U.S. patent application number 14/481706 was filed with the patent office on 2014-12-25 for sonic drill head.
The applicant listed for this patent is Layne Christensen Company. Invention is credited to Brian Smith, Krasimir Zahariev.
Application Number | 20140374162 14/481706 |
Document ID | / |
Family ID | 46965231 |
Filed Date | 2014-12-25 |
United States Patent
Application |
20140374162 |
Kind Code |
A1 |
Smith; Brian ; et
al. |
December 25, 2014 |
SONIC DRILL HEAD
Abstract
A sonic drill head comprising an outer housing, an isolation
system, a sine generator and a spindle. The sine generator
generates a linear sinusoidal vibration force through the rotation
of a plurality of eccentric masses. The sine generator is
configured to translate the linear sinusoidal force to the spindle
in a direction corresponding to the spindle's axis of rotation. The
sine generator supports the spindle within the housing such that
the spindle is free to rotate about the spindle axis. The spindle
is generally a hollow tube section thereby allowing the passage of
drilling fluid, mud, cuttings, and/or tooling. The isolation system
generally reduces the transfer of the vibration force generated by
the sine generator to the outer housing, yet is able to transfer an
applied thrust force from the outer housing to the sine
generator.
Inventors: |
Smith; Brian; (The
Woodlands, TX) ; Zahariev; Krasimir; (Carol Stream,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Layne Christensen Company |
Kansas City |
KS |
US |
|
|
Family ID: |
46965231 |
Appl. No.: |
14/481706 |
Filed: |
September 9, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13082837 |
Apr 8, 2011 |
8851203 |
|
|
14481706 |
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Current U.S.
Class: |
175/56 |
Current CPC
Class: |
E21B 7/24 20130101 |
Class at
Publication: |
175/56 |
International
Class: |
E21B 7/24 20060101
E21B007/24 |
Claims
1. A vibratory drill head comprising: a housing; a spindle mounted
to said housing for axial rotation, said spindle presenting a
passage therethrough extending between upper and lower ends of said
spindle for introducing or removing materials through said upper
end of said spindle during axial rotation of said spindle; a sine
generator in said housing coupled to said spindle between said
upper end and said lower end of said spindle in a manner to apply a
sinusoidal vibration to said spindle; and an isolation mechanism in
said housing acting between said sine generator and said housing to
dampen the effect on said housing of the sinusoidal vibration
applied to said spindle by said sine generator.
2. A vibratory drill head according to claim 1 wherein said sine
generator comprises six eccentric rotors radially distributed about
a center point, each said rotor having an eccentric weight, wherein
all said eccentric weights reach top dead center and bottom dead
center simultaneously.
3. A vibratory drill head according to claim 2 wherein each of said
six eccentric rotors include an axis of rotation, wherein the six
axes of rotation are spaced radially equidistant.
4. A vibratory drill head according to claim 3 wherein each of said
axes of rotation are tilted from horizontal.
5. A vibratory drill head according to claim 2 wherein each of said
eccentric rotors includes an inside face wherein said inside faces
of said six eccentric rotors substantially define an aperture and
said spindle passes through said aperture.
6. A vibratory drill head according to claim 1 wherein said spindle
protrudes outside said housing.
7. A vibratory drill head according to claim 1 wherein said
material is selected from the group consisting of cuttings,
instrumentation, and drill tooling.
8. A vibratory drill head according to claim 1 wherein rotation of
said spindle about a spindle axis is effected independently of the
operation of said sine generator.
9. (canceled)
10. A vibratory drill head according to claim 1 wherein said
isolation mechanism is further configured to transfer a thrust
force from said housing to said sine generator and wherein said
sine generator is configured to transfer said thrust force to said
spindle.
11. (canceled)
12. (canceled)
13. (canceled)
14. A vibratory drill head according to claim 1 wherein said
spindle being adapted for connection to a drill bit to effect a
sonic drilling mode when said spindle is driven at a first speed
and a rotary drilling mode when said spindle is driven at a second
speed greater than said first speed.
15. (canceled)
16. (canceled)
17. (canceled)
18. (canceled)
19. (canceled)
20. (canceled)
21. A vibratory drill head according to claim 1 wherein said
spindle has an axis of rotation and a rotational drive for said
spindle is offset of said axis of rotation of the spindle.
22. A vibratory drill head according to claim 1 wherein said sine
generator includes a plurality of eccentric rotors, all of said
eccentric rotors being rotated by a single drive.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
BACKGROUND OF THE INVENTION
[0002] The present invention is generally directed to a sonic drill
head. Sonic drill heads generally impart a vibratory force and send
high frequency resonant vibrations down a drill string to a drill
bit. The sonic drill head combines this vibratory force with a slow
rotation of the drill string to ensure that the energy applied and
wear resulting from drilling are evenly distributed at the drill
face. Vibration generators for sonic drilling may be housed with a
rotary drive or may be a stand alone component of a drill string.
The frequency of vibration is generally between 50 and 120 hertz
(cycles per second) and the drill operator controls the frequency
of the vibrations to match the natural frequency of the drill
string to take advantage of the resonance effects of the drill
string and/or to suit the specific conditions of the soil/rock
geology. The resonance created at the selected frequency magnifies
the amplitude of the drill bit thereby allowing for fast and easy
penetration through many geological formations.
[0003] Since sonic drilling obtains its results through the
combination of resonant vibrations superimposed upon a slow drill
rotation, sonic drill heads are generally designed and constructed
with no consideration of operating the drill with a high-speed
spindle rotation suitable for traditional diamond core drilling or
other rotary drilling methods. Sonic drill heads known in the art
do not efficiently provide the ability to rotate the spindle at
high speeds without vibration such that the drill head can
additionally perform traditional diamond core or other rotary
drilling methods. Further, either the vibration generator or the
rotation drive of existing sonic drill heads is often located
directly above the spindle within the drill head that receives the
drill string. In one existing drill head, the vibration generator
or rotation drive is directly above the spindle thereby preventing
the passage of water, drilling fluids, mud, cuttings and/or
tooling, or any other materials through the top spindle to or from
the drill string and drill head. Other existing drill heads have
been adapted to provide a narrow passageway to facilitate the
injection of water or drilling fluid to aid in drilling. The
passage of materials through the spindle to or from the drill
string is generally not a consideration in sonic drill heads
currently in use because the slow rotation of sonic drilling does
not generally generate the same drilling conditions of other higher
speed rotary drilling methods that often require passage of
materials through the drill string to aid in the drilling process.
As a result, existing sonic drill heads do not currently allow the
passage of cuttings through the top of the drill head that are
desirable when performing deep drilling. Further, existing sonic
drill heads do not currently allow the passage of downhole
instrumentation, and/or tooling through the top of the drill head
which may be desirable when monitoring downhole conditions while
drilling.
[0004] Therefore, a need exists in the art for a sonic drill head
that allows an operator to perform both sonic drilling--slow rotary
motion superimposed to the vibratory motion--and high speed rotary
drilling. Accordingly, an additional need exists for a sonic drill
head that allows the passage of drilling fluids, mud, cuttings or
tooling to be introduced or removed as necessary through the top of
the drill head.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention is generally directed to a sonic drill
head comprising an outer housing, an isolation system, a sine
generator and a spindle. The isolation system is within the housing
and generally reduces the transfer of the vibration force generated
by the sine generator to the outer housing, yet is able to transfer
an applied thrust force from the outer housing to the sine
generator. The sine generator is also within the housing and
generates a linear sinusoidal vibration force through the rotation
of a plurality of rotors, each rotor having an eccentric center of
mass. The rotors are driven by meshing bevel gears and, as a
result, adjacent rotors rotate in opposite directions. In one
embodiment, the eccentric weights are synchronized such that the
eccentric masses reach top-dead-center and bottom-dead-center
simultaneously creating a linear sinusoidal force. Further, any
horizontal components of force generated by the rotation of the
eccentric masses generally cancel out because the rotors rotate in
opposite directions thereby resulting in a purely linear vertical
force generation. The sine generator is configured to translate
this linear sinusoidal force and/or the thrust force to the
spindle. The direction of force generally corresponds to the
spindle's axis of rotation.
[0006] The sine generator is configured to support the spindle
within the housing such that the spindle is free to rotate about
the spindle axis relative to the sine generator, yet the sine
generator still transfers the linear sinusoidal force to the
spindle along the spindle's axis of rotation. The sine generator is
configured to allow the spindle to pass through the sine generator
and the spindle may protrude outside the outer housing in some
embodiments. This configuration allows the spindle to rotate both
at low speeds used for sonic drilling and high speeds used for
diamond core or other rotary drill methods. Further, an embodiment
of the present invention includes the spindle being a continuous
and hollow tube section allowing the introduction or removal of
drilling fluid, mud, cuttings, and/or tooling, or other drilling
aids into or out of the drill string through the top of the
spindle.
[0007] Other aspects and advantages of the present invention will
be apparent from the following detailed description of the
preferred embodiments and the accompanying drawing figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0008] The accompanying drawing forms a part of the specification
and is to be read in conjunction therewith, in which like reference
numerals are employed to indicate like or similar parts in the
various views, and wherein:
[0009] FIG. 1 is a cross-sectional view of a sonic drill head in
accordance with one embodiment of the present invention;
[0010] FIG. 2 is a front perspective view of a sine generator and
isolation system in accordance with one embodiment of the present
invention;
[0011] FIG. 3 is a top perspective view of the rotors and vibration
drive system in accordance with one embodiment of the present
invention;
[0012] FIG. 4 is a cross-sectional view of the rotors in accordance
with one embodiment of the present invention;
[0013] FIG. 5 is a cross-sectional view taken along the line 5-5 of
a torque transfer assembly in accordance the embodiment of the
present invention in FIG. 1.
[0014] FIG. 6 is a cross-sectional view of the piston assembly in
accordance with one embodiment of the present invention;
[0015] FIG. 7 is a cross-sectional view of a water swivel in
accordance with one embodiment of the present invention;
[0016] FIG. 8A is a cross-sectional view of an anti-rotation
assembly in accordance with one embodiment of the present
invention; and
[0017] FIG. 8B is a cross-sectional view taken along the line 8B-8B
of an anti-rotation assembly in accordance with the embodiment
shown in FIG. 8A.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The following detailed description of the invention
references the accompanying drawing figures that illustrate
specific embodiments in which the invention can be practiced. The
embodiments are intended to describe aspects of the invention in
sufficient detail to enable those skilled in the art to practice
the invention. Other embodiments can be utilized and changes can be
made without departing from the scope of the present invention. The
present invention is defined by the appended claims and the
description is, therefore, not to be taken in a limiting sense and
shall not limit the scope of equivalents to which such claims are
entitled.
[0019] Now turning to FIG. 1, a sonic drill head 10 comprises an
outer housing 12, a sine generator 14, a spindle 16, and an
isolation system 18. Outer housing 12 generally encloses the other
components of sonic drill head 10 including sine generator 14;
spindle 16 and isolation system 18. An embodiment of outer housing
12 may be assembled such that the entire outer housing 12 or a
portion thereof maybe removed to allow access to sine generator 14,
spindle 16, or isolation system 18 for upkeep, replacement, repair,
other maintenance or any other reason required in the art. Outer
housing 12 can be a single cast or molded piece or, alternatively,
a plurality of component pieces coupled together to enclose sine
generator 14, spindle 16 and isolation system 18. Outer housing 12
of the present invention can be made from any material known in the
art including steel, iron, titanium, aluminum, industrial plastics,
fiber glass, carbon-fiber composite, any other industrial material
having the required strength properties, or any combination
thereof.
[0020] Sine generator 14 is driven by a vibration drive system 20
and comprises a motor 22, a gearing system 24, and drive shaft 26.
Motor 22 includes an output shaft 28. Motor 22 can be any motor
type known in the art including hydraulic, pneumatic, electric, gas
turbine engine, or an internal combustion engine. Output shaft 28
removably and drivingly engages gearing system 24 described in
detail below. Gearing system 24 is configured to drivingly engage
drive shaft 26 and increase the speed of rotation of drive shaft 26
when compared to the rotation speed of output shaft 28. One
embodiment of gearing system 24 is a planetary gearing system
comprising a ring gear 30, a plurality of planetary gears 32, and a
sun gear 34. Gearing system 24 can be configured to any speed
increasing ratio known in the art as necessary to obtain the
desired vibration force and frequency. An embodiment of gearing
system of the present invention can incorporate a speed increasing
ratio in the range between one and one-half to one (11/2:1) and six
to one (6:1). An embodiment of gearing system 24 of the present
invention incorporates a speed increasing ratio around three to one
(3:1).
[0021] FIG. 1. illustrates an embodiment of drive shaft 26 having a
first end 36 and a second end 38 wherein first end 36 and second
end 38 of drive shaft 26 include crowned splines 40. The crowned
splines 40 of first end 36 of drive shaft 26 allow for engagement
with mating splines contained in sun gear 34. First end 36 of drive
shaft 26 is retained in sun gear 34 through a pair of spring loaded
spherical bearings 42. The crowned splines 40 of second end 38 of
drive shaft 26 allow for mating engagement with splines contained
in a bevel gear 44 coupled to an eccentric rotor 46 of sine
generator 14. The crowned splines 40 allow drive shaft 26 to
transmit power from sun gear 34 to bevel gear 44 while bevel gear
44 and eccentric rotor 46 are vibrating with sine generator 14.
[0022] Sine generator 14 generally comprises a top plate 48, a
bottom plate 50, and a plurality of eccentric rotors 46, each rotor
46 within a rotor housing 52. Each rotor housing 52 is positioned
between top plate 48 and bottom plate 50. Rotor housing 52 is
generally coupled to top plate 48 and bottom plate 50. Eccentric
rotor 46 is journaled for rotation within rotor housing 52 upon
rotor bearings 54. Eccentric rotor 46 has an eccentric mass 56 that
offsets the center of mass of eccentric rotor 46 from the center of
rotation of eccentric rotor 46 by a selected amount. Eccentric
rotor 46 further includes an inside face 58 and an outside face 60.
Bevel gear 44 is coupled to the inside face 58 of eccentric rotor
46 using any method known in the art. Through out this description,
the term "coupling" shall be interpreted to include all coupling
methods known in the art including, but not limited to: bolts,
screws, pins, rivets, welds, retention rings, compression rings, or
any other mechanical coupling method known in the art.
Alternatively, bevel gear 44 may be cast with eccentric rotor 46 as
one component piece.
[0023] Sine generator 14 and its components described above can be
of any material known in the art including steel, iron, titanium,
aluminum, industrial plastics, fiber glass, carbon-fiber composite,
any other industrial material having the required strength
properties, or any combination thereof.
[0024] Spindle 16 includes a first end 62 and a second end 64.
First end 62 and second end 64 generally define spindle axis 66.
Spindle 16 is rotated about spindle axis 66 during drilling
operations. Spindle 16 is driven by at least one spindle motor 68.
An output shaft 70 of spindle motor 68 operably engages a pinion
gear 72. In one embodiment, output shaft 70 is splined and pinion
gear 72 includes a mating splined inner face 73 to align with and
receive output shaft 70. Any other mechanical coupling methods
known in the art, including those described above, may be
instituted such that output shaft 70 drivingly engages pinion gear
72. Pinion gear 72 engages rotation gear 74 that transfers the
torque generated by spindle motor 68 to spindle 16 through torque
transfer assembly 76 thereby causing rotation of spindle 16 about
spindle axis 66. An embodiment of the present invention includes
two spindle motors 68, each spindle motor 68 driving a pinion gear
72 that is drivingly engaged with rotation gear 74. Rotation gear
74 and torque transfer assembly 76 are journaled for rotation
relative to outer housing 12 upon rotation drive bearings 78.
Rotation drive bearings 78 are generally roller bearings, but can
be any bearing type or configuration known in the art that
facilitates the rotation of spindle 16 with respect to outer
housing 12.
[0025] Spindle 16 is mounted to sine generator 14 with upper
spindle bearing 80 and lower spindle bearing 82. Spindle bearings
80, 82 allow independent rotary motion of spindle 16 with respect
to a center 84 of sine generator 14. Spindle bearings 80, 82 also
the transfer the vibration force from sine generator 14 to spindle
16. The spindle bearing configuration of the present invention
allows sonic drill head 10 to be utilized for sonic drilling--the
superposition of slow rotation with vibration upon spindle 16--and
traditional high speed rotary drilling including, but not limited
to diamond core, and other rotary drill methods known in the art.
One embodiment of the present invention includes spindle bearings
80, 82 being spherical roller thrust bearings. Any other bearing
type or configuration known in the art that supports spindle 16
upon sine generator 14 while allowing for free rotation of spindle
16 with respect to sine generator 14 and also transferring the
vibratory force from sine generator 14 to spindle 16 is within the
scope of the present invention. In one embodiment of the present
invention, the spindle bearing preload is adjusted by means of a
spindle lock nut 83 and thrust sleeve 85. The nut contains jack
screws 87 that each individually contribute to the entire developed
preload, thereby eliminating the need to torque the spindle lock
nut 83. Tightening of the jack screws 87 creates an upward acting
force on spindle 16 and an equal and opposite downward acting force
on the thrust sleeve 85 and associated components which places
upper and lower spindle bearings 80, 82 into compression, or
preload, against sine generator 14.
[0026] Spindle 16 generally is a continuous member having a hollow
cross section as shown in FIG. 1. Spindle 16 is a member generally
having circular cross-section; however, any member shape in the art
known to be used as a spindle 16 may be used. One embodiment of
spindle 16 includes a one piece hollow shaft. An alternative
embodiment of spindle 16 may include a plurality of members coupled
together having an uninterrupted hollow cross-section. An
embodiment of the present invention may include spindle 16 having a
solid cross-section. An embodiment of spindle 16 includes first end
62 and second end 64 of spindle 16 protruding through the outer
housing 12. Embodiments of the present invention may include
spindle 16 protruding out of the top or the bottom of the outer
housing, or both. The continuous hollow cross section of spindle 16
is configured for the addition or removal of cuttings, materials,
lubricants, tools, instrumentation, or other drilling aids.
[0027] Common materials that may be introduced into drilling string
through first end 62 of spindle 16 may include drilling fluid, mud,
and tooling (not shown). In addition, materials including drilling
fluid, mud, tools, or cuttings resulting from the drilling process
may be removed through the first end 62 of spindle 16. It will be
appreciated by one of skill in the art that any of a number of
materials, tools, or other drilling aids may be introduced into or
removed from the drill string through first end 62 of spindle 16.
When no materials, tools or drilling aids are to be removed or
introduced through first end 62 of spindle 16, an embodiment of the
present invention may include a cap 86 removably coupled to first
end 62 of spindle 16 or to outer housing 12 as shown.
[0028] The second end 64 of spindle 16 can be configured to receive
a drill string (not shown). Any drill string known in the art for
sonic drilling, diamond core drilling, rotary drilling, or any
other drilling method known in the art suitable for use with sonic
drill head 10 is within the scope of the present invention. There
are many connection types known in the art to removingly couple a
drill string to second end 64 of spindle 16, all of which a person
of skill in the art would appreciate to be within the scope of the
present invention.
[0029] Spindle 16 is generally journaled for rotation and axial
movement with respect to outer housing 12 of sonic drill head 10.
One embodiment of the present invention includes first end 62 and
second end 64 journaled through an upper hydrostatic bearing 88
proximate first end 62 of spindle 16 and a lower hydrostatic
bearing 90 proximate second end 64 of spindle 16. The hydrostatic
bearings 88, 90 float spindle 16 on a thin film of oil that is
pumped in under pressure. Hydrostatic bearings 88, 90 contain a
plurality of inner pockets (not shown) that are fed with supply oil
through a metering orifice. In one embodiment, a clearance gap 92
between the spindle journal 94 and the bearing inner diameter (not
shown) is maintained to restrict oil leakage and prevent reduced
bearing capacity. Hydrostatic bearings 88, 90 have a low
coefficient of friction and virtually unlimited wear life. An
alternate embodiment (not shown) includes using commercially
available non-hydrostatic slide bearings comprising a steel base
layer, a bronze mid-layer and a low-friction polymer top-layer.
This slide bearing may or may not be lubricated. A person of skill
in the art will appreciate that the present invention is not
limited to use of hydrostatic bearings to facilitate rotation and
axial translation of spindle 16 with respect to outer housing 12 as
described herein, but any traditional sliding bearing that
facilitates this relative movement now known or hereafter developed
is within the scope of the present invention.
[0030] Spindle 16 and its components described above can be of any
material known in the art including steel, iron, titanium,
aluminum, industrial plastics, fiber glass, carbon-fiber composite,
any other industrial material having the required strength
properties, or any combination thereof.
[0031] FIG. 1 further illustrates an embodiment of isolation system
18. Isolation system 18 generally isolates the high amplitude
vibratory motion of spindle 16 from outer housing 12 wherein outer
housing 12 remains relatively stationary. An embodiment of the
isolation system 18 of the present invention includes a plurality
of assemblies comprising an air piston 96 and a cylinder 98 that
provide separation of the stationary and moving parts with a
cushion of compressed air 100. An embodiment of the present
invention includes twelve (12) air piston 96 and cylinder 98
assemblies. Embodiments of isolation system 18 of the present
invention can alternatively include, but are not limited to:
mechanical springs or shocks, air springs or shocks, hydraulic
springs or shocks, fluid dampers, passive or active mass dampers,
or any other system known in the art to isolate the vibration
generated by sine generator 14 from outer housing 12.
[0032] An embodiment of the present invention may also include an
isolation system 18 and sine generator 14 that translates a thrust
force during drilling from the outer housing 12 to spindle 16. An
embodiment of the present invention includes piston 96 and cylinder
98 assemblies translating thrust forces from the outer case to the
drill spindle during drilling. Properly sized and placed inlet and
exhaust porting (not shown) within cylinders 98 cause sine
generator 14 to seek a centered position within outer housing 12
when acted upon by external forces. An embodiment of isolation
system 18 may also include a bumper 102 to limit the motion of sine
generator 14 to reduce or prevent damage to outer housing 12 or
piston 96 in the event of a force overload. Bumper 102 can be any
configuration and material known in the art to reduce or prevent
damage during the impact of two members. Embodiments of bumper 102
may include mechanical springs or elastomeric pads.
[0033] An embodiment of isolation system 18 further includes an
upper piston assembly 104 proximate top plate 48 of sine generator
14 and a lower piston assembly 106 proximate bottom plate 50 of
sine generator 14 wherein upper piston assembly 104 and lower
piston assembly 106 are aligned. Upper piston assembly 104 and
lower piston assembly 106 further include a sealing member 108 that
engages a wall 110 of cylinder 98 to form a substantially air tight
seal. Sealing member 108 can be any material having a resiliency to
withstand many cycles of vibratory motion relative wall 100 of
cylinder 98 and maintain a substantially air-tight seal including,
but not limited to: cast iron, aluminum, steel, brass, rubber,
polymeric composite blends, fiber-reinforced composites, and
elastomeric materials. An embodiment uses a cast iron sealing
member 108.
[0034] Isolation system 18 may further include a spacer 112 between
top plate 48 and bottom plate 50 of sine generator 14 and a
threaded rod 114 through apertures (not shown) in upper piston
assembly 104, top plate 48, spacer 112, bottom plate 50, and lower
piston assembly 106 as shown in FIG. 2. The present invention is
not limited to a threaded rod, but any smooth rod having threading
at each end may be used. Further, a nut 116 engages each end of
threaded rod 114 and is tightened thereby clamping upper piston
assembly 104, top plate 48, spacer 112, bottom plate 50, and lower
piston assembly 106 into a substantially rigid assembly. This
assembly must transfer force axially in the direction of vibration.
Alternatively, any other method of assembling upper piston 104, top
plate 48, spacer 112, bottom plate 50, and lower piston 106 such
that they form a substantially rigid member capable of transferring
force in the direction of vibration is within the scope of the
present invention, including threading components such that they
matingly engage with the other components as required or welding
components together.
[0035] Isolation system 18 and its components described above can
be of any material known in the art including steel, iron,
titanium, aluminum, industrial plastics, fiber glass, carbon-fiber
composite, any other industrial material having the required
strength properties, or any combination thereof.
[0036] Now turning to FIG. 2, one embodiment of sine generator 14,
spindle 16 and isolation system 18 is further illustrated. This
embodiment includes six rotors 46, each rotor 46 journaled for
rotation in a rotor housing 52. A plurality of rotor bearings 54
facilitates the rotation of rotor 46 within rotor housing 52. One
embodiment of the present invention includes rotor bearings 54
being angular contact rolling element bearings mounted in a back to
back arrangement. A person of skill in the art will appreciate that
the present invention is not limited to a particular rotor bearing
type, but any known bearing types in the art are within the scope
of the present invention. In one embodiment, rotor housing 52 is
coupled to both top plate 48 and bottom plate 50 of sine generator
14 with six bolts 118 at each plate 48, 50 as shown. The coupling
of rotor housing 52 to both plates 48, 50 of sine generator 14
shall not be limited to a bolted connection, but can be any
coupling method known in the art using any number of fasteners
including: bolts, screws, pins, rivets, welds, retention rings,
compression rings, clamps, or any other mechanical coupling method
known in the art.
[0037] FIG. 2 also demonstrates an embodiment of top plate 48 and
bottom plate 50 that further includes two stiffener ribs 120
proximate each coupling position of housing 52. Ribs 120 generally
stiffen plates 48, 50 at or near where rotor housing 52 applies the
vibration force to plates 48, 50. Further, an embodiment of top
plate 48 and bottom plate 50 includes a stiffener 122 proximate a
piston housing 124 that receives upper piston 104 in top plate 48
and lower piston 106 in bottom plate 50 wherein piston housing 124
is proximate an outside face 126 of top plates 48 or proximate an
outside face 127 of bottom plate 50. Ribs 120 generally extend from
outer face 126 or 127 to an inner face 128 of sine generator 14 and
are integral with top plate 48 or bottom plate 50. Stiffeners 122
generally extend from piston housing 124 to inner face 128 in a
radial direction from center 84 of sine generator 14 on either
plate 48, 50. Embodiments of the present invention may include
center 84 being located on spindle axis 66 of spindle 16 as
shown.
[0038] FIG. 2 illustrates an embodiment of the present invention
wherein the six rotors 46 are in a hexagonal shape, extending
radially from spindle axis 66. The layout of rotors 46 forms an
aperture (not shown) that generally corresponds with inner face 128
of sine generator 14. This configuration of sine generator 14
allows spindle 16 to be a continuous member that extends through
sine generator 14 as shown. FIG. 2 also illustrates the location of
upper spindle bearing 80 with respect to top plate 48. One
embodiment of the present invention includes upper and lower
spindle bearings 80, 82 being a spherical thrust bearing assembly.
One embodiment includes spindle bearings 80, 82 having a cage 130
made of light weight polymer. The lightweight polymer helps to
eliminate damage caused by inertial effects. An alternative
embodiment includes cage 130 being made from lightweight, high
strength steel. Further, the geometry of the cage is modified to
minimize axial clearance with respect to the bearing elements,
thereby reducing the impact forces cause by the high level of
vibration.
[0039] FIG. 2 further illustrates an embodiment of torque transfer
assembly 76 that includes a plurality of lobes 132 wherein the
lobes 132 are coupled to or integral with a continuous ring 134.
Other members of torque transfer assembly (not shown) drivingly
engage lobes 132 causing the lobes 132 and continuous ring 134 to
rotate about spindle axis 66. Continuous ring 134 is configured to
engage spindle 16 such that torque applied to continuous ring 134
causes the rotation of spindle 16 about spindle axis 66.
[0040] FIG. 2 further illustrates an embodiment of isolation system
18 of the present invention. In the illustrated embodiment, upper
piston 104 is received into piston housing 124 of top plate 48 and
lower piston 106 is received into piston housing 124 of bottom
plate 50. Further, spacer 112 is located between top plate 48 and
bottom plate 50. One embodiment includes spacer 112 being received
into a recess in the surface of top and bottom plates 48, 50
configured receive spacer 112. One embodiment includes spacer 112
bearing directly on top and bottom plates 48, 50. FIG. 2 also
further illustrates sealing member 108 on an outside face 136 of
piston 96.
[0041] Now turning to FIG. 3, components of vibration drive system
20, gearing system 26 and the configuration of eccentric rotors 46
of one embodiment of the present invention are illustrated. FIG. 3
illustrates gearing system 26 including a ring gear 30, three
planet gears 32, a sun gear 34, and a ring gear drive assembly 135
wherein ring gear drive assembly 135 further comprises input
housing 137, radial arms 139, and attachment ring 141. Motor 22
turns output shaft 28 that provides input torque to ring gear
assembly 30. Output shaft 28 includes radial extending teeth or
splines that matingly engage teeth or splines on an inner face 143
of input housing 137 of ring gear assembly 135. The present
invention may include embodiments wherein input housing 137, radial
arms 139 and attachment ring 141 of ring gear assembly 135 are
stand alone parts coupled together, integrally cast into one part,
or any combination thereof. A first end 145 of radial arms 139 are
rigidly coupled to or cast integral proximate housing 137 and
radial arms 139 extend radially from housing 137 wherein a second
end 147 of radial arms 139 is proximate attachment ring 141. Radial
arm 139 may be one piece or a plurality of components coupled
together. An embodiment of the present invention may alternatively
use a substantially solid formed plate instead of the radial arms
139 to transfer torque from input housing 137 to attachment ring
141. Attachment ring 141 is generally coupled to or cast integral
with ring gear 30. Ring gear 30 is drivingly engaged with three
planetary gears 32. The axis of rotation for each planetary gear 32
is held static and the planetary gears 32 drivingly engage sun gear
34 and create output torque that rotates sun gear 34.
[0042] Sun gear 34 engages and thereby causes the rotation of drive
shaft 26. First end 36 of drive shaft 26 may have crowned splines
40 that removably engage with mating splines 138 of sun gear 34.
Second end 38 of drive shaft 26 engages with a driven bevel gear
140. Driven bevel gear 140 drivingly engages two adjacent bevel
gears 44. FIG. 3 illustrates an embodiment of the present invention
wherein the six bevel gears 44, 140, eccentric rotors 46, and
housings 52 are configured in a hexagonal distribution around the
center 84 of sine generator 14. This embodiment further includes
each bevel gear 44 being paired with an opposite bevel gear 44,
resulting in three pairs of bevel gears. Each pair of bevel gears
44 is aligned along a first pair line 142, a second pair line 144,
and a third pair line 146. One embodiment of the present invention
includes the pair lines 142, 144, 146 intersecting at a common
point 148. An embodiment of the present invention includes lines
142, 144, 146 all including an intersecting angle 150 of sixty (60)
degrees. Other intersecting angles are also within the scope of the
present invention. An embodiment of the present invention includes
common point 148 being on spindle axis 66.
[0043] In general, the six bevel gears 44 operate in series;
therefore, rotating driven bevel gear 140 causes the rotation of
all the other bevel gears. Each bevel gear 44, 140 are integral
with or coupled to an eccentric rotor 46 within rotor housing 52
and the rotation of each bevel gear 44 causes the rotation of each
rotor 46. An embodiment of bevel gear 44 includes spiral bevel gear
although a person of skill in the art will appreciate any of a
number of bevel gear types and configurations known in the art are
within the scope of the present invention.
[0044] FIG. 4 illustrates an embodiment of sine generator 14 of
sonic drill head 10 wherein eccentric rotor 46 axis of rotation 152
is tilted from horizontal. This embodiment results in all six
rotors 46 having an individual axis of rotation 148. FIG. 4 further
illustrates an embodiment of the sine generator 14 of the present
invention wherein rotors 46 are synchronized with bevel gears 44
such that all eccentric masses 56 reach top-dead-center and
bottom-dead-center simultaneously. Specifically, it can be seen in
FIG. 4 that a first eccentric mass 154 of a first rotor 156 and a
second eccentric mass 158 of a second rotor 160 are both at
bottom-dead-center. In this embodiment, the other eccentric masses
56 of the other two rotors 162 shown in FIG. 4 and the two rotors
not shown are also at bottom-dead-center. When the eccentric masses
56 of all rotors 46 are synchronized and rotate about their
individual axis of rotation 152, the forces in the top-dead-center
direction and bottom-dead-center direction are additive creating a
linear sinusoidal force in a direction corresponding with
top-dead-center and bottom-dead-center. No resultant horizontal
force is present because bevel gears 44 cause adjacent rotors 46 to
rotate in opposite directions and, as a result, any horizontal
force components created by the rotation of eccentric rotors 46
cancel out when an even number of eccentric rotors 46 are present
as shown.
[0045] Now turning to FIG. 5, an embodiment of torque transfer
assembly 76 of sonic drill head 10 is illustrated. Torque transfer
assembly 76 generally transfers the drive force generated by at
least one spindle motor 68 to spindle 16. FIG. 5 illustrates an
embodiment of sonic drill head 10 powered by two spindle motors 68.
Output shafts 70 of each spindle motor 68 are shown in FIG. 5 to be
splined and engaging a mating splined inside face 73 of pinion gear
72. Pinion gears 72 are drivingly engaged with rotation gear 74.
The relative size difference between the pinion gears 72 and
rotation gear 74 determines the torque increasing ratio.
Embodiments of the present invention include a torque increasing
ratio being in the range between one and one-half to one (11/2:1)
and ten to one (10:1). An embodiment of the present invention may
have a torque increasing ratio of generally around five to one
(5:1). Spindle motor 68 operates at its highest displacement during
sonic drilling providing a low speed output with high torque.
Spindle motor 68 may alternatively operate at its minimum
displacement to perform diamond core or other known high speed
rotary drill methods providing a high speed output with low
torque.
[0046] Torque is generally transferred from the spindle motor 68,
pinion gear 72, and rotation gear 74 to spindle 16 through torque
transfer assembly 76 in the present invention. An embodiment of the
driving half of torque transfer assembly 76 as shown in FIG. 5
includes a plurality of housings 164 coupled to rotation gear 74
wherein a pair of bearing pads 166 are coupled to each housing 164.
One embodiment includes bolting housing 164 to rotation gear 74,
but any coupling method known in the art including: bolts, screws,
pins, rivets, welds, retention rings, compression rings, or any
other mechanical coupling method known in the art is within the
scope of the present invention. An embodiment of the driven half of
torque transfer assembly 76 as shown includes a plurality of lobes
132 that radiate outward from an outer face 168 of continuous ring
134. Lobes 132 may be evenly spaced around circumference of
continuous ring 134 or, alternatively, may be unevenly spaced.
Housings 164 are configured on rotation gear 74 to matingly engage
lobes 132 whether lobes 132 are evenly or unevenly spaced.
[0047] Continuous ring 134 is shown to have a splined inner face
170. Splined inner face 170 of continuous ring 134 mates with
splines 172 integral to spindle 16. Splines 172 not only transfer
torque, but are configured to allow axial slip of ring 134 and
thrust sleeve 85 to effect preload of spindle bearings 80, 82. Each
lobe 132 is configured to be located between two housings 164 and
bear against a pair of bearing pads 166, yet remain axially
translatable with respect to the bearing pad 166 pairs and housings
164. One bearing pad 166 engages with a side 174 of each lobe 132
for the purpose of transferring torque in two directions. The
embodiment shown in FIG. 5 includes eighteen (18) bearing pads 166
coupled to nine (9) housings 164 and nine (9) lobes 132 to complete
the transfer of torque from the spindle motor(s) 68 to spindle
16.
[0048] An embodiment of an upper piston assembly 104 of the present
invention is shown in FIG. 6. Lower piston assembly 106 can be
constructed in a substantially identical manner. Upper piston
assembly 104 as shown includes an upper piston support 176, lower
piston support 178, and piston 180. Upper piston support 176
includes an upper support flange 182 having a lower surface 184.
Lower piston support 178 includes a lower support flange 186 having
an upper surface 188. Piston 180 includes a top surface 190, a
bottom surface 192, an inner aperture 194, and outer surface 196.
Upper piston support 176 passes through the inner aperture 194 of
piston 180 and nests in lower piston support 178 as shown and
piston 180 is thereby sandwiched between lower surface 184 of upper
piston support 176 and upper surface 188 of lower piston support
178. Upper piston support 176 and lower piston support 178 are
configured such that rod 114 passes through both members and upper
piston support 176 is coupled to lower piston support 178 and
secured thereto by nut 116 as shown.
[0049] One embodiment of piston assembly 104, 106 includes a
clearance gap 198 between lower surface and a sealing member 108.
Clearance gap 198 may be configured to allow a lubricant to be
introduced between the piston supports 176, 178 and piston 180. An
upper o-ring 200 nests in lower surface 194 of upper piston support
176 and a lower o-ring 202 nests in upper surface 188 of lower
piston support 178 as shown wherein o-rings 200, 202 retain the
lubricant. Clearance gap 198 allows the upper and lower piston
supports 176, 178 to shift relative to piston 180. This embodiment
provides the piston 180 interface with cylinder wall 110 to react
and resist torsion forces developed in spindle bearings 80, 82. One
embodiment includes a clearance gap of 0.010 inches, though any gap
providing lubrication and relative slip of piston 180 with upper
support 176 and lower support 178 is within the scope of the
present invention. In one embodiment of the present invention,
isolation system 18 performs at least three functions including,
but not limited to vibration isolation, thrust force transfer, and
torque resistance.
[0050] Outer surface 196 of piston 180 may include sealing member
108 nested into a grove or housing machined into outer surface 196
as shown. Further piston 180 may also include a lubrication
metering orifice 204 located in at least one location on outside
surface 196 of piston 180. Lubrication metering orifice 204 allows
for manual or automated measurement of lubricant level or operating
temperature. Outer surface 196 may also include a lubrication
groove 206 as shown to lubricate the relative movement between
outer surface 196 and cylinder wall 110. Any lubrication method
know in the art to lubricate piston 180 for translation relative to
cylinder wall 110 may be implemented to supply liquid or dry
lubricants to outer surface 196 and the piston assembly 104,
106.
[0051] An embodiment of the present invention including water
swivel 206 at the first end 62 of spindle 16 is shown in FIG. 7.
Water swivel 206 generally includes a stator 208, a rotor 210, and
a bonnet 212. Stator 208 is generally configured to be a
non-rotating component that facilitates fluid entry into spindle 16
as shown. Stator 208 generally includes a hollow cross-section
configured to receive a pressure hose fitting as shown and to
facilitate the passage of fluid in or out of stator 208. The shape
of stator 208 may be any shape known in the art, including the
configuration shown in FIG. 7. Stator 208 may include a housing 214
that receives seal 216, wherein seal 216 may include bearings 218
that facilitate the relative rotation of rotor 210 with respect to
stator 208. Stator 208 may also include grease groove 220 as
shown.
[0052] Rotor 210 is generally attached to and configured to rotate
with spindle 16. Rotor 210 may include a first end 222, a second
end 224, a flange 226, a polished ceramic liner 228, a wiper 230,
and a groove 232 that receives a static o-ring 234. Rotor 210 is
generally configured to be received into first end 62 of spindle 16
substantially as shown. One embodiment includes rotor 210 being
coupled to spindle lock nut 83 with jack screws 87 wherein spindle
lock nut 83 is threaded onto first end 62 of spindle 16.
[0053] An embodiment of rotor 210 may include a hollow cross
section configured to receive stator 208 as shown. The hollow
cross-section also allows fluid to pass through the ends of rotor
210. In this embodiment, static o-ring 234 is configured to provide
a fluid-tight seal between the rotor 210 and the spindle 16 to
prevent any introduced water from being unwantingly expelled out of
first end 62 of spindle 16. Polished ceramic liner 228 is
configured to provide a surface that offers reduced friction during
the rotation of rotor 210 about stator 208 while in contact with
seal 216 of stator 208. An embodiment of rotor 210 may also include
wiper 230 generally configured to exclude dirt, dust, or other
contaminants from affecting the seal between stator 208 and rotor
210. As shown in FIG. 7, wiper 226 is proximate an inner surface
236 of rotor 210 and rests against an outer surface 238 of stator
208.
[0054] An embodiment of the present invention may include bonnet
212 that covers the stator 208 and rotor 210 as shown. Bonnet 212
may be removably coupled to stator 208. Further, bonnet 212 may be
removably coupled to outer housing 12. An embodiment of bonnet 212
includes access apertures 240 allowing an operator to rotate jack
screws 87 thereby adjusting the pre-load of spindle bearings 80, 82
as described above without removing the bonnet for minimal
interruption of the operation of the sonic drill head 10 of the
present invention.
[0055] An embodiment of the sonic drill head 10 of the present
invention illustrated in FIGS. 8A and 8B may further include at
least one anti-rotation assembly 242 to resist torsion forces
developed in spindle bearings 80, 82 and thereby prevent rotational
displacement of sine generator 14. Anti-rotation assembly 242
includes a reaction bar 244 coupled to upper sine generator plate
48 and lower sine generator plate 50, a first substantially
vertical bearing pad 246 and a second substantially vertical
bearing pad 248 opposite said first bearing pad 246 separated by a
distance D. Reaction bar 244 includes a first substantially
vertical face 250, a second substantially vertical face 252
opposite first vertical face 250, a thickness T of material defined
by first vertical face 250 and second vertical face 252, and a
length L. Length L is generally such that reaction bar 244 spans
continuously between upper and lower sine generator plates 48 and
50. Thickness T is generally slightly less than distance D such
that reaction bar 244 slides vertically between first bearing pad
246 and second bearing pad 248, but substantial horizontal movement
of reaction bar in both directions is resisted by bearing pads 246
and 248. First and second vertical faces 250, 252 of reaction bar
244 are cast or machined smooth so as to easily slide vertically
relative to first and second bearing pads 246, 248 thereby allowing
substantially frictionless vertical displacement of sine generator
14 relative to outer housing 12.
[0056] First bearing pad 246 engages first vertical face 250 of
reaction bar 244 and second bearing pad 248 engages second vertical
face 252 of reaction bar 244 to prevent rotation of the sine
generator 14 within outer housing 12 due to the friction of spindle
bearings 80, 82 when spindle 16 is rotating. In one embodiment,
first bearing pad 246 and second bearing pad 248 are supplied with
lubricating oil through an oil inlet hole 254 within the pad. The
oil inlet hole 254 communicates with a plurality of serrations or
channels (not shown) in first and second bearing pads 246, 248. The
serrations or channels distribute the oil uniformly over the entire
surface of interaction between bearing pads 246, 248 and vertical
faces 250, 252 of reaction bar 244. First bearing pad 246 and
second bearing pad 248 are coupled to anti-rotation housing 256.
Anti-rotation housing 256 is generally coupled to outer housing 12
as shown. An external hose 258 and pump (not shown) supplies the
lubricating oil to first and second bearing pads 246 and 248. Thus,
anti-rotation assembly 242 allows for virtually frictionless
vertical translation of sine generator 14 relative to outer housing
12, yet effectively prevents sine generator 14 from rotating about
spindle axis 66 due to the frictional resistance of spindle
bearings 80, 82.
[0057] From the foregoing, it may be seen that the sonic drill head
of the present invention is particularly well suited for the
proposed usages thereof. Furthermore, since certain changes may be
made in the above invention without departing from the scope
hereof, it is intended that all matter contained in the above
description or shown in the accompanying drawing be interpreted as
illustrative and not in a limiting sense. It is also to be
understood that the following claims are to cover certain generic
and specific features described herein.
* * * * *