MULTIPLE-PHASE ELECTRIC MACHINE WITH A SPACE-OPTIMISED TURN-TO-TURN WINDING

MACHINE ELECTRIQUE POLYPHASEE A ENROULEMENTS EN NAPPES A ESPACE OPTIMISE

English Abstract

Known turn-to-turn windings with overlapping,
sinuous conductor strands either only insufficiently use
the slot space or are difficult to produce. In addition, no
uniform distribution of the current intensity is achieved
in the winding head space. The disclosed multiple-phase
conductor layers are made of identical conductor strands
located in the slot space at the same distance from the air
gap surface. The conductor layers superimposed in the
slots supplement each other in the use of the winding
head space in that they lead the current in opposite
directions across the width of the slot. A uniform
distribution of the current intensity and a high space
utilisation are achieved in that the layered winding heads
are offset relative to the layers in the slot in the direction
of the slot depth by half the height of a layer. Each conductor strand
occupies two winding head layers when crossing the winding
heads, the layers being exchanged at about the centre of the connection
section at the outside of the winding heads. Alternating second
conductor layers in succession are directly interconnected. Engines and
generators equipped with space-optimised turn-to-turn windings are
characterised by a high effectiveness and power density.

French Abstract

Les enroulements en nappes de types connus, à conducteurs de phase sinueux et se chevauchant, entraînent soit une utilisation insuffisante des espaces des encoches, soit des difficultés de fabrication. De plus, on n'obtient aucune répartition uniforme de la densité de courant dans l'espace de tête d'enroulement. Conformément à l'invention, des couches de conducteurs polyphasés sont constituées par des conducteurs de phase identiques logés dans des espaces d'encoches, à la même distance par rapport à la surface d'entrefer. Les couches de conducteurs superposées dans les encoches se complètent mutuellement par utilisation de l'espace de tête d'enroulement, du fait qu'elles conduisent le courant en des sens opposés, à travers la largeur de l'encoche. On obtient une répartition uniforme de la densité de courant, ainsi qu'une utilisation élevée de l'espace, grâce au fait que les couches des têtes d'enroulement sont décalées, par rapport aux couches des encoches, de la moitié de la hauteur d'une couche, en direction de la profondeur d'encoche. Lors de la traversée des têtes d'enroulement, chaque conducteur occupe deux couches de tête d'enroulement, un changement de couche s'effectuant sensiblement au milieu du parcours de connexion, à l'extérieur des têtes d'enroulement. Les secondes couches sont connectées chacune directement entre elles. Les moteurs et les générateurs équipés d'enroulements en nappes à espace optimisé sont remarquables en ce qu'ils présentent des rendements et des densités de puissance élevés.

Claims

CLAIMS:
1. Multiple phase electric machine with at least one soft magnetic body with
grooves,
said grooves having a length, a width, and a depth, and said grooves
interrupting a groove surface of said soft magnetic body,
within said grooves being arranged a part of a layered winding, and other
parts of said layered winding being arranged outside said soft magnetic body
in winding
overhangs,
said layered winding consisting of conductor lanes of different phases,
said conductor lanes in said grooves possessing groove layers with
surfaces that are approximately parallel to said groove surface of said soft
magnetic
body,
distance between said surfaces of said conductor lanes, which are parallel
to the grooved surface, corresponding to a height of said conductor lanes in
direction of
said groove depth,
sections of said conductor lanes of different phases that are arranged in
said grooves and that possess the same distance to said groove surface of said
soft
magnetic body comprising together a multiple phase conductor layer,
said conductor lanes of different phases within said multiple phase
conductor layer are overlapping in said winding overhangs by being aligned
concurrently in direction of said groove length and in direction of said
groove width,
and a change-over in comparison to the groove layers, between winding
overhang layers stacked in said winding overhangs occurring in each pass of
said
6

conductor lanes through said winding overhangs, wherein
each said conductor lane within said winding overhangs is arranged in winding
overhang layers with surfaces parallel to the groove surface and said winding
overhang
layers are offset in relation to the said groove layers by a fraction (=value
smaller than
1) of said height of said conductor lanes in direction of said groove depth.
2. Multiple phase electric machine in accordance with claim 1, wherein
said winding overhangs have outsides in which said change-over between
winding overhang layers is arranged,
between said outsides of said winding overhangs said conductor lane
possesses at least three sections parallel to said groove surface,
said three sections being connected by two transitional sections, and said
conductor lane covering a distance in direction of said groove depth in said
transitional
sections.
3. Multiple phase electric machine in accordance with claim 1, wherein said
conductor lanes between said change-over of layers possess a constant
conductor
height in direction of said groove depth.
4. Multiple phase electric machine .in accordance with claim 1, wherein
said conductor lanes are composed of identical conductor elements that
correspond to a portion of said conductor lanes between two successive said
change-
7

overs between winding layers.
5. Multiple phase electric machine in accordance with claim 1, wherein the
conductor cross section of said conductor lanes at the transition from said
groove to
said winding overhang is enlarged in direction of said groove width
and said conductor elements at their two respective ends are elongated in
direction of said groove length.
6. Multiple phase electric machine in accordance with claim 1, wherein
in linear machines and in machines divided into sectors said conductor
layers terminate in end sections that correspond to middle sections,
said middle sections being arranged between the winding overhangs,
said end sections having end surfaces facing in direction of said groove
width and said end sections of said conductor layers are connected in pairs at
said end
surfaces.
7. Multiple phase electric machine in accordance with claim 1, wherein
the entire mass of a conductor lane of one of said phases in one multiple
phase
conductor layer is a unitary conductor part,
said unitary conductor part is provided with electrical insulation,
identical said unitary conductor pads forming a multiple phase conductor
8

layer of said layered winding,
said unitary conductor parts are in the area of said groove separated by a
multiple phase conductor layer that is set off by one pole pitch, and
in a layered winding with at least two multiple phase conductor layers said
unitary conductor parts of one phase are joined electrically conductive at the
outside of
said winding overhangs.
8. Multiple phase electric machine in accordance with claim 1, wherein
a conductor lane of one of said phases in one multiple phase conductor
layer having a meander-shaped configuration,
said meander-shaped configuration having in direction of said groove
depth a height and rim ranges, where said change-over of said winding overhang
layers
occurs,
said meander-shaped configuration possessing at its rim ranges twice the
height in relation to the sections between said rim ranges,
and said meander-shaped configuration is a prefabricated conductor part
with an insulation layer on its surface,
a number of identical said conductor parts corresponding to said number
of phases of said electric machine forming a multiple phase conductor layer
comprising
several pole pitches by pushing together identical said conductor parts,
said multiple phase conductor layer having a height that is corresponding
to said height of said configuration.
9

9. Multiple phase electric machine with a layered winding,
said layered winding consisting of at least two multiple-phase conductor
layers,
each of said multiple-phase conductor layers having a thickness and
meander-shaped conductor lanes of different phases,
said conductor lanes overlapping in two winding overhangs of said
multiple phase conductor layers,
between said two winding overhangs said meander-shaped conductor
lanes having middle sections,
said middle sections having a height in direction of said thickness of said
multiple phase conductor layers,
said thickness of said multiple phase conductor layer corresponding
between said winding overhangs to said height of said middle sections,
in said winding overhangs of one multiple phase conductor layer using two
winding overhang layers,
said two winding overhang layers being offset against said middle sections
of said conductor lanes,
between said middle sections and sections of said conductor lanes in said
winding overhangs being transition sections of said conductor lanes which
realize said
offset, and
said conductor lanes of said at least two multiple phase conductor layers
stacked between said winding overhangs being offset perpendicularly to said
direction
of said conductor height and using in said winding overhangs partially the
same winding

overhang layer.
11

Description

CA 02262619 1999-O1-29
Wolfgang Hill PCT/DE97/01667
TITLE
MULTIPLE PHASE ELECTRIC MACHINE
WITH A SPACE-OPTIMIZED TURN-TO-TURN WINDING
OF THE INVENTION
1. Field of the Invention
The invention concerns a multiple phase electric
machine with a turn-to-turn winding as well as a process for
the production of such machines.
2. Description of the Prior Art
Good space utilization in the winding overhangs due
to short connection paths and large conductor cross sections
create favorable conditions for an increase in power density
and efficiency.
Although it is possible to achieve high groove space
factors by means of turn-to-turn windings consisting of
conductor layers of rectangular cross section which are
stacked in direction of the groove depth, their production
remains a problem.
In the three-layer winding described in DE-AS
1,005,611 all three layers are bent at different angles
towards the shaft.
From DE-AS 1,025,058 a single-layer rotor winding
with groove bars is known in which the intersection problem is
solved by bending the groove bar only on one side by the full
height of the layer towards the shaft and always designing
adjacent groove bar ends differently.
Furthermore, turn-to-turn windings made of
prefabricated conductor parts that are free of bending radii
are known. For instance, in DE 41 25 044 C2 multi-phase
conductor layers are described in which the conductor cross
section in the winding overhangs varies. The number of
different conductor designs corresponds to the number of
phases resulting in uniform distribution of current density in

CA 02262619 1999-O1-29
the winding overhang space.
In DE 42 34 145 C1 turn-to-turn windings are
described whose conductor lanes of different phases yield to
each other in the winding overhang in direction of the groove
depth and thereby utilize the space in front of the yoke. The
length of the conductor is therefore dependent on the groove
depth and conductor lanes of different phases are of different
designs.
From DE 43 21 236 C1 a turn-to-turn winding is known
that is characterized by intertwined conductor lanes.
Conductor lanes of a double layer can not be produced
independently of each other. The conductor layers consist of
many individual parts that have to be positioned into their
final location prior to joining them.
The objective of the present invention is to advance
a multiple phase electric machine with overlapping conductor
lanes in such a manner that short connection paths and
complete and uniform space utilization in the winding
overhangs is achieved at the lowest possible production cost.
SUI~IARY OF THE INVENTION
In accordance with the invention, this objective is
achieved by the characteristics of claims 1 and 8. In
accordance with the invention, all conductor lanes of a
conductor layer are identical. In the winding overhangs,
sections of the conductor lanes are aligned concurrently in
direction of the groove length and the groove width. Each
pass through a winding overhang consists of two such sections
that lie in different layers of the winding overhang and these
layers of the winding overhang, in relation to the layers in
the grooves, are set off by one half the conductor height in
direction of the groove depth.
The transition from a layer in the groove to one in
the winding overhang occurs preferably in a continuous
transition retaining the height of the conductor. In the
2

CA 02262619 2002-12-17
middle of each pass through the winding overhang the conductor lane changes
over
into another layer of the winding overhang. Following the second diagonal
section a
second transition returns the conductor lane, again by one half the height of
the layer,
back into the original groove layer. Thus, the two transition zones compensate
the
distance covered during the change of the layer in direction of the groove
depth.
On the other hand, if the change of a layer on the outside of the winding
overhang is a change of a conductor layer, then the change of the layer and
also the
second transition of this pass through the winding overhang occur in the same
direction
of the groove depth as the first transition . Here, not adjacent layers but
always the
conductor layers once removed are switched in series. Conductor layers stacked
in the
grooves conduct the current in the winding overhangs in opposition directions
with
reference to the groove width. They belong to the same phase and can be
switched
parallel as well as in series outside the winding overhangs.
Because the conductor configuration does not require variations in the
conductor cross section, the conductor lanes can also be produced by
deformation of
profile wire. The identical meander-shaped conductor parts can also be
produced in
one piece and free of bending radii as sintered or cast part. For larger
conductor cross
sections, the conductor parts are preferably assembled from a multitude of
identical
conductor elements that have been prefabricated to exact dimensions by, e.g.
drop
forging. Joining the conductor layers is accomplished by, e.g. electron or
laser beam,
prior to the application of insulation.
According to one aspect, the invention provides a multiple phase electric
3

CA 02262619 2002-12-17
machine with at least one soft magnetic body with grooves, the grooves having
a length,
a width, and a depth, and the grooves interrupting a groove surface of the
soft magnetic
body. Within the grooves is arranged a part of a layered winding, and other
parts of the
layered winding are arranged outside the soft magnetic body in winding
overhangs.
The layered winding consists of conductor lanes of different phases,
the conductor lanes in the grooves possessing groove layers with surfaces that
are
approximately parallel to the groove surface of the soft magnetic body,
distance
between the surfaces of the conductor lanes which are parallel to the grooved
surface
corresponding to a height of the conductor lanes in direction of the groove
depth,
sections of the conductor lanes of different phases that are arranged in the
grooves and
that possess the same distance to the groove surface of the soft magnetic body
comprising together a multiple phase conductor layer. The conductor lanes of
different
phases within the multiple phase conductor layer are overlapping in the
winding
overhangs by being aligned concurrently in direction of said groove length and
in
direction of the groove width. A change-over in comparison to the groove
layers,
between winding overhang layers stacked in the winding overhangs occurrs in
each
pass of the conductor lanes through the winding overhangs, wherein each
conductor
lane within the winding overhangs is arranged in winding overhang layers with
surfaces
parallel to the groove surface, and the winding overhang layers are offset in
relation to
the said groove layers by a fraction (=value smaller than 1 ) of the height of
the
conductor lanes in direction of the groove depth.
According to another aspect, the invention provides a multiple phase
electric machine with a layered winding, the layered winding consisting of at
least two
3a

CA 02262619 2002-12-17
multiple-phase conductor layers, each of the multiple-phase conductor layers
having a
thickness and meander-shaped conductor lanes of different phases, the
conductor
lanes overlapping in two winding overhangs of the multiple phase conductor
layers.
Between the two winding overhangs the meander-shaped conductor lanes having
middle sections, the middle sections having a height in direction of the
thickness of the
multiple phase conductor layers. The thickness of the multiple phase conductor
layer
corresponds between the winding overhangs to the height of the middle
sections, in the
winding overhangs of one multiple phase conductor layer using two winding
overhang
layers, the two winding overhang layers being offset against the middle
sections of the
conductor lanes, between the middle sections and sections of the conductor
lanes in
the winding overhangs being transition sections of the conductor lanes which
realize the
offset, and the conductor lanes of at least two multiple phase conductor
layers stacked
between the winding overhangs being offset perpendicularly to the direction of
the
conductor height and using in the winding overhangs partially the same winding
overhang layer.
Advantageous embodiments of the invention are displayed in the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows a conductor element that corresponds to
3b

CA 02262619 1999-O1-29
the conductor configuration for one pole pitch.
Fig. 2 shows two conductor elements joined together.
Fig. 3 shows a linearized cutout of two stacked
three-phase conductor layers.
Fig. 4 shows in three cutouts the insertion of a
three-phase, four-layer turn-to-turn winding into a grooved
soft magnetic body of a linear motor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In Figure 1 the conductor element (1) shown in
linearized form corresponds to the smallest subdivision of a
conductor lane into identical conductor elements. Each of the
two ends (2) and (9) are a part of the outer surface of the
winding overhangs. This typical configuration can be divided
into seven subdivisions where the middle section (5 - 6) is
arranged within a groove. After leaving the groove, the
conductor lane continues in so-called transition zones (4 - 5)
and (5 - 6) in direction of the groove length and also
concurrently in direction of the groove depth, each
transitional section covering on its respective side of the
middle section a distance in opposite directions of the groove
depth that corresponds to one half of the height of the
conductor. Sections (3 - 4) and (7 - 8) are, therefore,
arranged in winding overhang layers at a different distance to
the air gap surface. They are progressing concurrently in -
direction of the groove length and the groove width. At the
ends of the conductor element (1) extensions (2 - 3) and (8 -
9) in direction of the groove length are provided in order to
avoid a narrowing of the conductor cross section when changing
over to another layer.
As shown in Figure 2, this change-over occurs when
the conductor ends of two identical conductor elements (10a,
b) are stacked in direction of the groove depth at the
outsides of the winding overhang. The distance covered in
direction of the groove depth at the change-over location (11)
4

CA 02262619 1999-O1-29
is compensated within a conductor layer by the two transition
zones (12a, b). The sections in the grooves (13a, b) _
connected in this manner show the same distance to the air gap
surface. In the winding overhangs the diagonal sections (14a,
b) and (15a, b) respectively are also arranged in layers
parallel to the air gap. A conductor layer is, therefore,
always composed of two winding overhang layers that are
stacked and one groove layer wherein the winding overhang
layers are set off in relation to the groove layer by one half
of the height of a layer.
While a conductor layer occupies its groove layer
alone, it shares each of its two winding overhang layers with
one of the adjacent conductor layers. This layer design is
illustrated in Figure 3 by a cutout comprising four pole
pitches of two stacked three-phase conductor layers (20, 21).
The two conductor layers utilize together three winding
overhang layers (22a - c) jointly completely filling the
middle winding overhang layer (22b). Furthermore, the
conductor layers (20, 21) stacked in the grooves conduct the
current in the winding overhangs (23a, b) in opposite
directions in relation to the groove width. Each conductor
layer consists of identical conductor lanes (24 - 29) the
number of which corresponds to the number of phases and which
are differently densely hatched.
In Figure 4 the insertion of a four-layer winding
(30) into the grooved soft magnetic body (35) of a linear
motor is shown in three successive work steps. While in Fig.
4a the two lower conductor layers (31, 32), analogous to Fig.
3, form a compact package, a third conductor layer (33) is
added in Fig. 4b and the uppermost conductor layer (34) is
added in Fig. 4c. The conductor lanes of each layer can,
therefore, be inserted individually or as a ready-to-function
package into the grooved soft magnetic body (35). The open
grooves (36) are closed by partially soft magnetic retainer
keys (not shown).

CA 02262619 1999-O1-29
By bending around various axes the illustrated
linear design can be adapted to axial and/or radial flux
machines.
5a

Representative Drawing