least one
feature comprises surfaces of the bearing element assembly arranged
in a hexagonal pattern and configured to interface with a socket
wrench.
14. The earth-boring tool of claim 1, wherein the at least one
feature comprises at least one notch arranged around a periphery of
the holder, the at least one notch configured to receive
protrusions of the tool.
15. A method of replacing a bearing element of an earth-boring
tool, comprising: disengaging a mechanical retention device
retaining a first bearing element within a pocket in a body of the
earth-boring tool by rotating the bearing element relative to the
pocket to disengage threads on an outer surface of the bearing
element from threads in a sidewall of the pocket; removing the
first bearing element from the pocket; placing a second bearing
element in the pocket, wherein the second bearing element comprises
at least one of a shape of a bearing surface and an exposure of a
bearing surface different from the first bearing element; and
engaging the mechanical retention device to retain the second
bearing element within the pocket.
16. The method of claim 15, wherein disengaging the mechanical
retention device comprises applying a force to a surface of the
bearing element with a tool inserted in a removal access hole
extending through an exterior surface of the body and intersecting
the pocket.
17. The method of claim 16, wherein applying the force to the
surface of the bearing element with the tool inserted in the
removal access hole comprises inserting the tool into the removal
access hole extending through a leading end of the body.
18. The method of claim 15, wherein disengaging the mechanical
retention device comprises rotating the bearing element relative to
a sleeve within the pocket in the body of the earth-boring tool to
disengage the threads on the outer surface of the bearing element
from threads in an inner sidewall of the sleeve.
19. The method of claim 15, wherein: removing the first bearing
element comprises removing a first non-cutting bearing element; and
placing the second bearing element comprises placing a second
non-cutting bearing element, each of the first non-cutting bearing
element and the second non-cutting bearing element being positioned
and oriented on the body as a rubbing surface configured to rub
against a formation as the body of the earth-boring tool is rotated
within a wellbore.
20. The method of claim 15, wherein engaging the mechanical
retention device comprises securing the second bearing element with
a mechanical locking device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/276,587, filed May 13, 2014, pending. The subject
matter of this application is related to the subject matter of U.S.
patent application Ser. No. 15/155,470, filed May 16, 2016,
pending, titled "Earth-Boring Tools Including Formation-Engaging
Structures Having Retention Features and Related Methods," which is
a continuation of U.S. patent application Ser. No. 14/272,360,
filed May 7, 2014, now U.S. Pat. No. 9,359,826, issued Jun. 7,
2016, titled "Formation-Engaging Structures Having Retention
Features, Earth-Boring Tools Including Such Structures, and Related
Methods," to the subject matter of U.S. patent application Ser. No.
15/293,955, filed Oct. 14, 2016, pending, titled
"Formation-Engaging Assemblies, Earth-Boring Tools Including Such
Assemblies, and Associated Methods," which is a continuation of
U.S. patent application Ser. No. 14/272,369, filed May 7, 2014, now
U.S. Pat. No. 9,476,257, issued Oct. 25, 2016, titled
"Formation-Engaging Assemblies and Earth-Boring Tools Including
Such Assemblies," and to the subject matter of U.S. patent
application Ser. No. 14/933,908, filed Nov. 5, 2015, pending,
titled "Earth-Boring Tools Carrying Formation-Engaging Structures,"
pending, the disclosure of each of which is hereby incorporated
herein in its entirety by this reference.
TECHNICAL FIELD
[0002] Embodiments of the present disclosure relate to earth-boring
tools including bearing element assemblies, and related
methods.
BACKGROUND
[0003] Earth-boring tools are used to form boreholes (e.g.,
wellbores) in subterranean formations. Such earth-boring tools
include, for example, drill bits, reamers, mills, etc. For example,
a fixed-cutter earth-boring rotary drill bit (often referred to as
a "drag" bit) generally includes a plurality of cutting elements
secured to a face of a bit body of the drill bit. The cutters are
fixed in place when used to cut formation materials. A conventional
fixed-cutter earth-boring rotary drill bit includes a bit body
having generally radially projecting and longitudinally extending
blades. During drilling operations, the drill bit is positioned at
the bottom of a well borehole and rotated.
[0004] A plurality of cutting elements is positioned on each of the
blades. The cutting elements commonly comprise a "table" of
superabrasive material, such as mutually bound particles of
polycrystalline diamond, formed on a supporting substrate of a hard
material, such as cemented tungsten carbide. Such cutting elements
are often referred to as "polycrystalline diamond compact" (PDC)
cutting elements or cutters. The plurality of PDC cutting elements
may be fixed within cutting element pockets formed in rotationally
leading surfaces of each of the blades. Conventionally, a bonding
material, such as a braze alloy, may be used to secure the cutting
elements to the bit body.
[0005] Some earth-boring tools may also include bearing elements
that may limit the depth-of-cut (DOC) of the cutting elements,
protect the cutting elements from excessive contact with the
formation, enhance (e.g., improve) lateral stability of the tool,
or perform other functions or combinations of functions. The
bearing elements conventionally are located entirely rotationally
behind associated leading cutting elements to limit DOC as the
bearing elements contact and ride on an underlying earth formation,
although bearing elements rotationally leading cutting elements are
also known.
BRIEF SUMMARY
[0006] In one aspect of the disclosure, an earth-boring tool
includes a body with a pocket in a leading end thereof for
accepting at least a portion of a bearing element assembly. A
bearing element assembly is disposed within the pocket, and the
bearing element assembly includes a retaining element at least
partially disposed in a groove in a sidewall of the pocket and a
bearing element. The bearing element includes a distal end having a
bearing surface, a proximal end, and a side surface between the
distal end and the proximal end. The side surface includes a
feature configured to abut the retaining element, and mechanical
interference between the feature and the retaining element axially
retains the bearing element within the pocket.
[0007] In another aspect of the disclosure, an earth-boring tool
includes a body with a threaded receptacle in a leading end thereof
for accepting at least a portion of a bearing element assembly. A
bearing element assembly is disposed within the threaded
receptacle, and the bearing element assembly may include a holder
with a receptacle at a distal end thereof for receiving a bearing
element, a threaded outer surface at a proximal end thereof for
engagement with the threaded receptacle in the body of the
earth-boring tool, and at least one feature proximate the distal
end of the holder configured to interface with a tool adapted to
apply torque to the holder.
[0008] In yet another aspect of the disclosure, a method of
replacing a bearing element of an earth-boring tool includes
disengaging a mechanical retention device retaining a first bearing
element within a pocket in a body of the earth-boring tool,
removing the first bearing element from the pocket, placing a
second bearing element in the pocket, wherein the second bearing
element comprises at least one of a shape of a bearing surface and
an exposure of a bearing surface different from the first bearing
element, and engaging the mechanical retention device to retain the
second bearing element within the pocket.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] While the specification concludes with claims particularly
pointing out and distinctly claiming what are regarded as
embodiments of the present invention, various features and
advantages of disclosed embodiments may be more readily ascertained
from the following description when read with reference to the
accompanying drawings, in which:
[0010] FIG. 1 is a perspective view of an earth-boring drill bit
with bearing element assemblies of the disclosure;
[0011] FIG. 2 is a side cross-sectional view of a bearing element
assembly of the disclosure;
[0012] FIG. 3 is a side cross-sectional view of another bearing
element assembly of the disclosure;
[0013] FIG. 4 is a side cross-sectional view of another bearing
element assembly of the disclosure;
[0014] FIG. 5 is a side cross-sectional view of a bearing element
assembly and sleeve of the disclosure;
[0015] FIG. 6 is a side cross-sectional side of another bearing
element assembly and sleeve of the disclosure;
[0016] FIG. 7 is a perspective view of another bearing element
assembly of the disclosure disposed in a blade of an earth-boring
tool;
[0017] FIG. 8 is a perspective view of another bearing element
assembly of the disclosure;
[0018] FIG. 9 is a perspective view of another bearing element
assembly of the disclosure; and
[0019] FIG. 10 is a perspective view of the bearing element
assembly of FIG. 9 installed in an earth-boring drill bit.
DETAILED DESCRIPTION
[0020] The illustrations presented herein are not actual views of
any particular material, bearing element assembly, or earth-boring
tool, but are merely idealized representations employed to describe
embodiments of the present disclosure. Additionally, elements
common between figures may retain the same numerical
designation.
[0021] As used herein, the term "bearing element" means an element
configured to be mounted on a body of an earth-boring tool, such as
a drill bit, and to rub against a formation as the body of the
earth-boring tool is rotated within a wellbore. Bearing elements
include, for example, what are referred to in the art as
depth-of-cut (DOC) control elements. Bearing elements do not
include conventional PDC cutting elements configured to cut
formation material by a shearing mechanism.
[0022] FIG. 1 is a perspective view of an embodiment of an
earth-boring tool 100 of the present disclosure. The earth-boring
tool 100 of FIG. 1 is configured as an earth-boring rotary drill
bit. The earth-boring tool 100, more specifically, comprises a drag
bit having a plurality of cutting elements 102 affixed to a body
104 of the earth-boring tool 100. The earth-boring tool 100 also
includes one or more bearing element assemblies 106 that are
attached to the body 104. The present disclosure relates to
embodiments of earth-boring tools including bearing element
assemblies 106 that enable replacement of bearing elements without
returning the bit to a manufacturing facility, (i.e., embodiments
that enable replacement in the field of use), and without requiring
a brazing process to mount the bearing element to the body 104 of
the earth-boring tool 100. The bearing element assemblies 106 may
include features that interact with features of the earth-boring
tool 100 to facilitate retention of the bearing element assemblies
106 within the earth-boring tool 100 and removal of the bearing
element assemblies 106 from the earth-boring tool 100, as discussed
in further detail below.
[0023] The body 104 of the earth-boring tool 100 may be secured to
a shank 108 having a threaded connection portion 110, which may
conform to industry standards, such as those promulgated by the
American Petroleum Institute (API), for attaching the earth-boring
tool 100 to a drill string (not shown).
[0024] The body 104 may include internal fluid passageways that
extend between fluid ports 112 at the face of the body 104 and a
longitudinal bore that extends through the shank 108 and partially
through the body 104. Nozzle inserts 114 may be secured within the
fluid ports 112 of the internal fluid passageways. The body 104 may
further include a plurality of blades 116 that are separated by
fluid courses 118, which may be referred to in the art as "junk
slots." In some embodiments, the body 104 may include gage wear
plugs 120, wear knots 122, or both.
[0025] Each bearing element assembly 106 may be positioned on a
blade 116 to rotationally trail at least one cutting element 102,
as shown in FIG. 1. In some embodiments, the bearing element
assemblies 106 may be positioned to rotationally follow cutting
elements 102 on the same blade 116 at the same radius from the
center of the earth-boring tool 100, or may be disposed at
positions intermediate at least two cutting elements 102 along a
radial axis. The bearing element assemblies 106 may be formed
partially or fully of a wear-resistant material, such as cemented
tungsten carbide, or distal ends thereof may comprise a
wear-resistant material, such as cemented tungsten carbide or a
superabrasive material such as polycrystalline diamond or cubic
boron nitride. The wear-resistant material may comprise a coating
or particles of the wear-resistant material over an entirety of the
distal end, or inserts of the wear-resistant material embedded in a
surface of the distal end.
[0026] Bearing element assemblies like the bearing element
assemblies 106 may serve to limit the depth-of-cut (DOC) of the
cutting elements 102. Drilling characteristics of a particular bit,
such as DOC, may depend on exposure of bearing surfaces of the
bearing element assemblies 106. Thus, bearing element assemblies
having different exposures may impart different drilling
characteristics to a particular bit design. Conventionally, bearing
elements similar to bearing element assemblies 106 may be brazed
into pockets in the earth-boring tool 100. Replacement of brazed
bearing elements typically requires the earth-boring tool 100 to be
returned to a manufacturing facility where the bit body may undergo
heat cycles during a brazing process. Embodiments of the present
disclosure relate to earth-boring tools and bearing element
assemblies that enable replacement of the bearing element
assemblies in the field of use.
[0027] Referring now to FIG. 2, a bearing element assembly 200 is
shown disposed within a pocket 202 of a blade 204 of an
earth-boring tool 100 (FIG. 1). The bearing element assembly 200
may include a bearing element 201 and a retaining element 216. The
bearing element 201 may include a distal end 206 with a bearing
surface 208. The bearing surface 208 may have a convex shape, such
as a shape generally defined by a portion of a sphere. In some
embodiments, the bearing surface 208 may be substantially
hemispherical, substantially conical, or chisel-shaped. A bearing
element assembly such as bearing element assembly 200 may be
referred to in the art as an "ovoid." In some embodiments, the
bearing surface 208 may comprise an asymmetrical shape.
[0028] The bearing element 201 may comprise a proximal end 210 and
a side surface 212 between the distal end 206 and the proximal end
210. The side surface 212 may also be characterized as a sidewall.
In the embodiment shown in FIG. 2, the side surface 212 may
comprise a circular transverse cross-sectional shape, imparting to
the side surface 212 a substantially cylindrical shape. In other
embodiments, the transverse cross-sectional shape may include,
without limitation, other shapes such as ellipses, polygons, and
shapes including both arcuate and rectilinear portions.
[0029] The pocket 202 may have a transverse cross-sectional shape
generally similar to the transverse cross-sectional shape of the
side surface 212 of the bearing element assembly 200. In some
embodiments, the side surface 212 may be sized such that the
bearing element 201 fits within the pocket 202 with an interference
fit. In other embodiments, the side surface 212 and the pocket 202
may be sized such that a clearance exists between the side surface
212 of the bearing element 201 and a sidewall 203 of the pocket
202. Such a clearance may be provided intentionally to ease
insertion and removal of the bearing element assembly 200, or the
clearance may be the result of inaccuracy inherent in the
manufacturing process.
[0030] The sidewall 203 of the pocket 202 may include a groove 214
in a plane generally normal to a central axis A.sub.c of the pocket
202. The groove 214 may be substantially annular. A retaining
element 216 may be at least partially disposed within the groove
214. The retaining element 216 may also be characterized as a
mechanical retention device. As a non-limiting example, the
retaining element 216 may have a substantially circular transverse
cross-sectional shape (i.e., in the cross-section of FIG. 2) and
partially surround a portion of the periphery of the side surface
212. In other words, the retaining element 216 may be substantially
annularly shaped, but may include a gap to allow circumferential
expansion and contraction of the retaining element 216. The
retaining element 216 may have any suitable transverse
cross-sectional shape, such as arcuate shapes, linear shapes, and
combinations thereof. The retaining element 216 may comprise a
resilient material, such as a steel alloy.
[0031] The side surface 212 of the bearing element 201 may include
a feature against which a portion of the retaining element 216 may
abut to retain the bearing element 201 within the pocket 202. For
example, a portion of the retaining element 216 may extend from the
groove 214 and into a recess 218 in the side surface 212 of the
bearing element 201. Mechanical interference between the retaining
element 216, a surface of the blade 204 within the groove 214, and
a portion 220 of the side surface 212 of the bearing element 201
within the recess 218 may retain the bearing element 201 within the
pocket 202.
[0032] One or more removal access holes may extend through an
exterior surface of the blade 204 and intersect at least a portion
of the pocket 202. For example, one or more channels 222 may be
disposed in the sidewall 203 of the pocket 202. For example, the
one or more channels 222 may extend into a surface of the blade 204
in a direction substantially parallel to the central axis A.sub.c
of the pocket 202, and may intersect the pocket 202 adjacent a
portion of the side surface 212 of the bearing element assembly
200. The one or more channels 222 may be configured to accept a
removal tool used to facilitate removal of the bearing element
assembly 200 from the pocket 202 of the blade 204, as will be
described in greater detail below. The one or more channels 222 may
be spaced equidistantly about a circumference of the pocket 202.
For example, in the embodiment of FIG. 2, two channels 222 may be
spaced one hundred eighty degrees (180.degree.) apart.
[0033] The side surface 212 of the bearing element 201 may include
a notch 224 positioned adjacent the one or more channels 222. As a
non-limiting example, the notch 224 may have an annular shape,
i.e., the notch 224 may extend around a circumference of the side
surface 212 of the bearing element 201.
[0034] To remove the bearing element 201 from the pocket 202 of the
blade 204, an operator may insert a tool (e.g., a prying tool, such
as a pry bar or flat-bladed screwdriver, or a pulling tool, such as
a multi jawed puller) into the one or more channels 222, such that
a portion of the tool rests within the notch 224 in the side
surface 212. Using the tool, the operator may apply a force F
generally parallel to the central axis A.sub.c of the pocket 202,
e.g., by prying or pulling against the bearing element 201 within
the notch 224. Under the applied force F, a portion of the side
surface 212 within the recess 218 may bear against the retaining
element 216 and urge the retaining element 216 to expand
circumferentially into the groove 214. The retaining element 216
may move free of the recess 218 to enable removal of the bearing
element 201 from the pocket 202. The retaining element 216 may be
left within the groove 214, or may be circumferentially compressed
and removed from the groove 214 and the pocket 202. A replacement
retaining element may be inserted into the pocket 202 and into the
groove 214.
[0035] A replacement bearing element may be inserted into the
pocket 202 by the operator. As shown in FIG. 2, the bearing element
201 may include a chamfered edge 226 in the side surface 212
adjacent the proximal end 210. As the bearing element 201 is
inserted into the pocket 202, the chamfered edge 226 may cause the
retaining element 216 to expand circumferentially into the groove
214 and slide along the side surface 212. When the bearing element
201 is fully inserted into the pocket 202, the retaining element
216 may circumferentially contract such that a portion of the
retaining element 216 is disposed within the recess 218, as
described above.
[0036] When necessary, the operator may replace the bearing element
201 with another bearing element having different characteristics,
e.g., a different exposure or shape of the bearing surface 208, to
impart to the earth-boring tool 100 (FIG. 1) different drilling
characteristics.
[0037] Referring now to FIG. 3, an embodiment of a bearing element
assembly 300 is shown. The bearing element assembly 300 may include
a bearing element 301 and a retaining element 324. The bearing
element assembly 300 may be disposed in a pocket 302 of a blade 304
of an earth-boring tool (e.g., earth-boring tool 100 shown in FIG.
1). The bearing element 301 may include a distal end 306 with a
bearing surface 308. The bearing surface 308 may include any of the
materials, shapes, and characteristics discussed above. The bearing
element 301 may include a proximal end 310 and a side surface 314
between the distal end 306 and the proximal end 310.
[0038] A feature such as a flange 316 may extend from the side
surface 314. As a non-limiting example, the flange 316 may be
substantially annular. The pocket 302 may be shaped to receive the
flange 316. For example, the pocket 302 may include a first portion
318 having a first diameter D.sub.1, the first portion 318
extending a first depth Dp.sub.1 into the blade 304 along a central
axis A.sub.c of the pocket 302. The pocket 302 may have a second
portion 320 having a second diameter D.sub.2, the second portion
320 extending a second depth Dp.sub.2 into the blade 304 along the
central axis A.sub.c. The first diameter D.sub.1 may be greater
than the second diameter D.sub.2, and the first depth Dp.sub.1 may
be less than the second depth Dp.sub.2. The first diameter D.sub.1
may be substantially the same as a diameter of the flange 316, and
the flange 316 may be substantially received within the first
portion 318 of the pocket 302.
[0039] The first portion 318 of the pocket 302 may include a groove
322 in a sidewall thereof. A retaining element 324 may be disposed
at least partially within the groove 322. In this embodiment, the
groove 322 is substantially annular in shape. The retaining element
324 may abut a portion of the flange 316 to retain the bearing
element 301 within the pocket 302. As a non-limiting example, the
retaining element 324 may be a spiral snap ring. In other
embodiments, the retaining element may be an internal split snap
ring (which may be referred to in the art as a "circlip").
[0040] One or more removal access holes may extend through an
exterior surface of the blade 304 and intersect the pocket 302
adjacent a portion of the bearing element 301. For example, the one
or more removal access holes may be defined by one or more channels
326 disposed in a sidewall 303 of the pocket 302. The one or more
channels 326 may extend from an exterior surface of the blade 304
into the blade 304 in a direction generally parallel to the central
axis A.sub.c of the pocket 302. The one or more channels 326 may
intersect the first portion 318 of the pocket 302 adjacent a
portion of the flange 316. The one or more channels 326 may be
equidistantly spaced around a circumference of the pocket 302. For
example, three channels 326 may be spaced about one hundred twenty
degrees (120.degree.) apart.
[0041] To remove the bearing element 301, an operator may remove
the retaining element 324 by, e.g., prying an end of the retaining
element 324 out of the groove 322 and gradually prying the
retaining element 324 from the groove 322 around a circumference
thereof in the case of a spiral snap ring. As another example, the
operator may use snap ring pliers or a similar tool to
circumferentially contract a split ring and remove it from the
groove 322. A removal tool such as a prying or pulling tool as
described above may be inserted into the one or more channels 326,
such that a portion of the removal tool contacts a proximal surface
328 of the flange 316. Using the tool, the operator may apply a
force F generally along the central axis A.sub.c, e.g., by prying
or pulling, to release the bearing element 301 from the pocket
302.
[0042] Referring now to FIG. 4, a bearing element assembly 400 may
be disposed within a pocket 402 of a blade 404. The bearing element
assembly 400 may include a bearing element 401 and a retaining
element 416. A removal access hole may be defined by a bore 406
that extends through an exterior surface of the blade 404 and
intersects a floor 408 of the pocket 402 adjacent a proximal
surface 410 of the bearing element 401. The pocket 402 may include
a groove 414 in a sidewall thereof, and a retaining element 416 at
least partially disposed within the groove 414 and contacting a
recess 418 in a side surface 412 of the bearing element 401.
[0043] To remove the bearing element 401 from the pocket 402, an
operator may insert a portion of a tool 420 into the bore 406. For
example, the tool 420 may be a tool with an elongated shank at a
working end, such as a pin punch. The operator may drive the tool
420 into the bore 406 until the tool abuts the proximal surface 410
of the bearing element 401. Driving the tool 420 further into the
bore 406 may cause the tool 420 to bear against the proximal
surface 410 of the bearing element 401 and force the bearing
element 401 from the pocket 402.
[0044] In some embodiments of the present disclosure, bearing
element assemblies may include a bearing element disposed within a
receptacle of a holder. The holder may include a mechanical
retention device (e.g., a threaded outer surface configured to
interface with a threaded receptacle in a blade of an earth-boring
tool 100 (FIG. 1)) to enable retention and replacement of the
bearing element assemblies.
[0045] For example, referring now to FIG. 5, a bearing element
assembly 500 may include a bearing element 502 and a holder 504.
The bearing element 502 may have a bearing surface 503 including
any of the shapes and materials discussed above in connection with
bearing surface 208 (FIG. 2). The holder 504 may include a distal
end 506 with a receptacle 508 in which the bearing element 502 is
disposed. The bearing element 502 may be affixed within the
receptacle 508 by brazing, an interference fit, adhesives, or other
methods. The holder 506 may include a proximal end 510 with a
threaded outer surface 512, which may also be characterized as a
threaded shank. In other embodiments, the bearing element assembly
500 may be a unitary structure, i.e., the bearing element 502 and
the holder 504 may be formed as a single component.
[0046] In FIG. 5, the threaded outer surface 512 is shown threaded
into a sleeve 514 with a threaded inside diameter 516 and a
substantially smooth outside diameter 518. The sleeve 514 may be
received (e.g., affixed) within a pocket of a blade of an
earth-boring tool to form a threaded receptacle, as described below
in connection with FIG. 7.
[0047] A mechanical locking device 520 may be disposed between a
distal surface 522 of the sleeve 514 and a proximal surface 524 of
the holder 504. The mechanical locking device 522 may include, as
non-limiting examples, a locking washer such as a split washer or
star washer, a Belleville (i.e., conical) washer, or other locking
washers.
[0048] Referring now to FIG. 6, a bearing element assembly 600 may
include a bearing element 602 and a holder 604. The holder 604 may
include a distal end 606 with a receptacle 608 in which the bearing
element 602 may be disposed. The holder 604 may include a proximal
end 610 with a threaded outer surface 612. The threaded outer
surface 612 may be threaded into a sleeve 614 with a threaded
inside diameter 616 and a substantially smooth outside diameter
618.
[0049] The holder 604 may include a conical portion 620 between the
distal end 606 and the proximal end 610. The sleeve 614 may include
a corresponding conical surface 622 on an inner diameter at a
location distal to the threaded inside diameter 616. Contact
between the conical portion 620 of the holder 604 and the conical
surface 622 of the sleeve 614 may enhance (e.g., increase) a
frictional force between the holder 604 and the sleeve 614,
preventing the holder 604 from rotating relative to the sleeve 614
and consequently loosening from the sleeve 614.
[0050] Referring now to FIG. 7, a bearing element assembly 700
similar to bearing element assemblies 500 and 600 (FIGS. 5 and 6)
is shown disposed within a threaded receptacle 702 of a blade 704.
The bearing element assembly 700 may include features configured to
interface with a tool adapted to apply torque to the bearing
element assembly 700. As a non-limiting example, the bearing
element assembly 700 may include surfaces arranged in a hexagonal
pattern (e.g., wrench flats 706) for interfacing with a tool such
as a socket wrench. It should be understood that any known feature,
shape, surface, or configuration thereof that enables the bearing
element assembly 700 to interface with a tool adapted to apply
torque to the bearing element assembly 700 is within the scope of
the present disclosure.
[0051] The threaded receptacle 702 of the blade 704 may include a
pocket 708 and a sleeve 710 disposed in the pocket 708. The sleeve
710 may be similar to sleeves 514 and 614 described above with
reference to FIGS. 5 and 6, respectively. In some embodiments, the
sleeve 710 may be brazed within the pocket 708.
[0052] The pocket 708 may include a slot 712 adjacent an outside
diameter 718 of the sleeve 710. The slot 712 may extend through the
blade 704 to expose a portion of the outside diameter 718 of the
sleeve 710, as shown in FIG. 7. The slot 712 may provide an access
location for brazing the sleeve into the pocket 708. For example,
heat and braze material may be applied to the outside diameter 718
of the sleeve 710 through the slot 712 as the sleeve 710 is rotated
to ensure the braze material is distributed around substantially
the entire outside diameter 718 of the sleeve 710.
[0053] To remove the bearing element assembly 700 from the blade
704, an operator may place a tool, e.g., a socket wrench, over the
wrench flats 706 and apply a rotational force with the tool to the
bearing element assembly 700. The operator may remove the bearing
element assembly 700 from the sleeve 710 and pocket 708. The
operator may place a replacement bearing element assembly 700
within the pocket 708 and use the tool to tighten threads (e.g.,
threaded shank 512, 612 of holders 504, 604 shown in FIGS. 5 and 6,
respectively) of the bearing element assembly 700 into a threaded
inside diameter (e.g., 516, 616 of FIGS. 5 and 6) of the sleeve
710. As described above, the bearing element assembly 700 may be
replaced when necessitated by damage, or when changed drilling
conditions require different bit characteristics that can be
obtained by replacing the bearing element assembly 700 with a
bearing element assembly having a different exposure of a bearing
surface (e.g., bearing surface 503 (FIG. 5)).
[0054] FIG. 8 shows another embodiment of a bearing element
assembly 800 according to the disclosure. The bearing element
assembly 800 includes a bearing element 802 and a holder 804. The
bearing element 802 may exhibit an exposure above the holder 804
that may be chosen based on the desired bit depth-of-cut
characteristics, as described above. The holder 804 may comprise
one or more notches 806 configured to interface with a tool adapted
to apply torque to the holder 804. For example, the one or more
notches 806 may be arranged around a periphery of the holder 804
and may be configured to receive protrusions of a tool (e.g.,
protrusions on a wrench or a socket wrench specially configured to
interface with the notches 806). The holder 804 may include a
threaded outer surface 808 configured to interface with threads of
a threaded receptacle in an earth-boring tool 100 (FIG. 1). The
threaded receptacle may include a pocket and a threaded sleeve,
e.g., pocket 708 and threaded sleeve 710 (FIG. 7), or the threaded
receptacle may include threads formed directly in the body of the
earth-boring tool 100. Such threads may be machined in a bit body
comprising a metal alloy, e.g., a steel-bodied bit, or may be cast
in a bit body comprising a particle-matrix composite material.
[0055] The threaded outer surface 808 may be configured
substantially identically to an outer surface of a nozzle insert
114 (FIG. 1) also mounted on the earth-boring tool 100. In other
words, the lateral exterior side surfaces of the holder 804 may
have a configuration (size, shape, and dimensions) substantially
similar, or even identical to the exterior side surfaces of at
least one nozzle insert 114 also mounted to the earth-boring tool
100. For example, parameters such as a diameter and thread shape of
the threaded outer surface may be substantially identical to the
diameter and thread shape of the outer surface of the nozzle insert
114. Accordingly, a drill bit manufacturer may use methods and
tooling associated with the production of nozzle inserts 114 and
threaded interiors of fluid ports 112 (FIG. 1) to produce bearing
element holders, e.g., bearing element holders 804, and threaded
receptacles in bit bodies as described above. Thus, such bearing
element holders and threaded receptacles in bit bodies may be
produced economically, as the drill bit manufacturer may not have
to make a significant investment in new or additional tooling.
[0056] Referring now to FIG. 9, a bearing element assembly 900
includes a bearing element 902 disposed in a holder 904, the
bearing element 902 having an elongated side surface 910 and one or
more fluid outlets 912 in communication with an internal fluid
passageway 914 (indicated with broken lines). The internal fluid
passageway 914 may extend through a proximal end 916 of the bearing
element assembly 900. The bearing element assembly 900 may include
a threaded outer surface 908 configured substantially identically
to an outer surface of a nozzle insert, e.g., nozzle insert 114
(FIG. 1). In other words, the bearing element assembly 900 may be
configured to be threaded into fluid ports 112 (FIG. 1) in place of
nozzle inserts 114. Fluid flow from the fluid ports 112 may flow
into the internal fluid passageway 914 and exit the one or more
fluid outlets 912. A height H of the elongated side surface 906 may
be chosen so that the bearing element 902 extends from the fluid
port 112 a sufficient distance to limit the DOC of cutting elements
102 (FIG. 1) a desired amount. As a non-limiting example, the
holder 904 may include notches 906 configured to interface with a
tool adapted to apply torque to the holder 904, as described in
FIG. 8 in connection with notches 806.
[0057] Referring now to FIG. 10, a bearing element assembly 1000
similar to the bearing element assembly 900 described in connection
with FIG. 9 is shown installed in an earth-boring tool 1002. The
bearing element assembly 1000 may be installed in a fluid port 1004
disposed in the bottom surface within a fluid course 1006 between
blades 1008 of the earth-boring tool 1002. The bearing element
assembly 1000 may extend from the fluid port 1004 toward leading
ends 1010 of the blades 1008 a distance sufficient to limit a DOC
of cutting elements 1012 disposed in the leading ends 1010 of the
blades 1008. During use, a flow of drilling fluid exiting the fluid
port 1004 may flow into an internal fluid passageway (not shown) in
the bearing element assembly 1000 similar to internal fluid
passageway 910 described above in connection with FIG. 9. The fluid
may flow from outlet ports 1014 and into the fluid course 1006 to
flush formation cuttings and drilling debris away from the blades
1008 and cutting elements 1012.
[0058] Additional non-limiting example embodiments of the
disclosure are set forth below.
Embodiment 1
[0059] An earth-boring tool, comprising: a body comprising a pocket
in a leading end thereof for accepting at least a portion of a
bearing element assembly; and a bearing element assembly disposed
within the pocket, the bearing element assembly comprising: a
retaining element at least partially disposed in a groove in a
sidewall of the pocket; and a bearing element comprising: a distal
end having a bearing surface; a proximal end; and a side surface
between the distal end and the proximal end, the side surface
comprising a feature configured to abut the retaining element,
wherein mechanical interference between the feature and the
retaining element axially retains the bearing element within the
pocket.
Embodiment 2
[0060] The earth-boring tool of Embodiment 1, further comprising at
least one removal access hole extending through an exterior surface
of the body and intersecting the pocket, wherein the at least one
removal access hole is configured to receive a removal tool.
Embodiment 3
[0061] The earth-boring tool of Embodiment 2, wherein the at least
one removal access hole is defined by a channel in the sidewall of
the pocket and extending in a direction substantially parallel to a
central axis of the pocket.
Embodiment 4
[0062] The earth-boring tool of Embodiment 3, wherein the at least
one removal access hole comprises a plurality of channels spaced
equidistantly around the sidewall of the pocket.
Embodiment 5
[0063] The earth-boring tool of Embodiment 3 or Embodiment 4,
wherein the side surface of the bearing element comprises a notch
adjacent the channel.
Embodiment 6
[0064] The earth-boring tool of any one of Embodiments 2 through 5,
wherein the at least one removal access hole comprises a bore
extending through an exterior surface of the body and intersecting
the pocket.
Embodiment 7
[0065] The earth-boring tool of Embodiment 6, wherein the bore
intersects the pocket adjacent a proximal surface of the bearing
element.
Embodiment 8
[0066] The earth-boring tool of any one of Embodiments 1 through 7,
wherein the protrusion comprises a substantially annular flange
extending laterally from the side surface of the bearing
element.
Embodiment 9
[0067] The earth-boring tool of Embodiment 8, wherein the sidewall
of the pocket comprises a first portion having a first diameter
extending into the body a first depth along a central axis of the
pocket and a second portion having a second diameter extending into
the body a second depth along the central axis of the pocket,
wherein the first diameter is greater than the second diameter and
the second depth is greater than the first depth.
Embodiment 10
[0068] The earth-boring tool of any one of Embodiments 1 through 7,
wherein the feature comprises a portion of the side surface of the
bearing element within a substantially annular recess.
Embodiment 11
[0069] The earth-boring tool of any one of Embodiments 1 through
10, wherein the earth-boring tool is a fixed-cutter rotary drill
bit.
Embodiment 12
[0070] An earth-boring tool, comprising: a body comprising a
threaded receptacle in a leading end thereof for accepting at least
a portion of a bearing element assembly; and a bearing element
assembly disposed within the threaded receptacle, the bearing
element assembly comprising: a holder with a receptacle at a distal
end thereof for receiving a bearing element and a threaded outer
surface at a proximal end thereof for engagement with the threaded
receptacle in the body of the earth-boring tool; and at least one
feature proximate the distal end of the holder configured to
interface with a tool adapted to apply torque to the holder.
Embodiment 13
[0071] The earth-boring tool of Embodiment 12, wherein the threaded
receptacle comprises a sleeve with an at least partially threaded
inner diameter and a generally smooth outer diameter, and the
sleeve is disposed within a pocket of the body.
Embodiment 14
[0072] The earth-boring tool of Embodiment 12 or Embodiment 13,
further comprising a slot extending from an exterior surface of the
body to a portion of an outer surface of the sleeve.
Embodiment 15
[0073] The earth-boring tool of any one of Embodiments 12 through
14, wherein the threaded outer surface of the holder is configured
substantially identically to an outer surface of a nozzle insert
for insertion in a fluid outlet port in the body of the
earth-boring tool.
Embodiment 16
[0074] The earth-boring tool of Embodiment 15, wherein the bearing
element assembly comprises an internal fluid passageway in
communication with a fluid port in the body of the earth-boring
tool and in communication with one or more fluid outlets in a side
surface of the bearing element.
Embodiment 17
[0075] A method of replacing a bearing element of an earth-boring
tool, comprising: disengaging a mechanical retention device
retaining a first bearing element within a pocket in a body of the
earth-boring tool; removing the first bearing element from the
pocket; placing a second bearing element in the pocket, wherein the
second bearing element comprises at least one of a shape of a
bearing surface and an exposure of a bearing surface different from
the first bearing element; and engaging the mechanical retention
device to retain the second bearing element within the pocket.
Embodiment 18
[0076] The method of Embodiment 17, wherein disengaging the
mechanical retention device comprises rotating the bearing element
relative to the pocket to disengage threads on an outer surface of
the bearing element from threads in a sidewall of the pocket.
Embodiment 19
[0077] The method of Embodiment 17, wherein disengaging the
mechanical retention device comprises removing a retaining element
from a groove in a sidewall of the pocket.
Embodiment 20
[0078] The method of Embodiment 17, wherein disengaging the
mechanical retention device comprises applying a force to a surface
of the bearing element with a tool inserted in a removal access
hole extending through an exterior surface of the body and
intersecting the pocket.
[0079] Although the foregoing description contains many specifics,
these are not to be construed as limiting the scope of the present
invention, but merely as providing certain exemplary embodiments.
Similarly, other embodiments of the invention may be devised, which
do not depart from the spirit or scope of the present disclosure.
For example, features described herein with reference to one
embodiment also may be provided in others of the embodiments
described herein. The scope of the invention is, therefore,
indicated and limited only by the appended claims and their legal
equivalents, rather than by the foregoing description. All
additions, deletions, and modifications to the disclosed
embodiments, which fall within the meaning and scope of the claims,
are encompassed by the present disclosure.
* * * * *