MULTI-PHASE ELECTRIC MACHINE WITH JOINED CONDUCTOR LANES

MACHINE ELECTRIQUE POLYPHASEE A CONDUCTEURS DE PHASE REUNIS

English Abstract

In prior art multi-phase electric machines in which
conductor parts are interlace to form conductor lanes for various
phases, the connection points are on the winding end, thus
permitting only a very limited local possibility for welding of
the conductor ends. In addition, the manufacturing cost is
increased with an odd number of phases, since the design is
asymmetrical and a number of different formers necessary is
relatively high. The invention calls for prefabricated conductor
parts (17) to be welded or soldered in the zones which will
subsequently be located in the soft magnetic body. Divided bars
with a high conductor cross-sectional area are connected before
the insertion of soft magnetic segments, connection zones which
are large relative to the conductor cross-sectional area are
realized, and problems with the insulation are avoided. In
three-phase machines, the conductor lanes are interlaced with
each other, all conductor lanes being identical in design and the
same pattern is repeated every four pole pitches. This
connection technique and conductor progression permits the
inexpensive manufacture of reliable electric motors and
generators as well as uniform space utilization in three-phase
equipment.

French Abstract

Dans les machines électriques polyphasées connues, à conducteurs de phase formés par des éléments conducteurs réunis, les points de jonction se situent dans la tête de bobine et ne permettent qu'un soudage par refusion extrêmement limité localement des extrémités des conducteurs. De plus, en cas de nombre impair de phases, la production devient plus complexe, en raison d'asymétries qui interviennent alors et de la diversité relativement importante des formes de construction des conducteurs. Selon l'invention, des éléments conducteurs (17) préfabriqués sont soudés ou brasés dans les zones conductrices qui sont ensuite placées dans des corps de basse coercitivité. Des tiges plastiques de section transversale conductrice importante sont connectées avant l'insertion de segments de basse coercivité, ce qui permet de réaliser des zones de jonction relativement importantes comparativement à la section transversale conductrice, et d'éviter l'émergence de problèmes d'isolation. Dans les machines triphasées, les conducteurs de phase sont entrelacés au moment où ils sont réunis. Tous les conducteurs de phase sont de structure identique et leur configuration se répète tous les quatre pas polaires. La technique de raccordement et la configuration des conducteurs permettent de produire de manière économique et fiable des moteurs électriques et des générateurs, et de parvenir à une utilisation homogène de l'espace disponible dans les machines triphasées.

Claims

CLAIMS
1. A multi-phase electric machine, the conductor lanes (1)
of said machine being joined from prefabricated conductor parts
(2 to 5) in sections (6) of said conductor lanes (1), said
sections being located in the magnetic field of the machine
during operation and with cross sections of said conductor lanes
(1) remaining approximately constant, wherein the prefabricated
conductor parts (2 to 5) consist of at least two sections which
are located in the magnetic field during the operation of the
machine and which are separated by at least one section which is



located outside the magnetic field during operation of the
machine.
2. A multi-phase electric machine as recited in claim 1,
wherein the conductor parts (2 to 5, 12, 13, 17) possess a U-
shaped form in which the two ends form halves of groove bars and
the cross sections of said groove bars are decreasing
continuously towards the ends.
3. A multi-phase electric machine as recited in claim 2,
wherein the two ends of conductor parts (17) connected in one
groove are arranged in different halves of the groove with
respect to the groove width.
4. A multi-phase electric machine as recited in claim 1,
wherein the conductor parts are prefabricated without bending
radii and where the weld is located in the surface of a conductor
lane whose normal lies approximately parallel to the direction of
the magnetic field.
5. A process for the manufacture of a multi-phase electric
machine, the conductor lanes of said machine being joined from
prefabricated conductor parts, wherein several directly serially
switched, U-shaped conductor parts are welded together in partial
areas of the conductor lanes, said partial areas being thereafter
located in the magnetic field.
6. A process for the manufacture of a multi-phase electric
machine as recited in claim 5, wherein the conductor parts are
prefabricated without bending radii by joining into U-shaped
parts sections which have been cut from sheet metal and which,
except for their ends, are subsequently coated with an insulating
layer.~
6


7 A process for the manufacture of a multi-phase electric
machine as recited in claim 5, wherein all conductor parts in a
multi-phase conductor layer are assembled into two winding
overhang packets with protruding groove bar halves and wherein
the said two packets are joined in one work step and subsequently
welded together at the uninsulated conductor ends.
8. A process for the manufacture of a multi-phase electric
machine as recited in claim 5, wherein, only after the winding
has been joined completely and the junctures have been supplied
with an insulating layer, the segments that carry magnetic flow
are inserted into the ready-to-function winding.
7

Description

.,
' . . ~1LE~, P~-li~ THIS AMENDED
T~'X'~' TRANSLATION 21 ~ 7 2 0 8
TITLE
MULTI-PHASE ELECTRIC MACHINE WITH JOINED CONDUCTOR LANES
BACICC~ROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a multi-phase electric machine with
joined windings as well as a manufacturing process for such a
machine.
2. Descrivtion of the Prior Art
From US Patent 4 115 915, DE 41 11 626 C2, and DE 42 34 145
C1 bar windings are known wherein the conductor lanes are joined
together from sections. The junctures of said sections lie in
the winding overhangs and permit only locally limited welding of
the contact surfaces in order to decrease transition resistance.
In DE-B-1 026 841, a bar-shaped conductor is described
wherein the center section consists of sectional conductors
which, still inside the groove, are morticed to solid conductor
parts. The winding overhangs are joined to the solid conductor
parts in the usual manner. In the solid conductors which are
lying in the groove elevated losses occur due to current
displacement and the costs for executing the many junctures are
high.
In H. Sequenz: "Wechselstrom-Sonderwicklungen" ["Alternating
Current Special Windings], Vol. 3, Vienna 1954, page 348, divided
bars are described which, complementing each other in pairs, are
each twisted 180°. The bars which are cut from sheet metal
receive their final shape by bending and are subsequently axially
inserted into the grooves by pairs.
Further, from DE-AS 27 41 415 a two-layer bar winding is
known wherein the center groove of a group of coils is used for
only one current pass-through each by means of asymmetric
utilization. In this configuration, a special bar realizes the
transition from the upper to the lower layer. The special bar
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possesses in the grooves twice the cross section of the regular
bars and, like the regular bars, is joined in the winding
overhangs to the succeeding groove bars.
The invention is, therefore, based on the objective to
advance the development of a multi-phase electric machine wherein
the conductor lanes are joined from prefabricated parts in such a
manner that a simple and secure connection of conductor parts,
even of those with large conductor cross sections, is possible
and a complete and even utilization of space is achieved.
SUb~IARY OF THE INVENTION
The objective is solved in accordance with the invention by
the characteristics of claim 1 and claim 5.
In accordance with the invention, the complete and even
utilization of space is achieved in multi-phase electric machines
by joining conductor lanes (1) made from prefabricated conductor
parts (2-5) in sections (6) of said conductor lanes (1), said
conductor lanes (1) having an approximately constant cross
section, in such a manner that the prefabricated conductor parts
(2-5) possess at least 2 sections that are located in a magnetic
field during operation of the machine and that are separated by
at least one section that is located outside the magnetic field
during operation of said machine.
Without having to consider bending radii, U-shaped
prefabricated conductor parts are brought into their final
position and are welded together in those sections that
thereafter are lying within the magnetic field. This permits the
production of interlaced multi-phase windings wherein the
prefabricated parts, even for large machines, are of small outer
dimensions and that are prefabricated as drop-forged part, cast
part or from powdered metal. By welding in the area of the
grooves instead of on the faces of the winding overhangs, large
contact areas can be realized that are weldable without problem,
since insulation is applied after that step prior to insertion of
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the soft magnetic segments.
Advantageously, groove bars fill the space of a groove
completely by twisting said groove bars at their ends by 180°,
said groove bars lying side by side parallel to the groove width,
and by welding their prefabricated halves located inside the
groove to opposite surfaces which lie parallel to the groove
depth. The welding area consists of almost the entire length of
the groove which permits the realization of large welded
connection zones, even for small welding depth relative to the
conductor cross section.
In three-phase machines, interlaced conductor configurations
result in identical conductor lanes, said conductor
configurations repeating periodically every four pole pitches and
in which within one period four differently configured conductor
parts are switched in series. This ensures a stable construction
free from play and the space in the winding overhangs is
completely and evenly utilized.
The drawings show advantageous embodiments of the invention.
BRT_EF' DESCRIPTION OP' THE DRAWINGS
Figure 1 shows a section of a linearized conductor lane from
a three-phase conductor layer as it is joined;
Figure 2 shows a section from a linearized three-phase
conductor layer prior to joining of the two winding overhang
packets;
Figure 3 shows the construction of a conductor lane of a 24-
pole, three-phase radial air gap machine with one groove bar per
groove;
Figure 4 shows the complete winding of the machine from
Figure 3;
Figure 5 shows a section from a linearized conductor lane
with two divided bars per groove during joining of the
prefabricated U-shaped parts.
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2187288
DETAILED DESCRIPTION OF THE PREFERRED EM80DIMENT
The section from a conductor lane (1) in a three-phase
conductor layer shown in Figure 1 contains seven pole pitches or
seven prefabricated U-shaped parts (2 to 5) respectively that are
joined in the area of the groove at long, slanted contact
surfaces (6). The conductor progression repeats every four pole
pitches wherein by utilization of symmetries two U-shaped
structural parts each (2 and 3) or (4 and 5) respectively are
identical. This advantageous reduction of structural conductor
parts does not only apply to linear motors but, when bent at
different axes and with differently configured ends, is also
transferrable to rotating radial and axial air gap machines.
All conductor lanes of a three-phase machine are identical
due to their interlaced conductor progression wherein all
conductor parts (2 to 5 ") of an interlaced conductor layer are
assembled into two winding overhang packets in a previous work
step.
Figure 2 shows the two winding overhang packets (7, 8) of a
linearized three-phase machine which have been joined already in
four pole pitches prior to pushing said packets together.
Welding takes place exclusively in the area of the grooves prior
to application of groove insulation. In this way, in spite of
the low depth of penetration of a laser beam into pure conductor
material, windings with very large cross sections can also be
produced without problem. In multi-layer windings the interlaced
conductor layers are stacked parallel to the groove depth wherein
the transition between layers occurs either through a special
asymmetric U-part or outside the winding overhang. The conductor
parts (2 to 5 ") of the three phases are differently hatched.
In Figure 3 and 4 a conductor lane (9) and the complete
winding (10) of a 24-pole, three-phase machine with one groove
bar per groove is shown. Beginning from the supply (11), the
conductor lane (9) passes once in a meandering pattern through
the circumference of the machine, requiring only two different U-
parts (12, 13). All conductors are identical and are progressing
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2187208
w w-ia a set off pattern to each other by four groove separations
each, so that the winding overhangs are utilized completely and
uniformly. While the outer connections (13) progress only at the
groove height (14), the inner connections (12) utilize the space
(15) which lies axially in front of the yoke. The tangential
connection of a conductor lane in a winding overhang occurs,
therefore, always alternately in two different, annular winding
overhang areas (1.4,15). After the entire winding (10) has been
assembled and is ready to function, soft magnetic tooth segments
are radially inserted into the free space between the conductors.
In Figure 5, eight identical U-parts (17) are shown in a
linearized section comprising four pole pitches, wherein the ends
of four U-parts together fill one rectangular groove. They belong
to two conductor lanes (18, 19) which are advantageously switched
in series and conduct current in the winding overhangs in
different directions. At each passage through the groove each
conductor lane is twisted I80°. In order to illustrate the
change between the sides (20) of the groove, the two U-parts of a
conductor lane (18) are pulled apart parallel to the groove
length. If the U-parts (17) have at their ends indentations (21),
a divided bar winding manufactured at little expense is the
result, said divided.bar winding utilizing, without being limited
by current displacement, by means of only two divided bars even
large groove cross sections with a very high space factor.
. 4a -

Representative Drawing