U.S. patent application number 15/160850 was filed with the patent office on 2016-11-24 for thrust bearing surface for floater-style centrifugal pumps.
The applicant listed for this patent is Summit ESP, LLC. Invention is credited to Gregory Austin Davis, David Thomas Jolly, Freddie George Walton.
Application Number | 20160341206 15/160850 |
Document ID | / |
Family ID | 57287220 |
Filed Date | 2016-11-24 |
United States Patent
Application |
20160341206 |
Kind Code |
A1 |
Davis; Gregory Austin ; et
al. |
November 24, 2016 |
THRUST BEARING SURFACE FOR FLOATER-STYLE CENTRIFUGAL PUMPS
Abstract
A thrust bearing surface for a floater-style centrifugal pump is
described. A thrust bearing system includes a rotatable member
including a sleeve, and a flange extending radially on a downstream
side of the sleeve, a swirling member on a top of the flange, the
swirling member extending axially towards an impeller bottom,
wherein as the swirling member rotates, the swirling member guides
working fluid in an outwards and upwards direction from the
swirling member. A rotating member of a thrust bearing surface
includes a sleeve securable to a rotatable shaft of a stage, a
flange extending radially around a top of the sleeve, and at least
one swirling member extending axially downstream from a top of the
flange towards a bottom of an impeller, wherein each of the at
least one swirling member extends from an outer diameter towards an
inner diameter of the flange.
Inventors: |
Davis; Gregory Austin;
(Broken Arrow, OK) ; Walton; Freddie George;
(Midland, TX) ; Jolly; David Thomas; (Midland,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Summit ESP, LLC |
Tulsa |
OK |
US |
|
|
Family ID: |
57287220 |
Appl. No.: |
15/160850 |
Filed: |
May 20, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62164829 |
May 21, 2015 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 13/10 20130101;
F04D 29/0413 20130101; F05D 2260/36 20130101; F04D 1/06 20130101;
F16C 17/047 20130101; F16C 33/101 20130101; F04D 29/042 20130101;
F16C 2360/44 20130101; F16C 32/0685 20130101 |
International
Class: |
F04D 29/041 20060101
F04D029/041; F04D 1/00 20060101 F04D001/00; F04D 29/22 20060101
F04D029/22; F04D 29/043 20060101 F04D029/043; F04D 29/046 20060101
F04D029/046; F16C 32/06 20060101 F16C032/06; F04D 7/04 20060101
F04D007/04 |
Claims
1. A rotating member of a thrust bearing surface comprising: a
sleeve securable to a rotatable shaft of a stage; a flange
extending radially around a top of the sleeve; and at least one
swirling member extending axially downstream from a top of the
flange towards a bottom of an impeller; wherein each of the at
least one swirling member extends along the top of the flange from
an outer diameter towards an inner diameter of the flange.
2. The rotating member of claim 1, wherein there are a plurality of
swirling members arranged circumferentially around the top of the
flange.
3. The rotating member of claim 1, wherein each of the at least one
swirling member terminates prior to the inner diameter to form a
clearance occupied by one of an impeller hub or a standoff
sleeve.
4. The rotating member of claim 1, wherein each of the at least one
swirling member is one of fin, ramp or foil shaped.
5. The rotating member of claim 1, wherein the flange comprises a
circumferential chamfer and the at least one swirling member
extends over at least a portion of the chamfer.
6. The rotating member of claim 1, wherein each swirling member is
a ramp comprising a sloped top surface.
7. The rotating member of claim 6, wherein the sloped surface
slopes upwards towards a trailing edge of the swirling member.
8. The rotating member of claim 1, wherein each of the at least one
swirling member comprises one of a beveled leading edge or a
beveled corner on a top surface of the at least one swirling
member.
9. The rotating member of claim 1, wherein each of the at least one
swirling member commences at the outer diameter and terminates
prior to the inner diameter of the top of the flange.
10. The rotating member of claim 1, wherein each of the at least
one swirling member commences at the outer diameter and terminates
at the inner diameter of the top of the flange.
11. The rotating member of claim 1, wherein the at least one
swirling member is a single foil.
12. A centrifugal pump comprising: a rotatable shaft; an impeller
stacked on the shaft; a rotatable sleeve secured around the shaft
below the impeller, the sleeve comprising a flange extending
radially on a downstream side of the rotatable sleeve; and a
swirling member protruding axially downstream from the flange.
13. The centrifugal pump of claim 12, wherein the swirling member
is one of a hexafoil, quatrefoil or enneafoil.
14. The centrifugal pump of claim 12, wherein the swirling member
holds the impeller in a running position.
15. The centrifugal pump of claim 12, wherein a standoff sleeve
extends between the swirling member and the rotatable shaft.
16. The centrifugal pump of claim 12, wherein the swirling member
is one of a ramp or fin.
17. A thrust bearing system for a floater-style stage comprising: a
thrust bearing surface comprising a rotatable member, the rotatable
member comprising a tubular sleeve and a flange extending radially
on a downstream side of the tubular sleeve; a swirling member on a
top of the flange, the swirling member extending axially towards a
bottom of an impeller, wherein as the swirling member rotates, the
swirling member guides working fluid in an outwards and upwards
direction from the swirling member.
18. The thrust bearing system of claim 17, wherein the swirling
member comprises a plurality of fins.
19. The thrust bearing system of claim 18, wherein there are five
fins spaced around the top of the flange.
20. The thrust bearing system of claim 18, wherein each of the
plurality of fins extends radially between an outer diameter and
inner diameter of the radial surface of the flange.
21. The thrust bearing system of claim 17, wherein the swirling
member comprises a foil.
22. The thrust bearing system of claim 17, wherein one of a hub of
the impeller or a standoff sleeve is between the swirling member
and a shaft, the rotatable member secured to the shaft.
23. The thrust bearing system of claim 17, wherein the thrust
bearing surface is downhole in subsurface formation and the working
fluid comprises one of water, oil, natural gas or a combination
thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/164,829 to Davis et al., filed May 21, 2015 and
entitled "LEAK RESISTANT FLANGED SLEEVE," which is hereby
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention described herein pertain to the
field of floater-style centrifugal pump stages. More particularly,
but not by way of limitation, one or more embodiments of the
invention enable a thrust bearing surface for floater-style
centrifugal pumps.
[0004] 2. Description of the Related Art
[0005] Fluid, such as natural gas, water, oil or other
hydrocarbons, is often located in underground formations. In such
situations, the fluid is commonly pumped to the surface so that it
can be collected, separated, refined, distributed and/or sold.
Centrifugal pumps are typically used in submersible pump
applications for lifting well fluid to the surface. Centrifugal
pumps impart energy to a fluid by accelerating the fluid through a
rotating impeller paired with a stationary diffuser. A rotating
shaft runs through the central hub of the impeller and diffuser. A
motor upstream of the pump turns the shaft of the pump motor. The
shaft of the pump motor turns the pump shaft, and the impeller is
keyed to the pump shaft, causing the impeller to rotate with the
pump shaft.
[0006] Each rotating impeller and stationary diffuser pair is
called a "stage". The impeller's rotation confers angular momentum
to the fluid passing through the pump. The angular momentum
converts kinetic energy into pressure, thereby raising the pressure
on the fluid and lifting it to the surface. Multiple stages of
impeller and diffuser pairs may be used to further increase the
pressure lift. The stages are stacked in series around the pump's
shaft, with each successive impeller sitting on a diffuser of the
previous stage.
[0007] As fluid moves upward through the pump, the rotating
impellers exert a downward force as discharge pressure acts on the
top of the impeller. The pump also experiences upward force from
discharge pressure acting against the bottom of the impeller, and
also due to the force produced by the momentum of the fluid making
its turn in the impeller passageway. These axial forces are
referred to as "thrust" experienced by the pump. Pumps capable of
handling higher down thrust loads are able to operate at lower
rates, which is beneficial due to extended operating ranges.
[0008] In both radial and mixed flow stages, one approach to
handling the axial thrust of the pump is to allow each impeller to
move axially on the pump shaft between the diffusers. In such
instances, the impeller is keyed to the shaft within a key groove
that runs axially along the length of the shaft. When the impellers
can move independently of the shaft, the pump is referred to as a
"floater style" pump.
[0009] To further improve a pump's thrust handling capabilities,
thrust bearing surfaces consisting of a conventional nonrotating
bushing and a conventional rotating flanged sleeve are typically
inserted into pump stages. Together, the conventional bushing and
conventional flanged sleeve form a conventional thrust bearing set.
Typically, the conventional bushing is attached to the wall of the
diffuser of the submersible pump and should not rotate. The sleeve
is keyed to the shaft of the submersible pump and rotates with the
shaft as fluid is pumped to the surface of a well. The conventional
bushing is positioned concentrically around the conventional
flanged sleeve, such that the conventional sleeve rotates within
the bushing. As the pump operates, fluid is pulled between the
bearing surfaces, increasing the pump's ability to handle thrust
loads by providing hydrodynamic lift.
[0010] A conventional sleeve is illustrated in FIG. 1. As shown in
FIG. 1, in conventional floater stages, conventional sleeve 100
includes a thin, disc-shaped conventional flange 105 at the top of
the conventional sleeve. The flange is typically between 0.08
inches and 0.200 inches in thickness. The conventional flanged
surface rotates inside the pump fluid, and also makes contact with
a standoff sleeve. The standoff sleeve only makes contact with a
narrow portion of the conventional flanged sleeve 100, closest to
the shaft. The standoff sleeve supports the impeller. and the
standoff sleeve length determines the operating height of the
impeller. The standoff sleeve is typically Ni-resist austenitic
cast iron alloy or stainless steel if shimmed.
[0011] Abrasives such as consolidated and unconsolidated sand,
quartz or iron sulfide commonly mix with fluid pumped from downhole
formations. As the fluid moves through the pump, the abrasives
damage the pump components through erosive wear, and thrust
bearings are no exception. Although thrust bearings are
conventionally made of hard materials such as titanium carbide,
tungsten carbide or silicon carbide, the thrust bearings are still
susceptible to erosive wear from abrasives. Erosive wear to the
thrust bearings causes them to leak, and the leakage reduces the
hydrodynamic lift provided by the bearings and undesirably
decreases head.
[0012] It would be an advantage for thrust bearings to have
improved abrasive handling capability and improved resistance to
leaks. Therefore, there is a need for improved thrust bearing
surface for floater-style centrifugal pumps.
BRIEF SUMMARY OF THE INVENTION
[0013] A thrust bearing surface for floater-style centrifugal pumps
is described. An illustrative embodiment of a rotating member of a
thrust bearing surface includes a sleeve securable to a rotatable
shaft of a stage, a flange extending radially around a top of the
sleeve, and at least one swirling member extending axially
downstream from a top of the flange towards a bottom of an
impeller, wherein each of the at least one swirling member extends
along the top of the flange from an outer diameter towards an inner
diameter of the flange. In some embodiments there are a plurality
of swirling members arranged circumferentially around the top of
the flange. In certain embodiments, each of the at least one
swirling member terminates prior to the inner diameter to form a
clearance occupied by one of an impeller hub or a standoff sleeve.
In some embodiments, each of the at least one swirling member is
one of fin, ramp or foil shaped. In certain embodiments, the flange
comprises a circumferential chamfer and the at least one swirling
member extends over at least a portion of the chamfer. In some
embodiments, each swirling member is a ramp comprising a sloped top
surface and the sloped surface slopes upwards towards a trailing
edge of the swirling member. In some embodiments, each of the at
least one swirling member comprises one of a beveled leading edge
or a beveled corner on a top surface of the at least one swirling
member. In certain embodiments, each of the at least one swirling
member commences at the outer diameter and terminates prior to the
inner diameter of the top of the flange. In some embodiments, each
of the at least one swirling member commences at the outer diameter
and terminates at the inner diameter of the top of the flange. In
certain embodiments, the at least one swirling member is a single
foil.
[0014] An illustrative embodiment of a centrifugal pump includes a
rotatable shaft, an impeller stacked on the shaft, a rotatable
sleeve secured around the shaft below the impeller, the sleeve
comprising a flange extending radially on a downstream side of the
rotatable sleeve, and a swirling member protruding axially
downstream from the flange. In some embodiments, the swirling
member is one of a hexafoil, quatrefoil or enneafoil. In certain
embodiments, wherein the swirling member holds the impeller in a
running position. In some embodiments, a standoff sleeve extends
between the swirling member and the rotatable shaft. In certain
embodiments, the swirling member is one of a ramp or fin.
[0015] An illustrative embodiment of a thrust bearing system for a
floater-style stage includes a thrust bearing surface including a
rotatable member, the rotatable member comprising a tubular sleeve
and a flange extending radially on a downstream side of the tubular
sleeve, a swirling member on a top of the flange, the swirling
member extending axially towards a bottom of an impeller, wherein
as the swirling member rotates, the swirling member guides working
fluid in an outwards and upwards direction from the swirling
member. In some embodiments the swirling member includes a
plurality of fins. In certain embodiments, there are five fins
spaced around the top of the flange. In some embodiments, each of
the plurality of fins extends radially between an outer diameter
and inner diameter of the radial surface of the flange. In certain
embodiments, the swirling member is a foil. In some embodiments,
one of a hub of the impeller or a standoff sleeve extends between
the swirling member and a shaft, the rotatable member secured to
the shaft. In some embodiments, the thrust bearing surface is
downhole in subsurface formation and the working fluid comprises
one of water, oil, natural gas or a combination thereof
[0016] In further embodiments, features from specific embodiments
may be combined with features from other embodiments. For example,
features from one embodiment may be combined with features from any
of the other embodiments. In further embodiments, additional
features may be added to the specific embodiments described
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other aspects, features and advantages of the
invention will be more apparent from the following more particular
description thereof, presented in conjunction with the following
drawings wherein:
[0018] FIG. 1 is a perspective view of a conventional flanged
sleeve of the prior art.
[0019] FIG. 2 is a perspective view of a flanged sleeve with
fin-shaped swirling members of an illustrative embodiment.
[0020] FIG. 3 is a perspective view of a flanged sleeve with
ramp-shaped swirling members of an illustrative embodiment.
[0021] FIG. 4 is a cross sectional view across line 4-4 of FIG. 2
of a flanged sleeve with a swirling member of an illustrative
embodiment.
[0022] FIG. 5 is a perspective view of a foiled flanged sleeve of
an illustrative embodiment.
[0023] FIG. 6 is a cross sectional view of a stage of an
illustrative embodiment.
[0024] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and may herein be described in
detail. The drawings may not be to scale. It should be understood,
however, that the embodiments described herein and shown in the
drawings are not intended to limit the invention to the particular
form disclosed, but on the contrary, the intention is to cover all
modifications, equivalents and alternatives to such embodiments
that fall within the scope of the present invention as defined by
the appended claims.
DETAILED DESCRIPTION
[0025] A thrust bearing surface for floater-style centrifugal pumps
now be described. In the following exemplary description, numerous
specific details are set forth in order to provide a more thorough
understanding of embodiments of the invention. It will be apparent,
however, to an artisan of ordinary skill that the present invention
may be practiced without incorporating all aspects of the specific
details described herein. In other instances, specific features,
quantities, or measurements well known to those of ordinary skill
in the art have not been described in detail so as not to obscure
the invention. Readers should note that although examples of the
invention are set forth herein, the claims, and the full scope of
any equivalents, are what define the metes and bounds of the
invention.
[0026] As used in this specification and the appended claims, the
singular forms "a", "an" and "the" include plural referents unless
the context clearly dictates otherwise. Thus, for example,
reference to a swirling member includes one or more swirling
members.
[0027] "Coupled" refers to either a direct connection or an
indirect connection (e.g., at least one intervening connection)
between one or more objects or components. The phrase "directly
attached" means a direct connection between objects or
components.
[0028] "Downstream" refers to the direction along a centrifugal
pump shaft away from the pump's motor and towards production tubing
and/or the pump discharge. Thus by way of example and without
limitation, in a vertical downhole submersible pump assembly, the
downstream direction may be towards the surface of the well. The
"top" of an element refers to the downstream side of the
element.
[0029] "Upstream" refers to the direction along a centrifugal pump
shaft towards the pump's motor and away from production tubing
and/or the pump discharge. Thus by way of example and without
limitation, in a vertical downhole submersible pump assembly, the
upstream direction may be towards the bottom of the assembly and/or
deeper in the ground. The "bottom" of an element refers to the
upstream side of the element.
[0030] As used in this specification and the appended claims, the
terms "inner" and "inwards" with respect to a thrust bearing or
other pump assembly component refer to the radial direction towards
the center of the shaft of the pump assembly and/or the center of
the aperture of the component through which the shaft would
extend.
[0031] As used in this specification and the appended claims, the
terms "outer" and "outwards" with respect to a thrust bearing or
other pump assembly component refer to the radial direction away
from the center of the shaft of the pump assembly and/or the center
of the aperture of the component through which the shaft would
extend.
[0032] As used in this specification and the appended claims, the
term "axial" and "axially" refers to the longitudinal direction
parallel to the length of the shaft of the centrifugal pump.
[0033] The inventors have observed a problem in conventional
submersible pumps. During operation, solid-laden fluid that should
be moving upward towards the surface of the well, and has
conventionally been thought to move upward, instead actually seeps
down through the conventional flanged sleeve and flows back to the
stage below. This seepage decreases head and erodes the bushing as
fluid and abrasives flow down the pump due to leaks in conventional
flanged sleeves.
[0034] Illustrative embodiments of the invention described herein
provide an improved thrust bearing surface for floater-style
centrifugal pump stages. The raised shapes formed on the top
(downstream) face of the flanged sleeve of illustrative embodiments
may positively impact the hydrodynamic flow, or barrier, created
around the thrust bearing by rotation of the flanged sleeve during
operation of the centrifugal pump. By altering this flow and/or
barrier, the potential for fluid to leak or bypass back into the
previous pump stage may be reduced and therefore increase pump head
per stage, which may improve overall efficiency. Swirling the flow
of pumped fluid upwards and outwards from the flange may reduce
erosion to the bushing that may occur as small abrasives such as
quartz or iron sulfide fall downwards during pumping operations.
Illustrative embodiments may guide such small abrasives upwards and
outwards into the successive pump stage, rather than downwards to
previous stages. Illustrative embodiments may carry a higher thrust
load and therefore operate at or below the volumetric rate (barrels
per day) of the same style of pump not making use of thrust
bearings.
[0035] A swirling member may extend axially from and/or be raised
above the downstream surface of the flange of the rotatable sleeve.
In some embodiments, the swirling members may be fin, ramp or foil
shaped. These axially protruding swirling member(s) may extend
towards the bottom of an impeller, impeller hub and/or standoff
sleeve. During rotation of the flanged sleeve, the swirling member
of illustrative embodiments may cause pumped fluid to swirl upwards
and outwards from the thrust bearings installed in the pump, and
thus may prevent or reduce leakage of pumped fluid downwards
towards preceding stages.
[0036] The thrust bearing surface of illustrative embodiments may
be a rotating member of a thrust bearing set. The rotating member
may be secured to the pump shaft, for example by friction or key,
such that the rotating member rotates with the shaft. The rotating
member may be paired with a stationary member, such as a bushing.
The stationary member may be pressed into the wall of a diffuser or
carrier by interference fit or glue and not substantially rotate
during operation of the pump. The rotating member may be a flanged
sleeve and be included in one or more centrifugal pump stages to
increase the thrust handling ability of the pump. The centrifugal
pump of illustrative embodiments may be a multi-stage centrifugal
pump or a charge pump, for example employed in an electric
submersible pump (ESP) assembly in a downhole and/or underground
formation application for pumping oil, water, natural gas or a
combination thereof. In some embodiments, the thrust bearing
surface of illustrative embodiments may be included in gas
separator stages included in an ESP assembly.
[0037] While for illustration purposes, illustrative embodiments
are described herein in terms of a thrust bearing set of a
centrifugal pump, nothing herein is intended to limit the invention
to those embodiments. Other components of ESP assemblies which may
include stages and/or thrust bearings, such as a charge pump or gas
separator may also make use of the improved flanged sleeve of
illustrative embodiments. In addition, any centrifugal pump
encountering abrasive materials, such as horizontal surface pumps,
may also make use of the improved flanged sleeve of illustrative
embodiments.
[0038] In illustrative embodiments, a flanged sleeve of a thrust
bearing set may be shaped to include a swirling member on a top
(downstream) surface of the flange. The shape of the swirling
member may be selected depending on pump conditions, the nature of
the pumped fluid and the ambient conditions in the geological
formation or other pump location. The axial height of swirling
members should be sufficient to modify the flow path of pumped
fluid at the inlet of the impeller and edge of the flanged sleeve.
In one example, the axial height of swirling members may extend
between 5/8 inch and 1 1/4 inch from the top surface of the flange,
depending on the type and size of stage employed. The flanged
sleeve of illustrative embodiments may replace a conventional
standoff sleeve or may be used in conjunction with a standoff
sleeve. In embodiments where the flanged sleeve replaces a standoff
sleeve, the axial height of the flanged sleeve of illustrative
embodiments may be determined so as to provide for the appropriate
impeller running height, which may be determined so the pump may
operate as if in compression.
[0039] FIG. 2 illustrates an exemplary rotatable thrust bearing
surface of an illustrative embodiment. Rotating member 200 may be
the rotatable member of a thrust bearing set. As shown in FIG. 2,
rotating member 200 may be a flanged sleeve including sleeve 205
and flange 210. Sleeve 205 may be tubular in shape such that the
shaft of the centrifugal pump may extend longitudinally through
central aperture 215. Sleeve 205 may include keyway 250 for
purposes of securing rotating member 200 to the rotatable shaft 615
(shown in FIG. 6) of the pump, charge pump or gas separator in
which the abrasion resistant trim (AR trim) is employed. Flange 210
may extend radially and circumferentially around the shaft and/or
central aperture 215 in a symmetric disc shape, and may include
chamfer 255 around its outer, top edge.
[0040] One or more swirling members may be formed, placed, jut,
extend and/or protrude upwards (downstream) on downstream surface
225 (top) of flange 210. An exemplary embodiment of a rotatable
thrust bearing with swirling members is illustrated in FIG. 2. In
FIG. 2, swirling members are fins 220 that extend downstream
towards an impeller hub and/or standoff sleeve, and also radially
from outer diameter 240 towards inner diameter 245. Fins 220 may be
shaped similarly to a rectangular prism or aquatic animal fin, and
may follow the shape of flange 210 on the bottom surface of fin
220. In some embodiments, such as shown in FIG. 2, fins 220 may not
reach inner diameter 245, but instead stop short of inner diameter
245. Fins 220 may commence at outer diameter 240 and terminate
short of inner diameter 245 forming clearance 510. Clearance 510
may allow a standoff sleeve or impeller hub to contact inner
diameter 245 of flange 210. In embodiments where flange 210
includes chamfer 255, fins 220 may extend over chamfer 255 so as to
be flush with and/or extend all the way to outer diameter 240 of
flange 210. Fins 220 may be wedges, paddles, blades, ribs or wings.
Fins 220 may be arranged around downstream surface 225 (top) of
flange 210. For example, two fins may be spaced at 180 degree
intervals, three fins 220 may be spaced every 120 degrees, five
fins 220 may be spaced every 72 degrees as shown in FIG. 2, etc.
Fins 220 may include bevel 230 on outer edge 235, which may be a
leading edge, top edge and/or outer, top edge of fins 220.
[0041] FIG. 4 illustrates a cross-sectional view of a finned
flanged sleeve of illustrative embodiments. FIG. 4 illustrates
axial height 505 of fin 220 that extends in a downstream direction,
clearance 510 and cross sectional shape of an exemplary fin 220 of
illustrative embodiments. In one exemplary embodiment, axial height
505 may be between 5/8 inch and 1 1/4 inches.
[0042] FIG. 3 illustrates a rotatable bearing surface with swirling
members of an illustrative embodiment. In the embodiment of FIG. 3,
swirling members are ramps 310 that include ramped surface 300.
Ramped surface 300 may decline towards leading edge 305 and
increase in height towards trailing edge 315. Ramped surface 300
may be sloped and/or curved and guide, scoop and/or swirl abrasive
solids upwards towards a successive stage, rather than permitting
such abrasive media to fall downwards. Flange 210 may be molded to
include ramps 310 and/or fins 220 as one continuous piece, and/or
the swirling members may be braised onto downstream surface 225,
ground or adhered. Ramps 310 and/or fins 220 may comprise the same
material as the remainder of rotating member 200, for example
titanium carbide, silicon carbide or tungsten carbide. As shown in
FIG. 3, five ramps 310 are spaced evenly around flange 210.
[0043] In some embodiments, the swirling member may be a foiled
surface such as a leaf, petal, clover or flower-shaped curve formed
by the cusping of an arch or circle. FIG. 5 illustrates an
exemplary foiled flanged sleeve of an illustrative embodiment. In
FIG. 5, an enneafoil is illustrated, but arced shapes having other
numbers of petals may also be employed, for example a hexafoil,
pentafoil, octofoil or quatrefoil. In foiled embodiments, outer
diameter 240 of flange 210 may be itself molded into the shape of
foil 500 and extended axially upwards, and/or foil 500 may be a
raised platform molded, adhered or ground onto downstream surface
225 of flange 210, such that the axial height 505 of flange 210 is
extended downstream towards an impeller positioning member (such as
an impeller hub or standoff sleeve) and/or impeller bottom.
Clearance 510 may remain open and/or uncovered by foil 500 to allow
a standoff sleeve or impeller hub to contact inner diameter 245. In
one exemplary embodiment, where the inner diameter of the standoff
sleeve is 1.193 inches and the inner diameter of foil 500 is 1.411
inches, clearance 510 may be about 0.110 inches.
[0044] FIG. 6 illustrates a floater-style centrifugal pump stage of
an illustrative embodiment. In the embodiment of FIG. 6, three
stages are shown with the thrust bearing surface of illustrative
embodiments included in one of the three stages. In other
embodiments, the thrust bearing surface of illustrative embodiments
may be included in multiple stages or every stage. The stages may
be incorporated into a pump, charge pump or gas separator of an ESP
assembly. As shown in FIG. 6, impeller hub 610 may place impeller
620 into its operating position when supported by rotating member
200. Rotating member 200 may be directly below impeller 620, as
illustrated in FIG. 6. Bushing 605 may be stationary during pump
operation and pressed into diffuser 625 or carrier. Swirling member
600 may protrude axially from downstream surface 225 (shown in FIG.
2) of flange 210 towards bottom of impeller 620, which impeller 620
may be directly above rotating member 200. Swirling member 600 may
extend axially and may contact and/or extend towards impeller hub
610 and/or standoff sleeve 630. As shown in FIG. 6, standoff sleeve
630 may extend between swirling member 600 and shaft 615, filling
clearance 510 as it extends between rotating member 200 and
impeller hub 610.
[0045] Rotating member 200 with swirling members 600 may be molded
into a single solid piece or may be braised, ground or adhered
together. As rotating member 200 rotates with shaft 615, swirling
member(s) 600 may modify the flow path of pumped fluid and
abrasives carried within the pump fluid in an upwards and outwards
direction, rather than downwards to a previous stage. Swirling
member 600 may be fin 220, ramp 310, foil 500 or other shape that
may provide the improved leak resistant benefits described herein.
In embodiments where no standoff sleeve 630 is employed, height 505
(shown in FIG. 4) of swirling member 600 may support impeller hub
610 in its operating position. In such instances clearance 510 may
be zero and swirling member 600 may extend from outer diameter 240
to all the way to inner diameter 245 of flange 210, and the running
position of impeller 620 may be determined by height 505 of
swirling member 600 proximate inner diameter 245.
[0046] Illustrative embodiments may provide a thrust bearing
surface for floater-style centrifugal pumps. The thrust bearing
surface of illustrative embodiments may provide one or more
swirling members on a top side of a flange of a rotatable member of
a thrust bearing set. The thrust bearing set may be located in a
stage of a floater-style pump, charge pump or gas separator. As the
rotatable member rotates, the swirling member(s) may cause abrasive
solids contained in working fluid to swirl upwards towards a
successive stage instead of falling down towards the thrust bearing
and causing erosive damage. Illustrative embodiments described
herein may improve the abrasive handling capability and/or leak
resistance of thrust bearing surfaces of illustrative
embodiments.
[0047] Further modifications and alternative embodiments of various
aspects of the invention may be apparent to those skilled in the
art in view of this description. Accordingly, this description is
to be construed as illustrative only and is for the purpose of
teaching those skilled in the art the general manner of carrying
out the invention. It is to be understood that the forms of the
invention shown and described herein are to be taken as the
presently preferred embodiments. Elements and materials may be
substituted for those illustrated and described herein, parts and
processes may be reversed, and certain features of the invention
may be utilized independently, all as would be apparent to one
skilled in the art after having the benefit of this description of
the invention. Changes may be made in the elements described herein
without departing from the scope and range of equivalents as
described in the following claims. In addition, it is to be
understood that features described herein independently may, in
certain embodiments, be combined.
* * * * *