THREE-PHASE ELECTRIC MACHINE WITH INTERLACED CONDUCTOR LAYERS

MACHINE ELECTRIQUE TRIPHASEE A COUCHES CONDUCTRICES ENTRELACEES

English Abstract

In prior art three-phase electric machines with a layered
winding, the conductor elements either make non-optimum use of
the space in the slot or the conductors for each phase are in the form
of large elements designed to be fitted into each other and whose
manufacture is complicated and costly. The invention calls for the
conductors (5-7) for each phase in the three-phase conductor layer
(11) to be identical in construction and for the construction to be
repeated every four pole pitches. While the phase conductors (5-7)
occupy the full height of the layer within the magnetic field, two
phase conductors (5-7) superposed one above the other in the slot
share the space at the coil ends (9). At the slot exit, the conductor
cross-section increases and only later, at the coil end (9), halved
from only one side at each passage through the coil end. In order
to alternate the layer halves, contact surfaces are available which
are large in comparison to the conductor cross-section and the two
winding ends (9) are uniformly utilized by virtue of the plaiting
of the layers. The production of three-phase conductor layers by
laying alternate conducting and insulating layers is particularly suitable for small electromagnetic machines, giving uniform space utilization
and hence high effectiveness and a high power density at low cost, and requiring only a few operations.

French Abstract

Dans les machines électriques triphasées connues, à enroulement en couches, les éléments conducteurs remplissent insuffisamment l'espace disponible dans les rainures ou bien les conducteurs de phase constituent des éléments de dimensions importantes, insérables les uns dans les autres, qui sont complexes et onéreux à produire. Selon l'invention, tous les conducteurs de phase (5-7) d'une couche conductrice (11) triphasée sont de structure identique et leur configuration se répète tous les quatre pas polaires. Alors que les conducteurs de phase (5-7) occupent toute la hauteur de la couche dans le champ magnétique, deux conducteurs de phase (5-7) qui se chevauchent dans le sens de la profondeur des rainures, se partagent l'espace dans les têtes de bobine (9). La section transversale du conducteur est augmentée à la sortie de la rainure et ce n'est que plus loin, dans la tête de bobine (9), qu'elle est réduite de moitié, d'un seul côté, à chaque passage à travers la tête de bobine. Des surfaces de contact, importantes comparativement à la section transversale des conducteurs, permettent d'alterner les moitiés de couches et la structure entrelacée des couches conductrices permet quant à elle d'utiliser de manière homogène les deux têtes de bobine (9). La production de couches conductrices triphasées par application alternée de couches conductrices et de couches isolantes s'applique notamment aux machines électromagnétiques de petites dimensions. En effet, avec un nombre réduit d'étapes, ce procédé permet une utilisation homogène de l'espace et par conséquent d'obtenir de manière économique, des rendements et des puissances volumiques élevés.

Claims

CLAIMS

1. ~A three-phase electric machine with a layered winding,
the conductor lanes (5-7) of said winding being partially
arranged in a soft magnetic body, said conductor lanes being of
different phases and being arranged within a conductor layer
(11), wherein all conductor lanes (5-7) of a three-phase
conductor layer (11) are of identical design and wherein partial
conductor sections (14-17) of a conductor lane (6) which are
placed sequentially in direction of the progression within the
winding overhang (9) are arranged in halves of layers (12, 13) of
the conductor layer (11) at different distances to the air gap.

2. ~A three-phase electric machine in accordance with claim
1, wherein the conductor height of the conductor lanes (5-7) in
the magnetic field of the height of the layer and in the partial
areas arranged parallel to the groove width corresponds to one
half the height of the layer, and wherein the change of the
conductor height occurs at a distance in front of the face of the
soft magnetic body that corresponds to approximately half the
width of the groove.

3. ~A multi-phase electric machine in accordance with claim
1, wherein the connection (20) of partial conductor sections (14-
17) of a conductor lane (6) from three-phase conductor layers
(21-23) which are stacked parallel to the groove depth occurs at
locations of the conductor which lie in the magnetic field.

4. ~A process for the manufacture of a three-phase electric
machine with a layered winding, the conductor lanes (5-7) of said
winding being arranged in a soft magnetic body, said conductor
lanes being of different phases and being arranged in one
conductor layer (11), wherein all three conductor lanes of a
three-phase winding layer are manufactured concurrently in one
process by alternating application of layers of insulating

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material and conductor material.

5. ~A process for the manufacture of a three-phase electric
machine in accordance with claim 4, wherein for the manufacture
of a three-phase conductor layer only four masks, two each for
the insulation layers and the conductor layers, are successively
employed.

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Description

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TITLE
THREE-PHA88 ELECTRIC MACHINE PITH INTERLACED CONDUCTOR LAYERS
$ACRCiROUND OF THE INVENTION
1. Fiend of the Invention
The invention concerns a three-phase electric machine with
an interlaced winding as well as a production process.
2.
From GB 13 29 205 conductor lanes for linear machines are
known which are manufactured as cast parts in a mould. Because
the conductor parts are individually manufactured and then
assembled, expensive moulds for prefabrication with low
tolerances are required. Further, the height of said conductor
parts decreases sharply at the end of the groove, thereby
resulting in a small critical cross section. The conductor parts
of all phases are stacked flat in the winding overhangs, thereby
creating large voids and, in case of three-phase conductor
layers, three partial layers in said winding overhangs.
The invention is, therefore, based on the objective to
advance the development of a three-phase electric machine with a
layered winding in which the conductor lanes of said winding are
in part arranged in a soft magnetic body in such a manner that
uniform utilization of space is achieved and manufacture is
simplified.
BUMLLARY OF HE INVENTTnN
In accordance with the invention, the uniform utilization of
space in a three-phase electric machine with a layered winding,
the conductor lanes (5-7) of said winding being arranged in a
soft magnetic body and said conductor lanes of different phases
being arranged within a conductor layer (11) is achieved by
arranging partial conductor sections (14-17) of a conductor lane
(6) which are sequentially placed in direction of the progression
within a winding overhang (9) in layer halves (12, 13) of the



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conductor layer (1l) at different distances to the air gap and
where all conductor lanes (5-7) are of identical structural
shape, as well as by manufacturing all three conductor lanes of a
three-phase winding layer concurrently in one process by
alternately applying layers of insulating material and conductor
material.
All conductor lanes of a three-phase conductor layer are of
identical structural shape, with the configuration of the
conductor lanes repeating every four pole pitches and each
conductor lane in this period possessing in both winding
overhangs two partial conductor sections in two different halves
of the layer. In the magnetic field, a conductor lane occupies
always the entire height of the layer, thereby avoiding
transitions between two halves of the layer within the pass-
through through a winding overhang. However, the three-phase
conductor layer consists in the winding overhangs of only two
partial layers. Additionally, the winding overhangs are being
completely and uniformly utilized, because in each half of the
winding overhang partial sections of the conductor lanes are
arranged tangentially in sequence and are separated only by thin
insulating layers. A narrowing of the cross section at the
transition of the winding overhang at the groove is avoided by
initially enlarging the width of the conductor parallel to the
groove width when said conductor is exiting the groove and by
bisecting the conductor height farther within the winding
overhang.
This optimal space utilization is possible for three-phase
conductor lanes only then, if the three conductor lanes are
interlaced, i.e. the conductor lanes of a layer can not be
manufactured independently of each other but only in a common
process. Besides welding of prefabricated parts in the groove
area, processes in which conductor layers and insulation layers
are alternately produced are suitable. Thick layer and thin
layer techniques enable the fully automated manufacture of
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2187~~~
extremely flat mini and micro motors.
The drawings show advantageous embodiments of the invention.
BRIEF DESCRIPTT_ON OF TH8 DRAWINGS
Figure 1 shows the masks for the manufacture of the three-
phase conductor layers.
Figure 2 shows the spatial construction of the conductor
layers from Figure 1.
Figure 3 shows the sequence of three sections of a conductor
lane from Figure 2, placed on top of each other.
DETAILED DESCRIPTION OF TH PREFERRED EMBODIME~1'T
Figure 1 shows on the left side the two conductor masks (1,
2) and on the right, somewhat smaller, the insulation masks (3,
4) for a 24-pole, three-phase conductor layer. Material is
applied on a flat surface, filling existing indentations in the
process. After exposure with the respective mask (1 - 4), the
non-hatched surfaces are removed again. The hatched surfaces of
the conductor masks (1 and 2), therefore, represent parts of the
three conductor lanes (5 - 7). In each half of each layer, only
two different structural shapes occur which can be assigned to
the respective phases on the basis of the different hatching. In
the insulation mask (3) for the center of the layer insulation
material remains only in the winding overhangs (9), except for
the three partial sections (8) in which a change of the layer
occurs. on the other hand, the lower insulation mask (4)
separates two identical, three-phase conductor layers and
therefore, insulation material remains on the surfaces, except in
the transition areas (8). The openings (10) within the layers
are intended for a magnetic conductive material - e.g. iron
powder or ferrite.
Figure 2 shows the construction of the three-phase
interlaced conductor layer (11) from Figure 1 in a spatial
depiction of a section of the circumference in which the
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2187096
differently hatched conductor lanes (5-7) of the two halves of
the layer (12, 13) are shown as being assembled from flat cuts of
sheet metal. On the right side of the illustration, the two
halves of the layer have been pulled apart parallel to the depth
of the groove in order to better clarify their shape. Each of the
three conductor lanes (5-7) consists of four differently arranged
partial conductor sections (14-17) which together bridge four
pole pitches and in which each of the small groove bar sections
(16, 17) for the groove pass-through without change of the halves
of the layers, as well as the large conductor sections (14, 15)
are identical. Since the three conductor lanes are identical,
the entire three-phase conductor layer (11) consists of only two
different partial conductor sections.
In Figure 3 the arrangement of the conductor lane (6) from
Figure 2 is shown in all layers (21-23) of a winding which
consists of three layers. Here that section of the circumference
was chosen in which the current supply and current derivation
(18, 19) as well as the change to another layer (20) occur.
Besides the two structural shapes (14, 15) and (16, 17)
respectively, the winding contains only two additional shapes,
(18 and 19). In the upper layer (21), the conductor lane
progresses, beginning from the current supply (18), clockwise
through the entire circumference of the machine minus one pole
pitch. At the end, the last partial conductor section in the
lower half of the layer is connected with the first partial
conductor section in the upper half of the middle layer (22).
After another complete progression through the circumference, the
conductor lane changes in the transition groove to the lower
layer (23), from which, after the third progression through the
circumference, the current derivation (19) occurs again in the
transition groove. The three transition grooves of the machine
should be executed in a position that is lower than the other
grooves by one half the thickness of a conductor layer in order
to avoid a narrowing of the conductor cross section in the last
partial conductor section (19).
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Representative Drawing