DE102017213106B4 - Method for producing an electrotechnical coil - Google Patents

Abstract

Method for producing an electrotechnical coil, comprising the steps:a. Step A: Providing a conductor (1) extending along a profile axis (A) and made of an electrically conductive material.b. Step B: Shaping the conductor (1) to form at least two forming sections (2), each by changing the cross-sectional shape of the conductor (1).c. Step C: Arranging the conductor (1) in the form of a winding with at least two turns extending around a winding axis (W), so that at least two of the forming sections (2) in adjacent turns lie flat on top of one another.d. Step D: Compressing the winding along the winding axis (W) so that the forming sections (2) in adjacent turns make flat contact with one another.e. Step E: Bundling at least some of the winding head sections (3) of the conductor (1) lying between the forming sections (2) by twisting them, wherein step E comprises at least the following sub-steps:Step E2: Enclosing two, several or all of the windings of the winding in the region of the winding head sections (3) with at least one bundling tool (B1, B2), by arranging a first section (B1a, B2a) of first and second bundling tools (B1, B2) on the side of the windings facing away from the winding axis (W) and arranging a second section (B1b, B2b) of the first and second bundling tools (B1, B2) on the side of the windings facing the winding axis (W), and connecting the first and second sections (B1a, B1b; B2a, B2b) of the first and second bundling tools (B1, B2) so that each of the first and second bundling tools (B1, B2) has the same winding head sections (3).Step E5: Twisting the winding head sections (3) by rotating the first and second bundling tools (B1, B2) in opposite directions so that the winding head sections (3) wind around each other in a helical manner, at least in sections.

Description

The present invention relates to a method for producing an electrotechnical coil.

Until now, coils have been wound from round wire, which due to the conductor shape results in a lack of space utilization, especially in conical coils, or they have been manufactured by casting, which is a very complex process.

According to the EP 2 387 135 A2 The achievable torque density of permanent magnet synchronous machines with tooth coil winding depends largely on the ratio of the total copper cross-sectional area to the slot area, the so-called slot fill factor. An increase in the fill factor enables a flatter stator structure or a widening of the teeth while maintaining the same torque, which helps to relieve the load on the magnetic circuit.

A major geometric limitation in the current state of the art is the limited possibilities for using different winding cross-sections: Round wires are usually used for the windings, which always leave an unusable gap between the individual windings even when used optimally. The necessary insulation, the wire insertion and the discrete distribution of the conductors also limit the fill factor. Since the slot fill factor ultimately achieved can only be estimated in the electromagnetic design and cannot be calculated due to a lack of knowledge of the actual design of the motor, higher masses are assumed for the motors (copper of the windings and laminated cores of the stator and rotor), which tends to result in machines that are (too) heavy and (too) large.

The main manufacturing difficulty lies in applying the windings to the tooth.

In summary, it can be stated that with the current methods of manufacturing coil windings, there are technical and economic limits to slot filling with individual turns. A slot filling factor of 70% is already a very good value. The technically and economically feasible limits are currently around 75% to 80% ( Source: Müller, Vogt, Ponick: “Calculation of electrical machines”, p. 168, 6th edition, Wiiey-VCH, Weinheim, 2008 .")

The EP 2 387 135 A2 The known process enables the production of coils by casting while fulfilling the above requirements, but is less economical than the forming production of coils (no lost mold, etc.).

From the protective rights EN 10 2013 012 659 A1 and EN 10 2014 000 636 A1 Manufacturing processes are developed which only affect the wire cross-section after the electric coil has been wound. Building on the EN 10 2013 012 659 A1 and the EN 10 2014 000 636 A1 New restrictions arise from the economy, which require a geometrical target shape of the wire section for the effective area and the original input shape of the wire for the area of the winding head of the electrotechnical coil. Furthermore, there will be a need to produce larger quantities of motors in the future.

Furthermore, with all the above-mentioned protective rights, no intentional difference in the size of the cross-sectional area of the conductor between the winding head and the effective area of the coil is mentioned.

The main protective rights include US 2005/0258704 A1 and WO 01/54254 A1 , as well as WO 2012/072695 A 2 and DE 103 15 361 A1 However, these methods have their limits in terms of productivity and continuity.

The patent documents EN 10 2015 201 630 A1 , DE 38 03 752 A1 , US 3 348 183 A , EN 10 2014 222 468 A1 , US 2016/0 254 718 A1 , DE 602 23 325 T2 , DE 602 08 387 T2 , WO 2017/ 092 945 A1 , JP 2010-268 575 A , DE 506 860 A , DE 10 76 251 A , US 2012/ 0 181 886 A1 , EN 10 2007 036 263 A1 , EN 10 2012 201 698 A1 , CH 65 801 A disclose further methods and devices for producing an electrotechnical coil according to the prior art.

Based on the prior art described above, the object of the present invention is to provide a method and a device for producing an electrotechnical coil, so that the electrotechnical coil can be produced reproducibly and economically in a reliable and simple manner while achieving an increased fill factor or slot fill factor.

• - Schritt A: Bereitstellen eines sich entlang einer Profilachse erstreckenden Leiters aus einem elektrisch leitenden Material.
• - Schritt B: Umformen des Leiters unter Ausbildung wenigstens zweier Umformabschnitte jeweils durch Veränderung der Querschnittsform des Leiters.
• - Schritt C: Anordnen des Leiters in Form einer Wicklung mit wenigstens zwei sich um eine Wicklungsachse erstreckenden Windungen, sodass wenigstens zwei der Umformabschnitte in benachbarten Windungen flächig übereinander liegen.
• - Schritt D: Komprimieren der Wicklung entlang der Wicklungsachse, sodass die Umformabschnitte in benachbarten Windungen einander flächig kontaktieren.
• - Schritt E: Bündelung wenigstens einiger der zwischen den Umformabschnitten liegenden Wickelkopfabschnitte des Leiters durch Biegung und/oder Verdrillung derselben wobei der Schritt E zumindest die folgenden Teilschritte aufweist:
  • Schritt E2: Umgreifen zweier, mehrerer oder sämtlicher Windungen der Wicklung im Bereich der Wickelkopfabschnitte mit wenigstens einem Bündelwerkzeug, durch Anordnen jeweils eines ersten Abschnitts von ersten und zweiten Bündelwerkzeugen auf der von der Wicklungsachse abweisenden Seite der Windungen und Anordnen jeweils eines zweiten Abschnitts der ersten und zweiten Bündelwerkzeuge auf der zur Wicklungsachse weisenden Seite der Windungen, und Verbinden jeweils der ersten und zweiten Abschnitte der ersten und zweiten Bündelwerkzeuge, sodass jedes der ersten und zweiten Bündelwerkzeuge dieselben Wickelkopfabschnitte umgibt.
• - Schritt E5: Verdrillung der Wickelkopfabschnitte durch Verdrehung der ersten und zweiten Bündelwerkzeuge in gegensätzliche Richtungen, sodass sich die Wickelkopfabschnitte zumindest abschnittsweise schraubenförmig umeinander winden.

To achieve the object, the present invention provides the method for producing an electrotechnical coil according to claim 1, comprising the steps:

• - Step A: Providing a conductor made of an electrically conductive material extending along a profile axis.
• - Step B: Forming the conductor to create at least two forming sections, each by changing the cross-sectional shape of the conductor.
• - Step C: Arranging the conductor in the form of a winding with at least two turns extending around a winding axis, so that at least two of the forming sections in adjacent turns lie flat on top of one another.
• - Step D: Compress the winding along the winding axis so that the forming sections in adjacent turns contact each other flatly.
• - Step E: Bundling at least some of the winding head sections of the conductor located between the forming sections by bending and/or twisting them, wherein step E comprises at least the following sub-steps:
  • Step E2: Enclosing two, several or all turns of the winding in the region of the winding head sections with at least one bundling tool, by arranging a first section of first and second bundling tools on the side of the turns facing away from the winding axis and arranging a second section of the first and second bundling tools on the side of the turns facing the winding axis, and connecting the first and second sections of the first and second bundling tools so that each of the first and second bundling tools surrounds the same winding head sections.
• - Step E5: Twisting the winding head sections by rotating the first and second bundling tools in opposite directions so that the winding head sections wind around each other in a helical manner, at least in sections.

According to the present invention, the forming sections of the conductor can be formed largely without taking into account the later arrangement of the winding head sections in between in the winding head of a winding made from the conductor, since the inventive bundling of the winding head sections in step E of the inventive method already enables a particularly compact arrangement of the coil, in particular in the winding head area. Especially in the case of conductors with small cross-sectional areas, the bundling of the winding head sections carried out according to the inventive method can prevent the winding head from spreading. It can prove advantageous if the winding head sections are brought into a compact and bundled shape by bending, which, in contrast to the regular coil shape, runs at least in sections in a wave-like manner, e.g. in the circumferential direction around the winding axis. However, it can also be useful if the winding head sections lying one above the other in adjacent turns are arranged at least in sections in a helical manner by twisting in the manner of a strand and thus brought into a particularly compact shape. Preferably, the winding head sections are plastically deformed by the bending and/or twisting with partial or complete elimination of the elastic restoring forces, so that the winding head sections remain in the compact arrangement after the corresponding tools have been removed, even without special aids. Various bundling tools can be used to act on the winding head sections at different points on the winding head in order to convert them into a particularly compact arrangement. According to the invention, two bundling tools that can be moved in different directions are suitable for bending the winding head sections. The twisting preferably leads at least partially to a plastic deformation of the winding head sections, so that the elastic restoring forces of the conductor material are eliminated and the winding head sections remain in the twisted form after the bundling tool has been removed.

• - Schritt A1: Bereitstellen des Leiters als Endlosleiter, vorzugsweise durch Strangpressen, Extrudieren oder Abwickeln von einer Spule.
• - Schritt A2: Bereitstellen des Leiters mit einer entlang seiner Profilachse konstanten Querschnittsform, wobei die Querschnittsform des Leiters vorzugsweise kreisförmig, oval oder polygonal ist.
• - Schritt A3: Bereitstellen des Leiters in linearer Form.

It may be useful if step A includes at least one of the following sub-steps:

• - Step A1: Providing the conductor as a continuous conductor, preferably by extrusion, spooling or unwinding from a coil.
• - Step A2: Providing the conductor with a constant cross-sectional shape along its profile axis, wherein the cross-sectional shape of the conductor is preferably circular, oval or polygonal.
• - Step A3: Providing the conductor in linear form.

With these features, a variety of different coils can be produced from a standardized starting material, so that the process according to this design proves to be particularly efficient.

• - Schritt B1: Vorformen des Leiters unter Veränderung der Querschnittsform des Leiters, vorzugsweise unter Abflachung des Leiters, bevorzugt ausgehend von einer kreisförmigen Querschnittsform in eine ovale oder polygonale Querschnittsform. Durch ein allgemeines Vorformen des Leiters kann dieser an die individuellen Gegebenheiten des konkreten Anwendungsfalls angepasst werden, sodass der Nachbearbeitungsaufwand bei der Ausbildung der einzelnen Umformabschnitte verringert werden kann.

• - Schritt B2: Veränderung der Querschnittsform des Leiters in jedem der Umformabschnitte unter Ausbildung wenigstens zweier komplementärer und/oder paralleler Seiten zur flächig übereinander liegenden Anordnung der Umformabschnitte. Nach dieser Ausführung können die Umformabschnitte besonders kompakt übereinander liegend angeordnet werden.
• - Schritt B3: Ausbildung der Umformabschnitte jeweils im Abstand voneinander entlang der Profilachse des Leiters, wobei die Abstände zwischen den Umformabschnitten vorzugsweise uneinheitlich sind und bevorzugt entlang der Profilachse des Leiters linear zunehmen oder abnehmen. Durch Variation der Abstände zwischen den Umformabschnitten ändert sich die Länge der zwischen den Umformabschnitten liegenden Wickelkopfabschnitte. Eine unterschiedliche Länge der Wickelkopfabschnitte ermöglicht eine versetzte Anordnung derselben in benachbarten Windungen einer Wicklung, wenn die Umformabschnitte exakt übereinanderliegend positioniert sind. Da die Umformabschnitte in der Regel flacher ausgebildet sind als die Wickelkopfabschnitte, kann durch diese Maßnahme die Bauhöhe der elektrotechnischen Spule verringert und damit der Füllfaktor erhöht werden.
• - Schritt B4: Umformen des Leiters in jedem der Umformabschnitte nach einem sich wiederholenden Muster, sodass die Umformabschnitte und/oder die Wickelkopfabschnitte im Hinblick auf wenigstens eines der folgenden Merkmale untereinander einheitlich ausgebildet sind: Länge, Breite, Höhe, Querschnittsform, Querschnittsfläche. Eine gleichbleibende Querschnittsfläche begünstigt eine konstante Stromdichte.

It may be advantageous if step B comprises at least one of the following sub-steps:

• - Step B1: Preforming the conductor by changing the cross-sectional shape of the conductor, preferably by flattening the conductor, preferably starting from a circular cross-sectional shape into an oval or polygonal cross-sectional shape. By generally preforming the conductor, it can be adapted to the individual conditions of the specific application. If necessary, the dimensions can be adjusted so that the post-processing effort required to form the individual forming sections can be reduced.

• - Step B2: Changing the cross-sectional shape of the conductor in each of the forming sections to form at least two complementary and/or parallel sides for the flat arrangement of the forming sections one above the other. According to this embodiment, the forming sections can be arranged one above the other in a particularly compact manner.
• - Step B3: Formation of the forming sections at a distance from one another along the profile axis of the conductor, whereby the distances between the forming sections are preferably non-uniform and preferably increase or decrease linearly along the profile axis of the conductor. By varying the distances between the forming sections, the length of the winding head sections located between the forming sections changes. A different length of the winding head sections enables them to be arranged offset in adjacent turns of a winding if the forming sections are positioned exactly one above the other. Since the forming sections are generally flatter than the winding head sections, this measure can reduce the height of the electrical coil and thus increase the fill factor.
• - Step B4: Forming the conductor in each of the forming sections according to a repeating pattern, so that the forming sections and/or the winding head sections are uniform with respect to at least one of the following features: length, width, height, cross-sectional shape, cross-sectional area. A constant cross-sectional area promotes a constant current density.

• - Schritt C1: Anordnen der Umformabschnitte um die Wicklungsachse, sodass sich jeder der Umformabschnitte entlang einer Geraden erstreckt, wobei vorzugsweise jeweils mehrere Umformabschnitte in einer Ebene übereinander liegen, wobei bevorzugt zwei dieser Ebenen auf diametral gegenüberliegenden Seiten parallel zur Wicklungsachse angeordnet sind. Durch die Abflachung der Umformabschnitte ist deren Biegbarkeit in der Ebene der größten Ausdehnung ihrer Querschnittsform stark eingeschränkt. Daher erweist es sich als sinnvoll, wenn die Umformabschnitte in der Ebene der größten Ausdehnung ihrer Querschnittsform nicht gebogen werden und sich entlang einer Geraden erstrecken.
• - Schritt C2: Biegen der zwischen den Umformabschnitten liegenden Wickelkopfabschnitte, vorzugsweise über eine Bogenlänge im Bereich von 45 bis 180°, insbesondere um 45°, 60°, 90°, 120° oder 180°, bevorzugt mit konstantem Biegeradius, besonders bevorzugt auf einer Biegemaschine und/oder unter Verwendung eines Dorns. Durch diese Maßnahmen lässt sich eine Vielzahl unterschiedlicher Spulen erstellen.
• - Schritt C3: Anordnen der Wickelkopfabschnitte, sodass diese in benachbarten Windungen zumindest abschnittsweise radial zur Wicklungsachse versetzt sind. Dadurch kann die Bauhöhe der elektrotechnischen Spule verringert werden.

However, it may also be useful if step C includes at least one of the following sub-steps:

• - Step C1: Arranging the forming sections around the winding axis so that each of the forming sections extends along a straight line, preferably with several forming sections lying one above the other in one plane, preferably with two of these planes being arranged on diametrically opposite sides parallel to the winding axis. Due to the flattening of the forming sections, their bendability in the plane of the greatest extent of their cross-sectional shape is greatly restricted. It therefore proves to be useful if the forming sections are not bent in the plane of the greatest extent of their cross-sectional shape and extend along a straight line.
• - Step C2: Bending the winding head sections located between the forming sections, preferably over an arc length in the range of 45 to 180°, in particular by 45°, 60°, 90°, 120° or 180°, preferably with a constant bending radius, particularly preferably on a bending machine and/or using a mandrel. These measures make it possible to produce a large number of different coils.
• - Step C3: Arrange the winding head sections so that they are at least partially offset radially to the winding axis in adjacent turns. This allows the overall height of the electrical coil to be reduced.

• - Schritt D1: Aufbringen einer Presskraft auf die Übergangsbereiche zwischen den Umformabschnitten und den Wickelkopfabschnitten, vorzugsweise einseitig oder beidseitig entlang der Wicklungsachse. Durch diese Maßnahme kann die Bauhöhe der elektrotechnischen Spule weiter verringert werden und der Füllfaktor erhöht werden.
• - Schritt D2: Veränderung der Querschnittsform der Wickelkopfabschnitte in den Übergangsbereichen angrenzend an die Umformabschnitte durch Verdrängung des Materials des Leiters infolge der Presskraft, vorzugsweise derart, dass die Querschnittsform der Wickelkopfabschnitte zumindest in den Bereichen, in denen die Wickelkopfabschnitte parallel zur Wicklungsachse unmittelbar übereinander liegen, an die Querschnittsform der Umformabschnitte angenähert oder angeglichen wird. Dieser Schritt führt dazu, dass das Leitermaterial durch plastische Umformung in den Übergangsbereichen zwischen den Wickelkopfabschnitten und den Umformabschnitten im Wesentlichen selbst organisierend in eine besonders kompakte Anordnung überführt wird.

It may be useful if step D includes at least one of the following sub-steps:

• - Step D1: Applying a pressing force to the transition areas between the forming sections and the winding head sections, preferably on one side or both sides along the winding axis. This measure can further reduce the height of the electrotechnical coil and increase the fill factor.
• - Step D2: Changing the cross-sectional shape of the winding head sections in the transition areas adjacent to the forming sections by displacing the material of the conductor as a result of the pressing force, preferably in such a way that the cross-sectional shape of the winding head sections is approximated or adjusted to the cross-sectional shape of the forming sections, at least in the areas in which the winding head sections lie directly on top of one another parallel to the winding axis. This step results in the conductor material being essentially self-organized into a particularly compact arrangement by plastic deformation in the transition areas between the winding head sections and the forming sections.

• - Schritt E1: Anordnen der Umformabschnitte in wenigstens einem Nutbereich eines Stators oder Rotors eines Elektromotors, sodass die zwischen den Umformabschnitten liegenden Wickelkopfabschnitte einen über den Nutbereich des Stators/ Rotors vorstehenden Wickelkopf bilden. Bei dieser Ausführung kommen die vorteilhaften Wirkungen der beanspruchten Erfindung besonders zur Geltung.
• - Schritt E3: Verringerung des Innenumfangs des wenigstens einen Bündelwerkzeugs zur Bündelung der Wickelkopfabschnitte, vorzugsweise durch gegenseitiges Annähern jeweils der ersten und zweiten Abschnitte der ersten und zweiten Bündelwerkzeuge, sodass die umgriffenen Wickelkopfabschnitte im Wesentlichen wenigstens abschnittsweise parallel zueinander ausgerichtet werden und/oder einander vorzugsweise linienförmig kontaktieren. Dadurch kann bereits vor der Biegung und/oder Verdrillung der Wickelkopfabschnitte eine vorläufige Bündelung erreicht werden, die die spätere Handhabung erleichtert.
• - Schritt E4: Biegung der Wickelkopfabschnitte durch Bewegung des wenigstens einen Bündelwerkzeugs mit den davon umgriffenen Wickelkopfabschnitten in einer Richtung radial zur Wicklungsachse und/oder parallel zur Wicklungsachse, vorzugsweise durch Bewegung der ersten und zweiten Bündelwerkzeuge in gegensätzliche Richtungen parallel zur Wicklungsachse, sodass das Bündel der Wickelkopfabschnitte wellenförmig ausgebildet ist. Die Biegung führt bevorzugt zumindest teilweise zu einer plastischen Umformung der Wickelkopfabschnitte, sodass die elastischen Rückstellkräfte des Leitermaterials eliminiert werden und die Wickelkopfabschnitte nach dem Entfernen des Bündelwerkzeugs in der gebogenen Form verbleiben. In einer bevorzugten Ausführung verlaufen die gebogenen Wickelkopfabschnitte zumindest abschnittsweise wellenförmig in Umfangsrichtung um die Wicklungsachse.

It may also prove useful if step E comprises at least one of the following substeps:

• - Step E1: Arranging the forming sections in at least one slot area of a stator or rotor of an electric motor, so that the winding head sections located between the forming sections form a winding head that protrudes beyond the slot area of the stator/rotor. In this embodiment, the advantageous effects of the claimed invention are particularly evident.
• - Step E3: Reducing the inner circumference of the at least one bundling tool for bundling the winding head sections, preferably by bringing the first and second sections of the first and second bundling tools closer together, so that the encompassed winding head sections are essentially aligned parallel to one another at least in sections and/or preferably contact one another in a linear manner. This makes it possible to achieve preliminary bundling before the winding head sections are bent and/or twisted, which facilitates subsequent handling.
• - Step E4: Bending the winding head sections by moving the at least one bundling tool with the winding head sections encompassed thereby in a direction radial to the winding axis and/or parallel to the winding axis, preferably by moving the first and second bundling tools in opposite directions parallel to the winding axis, so that the bundle of winding head sections is wave-shaped. The bending preferably leads at least partially to a plastic deformation of the winding head sections, so that the elastic restoring forces of the conductor material are eliminated and the winding head sections remain in the bent shape after the bundling tool is removed. In a preferred embodiment, the bent winding head sections run at least partially in a wave-like manner in the circumferential direction around the winding axis.

A further aspect, which is not part of the present invention, relates to a device for bundling windings of a winding made of a conductor made of an electrically conductive material, which windings extend around a winding axis, comprising first and second bundling tools, wherein a first section of the first and second bundling tools can be arranged on the side of the windings facing away from the winding axis and a second section of the first and second bundling tools can be arranged on the side of the windings facing the winding axis, wherein the first and second sections of the first and second bundling tools can be connected so that each of the first and second bundling tools surrounds the same windings, wherein the first and second bundling tools can be moved and/or rotated in different directions in order to bundle the windings by bending and/or twisting. With this device, the windings of a coil-shaped winding can be arranged particularly compactly.

It may be useful if the first and second sections of the first and second bundling tools are each designed as ring halves, which can be connected to form a self-contained ring, preferably perpendicular to their respective separation plane.

Preferably, the first and second bundling tools are movable radially and/or parallel to the winding axis of the winding.

Preferably, the first and second bundling tools are movable and/or rotatable in opposite directions, as corresponds to the method according to the invention.

These features facilitate the processing of the windings according to the method according to the invention.

terms and definitions

Director

The term conductor is intended to cover all electrically conductive profiles that can be processed using the method according to the invention and can be subjected to a forming process, i.e. in particular endless profiles and strip materials, etc. The conductor extends along a profile axis and preferably consists of homogeneous material, for example an electrically conductive material such as metal, in particular copper, aluminum, iron, silver or an alloy thereof. The conductor is preferably produced by extrusion (or extrusion in the case of an extruded profile made of plastic), for example with a constant cross-section along the profile axis. In preparation for a sequential local bending process, local cross-sectional changes can be made, for example by local material application and/or material removal.

Profile axis

The profile axis preferably corresponds to the centre of the maximum external dimensions of the cross-sectional shape or the centre of the smallest rectangle into which the cross-sectional shape of the conductor fits.

Cross-sectional shape

In the context of this description of the invention, the cross-sectional shape of the conductor refers to a cross-section perpendicular to the profile axis of the conductor, unless explicitly stated otherwise.

Short description of the characters

• 1 shows in view (a) a perspective view of a formed conductor made of an electrically conductive material, in which the cross-sectional shape of the conductor in the formed sections is changed from circular to rectangular, and in view (b) a perspective view of a corresponding winding made of the formed conductor according to view (a), wherein the formed sections are arranged one above the other in adjacent turns and the conductor sections lying between the formed sections lie at least partially above one another in the radial direction with respect to a winding axis and cross over one another.
• 2 shows in side view an arrangement according to view (b) of the 1 in the undeformed state.
• 3 shows in perspective view an arrangement with a partially shown winding arranged on a stator in the deformed state, wherein the forming sections are pressed flat against one another in a direction parallel to the winding axis and the conductor sections lying between the forming sections are disordered.
• 4 shows in perspective view an arrangement according to 3 , wherein the windings are each encompassed by first and second two-part bundling tools in the region of the conductor sections lying between the forming sections.
• 5 shows in another perspective view an arrangement according to 4 , whereby the conductor sections encompassed by the bundling tools are moved in opposite directions parallel to the winding axis.
• 6 shows in view (a) a side view, in view (b) a front view and in view (c) a plan view of the arrangement according to 5 .
• 7 shows a schematic view of an arrangement of forming coils without a stator.

Detailed description of the preferred embodiment

The preferred embodiment of the invention relates to a method for producing an electrotechnical coil for electric motors.

In step A of the method according to the invention, a conductor 1 extending along a profile axis A with a constant circular cross-section in linear form is provided.

Step B comprises the forming of the conductor 1 in several sub-steps to form at least two forming sections 2, each by changing the cross-sectional shape of the conductor 1.

In sub-step B1, the conductor 1 is preformed by changing the cross-sectional shape of the conductor 1 by flattening the conductor 1 from the circular cross-sectional shape into an oval or polygonal cross-sectional shape.

In the sub-steps B2, B3 and B4, the cross-sectional shape of the conductor 1 in each of the forming sections 2 is changed from the flattened cross-sectional shape to a flatter rectangular cross-sectional shape according to a repeating pattern with the formation of two parallel sides for the flat arrangement of the forming sections 2 one above the other, wherein the distances between the forming sections 2 are not uniform and increase or decrease linearly along the profile axis A of the conductor 1. The sections 3 of the conductor 1 lying between the forming sections 2 later form the winding head of the coil and are accordingly referred to as winding head sections 3. A semi-finished product according to sub-step B4 of the method according to the invention is shown in 1a shown in sections.

In step C, the conductor 1 is arranged in several sub-steps in the form of a winding with several turns extending around a winding axis W, so that the forming sections 2 in adjacent turns lie flat on top of one another.

In accordance with sub-step C1, each of the forming sections 2 extends along a straight line, with the forming sections 2 of all turns of the winding lying one above the other in one plane. Two of these planes are arranged on diametrically opposite sides parallel to the winding axis W.

According to sub-step C2, the winding head sections 3 located between the forming sections 2 are bent on a bending machine and using a mandrel, e.g. over an arc length of 180° with a constant bending radius.

Due to the different lengths of the winding head sections 3, these can be arranged offset from one another in the wound state in accordance with sub-step C3 with respect to the winding axis W, while the forming sections 2 lie flat on top of one another, as clearly shown in 2 is shown.

Step D involves compressing the winding along the winding axis W so that the forming sections 2 in adjacent turns contact one another over the surface. By applying a pressing force to the transition areas between the forming sections 2 and the winding head sections 3 on both sides along the winding axis W, the cross-sectional shape of the winding head sections 3 in the transition areas adjacent to the forming sections 2 is approximated or adjusted to the cross-sectional shape of the forming sections 2 by displacing the material of the conductor 1 (sub-steps D1 and D2).

• Da die Bündelung vorzugsweise im Einbauzustand der Spule erfolgt, werden zunächst im Teilschritt E1 die Umformabschnitte 2 im Nutbereich eines Stators S eines Elektromotors angeordnet, wobei die zwischen den Umformabschnitten 2 liegenden Wickelkopfabschnitte 3 einen über den Nutbereich des Stators S vorstehenden Wickelkopf bilden. In diesem Zustand, der in 3 teilweise dargestellt ist, verlaufen die Wickelkopfabschnitte 3 weitgehend ungeordnet.

Step E comprises the bundling of the winding head sections 3 of the conductor 1 located between the forming sections 2 by bending and, if necessary, twisting them according to the following sub-steps:

• Since the bundling preferably takes place in the installed state of the coil, the forming sections 2 are first arranged in the slot area of a stator S of an electric motor in sub-step E1, whereby the winding head sections 3 located between the forming sections 2 form a winding head that protrudes beyond the slot area of the stator S. In this state, which is shown in 3 As is partially shown, the winding head sections 3 are largely random.

The winding head sections 3 are bundled using a device with two ring-shaped bundling tools B1, B2, each consisting of two connectable ring halves.

According to sub-step E2, all the windings of the winding in the area of the winding head sections 3 are encompassed by the two ring-shaped bundling tools B1, B2. For this purpose, a first section B1a, B2a of the bundling tools B1, B2 is arranged on the side of the windings facing away from the winding axis W and the complementary second section B1b, B2b of the bundling tools B1, B2 is positioned on the side of the windings facing the winding axis W. The state before the two ring halves of the bundling tools B1, B2 are connected is shown in 4 clearly presented.

By connecting both sections B1a, B1b; B2a, B2b of the bundling tools B1, B2 in the direction of the arrow, each bundling tool B1, B2 surrounds the same winding head sections 3. By reducing the inner circumference of each bundling tool B1, B2 when connecting the two ring halves, the encompassed winding head sections 3 can already be aligned parallel to each other in sections so that they contact each other in a linear manner (sub-step E3).

The bending of the winding head sections 3 (sub-step E4) is carried out by moving the first and second bundling tools B1, B2 in opposite directions parallel to the winding axis W. After completion of the bending, the bundle of the winding head sections 3 is wave-shaped, as clearly shown in 5 and views a, b and c of the 6 is shown.

If necessary, the bundling of the winding head sections 3 is supported by twisting them as a result of a rotation of the bundling tools B1, B2 in opposite directions, so that the winding head sections 3 wind around each other in a helical manner in sections (sub-step E5).

In summary, according to the method according to the invention, a forming sequence is first formed from an electrical conductor 1 in such a way that the coil regions for the motor slot are expanded by forming until they would (almost) completely fill the slot width, taking insulation material into account.

In a preparatory step, the conductor 1 or the strand with a constant cross-sectional shape is locally adapted by forming so that the optimal cross-sectional shape is achieved in some areas in the forming sections 2. With a conical cross-sectional geometry of the coil (groove), this means that the sequence can have different cross-sectional dimensions. A corresponding continuous forming sequence of a conductor 1 with forming sections 2 and intermediate conductor sections 3 is shown in 1a shown.

This forming sequence is then wound up in the traditional way, so that the resulting winding head of the coil has the cross-section of the semi-finished product before the sequence is produced (intermediate conductor sections 3) and the groove area consists of solidly formed areas (forming sections 2). Another method according to the invention involves bending the conductor sequence (with sections of different cross-sectional shapes) on bending machines and/or automatic machines. The coil can be bent/wound on the fly or over a mandrel. The cross-sectional shape can change both during winding and when bending the conductor 1. This change is passive in nature and is not actively influenced.

1b shows a coil design with classic winding of the forming sequence by simple bending process and changing winding head length for every second wire layer, and 2 shows a coil design with classical winding of the forming sequence and pressing in the transition area of the conductor 1 between the forming sections 2 and the intermediate conductor sections 3.

In the area of the transitions from the winding head to the groove area, ie the areas between the forming sections 2 and the intermediate conductor sections 3, the simplified winding is formed/pressed to ensure permanent contact between the flat pressing sequences. Various approaches are available for a better arrangement of the wire layers, for example a winding head length that alternates from winding to winding. This can help to enable the space-saving arrangement of the wire layers in the winding head, as shown in the 1b and 2 is shown.

3 shows a coil design with classic winding of the forming sequence and pressed transition areas (image in half) and rearrangement of the wire layers.

For a better organization of the wire layers in the winding head, bundling tools B1 and B2 can first enclose the wire layers in the area of the intermediate conductor sections 3 and thus compress them somewhat, as in 4 , 5 and 6a to c is shown in different perspectives.

In the winding head area, laterally engaging tool elements (rings, split) B1, B2, each consisting of two ring halves B1a, B1b, B2a, B2b, give the wire bundle in the winding head area the final curved geometry, with one bundle tool element B1 moving downwards and the other bundle tool element B2 moving upwards. Both classic toolmaking and robot technology can be used to implement the forming movement.

This production sequence enables extensive automation of the winding process of coils made of semi-finished conductors with a sequence of different cross-sections, which increase the copper fill factor in the future slot areas, but are easier to handle in the area of the winding head due to their input wire cross-section (preferably round).

7 shows an arrangement of the forming coils without a stator, whereby the winding heads can be easily guided past each other.

For particularly thin wire, individual process steps such as subsequent calibration of the winding head can be omitted, since this forming process does not require great forces.

The use of preformed wire sections can be verified with little effort by cross-sections.

The different geometric shape of the winding head and the groove area requires a manufacturing step before winding the wire layers, which could also be carried out by machining or forming. Stranded conductors can also be used as input material.

The main area of application is coils for electric motors that are mass-produced.

The invention comprises the winding and bending of a preferably straight wire, which ultimately serves as an electrical conductor 1. To increase the efficiency of the resulting electrical coil (in electric machines), the conductor 1 consists of a sequence of locally adapted cross-sections (round - rectangular - round - rectangular - round, round - trapezoidal - round - trapezoidal - round, rectangular - trapezoidal - rectangular - trapezoidal - rectangular).

The conductor areas with different cross-sectional shapes can be designed symmetrically (coaxially) or offset from one another and parallel to one another. By pivoting the transitions in this way, an improved or self-organizing arrangement of the conductors in the winding head is achieved.

The conductor sequence can be produced by forming (casting, 3D printing), forming, or machining.

The bending of the conductor with an adapted cross-section sequence is carried out in such a way that the cross-sections adapted to fill the slot lie on top of each other and simpler semi-finished product cross-sections are used in the area of the winding head.

A twisting of the stacked conductors in the slot area relative to each other or to compact the turns in the winding area serves to improve the use of space or to reduce the size of the winding head.

List of reference symbols

1

Director

2

Forming section

3

Winding head section

B1

First bundling tool

B1a

First part of the first bundling tool

B1b

Second part of the first bundling tool

B2

Second bundling tool

B2a

First part of the second bundling tool

B2b

Second part of the second bundling tool

A

Profile axis

Q

Transverse side/winding head side of the stator/rotor

L

Longitudinal side/slot side of the stator/rotor

S

Stator/ Rotor

W

Winding axis

Claims (7)

Method for producing an electrotechnical coil, comprising the steps: a. Step A: Providing a conductor (1) extending along a profile axis (A) made of an electrically conductive material. b. Step B: Shaping the conductor (1) to form at least two forming sections (2), each by changing the cross-sectional shape of the conductor (1). c. Step C: Arranging the conductor (1) in the form of a winding with at least two turns extending around a winding axis (W), so that at least two of the forming sections (2) in adjacent turns lie flat on top of one another. d. Step D: Compressing the winding along the winding axis (W) so that the forming sections (2) in adjacent turns contact one another flatly. e. Step E: Bundling at least some of the winding head sections (3) of the conductor (1) lying between the forming sections (2) by twisting them, wherein step E has at least the following sub-steps: Step E2: Enclosing two, several or all of the windings of the winding in the region of the winding head sections (3) with at least one bundling tool (B1, B2), by arranging a first section (B1a, B2a) of first and second bundling tools (B1, B2) on the side of the windings facing away from the winding axis (W) and arranging a second section (B1b, B2b) of the first and second bundling tools (B1, B2) on the side of the windings facing the winding axis (W), and connecting the first and second sections (B1a, B1b; B2a, B2b) of the first and second bundling tools (B1, B2) so that each of the first and second bundling tools (B1, B2) has the same Wrapping head sections (3). Step E5: Twisting the wrapping head sections (3) by turning the first and second bundling tools (B1, B2) in opposite directions so that the wrapping head sections (3) wind around each other in a helical manner, at least in sections. Method for producing an electrotechnical coil, comprising the steps: a. Step A: Providing a conductor (1) extending along a profile axis (A) made of an electrically conductive material. b. Step B: Shaping the conductor (1) to form at least two forming sections (2) each by changing the cross-sectional shape of the conductor (1), the distances between the forming sections (2) increasing and decreasing linearly along the profile axis (A) of the conductor (1). c. Step C: Arranging the conductor (1) in the form of a winding with at least two turns extending around a winding axis (W) so that at least two of the forming sections (2) in adjacent turns lie flat on top of one another. d. Step D: Compressing the winding along the winding axis (W) so that the forming sections (2) in adjacent turns contact one another flatly. e. Step E: Bundling at least some of the winding head sections (3) of the conductor (1) lying between the forming sections (2) by twisting them, wherein step E comprises at least the following sub-steps: Step E2: Enclosing two, several or all of the windings of the winding in the region of the winding head sections (3) with at least one bundling tool (B1, B2), by arranging a first section (B1a, B2a) of first and second bundling tools (B1, B2) on the side of the windings facing away from the winding axis (W) and arranging a second section (B1b, B2b) of the first and second bundling tools (B1, B2) on the side of the windings facing the winding axis (W), and connecting the first and second sections (B1a, B1b; B2a, B2b) of the first and second bundling tools (B1, B2) so that each of the first and second bundling tools (B1, B2) has the same winding head sections (3). Step E5: Twisting the winding head sections (3) by rotating the first and second bundling tools (B1, B2) in opposite directions so that the winding head sections (3) wind around each other in a helical manner, at least in sections. Procedure according to Claim 1 or 2 , characterized in that step A comprises the following sub-steps: a. Step A1: Providing the conductor (1) as a continuous conductor. b. Step A2: Providing the conductor (1) with a constant cross-sectional shape along its profile axis (A). c. Step A3: Providing the conductor (1) in linear form. Method according to one of the preceding claims, characterized in that step B has the following sub-steps: a. Step B1: pre-forming the conductor (1) while changing the cross-sectional shape of the conductor (1). b. Step B2: changing the cross-sectional shape of the conductor (1) in each of the forming sections (2) while forming at least two complementary and parallel sides to the flat arrangement of the forming sections (2) one above the other. c. Step B3: forming the forming sections (2) at a distance from one another along the profile axis (A) of the conductor (1). d. Step B4: forming the conductor (1) in each of the forming sections (2) according to a repeating pattern so that the forming sections (2) and the winding head sections (3) are uniform with respect to at least one of the following features: length, width, height, cross-sectional shape, cross-sectional area. Method according to one of the preceding claims, characterized in that step C has the following sub-steps: a. Step C1: arranging the forming sections (2) around the winding axis (W) so that each of the forming sections (2) extends along a straight line. b. Step C2: bending the winding head sections (3) located between the forming sections (2). c. Step C3: arranging the winding head sections (3) so that they are at least partially offset radially to the winding axis (W) in adjacent turns. Method according to one of the preceding claims, characterized in that step D has the following sub-steps: a. Step D1: applying a pressing force to the transition areas between the forming sections (2) and the winding head sections (3). b. Step D2: changing the cross-sectional shape of the winding head sections (3) in the transition areas adjacent to the forming sections (2) by displacing the material of the conductor (1) as a result of the pressing force. Method according to one of the preceding claims, characterized in that step E further comprises the following sub-steps: a. Step E1: arranging the forming sections (2) in at least one groove region of a stator or rotor (S) of an electric motor, so that the winding head sections (3) lying between the forming sections (2) form a winding head protruding beyond the groove region of the stator or rotor (S). b. Step E3: reducing the inner circumference of the at least one bundling tool (B1, B2) for bundling the winding head sections (3). c. Step E4: bending the winding head sections (3) by moving the at least one bundling tool (B1, B2) with the winding head sections (3) encompassed thereby in a direction radial to the winding axis (W) and/or parallel to the winding axis (W).

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