U.S. patent application number 16/425633 was filed with the patent office on 2019-12-05 for drive flank engagement between rotating components and shaft of electrical submersible well pump.
This patent application is currently assigned to Baker Hughes Oilfield Operations LLC. The applicant listed for this patent is Baker Hughes Oilfield Operations LLC. Invention is credited to Risa Rutter, Brett T. Williams, Zheng Ye.
Application Number | 20190368511 16/425633 |
Document ID | / |
Family ID | 68693092 |
Filed Date | 2019-12-05 |
United States Patent
Application |
20190368511 |
Kind Code |
A1 |
Williams; Brett T. ; et
al. |
December 5, 2019 |
Drive Flank Engagement Between Rotating Components and Shaft of
Electrical Submersible Well Pump
Abstract
A well pump has a shaft with at least one shaft drive flank
extending a length of the shaft. Impellers are located between
non-rotating diffusers. Each impeller has a hub with an impeller
hub bore through which the shaft extends. The impeller hub bore has
at least one impeller drive flank that is in flush contact with the
shaft drive flank to impart rotation to the impeller. The shaft
drive flanks may be on opposite sides of the shaft and parallel
with each other. The shaft may have six of the shaft drive flanks
symmetrically arranged around the shaft and joining each other. The
shaft drive flanks may be three involute curved surfaces that join
each other.
Inventors: |
Williams; Brett T.;
(Claremore, OK) ; Rutter; Risa; (Claremore,
OK) ; Ye; Zheng; (Tulsa, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Oilfield Operations LLC |
Houston |
TX |
US |
|
|
Assignee: |
Baker Hughes Oilfield Operations
LLC
Houston
TX
|
Family ID: |
68693092 |
Appl. No.: |
16/425633 |
Filed: |
May 29, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62678313 |
May 31, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 7/04 20130101; F04D
29/708 20130101; F04D 1/06 20130101; F04D 13/10 20130101; F04D
29/20 20130101 |
International
Class: |
F04D 29/70 20060101
F04D029/70; F04D 1/06 20060101 F04D001/06; F04D 7/04 20060101
F04D007/04; F04D 29/20 20060101 F04D029/20 |
Claims
1. A well pump assembly, comprising: a pump having a housing with a
longitudinal axis; a shaft extending through the housing on the
axis, the shaft having at least one shaft drive flank integrally
formed thereon and extending substantially a length of the shaft; a
plurality of diffusers fixed in the housing against rotation, each
of the diffusers having diffuser passages extending from a diffuser
inlet to a diffuser outlet, each of the diffusers having a diffuser
bore through which the shaft extends; and an impeller located
between each of the diffusers, the impeller having impeller
passages extending from an impeller inlet to an impeller outlet,
the impeller having an impeller hub with an impeller hub bore
through which the shaft extends, the impeller hub bore having at
least one impeller drive flank integrally formed therein that is in
flush contact with the shaft drive flank to impart rotation to the
impeller.
2. The pump assembly according to claim 1, wherein the at least one
shaft drive flank comprises a plurality of shaft drive flanks
symmetrically arranged around an exterior of the shaft.
3. The pump assembly according to claim 1, wherein the at least one
shaft drive flank comprises two of the shaft drive flanks on
opposite sides of the shaft and parallel with each other.
4. The pump assembly according to claim 1, wherein the at least one
impeller drive flank comprises at least six of the impeller drive
flanks symmetrically arranged around the impeller hub bore and
joining each other.
5. The pump assembly according to claim 1, wherein the at least one
impeller drive flank comprises three involute curved surfaces that
join each other.
6. The pump assembly according to claim 1, wherein the at least one
impeller drive flank comprises a single flat surface asymmetrically
formed in the impeller hub bore.
7. The pump assembly according to claim 1, further comprising:
spacer rings through which the shaft extends, the spacer rings
being positioned between and in abutment with the impeller hub,
each of the spacer rings having a bore through which the shaft
passes, the bore in the each of the spacer rings having at least
one spacer ring drive flank that mates with the shaft drive
flank.
8. The pump assembly according to claim 1, further comprising: a
shaft coupling on a driven end of the shaft, the shaft coupling
having a coupling bore with at least one coupling drive flank that
mates with the shaft drive flank.
9. The pump assembly according to claim 1, wherein: an exterior of
the impeller hub is cylindrical and in rotating, sliding contact
with the diffuser bore in one of the diffusers.
10. A well pump assembly, comprising: a pump having a housing with
a longitudinal axis; a shaft extending through the housing on the
axis, the shaft having at least one shaft drive flank extending
substantially a length of the shaft, wherein a line normal to a
midpoint of the shaft drive flank passes through the axis; a
plurality of diffusers fixed in the housing against rotation, each
of the diffusers having diffuser passages extending from a diffuser
inlet to a diffuser outlet, each of the diffusers having a diffuser
bore through which the shaft passes but does not contact; and an
impeller located between each of the diffusers, the impeller having
impeller passages extending from an impeller inlet to an impeller
outlet, the impeller having an impeller hub with an impeller hub
bore through which the shaft extends, the impeller hub bore having
at least one impeller drive flank integrally formed therein that
mates with the shaft drive flank to impart rotation to the
impeller, wherein a line normal to a midpoint of the impeller drive
flank passes through the axis.
11. The pump assembly according to claim 10, wherein: the impeller
hub has a cylindrical exterior with a wall thickness measured
between the impeller drive flank and the cylindrical exterior; the
wall thickness between the impeller drive flank and the cylindrical
exterior is greatest at the midpoint of the impeller drive flank;
and the wall thickness between the impeller drive flank and the
cylindrical exterior is least at ends of the impeller drive
flank.
12. The pump assembly according to claim 10, wherein the at least
one impeller drive flank comprises two flat surfaces formed on
opposite sides of the impeller hub bore, the flat surfaces being
parallel with each other.
13. The pump assembly according to claim 10, wherein the at least
one impeller drive flank comprises six flat surfaces, defining a
hexagonal configuration for the impeller hub bore.
15. The pump assembly according to claim 10, wherein: the at least
one impeller drive flank comprises three involute, curved surfaces
formed in the impeller hub bore; and each of the curved surfaces
has a radial center point that is offset from the axis.
16. The pump assembly according to claim 10, wherein the impeller
drive flank comprises a single flat surface formed on one side of
the impeller hub bore.
17. A well pump assembly, comprising: a pump having a housing with
a longitudinal axis; a shaft extending through the housing on the
axis, the shaft having a plurality of shaft drive flanks extending
substantially a length of the shaft and symmetrically arranged
around the shaft; a plurality of diffusers fixed in the housing
against rotation, each of the diffusers having diffuser passages
extending from a diffuser inlet to a diffuser outlet, each of the
diffusers having a diffuser bore through which the shaft passes but
does not contact; and a plurality of impellers, each of the
impellers being located between each of the diffusers, each of the
impellers having impeller passages extending from an impeller inlet
to an impeller outlet, each of the impellers having an impeller hub
with an impeller hub bore through which the shaft extends, the
impeller hub bore having a plurality of impeller drive flanks, each
of the impeller drive flanks being in flush contact with one of the
shaft drive flanks.
18. The pump assembly according to claim 17, wherein: the shaft
drive flanks are flat, on opposite sides of the shaft and parallel
with each other.
19. The pump assembly according to claim 17, wherein the shaft
drive flanks comprise six flat surfaces symmetrically arranged
around the shaft and joining each other.
20. The pump assembly according to claim 17, wherein the shaft
drive flanks comprise three involute curved surfaces that join each
other.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to provisional application
62/678,313 filed May 31, 2018.
BACKGROUND
[0002] One type of submersible well fluid pump has an electrical
motor operatively connected with a centrifugal pump. The pump has a
large number of stages, each stage having an impeller and a
diffuser. A shaft rotated by the motor rotates the impellers
relative to the diffusers. Each impeller has passages that lead
upward and outward to the next upward diffuser. Each diffuser has
passages that extend upward and inward to the next upward
impeller.
[0003] The impellers and the shaft have mating keyway slots in
which a key is positioned to lock the impellers to the shaft for
rotation. While successful, during operation, sand from the well
fluid flowing through the pump may accumulate in the keyway slots,
creating problems.
SUMMARY
[0004] A well pump assembly comprises a pump having a housing with
a longitudinal axis. A shaft extends through the housing on the
axis, the shaft having at least one shaft drive flank integrally
formed thereon and extending substantially a length of the shaft. A
plurality of diffusers are fixed in the housing against rotation,
each of the diffusers having diffuser passages extending from a
diffuser inlet to a diffuser outlet. Each of the diffusers has a
diffuser bore through which the shaft extends. An impeller is
located between each of the diffusers. The impeller has impeller
passages extending from an impeller inlet to an impeller outlet.
The impeller has an impeller hub with an impeller hub bore through
which the shaft extends. The impeller hub bore has at least one
impeller drive flank integrally formed therein that is in flush
contact with the shaft drive flank to impart rotation to the
impeller.
[0005] In some embodiments, the at least one shaft drive flank
comprises a plurality of shaft drive flanks symmetrically arranged
around an exterior of the shaft. In one embodiment, the at least
one shaft drive flank comprises two of the shaft drive flanks on
opposite sides of the shaft and parallel with each other. In
another embodiment, the at least one impeller drive flank comprises
at least six of the impeller drive flanks symmetrically arranged
around the impeller hub bore and joining each other. In still
another embodiment, the at least one impeller drive flank comprises
three involute curved surfaces that join each other. The at least
one impeller drive flank may comprise a single flat surface
asymmetrically formed in the impeller hub bore.
[0006] The pump may have spacer rings through which the shaft
extends. The spacer rings are positioned between and in abutment
with the impeller hub. Each of the spacer rings has a bore through
which the shaft passes. The bore in the each of the spacer rings
has at least one spacer ring drive flank that mates with the shaft
drive flank.
[0007] The pump may have a shaft coupling on a driven end of the
shaft. The shaft coupling has a coupling bore with at least one
coupling drive flank that mates with the shaft drive flank.
[0008] An exterior of the impeller hub is cylindrical and in
rotating, sliding contact with the diffuser bore in one of the
diffusers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic side view of an electrical submersible
pump assembly in accordance with this disclosure.
[0010] FIG. 2 is a sectional view of a portion of the pump of FIG.
1.
[0011] FIG. 3 is a sectional view of the shaft and a coupling of
the pump of FIG. 2, taken along the line 3-3 of FIG. 2.
[0012] FIG. 4 is an perspective view from an upper side of one of
the impellers of the pump of FIG. 1, shown removed from the
pump.
[0013] FIG. 5 is a top view of the impeller of FIG. 4.
[0014] FIG. 6 is top view of an alternate embodiment of the
impeller of FIG. 4.
[0015] FIG. 7 is a transverse sectional view of the hub of an
alternate embodiment of one of the impellers of FIGS. 2 and 4.
[0016] FIG. 8 is a perspective view of a portion of the impeller
hub of FIG. 7.
[0017] FIG. 9 is a transverse sectional view of the hub of another
alternate embodiment of the impellers of FIGS. 2 and 4.
[0018] FIG. 10 is a perspective view of a portion of the impeller
hub of FIG. 9.
[0019] While the disclosure will be described in connection with
the preferred embodiments, it will be understood that it is not
intended to limit the disclosure to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the scope of the
disclosure as defined by the appended claims.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0020] The method and system of the present disclosure will now be
described more fully hereinafter with reference to the accompanying
drawings in which embodiments are shown. The method and system of
the present disclosure may be in many different forms and should
not be construed as limited to the illustrated embodiments set
forth herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey its
scope to those skilled in the art. Like numbers refer to like
elements throughout. In an embodiment, usage of the term "about"
includes +/-5% of the cited magnitude. In an embodiment, usage of
the term "substantially" includes +/-5% of the cited magnitude.
[0021] It is to be further understood that the scope of the present
disclosure is not limited to the exact details of construction,
operation, exact materials, or embodiments shown and described, as
modifications and equivalents will be apparent to one skilled in
the art. In the drawings and specification, there have been
disclosed illustrative embodiments and, although specific terms are
employed, they are used in a generic and descriptive sense only and
not for the purpose of limitation.
[0022] Referring to FIG. 1, a well with casing 11 is illustrated as
containing an electrical submersible pump assembly (ESP) 13. ESP 13
has a motor 15, which is normally a three phase electrical motor.
Motor 15 is filled with a dielectric motor lubricant. A pressure
equalizer or seal section 17 has features to equalize the internal
pressure of the motor lubricant with the hydrostatic pressure of
well fluid surrounding motor 15. Seal section 17 may be located
above motor 15, as shown, and will be in fluid communication with
the motor lubricant in motor 15. Alternately, a pressure equalizer
could be located below motor 15. Motor 15 has a drive shaft
assembly that extends through seal section 17 and drives a
centrifugal pump 19, which has an intake 21 for drawing well fluid
in.
[0023] A string of production tubing 23 extends to a wellhead (not
shown) and supports ESP 13. Tubing 23 may comprise sections secured
together by threads. Alternately, tubing 23 may comprise continuous
coiled tubing. A power cable 25 extends downward from the wellhead
and is strapped to tubing 23. A motor lead 27 connects to power
cable 25 at a splice or connection 29 located above ESP 13. Motor
lead 27 extends alongside ESP 13 and has a motor lead connector 31
on its lower end that plugs into a receptacle at the upper end of
motor 15. Pump 19 discharges well fluid through its upper end into
tubing 23 in this example. If tubing 23 is continuous coiled
tubing, power cable 25 could be located inside the coiled tubing,
in which case, pump 19 would discharge into an annulus surrounding
the coiled tubing.
[0024] Motor 15, pump 19 and seal section 17 comprise modules that
are brought separately to a well site, then secured together by
bolted flanges or threaded collars. ESP 13 may have other modules,
such as a gas separator and a thrust bearing unit. Alternately, a
thrust bearing unit could be formed as part of seal section 17.
Also, motor 15, pump 19 and seal section 17 each could be formed in
more than one module and connected in tandem.
[0025] Referring to FIG. 2, pump 19 has a tubular housing 33 with a
cylindrical inner side wall concentric with a longitudinal axis 35.
A steel drive shaft 37 extends through housing 33 concentric with
axis 35. Shaft 37 can be lengthy; for example, shaft 37 may be
20-30 feet in length. Referring to FIG. 3, shaft 37 has an exterior
surface with cylindrical portions 39 joined by drive flanks 41,
which in this example comprises two. Drive flanks 41 are flat
surfaces parallel with each other and on opposite sides of shaft 37
that are integrally formed in the cylindrical exterior surface 39.
Drive flanks 41 may vary in width, and in this example, each drive
flank has a width from one side edge to another of about half the
diameter of shaft 37 measured between cylindrical portions 39.
Cylindrical portions 39 are on opposite sides of shaft 37 and have
the same diameters.
[0026] Positioning drive flanks 41 on opposite sides of shaft 37
and parallel to each other makes drive shaft 37 symmetrical,
reducing vibration. A line 42 normal to one of the drive flanks 41
and at a midpoint between the side edges of the drive flank 41
passes through axis 35 and through the midpoint of the opposite
drive flank 41. Similarly, a line normal to the midpoint of one of
the cylindrical portions 39 passes through axis 35 and through the
midpoint of the opposite cylindrical portion 39. Drive flanks 41
are formed in one method by machining a cylindrical shaft.
[0027] Drive flanks 41 extend substantially the length of the
shaft. In this example, drive flanks 41 extend continuously to at
least one end of shaft 37, such as the lower end. A coupling 43
slides over the lower end of shaft 37 and couples shaft 37 to
another shaft 46, such as shaft 46 of seal section 17, which in
turn is driven by the shaft of motor 15 (FIG. 1). Shaft 46 may be
considered to be a motor shaft or a driving shaft. The lower end of
shaft 37 may be considered to be the driven end of shaft 37.
[0028] In this example, at least the upper half of coupling 43 has
a coupling bore 45 with two cylindrical portions 45a joined by two
drive flanks 45b. The dimensions of coupling bore 45 mate with
drive shaft 37 to cause drive shaft 37 to rotate in unison.
Coupling bore drive flanks 45b have the same dimensions as shaft
drive flanks 41, and coupling bore cylindrical portions 45a have
the same dimension as shaft cylindrical portions 39, within close
tolerances. Coupling 43 has a wall thickness measured from bore 45
to the cylindrical exterior surface. The wall thickness is uniform
where measured from the cylindrical portion of bore 45 to the
exterior. The wall thickness from the cylindrical exterior to one
of the coupling drive flanks 45b increases from the side edges of
the drive flank 45b to a greatest thickness at the midpoint where
intersected by line 42.
[0029] Shaft 46 within seal section 19 (FIG. 1) may have an upper
end with drive flanks in the same manner as pump shaft 37 for
sliding into a lower portion of coupling 43. Alternatively, the
upper end of seal section shaft 46 could be splined with
conventional triangular splines. If splined, the lower portion of
coupling bore 45 would have mating splines.
[0030] In this example, the upper end of pump shaft 37 is not
coupled to a shaft in another module. The exterior of shaft 37 at
the upper end could be completely cylindrical, or it could have
splines or it could have drive flanks 41. In the case of a tandem
pump (not shown) mounted above pump 19, the upper end of drive
shaft 37 could utilize drive flanks 41. If so, an upper drive shaft
coupling with drive flanks similar to coupling 43 could be employed
on the upper end of pump shaft 37.
[0031] A stack of diffusers 47 (only two shown) fits closely in
housing 33 for non-rotation. Diffusers 47 may be identical, each
having a central coaxial diffuser bore 49 through which drive shaft
37 extends but does not contact. Each diffuser bore 49 is
cylindrical. Each diffuser 37 has diffuser passages 51 that extend
from a lower inlet upward and radially inward to an upper
outlet.
[0032] An impeller 53 (only one shown) mounts between each of the
diffusers 47. Impeller 53 has impeller passages 55 that extend
upward and outward from a lower inlet to an upper outlet. Impeller
53 has a cylindrical hub 57 extending upward and outward into
diffuser bore 49 of the next upward diffuser 47. Impeller 53 has an
impeller bore 59 extending from its lower side to its upper side
through which shaft 37 extends.
[0033] Referring to FIGS. 4 and 5, in this embodiment, impeller
bore 59 has two cylindrical portions 59a joined by two flat drive
flanks 59b. Cylindrical portions 59a and drive flanks 59b are
dimensioned to mate and be in flush contact with shaft drive flanks
41, within close tolerances. Shaft drive flanks 41 cause impeller
53 to rotate in unison. Although is a sectional view of coupling
43, it also represents the engagement of shaft drive flats 41 with
impeller drive flanks 59b. Other than impeller bore 59, the
remaining configuration of impeller 53 may be conventional. The
discussion of the features of drive flanks 45b in coupling 43 also
applies to impeller drive flanks 59b.
[0034] Spacer rings 61 encircle shaft 37 and are located between
impellers 53. Spacer rings 61 abut the upper end of the hub 57 of a
next lower impeller 53 and the lower side of the next upward
impeller 53. Each spacer ring 61 rotates with shaft 37 and has a
bore 63 with drive flanks that mate with drive flanks 41 of shaft
37. The cross-section of one of the spacer rings 61 would appear to
be the same as the cross-section of coupling 43 of FIG. 3. The
discussion above of the features of coupling drive flanks 45b also
applies to the drive flanks in spacer ring 61.
[0035] During assembly, a technician alternates sliding each
diffuser 47 over shaft 35 with sliding one of the impellers 53 and
one or more of the spacer rings 61. If the lower end of shaft 37 is
the only end having drive flanks 41, the technician would slide the
diffusers 47, impellers 53 and spacer rings 61 over the lower
end.
[0036] Impellers 53 are free to slide upward and downward short
distances on drive shaft 37 between down thrust and up thrust
conditions. In the up thrust conditions, an upper side portion of
impeller 53 abuts a thrust washer on the lower side of the next
upward diffuser 47. In the down thrust condition, a lower side
portion of impeller 53 abuts a thrust washer on an upper side of
the next downward diffuser 47. Shaft drive flanks 41 can also cause
impellers 53 to spin shaft 37 in reverse rotation due to a falling
column of well fluid in production tubing 23 in the event motor 15
shuts off.
[0037] In many well installations, motor 15 (FIG. 1) is operated at
a fixed speed that is typically about 3600 rotations per minute
(RPM). Alternately, a variable speed drive near the wellhead (not
shown) may change the rotational speed of the motor from less than
3600 RPM to more.
[0038] Impellers 53 may be constructed of conventional materials,
such as a casting of a nickel iron alloy. The dimensions of
impeller bore 59 can be finalized by broaching.
[0039] Referring to alternate embodiment of FIG. 6, impeller 65 has
a bore 67 with more than two drive flanks 69. In this example,
there are six drive flanks 69, but the number could be more or
less. Bore 67 has no cylindrical portions. Drive flanks 69 are flat
surfaces with edges joining each other at 120 degree included
angles to define a hexagonal configuration for bore 67. As in FIG.
3, a line (not shown) normal to each drive flank 69 at its midpoint
will pass through the axis of rotation. The exterior of the hub of
impeller 65 is cylindrical, thus the wall thickness measured from
drive flanks 69 to the cylindrical exterior will change. The
thickest portion of the wall of the hub of impeller 65 will be at
the midpoint between side edges of each drive flank 69. The
thinnest wall thickness portion will be at the side edges of each
impeller drive flank 69.
[0040] Drive shaft 37 (FIG. 2) will have a mating hexagonal
configuration that closely receives each impeller 65. A hexagonal
exterior for drive shaft 37 is also symmetrical, reducing
vibration. Other than having hexagonal drive flanks 69, impeller 65
may be the same as impellers 53.
[0041] FIGS. 7 and 8 illustrate another embodiment of an impeller
hub 71. FIGS. 7 and 8 do not show the remaining portions of the
impeller of hub 71, but they may be the same as impeller 53 (FIGS.
2 and 4). Impeller hub 71 has three internal drive flanks 73 with
side edges that join each other. Each drive flank 73 is a curved
involute surface with a separate radial center point 75 offset from
axis 77 of rotation. Each curved flank 73 is formed with a radius
79 extending from a radial center point 75. Radius 79 has a greater
length than a radial line extending from rotational axis 77 to any
part of any of the impeller drive flanks 73. The radial center
point 75 for each drive flank 73 will be at a different location
from the radial center points of the other drive flanks 73. A line
80 normal to each drive flank 73 at a midpoint between the side
edges of each drive flank 73 will pass through axis 77.
[0042] The drive shaft (not shown) for impeller hub 71 will have
curved involute drive flanks on its exterior surface that mates in
flush contact with drive flanks 73. The curved drive flanks on the
drive shaft extend substantially a full length of the drive shaft
in the same manner as drive flats 41 (FIG. 3). Spacer rings (not
shown) similar to spacer rings 61 (FIG. 2) would have similar
internal curved drive flanks in their bores. A coupling similar to
coupling 43 (FIG. 2) could have similar internal drive flanks in
its bore, at least in the portion that slides over the lower end of
the drive shaft.
[0043] FIGS. 9 and 10 illustrate still another embodiment of an
impeller hub 81. FIGS. 9 and 10 do not show the remaining portions
of the impeller of hub 71, but they would be the same as impeller
53 (FIGS. 2 and 4). Impeller hub 81 has a cylindrical bore 83 with
a single flat drive flank 85 formed in it, generally defining a
D-shaped configuration. Drive flank 85 has a width from one side
edge to another side edge that may vary, and in this example, the
width of drive flank 85 is about half the inner diameter of hub
bore 83, measured through the axis between cylindrical portions of
bore 83. Drive flank 85 may be configured the same as one of the
drive flanks 45b of FIG. 3. As there is only one drive flank 85,
impeller hub bore 83 is asymmetrical.
[0044] A drive shaft for impeller hub 81 will have only a single
drive flank on its exterior surface that mates with drive flank 95.
The single drive flank on the drive shaft may extend a full length
of the drive shaft in the same manner as the two drive flats 41 of
FIG. 3. Spacer rings would have a similar single flat drive flank.
Optionally, a coupling could have a similar single, flat drive
flank, at least in the portion that slides over the lower end of
the drive shaft.
[0045] A pump designer when designing a pump with drive flanks will
consider the allowable torque. The designer will perform a stress
calculation using finite element analysis. The designer will
consider wear on the shaft and the bores of the rotating
components. The designer must also consider stage vibration.
Further, the designer will consider the difficulty of manufacturing
the shaft and rotating components as well as the assembly.
[0046] The present disclosure described herein, therefore, is well
adapted to carry out the objects and attain the ends and advantages
mentioned, as well as others inherent therein. While a few
embodiments of the disclosure have been given for purposes of
disclosure, numerous changes exist in the details of procedures for
accomplishing the desired results. These and other similar
modifications will readily suggest themselves to those skilled in
the art, and are intended to be encompassed within the scope of the
claims.
* * * * *