U.S. patent application number 14/932617 was filed with the patent office on 2016-05-19 for threaded connection with engaging lugs for electrical submersible pump.
The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to Jason E. Hill, Nicholas D. Johnson, Kenneth W. O'Grady, Michael R. Rumbaugh, Ryan P. Semple, Scott C. Strattan.
Application Number | 20160138613 14/932617 |
Document ID | / |
Family ID | 55961292 |
Filed Date | 2016-05-19 |
United States Patent
Application |
20160138613 |
Kind Code |
A1 |
Semple; Ryan P. ; et
al. |
May 19, 2016 |
Threaded Connection with Engaging Lugs for Electrical Submersible
Pump
Abstract
An electrical submersible pump assembly has modules including a
pump, a motor, and a seal section. A threaded connection between at
least two of the modules has a first adapter and a second adapter.
A collar rotatably carried and axially movable on one of the
adapters is in threaded engagement with threads of the other
adapter when the threaded connection is made up. First adapter lugs
are spaced circumferentially apart from each other around the first
adapter. Second adapter slots are spaced circumferentially apart
from each other around the second adapter. The lugs slide into the
slots while the adapters are brought together. Each of the lugs and
each of the slots have side edges that are parallel with the axis.
The side edges of the lugs abut the side edges of the slots to
prevent rotation of the first and second adapters relative to each
other.
Inventors: |
Semple; Ryan P.; (Owasso,
OK) ; O'Grady; Kenneth W.; (Collinsville, OK)
; Hill; Jason E.; (Catoosa, OK) ; Rumbaugh;
Michael R.; (Tulsa, OK) ; Johnson; Nicholas D.;
(Claremore, OK) ; Strattan; Scott C.; (Broken
Arrow, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated |
Houston |
TX |
US |
|
|
Family ID: |
55961292 |
Appl. No.: |
14/932617 |
Filed: |
November 4, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62081680 |
Nov 19, 2014 |
|
|
|
Current U.S.
Class: |
417/349 |
Current CPC
Class: |
F04D 13/10 20130101;
F04D 13/0693 20130101; F04D 29/628 20130101 |
International
Class: |
F04D 29/62 20060101
F04D029/62; F04D 7/02 20060101 F04D007/02; F04D 13/08 20060101
F04D013/08; F04D 1/06 20060101 F04D001/06 |
Claims
1. An electrical submersible pump assembly, comprising: a plurality
of modules including a pump, a motor, and a seal section for
reducing a pressure differential between lubricant in the motor and
hydrostatic pressure of well fluid; a threaded connection between
at least two of the modules, comprising: a first adapter and a
second adapter, the first and second adapters having a longitudinal
axis; a collar rotatably carried and axially movable on one of the
adapters, the collar being in threaded engagement with threads of
the other adapter when the threaded connection is made up; first
adapter lugs spaced circumferentially apart from each other around
the first adapter; second adapter slots spaced circumferentially
apart from each other around the second adapter; wherein the lugs
slide into the slots while the adapters are brought together; and
each of the lugs and each of the slots have side edges that are
parallel with the axis, the side edges of the lugs abutting the
side edges of the slots to prevent rotation of the first and second
adapters relative to each other.
2. The assembly according to claim 1, further comprising: a
plurality of first adapter electrical terminals mounted in the
first adapter and spaced circumferentially about the axis at a
lesser radial distance from the axis than the lugs; a plurality of
second adapter electrical terminals in the second adapter and
spaced circumferentially about the axis at a lesser radial distance
from the axis than the slots, for engagement by the first adapter
electrical connectors.
3. The assembly according to claim 2, further comprising: at least
one inclined cam surface on each the lugs extending between
opposite sides edges of each of the lugs; and wherein the cam
surfaces engage the side edges of the slots as the first and second
adapters are brought together to incrementally rotate one of the
adapters relative to the other until the electrical terminals of
the first adapter and the second adapter are axially aligned.
4. The assembly according to claim 2, further comprising: a pair of
inclined cam surfaces on each the lugs extending between opposite
sides edges of each of the lugs toward each other; wherein the lugs
protrude axially past the electrical terminals in the first
adapter; and the engagement of the cam surfaces of the lugs with
the side edges of the slots causes the first and second adapters to
incrementally rotate relative to each other until the electrical
terminals of the first adapter and the second adapter are axially
aligned.
5. The assembly according to claim 1, further comprising: a first
drive shaft in one of the modules, the first drive shaft having a
splined end; a second drive shaft in an adjoining one of the
modules, the second drive shaft having a splined end, a sleeve
coupling having a cylindrical body with an inner wall and an outer
wall and internal splines separated by spline grooves in the inner
wall that slide over and engage the splined end of the second drive
shaft, the sleeve having a rim on a first end; and teeth formed on
the rim of the coupling, each of the teeth extending from the inner
wall to the outer wall and being aligned with one of the spline
grooves for incrementally rotating the shafts relative toe ach
other and guiding the splined end of the first drive shaft into
engagement with the internal splines.
6. The assembly according to claim 1, wherein: the first adapter
has a cylindrical inner wall and a cylindrical outer wall that are
concentric with each other; circumferentially extending recesses
are located in the outer wall of the first adapter between adjacent
one of the lugs; and each of the recesses has a radial depth that
is less than a radial thickness of the first adapter measured the
inner and the outer walls of the first adapter.
7. The assembly according to claim 1, wherein: the first adapter
has a cylindrical inner wall and a cylindrical outer wall that are
concentric with each other; circumferentially extending recesses
are located in the outer wall of the first adapter between adjacent
one of the lugs; and each of the recesses has a radially outward
facing back wall.
8. The assembly according to claim 1, wherein: each of the lugs has
an inner side and an outer side that are cylindrical segments.
9. The assembly according to claim 1, wherein: each of the lugs has
an end that is located in a plane perpendicular to the axis.
10. The assembly according to claim 1, wherein: each of the lugs
has on an end two cam surfaces that incline from opposite side
edges of each of the lugs to a crest; and each of the slots has a
slot base having two inclined surfaces that incline from opposite
sides edges of each of the slots to a valley, defining a mating
contour for receiving one of the lugs.
11. An electrical submersible pump assembly, comprising: a
plurality of modules including a pump, a motor, and a seal section
for reducing a pressure differential between lubricant in the motor
and hydrostatic pressure of well fluid; a threaded connection
between at least two of the modules, comprising: a first adapter
having an axis; a second adapter; a collar rotatably carried and
axially movable on one of the adapters, the collar being in
threaded engagement with threads of the other adapter when the
threaded connection is made up; a male portion extending from one
of the adapters, the male portion having cylindrical, concentric
inner and outer walls; a receptacle portion in the other adapter,
the receptacle portion having cylindrical concentric inner and
outer walls; male portion lugs formed in the outer wall of the male
portion, the male portion lugs being spaced circumferentially apart
from each other by male portion slots, each of the male portion
slots having a back wall that faces radially outward; receptacle
portion lugs formed in the inner wall of the receptacle portion,
each of the receptacle portion lugs being spaced circumferentially
apart from each by receptacle portion slots, each of the receptacle
portion slots having a back wall that faces radially inward;
wherein the male portion lugs slide into the receptacle portion
slots and the receptacle portion lugs slide into the male portion
slots while the adapters are brought together; and each of the male
portion lugs and each of the receptacle portion lugs have side
edges that are parallel with the axis, the side edges of the male
portion lugs sliding along the side edges of the receptacle portion
slots as the male portion lugs slide into the receptacle portion
slots, to prevent rotation of the first and second adapters
relative to each other.
12. The assembly according to claim 11, wherein the outer wall of
the male portion is in contact with the back walls of the
receptacle portion slots when the connection is made up.
13. The assembly according to claim 11, wherein: each of the male
portion slots has a radial depth less than a radial thickness of
the male portion measured between the inner and outer walls of the
male portion at the male portion lugs.
14. The assembly according to claim 11, wherein: each of the
receptacle portion slots has a radial depth less than a radial
thickness of the receptacle portion measured between the inner and
outer walls of the receptacle portion at the receptacle portion
lugs.
15. The assembly according to claim 11, wherein: each of the male
portion slots has a shoulder extending between the side edges of
each of the male portion slots; and each of the receptacle portion
lugs has an end that abuts one of the shoulders when the connection
is made up.
16. An electrical submersible pump assembly, comprising: a
plurality of modules including a pump, a motor, and a seal section
for reducing a pressure differential between lubricant in the motor
and hydrostatic pressure of well fluid; a threaded connection
between at least two of the modules, comprising: a first adapter
having an axis; a second adapter; a collar rotatably carried and
axially movable on one of the adapters, the collar being in
threaded engagement with threads of the other adapter when the
threaded connection is made up; first adapter lugs spaced
circumferentially apart from each other around the first adapter;
second adapter lugs spaced circumferentially apart from each other
around the second adapter that slide between the first adapter lugs
while the first and second adapters are brought together; each of
the first adapter lugs and the second adapter lugs having side
edges that are parallel with the axis, the side edges of the first
adapter lugs abutting the side edges of the second adapter lugs to
prevent rotation of the first and second adapters relative to each
other; a plurality of first adapter electrical terminals mounted in
the first adapter and spaced circumferentially about the axis at a
lesser radial distance from the axis than the first adapter lugs; a
plurality of second adapter electrical terminals in the second
adapter and spaced circumferentially about the axis at a lesser
radial distance from the axis than the second adapter lugs, for
engagement by the second adapter electrical connectors; at least
one inclined cam surface on an end of each of the first adapter
lugs extending between opposite sides edges of each of the first
adapter lugs; at least one inclined cam surface on an end of each
of the second adapter lugs extending between opposite side edges of
each of the second adapter lugs; and wherein the cam surfaces of
the first adapter lugs engage the cam surfaces of the second
adapter lugs as the first and second adapters are brought together
to incrementally rotate one of the adapters relative to the other
until the electrical terminals of the first adapter and the second
adapter are axially aligned.
17. The assembly according to claim 16, wherein: the cam surfaces
on each of the lugs intersect each other at a crest equidistant
between the side edges of each of the lugs.
18. The assembly according to claim 16, wherein: the first adapter
lugs protrude axially past the electrical terminals in the first
adapter; and the second adapter lugs protrude axially past the
electrical terminals in the second adapter.
19. The assembly according to claim 16, further comprising: a first
drive shaft in one of the modules, the first drive shaft having a
splined end; a second drive shaft in an adjoining one of the
modules, the second drive shaft having a splined end, a sleeve
coupling having a cylindrical body with an inner wall and an outer
wall and internal splines separated by spline grooves in the inner
wall that slide over and engage the splined end of the second drive
shaft, the sleeve having a rim on a first end; and teeth formed on
the rim of the coupling, each of the teeth extending from the inner
wall to the outer wall and being aligned with one of the spline
grooves for incrementally rotating the shafts relative to each
other and guiding the spliend end of the first drive shaft into
engagement with the internal splines.
20. The assembly according to claim 16, wherein: the second adapter
lugs define slots between them; and each of the slots has a base
with a contour mating with the cam surface on each of the first
adapter lugs.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to provisional application
Ser. No. 62/081,680, filed Nov. 19, 2014.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates in general to electrical submersible
pumps for wells and in particular to a threaded connection between
modules of a pump assembly having lugs that mesh to prevent
relative rotation between the modules, and in the case where the
modules comprise tandem motors, to self-orient the mating
electrical terminals.
BACKGROUND
[0003] Submersible well pump assemblies (ESP) are commonly used to
pump well fluid from oil wells. A typical ESP includes a pump and
an electrical motor. The pump may be a centrifugal motor having a
large number of stages, each stage comprising an impeller and a
diffuser. Alternately, the pump may be another type, such as a
progressing cavity pump. An ESP includes a pressure equalizer that
couples to the motor to reduce a pressure difference between
dielectric lubricant in the motor and the hydrostatic pressure of
the well fluid. The ESP may include other components, such as a gas
separator and additional motors and pumps in tandem. The various
components are normally brought to a well site in separate modules,
then secured together.
[0004] Generally the modules of the ESP are connected together by
bolts that secure mating flanges. In some wells, a vertical section
leads around a bend to an inclined or horizontal section. Inserting
a lengthy ESP around the bend can cause stresses to the bolts.
[0005] It has been proposed instead of bolted flanges to employ
threaded collars that are rotated to secure the various modules of
the ESP. An example of a threaded collar arrangement is shown in
U.S. Pat. No. 6,557,905. The threaded collar fits around a neck of
an adapter of one of the modules and engages threads on the adapter
of the other module. Teeth on the rim of one of the adapters engage
mating teeth on the other adapter to prevent rotation between the
adapters.
[0006] If the modules being connected are tandem motors, electrical
terminals in each adapter must be aligned and stabbed together.
Alignment can be a problem during the connection process because
the terminals are not readily visible as the adapters are brought
together.
SUMMARY
[0007] An electrical submersible pump assembly has a plurality of
modules including a pump, a motor, and a seal section for reducing
a pressure differential between lubricant in the motor and
hydrostatic pressure of well fluid. A threaded connection between
at least two of the modules has a first adapter and a second
adapter. The first and second adapters have a longitudinal axis. A
collar is rotatably carried and axially movable on one of the
adapters, the collar being in threaded engagement with threads of
the other adapter when the threaded connection is made up. First
adapter lugs are spaced circumferentially apart from each other
around the first adapter. Second adapter slots are spaced
circumferentially apart from each other around the second adapter.
The lugs slide into the slots while the adapters are brought
together. Each of the lugs and each of the slots have slide edges
that are parallel with the axis. The side edges of the lugs abut
the side edges of the slots to prevent rotation of the first and
second adapters relative to each other.
[0008] If the threaded connection is between upper and lower
motors, a plurality of first adapter electrical terminals are
mounted in the first adapter and spaced circumferentially about the
axis at a lesser radial distance from the axis than the lugs. A
plurality of second adapter electrical terminals in the second
adapter are spaced circumferentially about the axis at a lesser
radial distance from the axis than the slots, for engagement by the
first adapter electrical connectors.
[0009] A motor-to-motor connection may have at least one inclined
cam surface on each the lugs extends between opposite sides edges
of each of the lugs. The cam surfaces engage the side edges of the
slots as the first and second adapters are brought together to
incrementally rotate one of the adapters relative to the other
until the electrical terminals of the first adapter and the second
adapter are axially aligned. The lugs protrude axially past the
electrical terminals in the first adapter.
[0010] A first drive shaft in one of the modules has a splined end.
A second drive shaft in an adjoining one of the modules has a
splined end. A sleeve coupling has a cylindrical body with an inner
wall and an outer wall and internal splines separated by spline
grooves in the inner wall. The internal splines slide over and
engage the splined end of the second drive shaft. The sleeve has a
rim on a first end. Teeth are formed on the rim of the coupling.
Each of the teeth extends from the inner wall to the outer wall and
is aligned with one of the spline grooves. The teeth incrementally
rotate the shafts relative to each other and guide the splined end
of the first drive shaft into engagement with the internal
splines.
[0011] The first adapter has a cylindrical inner wall and a
cylindrical outer wall that are concentric with each other.
Circumferentially extending recesses are located in the outer wall
of the first adapter between adjacent one of the lugs. Each of the
recesses has a radial depth that is less than a radial thickness of
the first adapter measured the inner and the outer walls of the
first adapter. Each of the recesses has a radially outward facing
back wall.
[0012] Each of the lugs has an inner side and an outer side that
cylindrical segments. Each of the lugs has an end that is located
in a plane perpendicular to the axis. Each of the lugs may have on
an end two cam surfaces that incline from opposite side edges of
each of the lugs to a crest. Each of the slots may have a slot base
having two inclined surfaces that incline from opposite sides edges
of each of the slots to a valley, defining a mating contour for
receiving one of the lugs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a cropped side view of an electrical submersible
pump assembly in accordance with this disclosure.
[0014] FIG. 2 is a cross-sectional view of the threaded connection
between the seal section and the pump intake of the pump assembly
of FIG. 1.
[0015] FIG. 3 is an exploded perspective view of the threaded
connection of FIG. 2.
[0016] FIG. 4 is an exploded perspective view of one embodiment of
a threaded connection between the tandem motors of FIG. 1.
[0017] FIG. 5 is a perspective view of the head of the lower tandem
motor of FIG. 4.
[0018] FIG. 6 is a perspective view of a second embodiment of a
threaded connection of the lower tandem motor of FIG. 1.
[0019] FIG. 7 is a perspective view of the second embodiment
threaded connection of the upper tandem motor of FIG. 1.
[0020] FIG. 8 is a sectional view of the second embodiment threaded
connection between the tandem motors of FIG. 1 in made-up
engagement.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0021] Referring to FIG. 1, electrical submersible pump (ESP) 11 is
employed to pump well fluid, typically a mixture of oil and water.
ESP 11 may be installed in a vertical portion or a horizontal or
inclined portion of a well. The terms "upper", "lower" and the like
are used only for convenience and not in a limiting manner.
[0022] ESP 11 has a number of modules, including a pump 13 that may
be a centrifugal pump having a large number of stages, each stage
having an impeller and a diffuser (not shown). Alternately, pump 13
may be another type, such as a progressing cavity pump. Pump 13 has
an intake 15 for drawing in well fluid. A pressure equalizer or
seal section 17 connects to the lower end of intake 15 in this
example. At least one electrical motor 19 connects to the lower end
of seal section 17. In this embodiment, two motors 19, 21 are
connected in tandem to each other. Seal section 17 may be
conventional and has components for reducing a pressure difference
between lubricant in motors 19, 21 and the hydrostatic pressure of
the well fluid. ESP 11 could have other modules, such as a gas
separator.
[0023] The various modules, including pump 13, seal section 17, and
tandem motors 19, 21 are typically brought separately to a well
site and connected together by connections 23a, 23b and 23c. In
this example, each connection 23a, 23b and 23c comprises a threaded
collar connection. However, some of the connections between
modules, such as the one between tandem motors 19, 21, could be
bolted types. FIG. 2 illustrates threaded connection 23a between
seal section 17 and pump intake 15.
[0024] Referring to FIG. 2, in this example, an intake adapter 25
extends downward from intake 15 (FIG. 1) concentric with a
longitudinal axis 26 of ESP 11. Intake adapter 25 may be an
integral portion of pump intake 15 or secured by threads (not
shown). Intake adapter 25 has a cylindrical neck 27 with a
cylindrical male portion or stab 29 on its lower end. A shoulder
ring 31 mounts within an external groove 33 on neck 27. Shoulder
ring 31 preferably comprises two semi-circular segments; in this
example, the segments are retained in groove 33 with a resilient
retainer ring 35 that encircles the outer diameter of shoulder ring
31. Neck 27 carries a collar 37 that is rotatable and axially
movable relative to neck 27 until the connection is made up. Collar
37 has an internal shoulder 39 that abuts an upper side of shoulder
ring 31 when connection 23a is made up. Collar 37 has internal
threads 41. A seal 43 seals between an outer diameter portion of
neck 27 and collar 37.
[0025] Male portion 29 has a cylindrical inner wall 44 and a
cylindrical outer wall 46 that are concentric with axis 26. Male
portion 29 has a rim 48 on its lower end that is in a plane
perpendicular to axis 26.
[0026] A seal section head or adapter 45 extends upward from seal
section 17 (FIG. 1) and may have lower threads (not shown) that
secure to internal threads in the housing of seal section 17.
Connection 23a could be inverted, with seal section adapter 45
having neck 27 that carries collar 37 instead of intake adapter 25.
A drive shaft (not shown in FIG. 2) extends through seal section
adapter 45 and has an upper end that mates with a shaft (not shown
in FIG. 2) in intake adapter 25 via an internally splined
coupling.
[0027] Seal section adapter 45 has a cylindrical receptacle portion
47 into which intake adapter male portion 29 stabs. Seal section
adapter 45 has external threads 49 on receptacle portion 47.
Internal threads 41 of collar 37 engage external threads 49 during
make up. Seals 51 on the exterior of receptacle portion 47 seal
against the inner diameter of collar 37 below internal threads
41.
[0028] Seal section adapter 45 has an inner cylindrical counterbore
wall 52 and an outer cylindrical wall 53 that are concentric with
axis 26. Seal section adapter 45 has a shoulder 56 at the base of
counterbore wall 52. Male portion rim 48 is spaced a short distance
from shoulder 56 when connection 23 is made up.
[0029] Referring also to FIG. 3, male portion 29 has a plurality of
male portion lugs 55 spaced circumferentially around it and formed
in male portion outer wall 46. The outer surfaces of male portion
lugs 55 are curved and form part of outer wall 46 for male portion
29. Male portion lugs 55 are preferably identical in
circumferential extent and are evenly spaced apart from each other.
A recess or male portion slot 57 separates each male portion lug 55
from adjacent lugs. The side edges 55a of male portion lugs 55 are
straight and parallel with axis 26.
[0030] In the example of FIG. 3, each male portion slot 57 has an
outward-facing curved wall 58 extending between lug side edges 55a,
thus slot 57 does not extend completely through male portion 29
from outer wall 46 to inner wall 44. The radial depth of each slot
57 is less than the radial thickness of male portion 29 between
inner wall 44 and outer wall 46. The radial depth of each male
portion slot 57 is the same as the radial dimension of each male
portion lug side edge 55a. In the example shown in FIG. 3, the
radial dimension of each lug side edge 55a and each slot 57 is
about half or less than the radial thickness of male portion 29
between inner wall 44 and outer wall 46.
[0031] An upper end or base 54 of each male portion slot 57 defines
a downward facing shoulder. The upper ends 54 of slots 57 in this
embodiment are located in a plane perpendicular to axis 26. Male
portion rim 48 defines the lower end of each male portion lug 55,
thus the lower ends of lugs 55 are also in a plane perpendicular to
axis 26. The lower ends of male portion lugs 55 are flush with the
circular rim 48 of male portion 29.
[0032] Receptacle portion 47 has receptacle portion lugs 59 formed
within that mate with intake adapter slots 57. Receptacle portion
lugs 59 are formed in receptacle portion inner cylindrical wall 52
and are separated from each other by receptacle portion slots 61.
The curved inner surfaces of receptacle portion lugs 59 define the
inner diameter of receptacle portion inner cylindrical wall 52.
Receptacle portion lugs 59 have straight side edges 59a that are
parallel with axis 26. Receptacle portion slots 61 have inward
facing curved surfaces 60 extending between lug side edges 59a.
Receptacle portion slots 61 have radial depths that are the same as
the radial dimensions of receptacle portion lug side edges 59a and
substantially the same as the radial dimensions of male portion lug
side edges 55a. The radial dimension of each lug side edge 59a is
less than the radial dimension between inner wall 52 and outer wall
53.
[0033] Receptacle portion slots 61 have substantially the same
circumferential width and may be slightly greater in axial length
than male portion lugs 55. The upper ends 62 of receptacle portion
lugs 59 define upward-facing shoulders that are abutted by
downward-facing shoulders 54 of male portion slots 57, as shown in
FIG. 2. Upper ends 62 are spaced a short distance below the rim of
receptacle portion 47 and are located in a plane perpendicular to
axis 26. When connection 23a is made up, shoulders 54 and ends 62
will be in abutting contact, transferring axial forces; however,
the lower ends of intake adapter lugs 55 which are located at rim
48, will not be in abutting contact with the lower ends of
receptacle portion slots 57.
[0034] FIG. 2 is taken along a section line passing through one of
the male portion lugs 55 on the left and one of the receptacle
portion lugs 59 on the right. When the connection is made up, the
curved outer surfaces of male portion lugs 55 will be in contact
with receptacle portion curved surfaces or back walls 60 of
receptacle portion slot 61s. Curved surfaces 58 of male portion
slots 57 will be in contact with the inner surfaces of receptacle
portion lugs 59, which define receptacle portion inner diameter or
inner wall 52.
[0035] To connect connector 23a, a technician will move collar 37
upward to a released position on neck 27. The technician aligns
intake adapter lugs 55 with seal section adapter slots 61, then
stabs male portion 29 into receptacle 47. At the same time, the
splines of one of the shafts (not shown) is aligned with splines in
the shaft coupling of the other of the shafts. The technician
brings collar 37 downward, engages threads 41 with threads 49, and
tightens collar 37. Collar shoulder 37 bears against shoulder ring
31, and when made up, seal section adapter slot upper ends 54 bear
against intake adapter lug upper ends 62. Male portion lug side
edges 55a will be in contact with receptacle portion lug side edges
59a. The meshing engagement of intake adapter lugs 55 with seal
section adapter slots 61 and the meshing engagement of seal section
adapter lugs 59 with intake adapter slots 57 prevent rotation of
intake adapter 25 and seal section adapter 45 relative to each
other during operation. Motor and seal section connection 23b may
be constructed in the same manner as connection 23a.
[0036] FIG. 4 illustrates one example of tandem motor connection
23c. Upper motor 19 has an adapter at its lower end with a
cylindrical receptacle portion 64. A plurality of electrical
terminals 63 are recessed within receptacle portion 64. Preferably,
there are at least three terminals 63, each connected to a
conductor wire (not shown) for one of the three phases of upper
motor 19. Terminals 63 are spaced 120 degrees apart from each other
around axis 26. Each terminal 63 is illustrated as being a pin, but
it could alternately comprises a sleeve. Upper motor 19 has a
rotatably driven drive shaft 65 located on axis 26. Drive shaft 65
has a lower splined end 67 that extends downward a short distance
from receptacle portion 64.
[0037] Upper motor receptacle portion 64 has a plurality of
internal lugs 69 spaced around axis 26 and formed within the inner
surface of receptacle portion 64. Lugs 69 extend circumferentially
and are spaced from each other by slots 71 of the same
circumferential width. Each slot 71 has a radial depth less than
the radial thickness of the wall defined by receptacle portion 64.
The radial thickness of each lug 69 is also less than the radial
thickness of the wall defined by receptacle portion 64. The lower
ends of upper motor lugs 69 are located in a single plane
perpendicular to axis 26. The number of upper motor lugs 69 may
vary and is illustrated to comprise three. The lower ends of
electrical terminals 63 are located above the lower ends of upper
motor lugs 69. Each upper motor lug 69 has a straight side edges
69a that are parallel with axis 26.
[0038] In this example, the adapter for lower motor 21 comprises
the male portion of the connection, but connection 23c could be
inverted. The head or adapter of lower motor 21 has a collar 75
movably carried on an upward-protruding neck 73. Collar 75 is
movable from the lower released position shown to an upper position
in threaded engagement with external threads 77 formed on upper
motor receptacle portion 64. Lower motor lugs 78 extend upward from
neck 73 and are dimensioned for close reception in upper motor
slots 71. In this example, slots 80 between lower motor lugs 78
extend completely through the wall that defines neck 73, rather
than partially as slots 57 and slots 59 in FIG. 3. The radial
thicknesses of lower motor lugs 78 is the same as the radial
thicknesses of upper motor slots 71. The upper ends of lower motor
lugs 78 are located in a single plane perpendicular to axis 26. The
side edges 78a of lower motor lugs 78 are parallel with axis 26 for
sliding engaging the side edges 69a of upper motor lugs 69 during
make-up.
[0039] Referring to FIG. 5, lower motor lugs 78 have cam surfaces
or bevels 84 on their upper edges. Cam surfaces 84 extend from
opposite side edges 78a and are inclined toward each other. Cam
surfaces 84 join the upper ends of lugs 78, which may be flat.
[0040] The head or adapter of lower motor 21 has electrical
terminals 74 mounted within neck 73 and arranged to mate with upper
motor electrical terminals 63. The upper ends of electrical
terminals 74 are below the upper ends of lower motor lugs 78. Lower
motor 21 has a shaft with a splined end and a splined coupling 76
that mate with upper motor shaft splined end 67 (FIG. 4). The upper
end of splined coupling 76 is recessed below the upper ends of
lower motor lugs 78. Lugs 69 and 78 are positioned so that when
upper motor lugs 69 align with lower motor slots 80 (FIG. 4), upper
motor electrical terminals 63 will be aligned with the mating
electrical terminals 74 of lower motor 21.
[0041] Referring to FIG. 4, when making up connection 23c, a
technician aligns lower motor lugs 78 with upper motor slots 71,
which also aligns each electrical terminal 74 (FIG. 5) of lower
motor 21 with one of the electrical terminals 63 of upper motor 19.
The operator brings motors 19, 21 toward each other, causing lower
motor lugs 78 to enter upper motor slots 71, and upper motor lugs
69 to enter lower motor slots 80. Cam surfaces 84 may engage the
lower ends of upper motor lugs 69, causing slight relative rotation
between upper motor 19 and lower motor 21. When this entry first
begins, electrical terminals 63, 74 will not yet be engaging each
other. Also, drive shaft splined end 67 will not yet be into
engagement with splined coupling 76 (FIG. 5). Continued movement
toward each other causes electrical terminals 63, 74 to engage each
other and drive shaft splined end 67 to engage splined coupling 76.
The technician then moves collar 75 upward and secures it to
threads 77. The lower edge of each lower recess 80 will abut the
lower end of each upper motor lug 69 when engaged.
[0042] FIGS. 6-8 illustrate a second embodiment for a connection
between upper and lower tandem motors. Lower motor 79 has a head or
adapter with a neck 82 that carries collar 81. Collar 81 abuts a
shoulder ring 83 on neck 82 in the same manner as the other
embodiments. Electrical terminals 85 are spaced 120 degrees apart
from each other. The drive shaft of lower motor 79 has an
internally splined coupling 87 at its upper end. Coupling 87
optionally may have sawtooth-shaped teeth 88 on its upper end that
face upward and extend between the inner and outer diameters of
coupling 87. Each tooth 88 defines a ridge 88a that axially aligns
with one of the internal splines 90 in coupling 87. Ridge 88a of
each tooth 88 extends from the inner diameter to the outer diameter
of coupling 87.
[0043] Lower motor lugs 89 extend upward and are spaced evenly
apart from each other. Lower motor lugs 89 are located radially
outward from electrical terminals 85. The curved outer sides of
lower motor lugs 89 are segments of a cylinder, defining the outer
diameter of neck 82. The curved inner sides of lower motor lugs 89
are segments of a cylinder, defining the inner diameter of neck 82.
The side edges of each lower motor lug 89 are parallel with axis
26.
[0044] Each lower motor lug 89 has a cam surface 91 on its upper
end that in this embodiment, comprises two inclined surfaces that
intersect each other at an apex 93. The inclined surfaces of cam
surface 91 may be generally flat and at an acute angle relative to
longitudinal axis 26. Apex 93 is preferably centered on each lower
motor lug 89. Alternatively, the cam surface on the upper end of
each lower motor lug 89 could be rounded, with curving inclined
surfaces joining a rounded apex. Lower motor cam surface 91 is
spaced above electrical terminals 85. Splined coupling 87 is shown
extending above cam surfaces 91 for illustration purposes, but
normally coupling 87 is also recessed below cam surfaces 91.
[0045] Lower motor slots 95 separate adjacent lower motor lugs 89
from each other. Slots 95 preferably are configured the same as
lower motor lugs 89. Lower motor slots 95 have side edges parallel
with axis 26 and a lower edge 97 that has a valley shape. Lower
edge 97 comprises two inclined surfaces that extend downward and
join each other an obtuse angle junction. Slots 95 extend through
the entire radial width of the wall defining neck 82. Lower motor
lugs 89 also have the same radial thickness of the cylindrical wall
defining neck 82.
[0046] Referring to FIG. 7, upper motor 101 has a lower adapter
with a cylindrical receptacle portion 103. Upper motor lugs 105 are
machined within receptacle portion 103 and have cam surfaces 107 on
their lower ends. Cam surfaces 107 may be identical to cam surfaces
91 (FIG. 6) on lower motor lugs 89, each having a triangular apex
109 on a lower end. Upper motor slots 111 separate upper motor lugs
105 and are contoured to accept lower motor lugs 89 (FIG. 6).
[0047] Upper motor 101 has electrical terminals 113 that mate with
lower motor electrical terminals 85 (FIG. 6). An upper motor drive
shaft 115 extends a short distance downward into upper motor
receptacle portion 103. The lower end of upper motor drive shaft
115 has axially extending splines 116 on its outer diameter. When
upper motor drive shaft 115 engages coupling 87 (FIG. 6), splines
116 engage teeth 88, which guide them into entry with internal
splines 90. Upper motor receptacle portion 103 has external threads
117 that are engaged by internal threads in collar 81 (FIG. 6). The
apex 109 of each upper motor lug 105 extends farther downward than
electrical terminals 113 and drive shaft 115, but is still recessed
from rim 114 of upper motor receptacle portion 103. Upper motor
lugs 105 are machined within the inner diameter of the cylindrical
wall of receptacle portion 103 and have a lesser radial thickness
than the cylindrical wall of receptacle portion 103. Similarly,
upper motor slots 111 have less radial depth than the wall defining
receptacle portion 103.
[0048] FIG. 8 is a sectional view illustrating upper motor 101
secured to lower motor 79. A motor wire 119 of upper motor 101
extends to each upper motor electrical terminal 113. A motor wire
121 of lower motor 79 extends to each lower motor electrical
terminal 85. Lower motor 79 has a drive shaft 123 extending upward
to splined coupling 87. When fully made up, the lower edge 97 of
each lower motor slot 95 (FIG. 6) abuts cam surface 107 of one of
the upper motor lugs 105.
[0049] The embodiment of FIGS. 6-8 makes up the same manner as the
motor connector embodiment of FIG. 4. Cam surfaces 91 and 107 allow
some initial rotational misalignment to exist between lower motor
lugs 89 and upper motor slots 111 and between upper motor lugs 105
and lower motor slots 95. Cam surfaces 91 and 107 will cause
incremental rotation of upper and lower motors 101 and 79 relative
toe ach other as the technician stabs lower motor neck 82 into
upper motor receptacle portion 103. The rotational movement to
axially align electrical terminals 85, 113 will occur before
electrical terminals 85 and 113 touch each other.
[0050] Similarly, the rotational movement caused by cam surfaces 91
and 107 occurs before upper motor drive shaft 115 engages splined
coupling 87 (FIG. 6). The lower ends of upper motor drive shaft
splines 116 land on teeth 88. If splines 116 and 90 are slightly
misaligned, teeth 88 will cause slight rotation between upper motor
drive shaft 115 and lower motor drive shaft 123 to align splines
116 and 90. Ridges 88a of teeth 88 cause splines 116 to slide into
the valley of each tooth 88.
[0051] The tandem motor connection of FIGS. 6-8 could be inverted
from the manner shown. Also, lugs and mating slots of this tandem
motor connection could be employed with bolted connections instead
of threaded connections having a rotatable collar.
[0052] Although the disclosure has been shown in several of its
forms, it should be apparent to those skilled in the art that it is
not so limited, but is susceptible to various changes without
departing from the disclosure.
* * * * *