Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
[0001] Method and Apparatus for Installing Multiple Continuous Strand
Conductor Sections Onto the Stator Frame of a Polyphase Dynamoelectric
Machine
FIELD OF THE INVENTION
[0002] The invention relates to polyphase dynamoelectric machines. In
particular, the invention relates to a method and apparatus for installing
multiple
conductor sections onto a stator frame, whereby the conductor sections for a
given phase are wound from a continuous strand of conductive wire.
BACKGROUND OF THE INVENTION
[0003] Known in the art, there is U.S. Pat. No. 5,714,824 granted on
February 3~d, 1998 to the Couture et al.. In this patent, there is disclosed a
stator
for a dynamoelectric machine and a method for mounting at least one stator
winding onto a circular shaped stator frame. The stator frame is provided with
a
series of parallel elongate slots adapted for receiving respectively a series
of
conductor sections. Each conductor section is essentially a rectangular shaped
coil fabricated from a conductive wire having a rectangular cross section.
Each
coil has two sides and two heads which serve to interconnect the sides, the
heads
being shorter in length than the sides. Typically, three windings make up each
coil. Additionally, the ends of the piece of conductive wire used to fabricate
the
coil extend beyond the coil.
[0004] The coil sides fit into two of the parallel elongate slots of the
stator
frame. Depending on the characteristics of the stator, a number of parallel
slots
are located between the two parallel elongate slots in question. The conductor
section is inserted in the parallel elongate slots such that the first of the
two coil
sides rests at the bottom of the parallel elongate slot while the second of
the two
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coil sides rests on the coil side of another conductor section. Given that one
or
more of the parallel slots are located between the two parallel elongate
slots, and
that the edges of two conductor sections are inserted into each slot, one on
top
of the other, the coils of the conductor sections are necessarily interleaved.
To
facilitate the interleaving and maintain sufficient distance between conductor
sections necessary to avoid short circuit, the two heads of each coil are
adequately shaped. The shape of the heads is substantially U-shaped when
viewed from above and substantially S-shaped when viewed from the side.
[0005] One drawback of the above cited prior art is that each conductor
section is fabricated individually from a continuous strand of wire, requiring
the
conductor sections for a given phase to be attached together using solder or
other
electrical interconnection technique once all the conductor sections have been
mounted on the stator frame.
OBJECT OF THE INVENTION
[0006] It is an objective of the present invention to reduce or eliminate the
need for interconnecting conductor sections by fabricating two or more
conductor
sections from a continuous strand of conductive wire and providing a method of
interleaving such multiple conductor sections so they may be assembled onto a
stator frame.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings:
[0007] Figure 1 is a top plan view of a stator assembly frame and a partially
mounted first continuous strand conductor segment according to an embodiment
of the present invention;
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[0008) Figure 2 is a top plan view of a stator assembly frame similar to
Figure 1 illustrating partially mounted first and second continuous strand
conductor segments;
[0009] Figure 3 is a top plan view of a stator assembly frame similar to
Figure 1 illustrating partially mounted first, second and third continuous
strand
conductor segments;
[0010] Figure 4 is a top plan view of a stator assembly frame similar to
Figure 1 illustrating partially mounted first, second, third and fourth
continuous
strand conductor segments;
[0011] Figure 5 is a top plan view of a stator assembly frame similar to
Figure 1 illustrating partially mounted first, second, third, fourth and fifth
continuous strand conductor segments;
[0012] Figure 6 is a top plan view of a stator assembly frame similar to
Figure 1 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments;
[0013] Figure 7 is a top plan view of a stator assembly frame similar to
Figure 1 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments, wherein the first conductor segment has
been manipulated such that the second coil of the first conductor segment is
on
the assembly frame;
[0014] Figure 8 is a top plan view of a stator assembly frame similar to
Figure 7 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments, wherein the first and second conductor
segments have been manipulated such that the second coils of the first and
second conductor segments are on the assembly frame;
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[0015] Figure 9 is a top plan view of a stator assembly frame similar to
Figure 7 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments, wherein the first, second and third
conductor segments have been manipulated such that the second coils of the
first, second and third conductor segments are on the assembly frame;
[0016] Figure 10 is a top plan view of a stator assembly frame similar to
Figure 7 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments, wherein the first, second, third and
fourth
conductor segments have been manipulated such that the second coils of the
first, second, third and fourth conductor segments are on the assembly frame;
[0017] Figure 11 is a top plan view of a stator assembly frame similar to
Figure 7 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments, wherein the first, second, third, fourth
and
fifth conductor segments have been manipulated such that the second coils of
the
first, second, third, fourth and fifth conductor segments are on the assembly
frame;
[0018] Figure 12 is a top plan view of a stator assembly frame similar to
Figure 7 illustrating partially mounted first, second, third, fourth, fifth
and sixth
continuous strand conductor segments, wherein the first, second, third,
fourth, fifth
and sixth conductor segments have been manipulated such that the second coils
of the first, second, third, fourth, fifth and sixth conductor segments are on
the
assembly frame;
[0019] Figure 13 is top plan view similar to Figure 6, where the stator
assembly frame has been removed to show the other conductor segments;
[0020] Figure 14 is a sectional side elevation view taken along line 14-14
in Figure 13.
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[0021] Figure 15 is a sectional side elevational view showing the insertion
of the coils onto a cylindrical stator; and
[0022] Figure 16 is a sectional side elevational view showing an alternative
method for the insertion of the coils onto a cylindrical stator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Referring now to the appended Figures, a preferred embodiment of
the method in accordance with the present invention will be described.
[0024] Figure 1 shows a first continuous strand conductor segment 20
provided with a plurality of coils (only two shown, referred to as 20a and
20b).
The first phase conductor 20 is fabricated from a wire 21 having a rectangular
cross section. The wire 21 is fabricated from a conductive material,
preferably
copper, coated with a non-conductive finish. It will be apparent to one of
ordinary
skill in the art that any other conductive material with suitable electrical
and
physical characteristics could be used for the wire.
[0025] Of course, a rectangular stranded conductor wire (not shown) could
also be used.
[0026] One phase conductor is required for each phase of the polyphase
dynamoelectric machine. In the three phase configuration, as described in the
present preferred embodiment, each phase conductor is fabricated from two (2)
continuous strand conductor segments similar to segment 20. As will be
described hereinbelow, following the assembly of the continuous strand
conductor
segments onto a cylindrical stator frame, the two (2) conductor segments for a
given phase are joined together, preferably by ultrasonic welding (in series
or
parallel depending on the implementation).
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[0027] In the preferred embodiment described herein, each continuous
strand conductor segment is comprised of seven (7) conductor coils as in, each
conductor coil being comprised of three (3) windings of the conductor wire.
The
use of a wire 21 with a rectangular cross section minimises the presence of
air
gaps between the windings increasing the efficiency of the dynamoelectric
machine.
[0028] Each conductor coil, for example coil 20a, is comprised of a pair of
connecting heads 22 and 24. Each connecting head 22, 24 is shaped such that
it is generally U-shaped when viewed from above and generally S-shaped when
viewed from the side. The shaping of the connecting heads 22, 24 allows
successive conductor coils of different phases to be interleaved while
maintaining
sufficient distance to avoid short circuit. Additionally, the shaping of the
connecting heads 22, 24 maintains the planes defined by the top and bottom
surface of the rectangular wire 21 parallel.
[0029] Referring now to Figures 1 through 12, the assembly of a three
phase stator comprised of fourteen (14) coils per phase will be disclosed,
although
it will be understood by one of ordinary skill in the art that the assembly
method
could be used to assemble a variety of stators for polyphase dynamoelectric
machines with varying number of phases and stator coils.
[0030) An assembly frame 26 comprised of forty-five (45) parallel elongate
slots 28. The open ends of the slots 18 are preferably wider than the closed
ends
to facilitate placing of conductor coils therein (see Figure 15, for example).
Additionally, the width of the slots 28 should be such that a conductor coil
fits
snugly therein. Finally, the placement of the slots 28 in relation to one
another
should be equal to 1/3 of the width of the coils.
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[0031] Referring now to Figure 1, the first coil 20a of the first segment 20
is placed on the assembly frame 26 with the lower edge of the first coil 20
resting
on the bottom of the first and fourth slots.
[0032] Referring to Figure 2, the second coil 20b and subsequent coils of
the first conductor segment 20 are deflected towards the front of the assembly
frame 26 and slightly upwards (see arrow 30) to facilitate placement of the
first coil
32a of the second conductor segment 32. The first coil 32a of the second
conductor segment 32 is then placed on the assembly frame 26 with the lower
edges of the first coil 32a resting on the bottom surface of the second and
fifth
slots.
[0033] The shape of the connecting heads 22, 24 of the first coil 20a of the
first conductor segment 20 and the first coil 32a of the second conductor
segment
32 are such that the first conductor segment 20 and the second conductor
segment 32 are not in contact when ultimately mounted to a cylindrical stator
as
will be described hereinbelow. Additionally, the second coil 32b of the second
conductor segment 32 is placed below the second coil 20b of the first
conductor
segment 20.
[0034] Referring now to Figure 3, continuing in a similar fashion, the second
coils 20b and 32b are deflected towards the front of the assembly frame 26
(see
arrows 34 and 36) to facilitate placement of the first coil 38a of the third
conductor
segment 38. The first coil 38a of the third conductor segment 38 is placed on
the
assembly frame 26 with the lower edges resting on the bottom surfaces of the
third and sixth slots.
[0035] Additionally, the second coil 38b of the third conductor segment 38
is placed below the second coil 20a and the second 32a.
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[0036] Referring now to Figure 4, continuing in a similar fashion, the second
coils 20b, 32b and 38b are deflected towards the front of the assembly frame
26
(see arrows 20, 42 and 44) to facilitate placement of the first coil 46a of
the fourth
conductor segment 46. The first coil 46a of the fourth conductor segment 46 is
placed on the assembly frame 26 with the lower edges respectively resting on
the
coil 20a, in the third slot, and into the seventh slot such that it rests on
the bottom
of the slot. Additionally, the second coil 46b of the forth conductor segment
46 is
placed below the second coil 20b, the second coil 32b and the second coil 38b.
It is to be noted that the second coil 46b is deflected towards the rear of
the
assembly frame 26 (see arrow 48).
[0037] Referring now to Figures 5 and 6, a similar procedure is used for
placing the first coil 50a and the first coil 52a of respectively, the fifth
conductor
segment 50 and the sixth conductor segment 52 onto the assembly frame 26.
(0038] Referring now to Figure 7, interconnection wire 54, integral with and
between the first coil 20a and the second coil 20b of the first conductor
segment
20 is bent such that the upper edge of the second coil 20b rests upon the
lower
edge of the first coil 46b of the forth conductor segment 46. The length of
interconnection wire 54 having been selected such that introduction of a bend
into
interconnection wire 54 does not bring it into contact with any of the
connecting
heads (for example 22 and 24). The third coil 20c of the first conductor
segment
20 is placed below the second coil 32b, the second coil 38b, the second coil
46b,
the second coil 50b and the second coil 52b.
(0039] Referring now to Figures 8 through 12 a similar procedure is used
for placing the second coil 32b, the second coil 38b, the second coil 46b, the
second coil 50b and the second coil 52b onto the assembly frame 26.
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[0040] This procedure is then repeated with the third conductor coils 20c,
32c, 38c, 46c, 50c and 52c, continuing until the seventh coil of the sixth
conductor
segment 52 has been placed on the assembly frame 26.
[0041] Figures 13 and 14 illustrate the position of the coils that are not yet
installed onto the assembly frame 26. These coils may be mounted to a post 54
to prevent them from becoming tangled.
[0042] Referring now to Figure 15, a first method to transfer the assembled
conductor segments from the assembly frame 26 to a cylindrical stator frame 56
will be described.
[0043] Following installation of all coils of all conductor segments on the
assembly frame 26, the lower edge of the first coil 20a of the first conductor
segment 20 is placed in an initial slot 58 of the stator frame 56.
[0044] The stator frame 56 is then rotated 1/42 of a turn clockwise (see
arrow 60) such that second slot 62 of the stator frame 56 is positioned over
the
lower edge of the first coil 32a of the second conductive segment 32 which is
then
inserted in slot 62 via a lifting action (see arrow 64).
[0045] The stator frame 56 is rotated another 1/42 of a turn clockwise such
that third slot 66 of the stator frame 56 is positioned over the lower edge of
the
first coil 38a of the third conductive segment 38 which is then inserted in
slot 66.
[0046] This procedure is continued for all lower edges of all subsequent
coils until the seven (7) coils of the six (6) conductor segments have been
inserted
into corresponding slots on the stator frame 56. The upper edges of the final
coils
of the fourth, fifth and sixth conductor segments rest in slots 58, 62 and 66
upon
the lower edge of, respectively, the first coil 20a of the first conductor
segment
20, the first coil 32a of the second conductor segment 32 and the first coil
38a of
the third conductor segment 38.
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[0047] Referring now to Figure 16 an alternative method to transfer the
assembled conductor segments from the assembly frame 26 to a cylindrical
stator
frame 56 will be described. Again, the stator frame 56 is provided with a
series
of forty-two (42) elongated parallel slots as in 58 adapted for receiving the
conductor coils.
[0048] Following installation of all coils of all conductor segments on the
assembly frame 26, the stator frame 56 is aligned with the center of the
assembly
frame 26. The coils are then removed from the assembly frame 26 and inserted
in the slots 58 (see arrows 68).
[0049] It is to be noted that, depending on the configuration of the stator of
the electric machine to be constructed, the number, order and size of each of
the
conductor segments would vary without departing from the present invention.
[0050] Although the present invention has been described hereinabove by
way of preferred embodiments thereof, it can be modified, without departing
from
the spirit and nature of the subject invention as defined in the appended
claims.
