The present invention relates to an electrical coil, a process for their preparation and to a solenoid or an electric machine with at least one such coil. In particular, the present invention relates to wire and cable produced by casting calibration of electrical coils made of electrically conductive materials with draft angles in a combined process.
Until now, coils are commonly wound from wire (round profile, a rectangular profile), which especially leads conically executed due to the coil conductor form for lack of space utilization (slot fill factor). An essential geometric restriction is located in the art in the limited possibilities for the use of different Windungsquerschnitte: Even with optimum utilization remains with the use of round wires for the windings of an unusable space between the individual windings. The necessary insulation, the wire introduction and discrete distribution of the printed circuit limit the fill factor. Since the slot fill factor ultimately achieved also only suitable estimated in the electromagnetic design and the engine can not be calculated due to the ignorance of the subsequent actual execution,

Compared to coils wound with round wire or rectangular wire coils produced by casting permit an enormous increase in the slot space factor for the high geometric design freedom. In addition, the geometry of the cast coils shows a significantly improved Entwärmungsverhalten.

A process for producing an electro-technical coil in casting technique is known from EP 2387135 A2.

According to the EP 2387135 A2 the achievable torque density depends permanently excited synchronous machines with a tooth coil winding largely on the ratio of total copper cross-sectional area to groove area, the so-called slot fill factor decreases. An increase of the fill factor enables a flatter construction of the stator or a widening of the teeth on the discharge of the magnetic circuit with a constant torque.

Until now, cast coils were manufactured by casting in an investment casting process using sprayed lost wax patterns and lost molds. Here, the injection molding tools by elaborate shape concepts have been kept as small as possible. However, this resulted in a significant overhead in the design of mold tools and made the Pro-process susceptible to interference. However, gaps are manufacturing reasons to provide castings between the windings for demolding. This lead cast coils to reduce the slot space factor and have a negative effect on the heat dissipation from.

In summary, it can be stated that consist of coil windings technical using today's methods of manufacture and economic boundaries of the slot filling with individual coils. A slot fill factor of 70% is already a very good value, both technically and economically feasible feasible limits are currently at about 75% to 80% (Source: Müller, Vogt, Ponick "Calculation of Electrical Machines", p 168, 6th Edition , Wiley-VCH, Weinheim, 2008. "). Furthermore, carry out the necessary for demoulding spaces between the windings as well as the surface quality of the casting technology generated coils to reduce the slot space factor, and considerable problems in the subsequent isolation.

Starting from the prior art, it is the object of the present invention to provide an electrical coil to achieve produce an increased slot space factor in a reliable and simple manner and to apply reproducibly and economically.

The object of the present invention is achieved by the method of claim 1, the electrical coil according to claim 9 and the electromagnet or the electric machine according to claim 10th

The inventive method for producing a electrical coil of claim 1 comprising the steps of:

- Step A: casting an electrical coil having at least one extending about a coil axis winding.

- Step B: forming the coil while changing the cross section of at least one turn, so that the centroid of the cross section of the at least one coil with respect to the coil axis is at least partially displaced in the radial direction.

The inventive method takes advantage of forming production, scoring little or no loss of material. Specifically, the coil by casting prepared in step A can be provided to facilitate removal from the mold with high angle draft angles, because

can be reduced, the draft angles in the subsequent step B to the plastic deformation of the coil under displacement of the centroid of the cross section of the coils in the radial direction or eliminated completely. The coil is compressed along the coil axis and the windings of the coil are pressed together, so that the coil material is displaced in the radial direction and the centroid of the cross section of the turns at least partially the coil axis is shifted with respect to the radial direction. In this case, a shift of the centroid partially in the axial direction is possible. Draft angles at large angles facilitate removal from the mold. The use of economic mass production methods such as. The pressure casting, mold draft should at least 1. 5 ° be provided that can fail even less for short Entformungswegen. Preferably, the coil is brought in the course of shaping into the final contour (calibrated). Along with this is the simplification of primary shaping process chains such as casting by eliminating preparation, manufacturing and processing steps. Furthermore, the surface quality can be adjusted by a follow-up the forming process, thereby decrease the quality required of the casting process, and process robustness increases.

Advantageous developments of the invention are objects of the dependent claims.

It may be advantageous when step A comprises at least one of the following substeps:

Step A1: providing a preferably reusable negative mold, preferably by embedding a positive model in an embedding medium, for example of sand or of metallic material, wherein particularly preferably the positive model from an impression in the embedding medium again is removed or remains as a lost form in the embedding medium. The reusability of the negative mold reduces the manufacturing effort in terms of time and cost.

- Step A2: casting of the coil material in the negative mold, preferably gravitational and / or pressure assisted, preferably upon the application of the negative mold with vacuum and / or in a protective gas atmosphere, particularly preferably in investment casting, centrifugal casting, vacuum casting or low pressure casting. Due to these measures can reduce the inclusion of pores or particles in the cast coil material or even completely prevented.

- Step A3: curing the cast coil material in the negative mold. The curing is preferably performed by (passive) cooling of the negative mold and the coil material contained therein.

- Step A4: removal of the coil from the negative mold. For this purpose, the negative mold is preferably constructed of several parts and can be opened.

- Step A5: cleaning the coil. In this step, residues can an existing embedding be removed.

- Step A6: soft annealing of the coil. This measure can facilitate the transformation and possibly calibration of the coil in the subsequent step B.

- Step A7: Electrical insulation of at least one turn of the coil, preferably by immersing the coil in insulating varnish (for example, in the CVD or PVD process) or tung by coating or shell, with an insulating layer. By this step, the individual turns of the coil are electrically separated from each other.

The sequence of the partial steps is preferably as indicated, but can also be changed in any manner, as far as the method with the changed sequence of substeps is technically feasible.

but it can also be useful when step B comprises at least one of the following substeps:

- Step B1: providing a multi-piece forming tool that forms in an assembled state a cavity for receiving the coil, wherein the cavity is preferably adapted to the inner contour and / or the outer contour of the coil, preferably a (conical and / or rotationally symmetric) punch forming an upper part of the forming tool and / or a (tapered and / or rotationally symmetric) die forming a bottom part of the forming tool.

- Step B2: placing the coil in the forming tool, preferably such that the coil radially on the inside and / or radially on the outside bears against the forming tool, wherein preferably the coil radially inward on the punch is applied and / or radially on the outside bears against the die.

- step B3: moving at least two parts of the multi-part forming tool relative to each other along the coil axis while reducing the volume of the cavity, whereby preferably retracts the plunger along the coil axis in the die.

- Step B4: forming the coil by compressing the coil along the coil axis, preferably wherein the turns of the coil are radially inwardly pressed, beginning against each other, so that the coil material of the coil axis is displaced in the radially outward direction with respect to, preferably such that the spaces between the be reduced or eliminated turns.

- Step B5: changing the cross-section of the at least one winding, preferably during the step B4, located so that an angle which the top and / or bottom of the cross-section includes a the coil axis perpendicularly intersecting plane, by at least 1 °; 1.5 °, 2 °, 2.5 °, 3 °, 4 ° or 5 ° from the undeformed state modified and / or reduced.

- Step B6: separating a sprue of the coil.

- Step B7: forming at least one connection region for an electrical contact with the coil, preferably by embossing.

- Step B8: calibrating the coil to the final contour, preferably using the forming the coil radially on the inside and / or radially on the outside and / or on the upper and / or lower axial end with respect to the coil axis calibrated, wherein in particular the stamp preferably, the coil radially on the inside and / or calibrated at the upper axial end and / or the die, the coil radially on the outside and / or calibrated at the lower axial end.

- Step B9: Electrical insulation of at least one turn of the coil, preferably by immersing the coil in insulating varnish (for example, in the CVD or PVD process) or tung by coating or shell, with an insulating layer.

The sequence of the partial steps is preferably as indicated, but can also be changed in any manner, as far as the method with the changed sequence of substeps is technically feasible.

The steps B1 to B9 proposed under and optional measures can promote the forming and calibration of the coil with the elimination of surface irregularities and compression of the coil material.

It may be useful when the cross-section of the coil axis is tapered at least one turn of the cast in step A coil with respect to in the radial direction inwardly or outwardly, wherein the cross section of at least one turn of the cast in step A coil preferably polygonal, and / or conical, and / or trapezoidal, preferably isosceles po- lygonal and / or conical and / or trapezoidal. In this embodiment, draft angles may be provided, while the subsequent conversion in step B is also favored.

It may prove advantageous if the angle enclosed by the top and / or bottom of the cross-section of at least one turn of the cast in step A coil having a coil axis perpendicular to the plane intersecting at least 1 °; 1.5 °, 2 °, 2.5 °, 3 °, 4 ° or 5 °. Such draft angles favor the use of economic mass production methods such as. The pressure casting.

but it may also be convenient if the inner contour and / or the outer contour corresponds to the coil obtained in step A and / or after step B the surface of a cylinder, cuboid, truncated cone or truncated pyramid correspond to /. Coils having such inner and / or outer contours are associated with the electromagnet and the electric machines, in particular three-phase synchronous machines used particularly advantageously in corresponding stator slots.

It may be useful if the electrical coil in step B is converted such that it occupies at least 95% of the volume of a body having the same inner and outer contour. In this embodiment, the use of the coil in the field of electrical machines a high torque density can be achieved.

It may be advantageous if the centroid of the cross section one turn in step B in the radial direction inwardly or outwardly of the coil axis is displaced with respect to the at least. This displacement of coil material serves to reduce or eliminate mold draft in an advantageous manner and thus the increase in the slot space factor of the respectively achieved with the coil torque density.

Another aspect of the present invention relates to an electrical coil produced by the method according to one of the preceding embodiments.

Another aspect of the present invention relates to an electric magnet or a electromag-machine, preferably a synchronous machine, preferably a three-phase synchronous machine, with at least one coil according to the foregoing embodiment.

Further advantageous developments of the present invention will become apparent by arbitrary combinations of the features disclosed in the claims, figures and the description of features.

terms and definitions

Electrical coil

In the present invention, a component of the electrical is meant by a coil: coil according to the invention are therefore suitable for any applications in the electrical engineering, for example, in electrical engineering, in particular in electric motors and Elektrogeneratorenbau. Coils according to the invention are hereinafter therefore referred to as electrical coils.

Such coils are one of the most important components of electrical engineering. You assume various functions in electrical circuits and electromechanical applications. In the field of electrical engineering coils are an essential functional component of the engine. Depending on the class and type of construction of the motor have the coils different geometries, shapes and winding turns.

The radius and / or the pitch and / or cross-sectional shape and / or the cross-sectional area of ​​the at least one turn of the coil is preferably over at least a central portion of constant between the axial end portions of the coil or over the entire coil. The number of turns can be arbitrarily selected.

The coil is preferably made of a moldable, electrically conductive material such as aluminum, silver, copper or alloy.

The coil is preferably straight, convex, concave, conical, rotationally symmetrical or non-rotationally symmetrical.

The electrical coil is made, for example, after the method described in EP 2387135 A2, in particular by the method according to any one of claims 1 to 6 of EP 2387135 A2, or is an electro-technical coil, in EP 2387135 A2 is described, in particular an electrical coil according to any one of claims 7 to 12 of EP 2387135 A2.

transformation

The term transformation is to be understood as plastic deformation, unless explicitly otherwise mentioned.

calibration

The term calibration refers to the shape of the coil in the final contour, unless explicitly otherwise mentioned. The step preferably comprises calibrating the compaction of the cast and cured coil material and / or the smoothing of surface irregularities and / or the separation of the gate in one process step.

coil axis

The coil axis is preferably the longitudinal axis of the coil or the axis about which the at least one turn of the coil unwinds around and is preferably a straight line.

cross-section

The cross section extending at least one turn of performing sectional view and preferably lies in a plane including the coil axis, unless explicitly otherwise is mentioned.

Centroid

The centroid of the cross-sectional shape of the extruded profile is the geometric focus of this cross-sectional shape. Mathematically, this corresponds to the average of all points within the cross-sectional shape. The centroid can be obtained by geometric considerations in simple cases, or generally calculate resources of mathematics by integration. To describe the body's methods of analytical geometry are used.

winding axis

The winding axis preferably corresponds to the midpoint of the maximum outer dimensions of the cross-section of at least one turn or the center of the smallest rectangle into which fits the cross section of at least one turn. With a rectangular cross-sectional shape of the area center of gravity coincides with the winding axis. In a triangular or trapezoidal cross-section of the area center of gravity, starting in each case offset from the winding axis in the direction of the wider side of the cross section. The (imaginary) axis of coiling winds helically around the (imaginary) coil axis.

mold draft

For manufacturing reasons, are advantageous on cast draft angles. Type and size of draft angles are depends on the selected casting process. This lead cast coils to reduce the slot space factor and have a negative effect on the heat dissipation from. The mold draft corresponds to the angle which the top and / or bottom of the enclosing of the cross section of one turn of the cast in step A coil having a coil axis perpendicular to the cutting plane.

Brief Description of Drawings

Fig. 1 is a schematic sectional view showing a cast and cured electro-technical coil with four turns and a constant pitch, wherein the cross-sections of the turns of the coil axis and taper in the radially outward direction formed in the shape of isosceles trapezoids with respect.

Fig. 2 is a schematic view showing a two-part pressing tool with a rotationally symmetrical stamp as a top part and a rotationally symmetrical die as the lower part.

Fig. 3 shows a schematic view of a press tool and arranged in the radially inside and radially outside from the pressing tool supported electrical coil in the state prior to forming, the pitch of the coil is neglected for purposes of illustration.

Fig. 4 shows a schematic view of the spaced crimping tool and radially inwardly and radially outwardly supported electrical coil in the state after the forming, wherein the cross-sections of the coils are substantially rectangular, and the pitch of the coil is neglected for purposes of illustration.

Fig. 5 shows a schematic view of the change of the cross section of the turn caused by deformation of the coil starting from the shape of an isosceles trapezium (solid contours) in a rectangular shape (broken contour line) and the associated displacement of the centroid of the cross section of the coil in the radial outward direction with respect to the coil axis.

Detailed Description of the Preferred Embodiment

The preferred embodiment of the present invention will be described below with reference to the accompanying drawings in detail. The skilled artisan will understand that the characteristics for the realization of the claimed invention described in connection with the embodiment need not be implemented in entirety, but can also be implemented independently of each other in other configurations. In particular, individual of the features described in the embodiment may be omitted or other features added.

In preparation for the casting the coil 1 in step A, the construction of the final geometry of the electrical coil 1 is carried out, for example, by means of CAD. Depending on the concrete application case number, radius, slope cross-sectional shape and cross-sectional area be found in the turns of the coil and defined the coil geometry in the installed state in dependence of the available installation space. It is understood that the number, radii, gradient, cross-sectional shape and cross-sectional area of ​​the windings of the coil can be changed, unless this is contrary to the teaching claimed. The embodiment described relates to a process for producing an electro-technical coil 1 with four extending about the coil axis A turns.

Based on the final geometry of the cast geometry of the electrical coil 1 is constructed under simulated unwinding of the engagement in Step B forming as well as taking into account material shrinkage, as well as draft angles. The spacing of the turns of the coil 1 is defined by the degree of deformation feasible, the casting requirements and the nature of the insulation job.

In step A1 of the preparation process is carried out to provide a reusable negative mold. For this, a positive model is embedded in an embedding medium such as sand or metallic material or bulk material, wherein the positive model to leaving his imprint is removed again in the embedding medium or remains as a lost form in the embedding medium.

The casting of the coil material in the negative mold in step A2 is carried out gravitational and preferably pressure-supported, for example, under a protective gas atmosphere, while the negative mold, if necessary, is subjected to negative pressure. The coil 1 according to the invention can in particular in fine-casting, centrifugal casting, vacuum casting or low pressure casting are manufactured.

After curing, the cast coil material in the negative mold (step A3), the cured and cooled coil 1 is made from the negative mold removed (step A4), freed from residues of the embedding and cleaned (step A5) and if necessary in preparation for the subsequent conversion in step B annealed (step A6).

The electrical insulation of the windings of the coil 1 (step A7) may be either before or be carried out after the success in stage B forming the coil 1 and is, for example, by immersing the coil 1 in the insulation coating, for example, in the CVD or PVD process, or by accomplished Beschich-tung or shell, with an insulating layer.

Is a schematic sectional view of an exemplary electrical coil 1, which was prepared in casting technology in order of the steps A1 to A7 / A8 is shown in FIG. 1 The sectional view shown in this case runs along the coil axis A and in a plane including the coil axis A. In the embodiment shown in Figure 1 view, the coil 1 comprises a cylindrical inner and outer contour and a total of four turns with a constant cross-sectional shape, the pitch or the distance of the coils to one another is reduced along the coil axis A in line with the casting facility to a minimum , The cross-section Q of each coil is tapered in radial direction relative to the coil axis A to the outside and has the shape of an equal give trapezoid,

5 shows in a continuous contour line of the cross-sectional shape Q of a turn of the coil 1 in front of the engagement in Step B forming. The angle a, to each of the top and bottom of the cross-section Q, of the winding of the cast in step A coil 1 having a the coil axis A perpendicularly intersecting plane E include, for example, is 1.5 ° and corresponds to the draft angles of the winding. With respect to a winding axis which defines the center of the smallest rectangle in which the cross-section Q fits into the turn, the centroid FS of the undeformed cross section Q of the coil radially offset inwards in the direction of the coil axis A.

By taking place in step B forming the cross-section Q 'of the turns of the coil 1 is changed such that the centroid FS' of the modified cross-section Q 'with respect to the coil axis A of unchanged cross-section Q is displaced in radial direction relative to the centroid of FS.

For this purpose, a diagrammatically illustrated in Figure 2, two-piece metal forming tools, in step B1, first 2, 3 provided with a rotationally symmetrical stamp 2 than the upper part and a rotationally symmetrical die 3 as the lower part. in an assembled state, the punch 2 and the die 3 to form an inner and outer contours of the tuned coil 1 cavity for receiving the coil. 1

With the arrangement of the coil 1 in the cavity of the forming die 2, 3 (step B2) of the stamp 2 are located radially inside and the radially outside die 3 at the coil 1 on. This state is shown schematically in FIG. 3

Starting from the illustrated schematically in Figure 3 state, the punch 2 in step B3 is under reduction of volume of the cavity along the coil axis A is moved and moves into the die. 3

The plastic deformation of the coil 1 is carried out in steps B4 and B5 by compressing the coil 1 along the coil axis A. The plunger 2 emerges from the top of the die 3 and pushes the tapered portions of the turns of the coil 1 flat. The turns of the coil 1 are thereby pressed against one another radially on the inside, starting, so that the coil material is displaced with respect to the coil axis A in radial direction R to the outside, until the interstices between the turns reduced or eliminated. In the course of forming the cross-section Q, Q is the coil axis A 'of the turns changed so located that the angle a, the in each case the top and bottom of the cross section Q, Q' with a plane perpendicularly intersecting E include reduced to 0 ° or about 1.5 reduces compared to the non-deformed state. 'Causes the winding, that the center of area FS, FS' This change of the cross section Q, Q of the cross section Q, Q 'with respect to the coil axis A is shifted in the radial direction R. The RFS is 'radius of the centroid FS' after forming greater than the radius of the centroid RFS before forming. The deformed cross-section Q 'of the turn of the coil 1 according to step B shown in FIG. 5 in a dotted line. By the step B was carried out in forming the coil 1 is compressed such that it occupies at least 95% of the volume of a body having the same inner and outer contour. Radius of the centroid FS 'after the deformation is larger than the radius of the centroid RFS before forming. The deformed cross-section Q 'of the turn of the coil 1 according to step B shown in FIG. 5 in a dotted line. By the step B was carried out in forming the coil 1 is compressed such that it occupies at least 95% of the volume of a body having the same inner and outer contour. Radius of the centroid FS 'after the deformation is larger than the radius of the centroid RFS before forming. The deformed cross-section Q 'of the turn of the coil 1 according to step B shown in FIG. 5 in a dotted line. By the step B was carried out in forming the coil 1 is compressed such that it occupies at least 95% of the volume of a body having the same inner and outer contour.

In the course of forming / can, for example, in a step B6, a gate of the coil 1 are separated and / or in a step B7, a connection region for an electrical Kon-clocking of the coil 1 are formed, for example by embossing.

In step B8, for example, carried out a calibration of the coil 1 to the final contour by the plunger 2 and forms the coil 1 radially on the inside at the upper axial end in the final contour, while the die 3, the coil 1 radially on the outside and formed on the lower axial end in the final contour , During the calibration surface irregularities are smoothed out.

Unless performed before, in step B9, the electrical insulation of the windings of the coil. 1

The effects and advantages of the invention can be summarized as follows:

The most important advantage is the efficiency of the production of Umformspulen with low use of manufacturing resources. In addition, the following advantages:

In the casting production of the preform, the use of reusable tools is possible because greater draft angles can be used

through continuous production sequence results in the highest productivity

Improvement in the surface quality for subsequent coating

Reduction of residual porosity in the casting reel

Increase the slot space factor

additional improvement of Entwärmungspfads

Reducing the minimum possible Windungsdicke over the casting of the coil in the final contour

Setting tighter geometric tolerances

high process stability

Combination with other process steps such as the separation of the gate system

Combination with embossing / forming processes of the terminal zones for electrical contacting of

Furthermore, the invention applies to coated materials, in which a subsequent necessary isolation step is omitted.

The preform is produced urformend. By grinding samples (destructive testing of materials) to Windungsquerschnitten is detectable whether a coil or its preform has been produced transformative.

Evidence of the technical casting manufacture of the preform due to significant and ever occurring errors in the cast structure (pores, oxides, also Abschreckgefüge on the surface if any) determined.

The field of application of the invention are coils for electric motors which are produced in mass production. Since electric drives and generators have a steadily rising sales and an ever-increasing penetration of different industries, all sectors from automotive, engineering, shipping, aviation and consumer spaces eingschlossen.

LIST OF REFERENCE NUMBERS

1 coil

2 stamp

3 die

α angle zw. Top / bottom of the cross section and plane perpendicular to the coil axis

A coil axis

E plane perpendicular to the coil axis

FS centroid (before forming)

FS 'centroid (after forming)

Q cross section of the convolution (before forming)

Q 'cross-section of the thread (after forming)

R Radial direction

RFS radius of the centroid (before forming)

RFS 'radius of the centroid (after forming)

Claims

1. A method for making an electro-technical coil (1), comprising the steps of:

a. Step A: casting an electrical coil (1) having at least one extending about a coil axis (A) turn.

b. Step B: deformation of the coil (1) by changing the cross-section (Q, Q ') of the at least one turn, so that the centroid (FS, FS') of the section (Q, Q ') of the at least one coil with respect to the coil axis (A is) at least partially displaced in the radial direction (R).

2. The method according to claim 1, characterized in that step A has one of the following sub-steps of at least:

a. Step A1: providing a preferably reusable negative mold, preferably by embedding a positive model in an embedding medium, for example of sand or of metallic material, wherein particularly preferably the positive model from an impression in the embedding medium again is removed or remains as a lost form in the embedding medium.

b. Step A2: casting of the coil material in the negative mold, preferably gravitational warrants and / or pressure assisted, preferably upon the application of the negative mold with vacuum and / or in a protective gas atmosphere, particularly preferably in investment casting, centrifugal casting, vacuum casting or low pressure casting.

c. Step A3: curing the cast coil material in the negative mold.

d. Step A4: extraction of the coil (1) from the negative form.

e. Step A5: cleaning of the coil (1).

f. Step A6: Annealing of the coil (1).

G. Step A7: Electrical insulation of at least one turn of the coil (1), preferably tung or by dipping the coil (1) in insulating paint or coating by shell, with an insulating layer.

3. The method according to any one of the preceding claims, characterized in that step B comprises one of the following sub-steps of at least:

a. Step B1: providing a multi-piece forming tool (2, 3) forming a cavity for receiving the coil (1) in an assembled state, the cavity is preferably on the inner contour and / or the outer contour of the coil (1) is tuned, wherein a plunger (2) is preferably an upper part of the forming tool (2, 3) and / or a die (3), a lower part of the forming tool (2, 3).

b. Step B2: placing the coil (1) in the forming tool (2, 3), preferably such that the coil (1) rests radially on the inside and / or radially externally on the forming tool (2, 3), wherein preferably the coil (1) radially inside rests on the punch (2) and / or radially on the outside bears against the die (3).

c. Step B3: moving at least two parts of the multi-part forming tool (2, 3) relative to each other along the coil axis (A) while reducing the volume of the cavity, wherein preferably the ram (2) retracts along the coil axis (A) into the die (3) ,

d. Step B4: forming the coil (1) by upsetting of the coil (1) along the coil axis (A), preferably wherein the turns of the coil (1) are radially inwardly pressed, beginning against each other, so that the coil material with respect to the coil axis (A) in the radial direction (R) is displaced outward, preferably such that the gaps are reduced or eliminated between the turns.

e. Step B5: variation of the cross section (Q, Q ') of the at least one turn, preferably during the step B4, located so that an angle (a), the top and / or bottom of the cross section (Q, Q') with the the coil axis (A) perpendicularly intersecting the plane (e) includes at least 1 °; 1.5 °, 2 °, 2.5 °, 3 °, 4 ° or 5 ° from the undeformed state modified and / or reduced.

f. Step B6: separating a sprue of the coil (1).

G. Step B7: forming at least one connection region for an electrical con- clocking of the coil (1), preferably by embossing.

H. Step B8: calibrating the coil (1) to the final contour, wherein preferably, the forming tool (2, 3) the coil (1) radially inside / or radially on the outside and and / or at the upper and / or lower axial end with respect to the coil axis ( A) calibrated, wherein in particular the plunger (2) is preferably the coil (1) radially on the inside and / or calibrated at the upper axial end and / or the die (3), the coil (1) radially on the outside and / or calibrated at the lower axial end ,

i. Step B9: Electrical insulation of at least one turn of the coil (1), preferably tung or by dipping the coil (1) in insulating paint or coating by shell, with an insulating layer.

Method according to one of the preceding claims, characterized in that the cross section (Q, Q ') that the at least one turn of the cast in step A coil (1) with respect to the coil axis (A) in the radial direction (R) inwardly or outwardly tapered, the cross-section (Q, Q ') of the at least one turn of the cast in step a coil (1) is preferably polygonal, and / or conical and / or trapezoidal, preferably isosceles, polygonal and / or conical and / or trapezium-shaped.

Method according to one of the preceding claims, characterized in that the angle (a), the top and / or bottom of the cross section (Q, Q ') of the at least one turn of the cast in step A coil (1) with the coil axis (A) perpendicularly intersecting the plane (e) includes at least; 1.5 °, 2 °, 2.5 °, 3 °, 4 ° or 5 °.

Method according to one of the preceding claims, characterized in that the inner contour and / or the outer contour of the coil obtained in step A and / or after step B (1) corresponds to the surface of a cylinder, cuboid, truncated cone or truncated pyramid / sector.

Method according to one of the preceding claims, characterized in that the electrical coil (1) is converted in step B such that it occupies at least 95% of the volume of a body having the same inner and outer contour.

Method according to one of the preceding claims, characterized in that the centroid (FS, FS ') of the section (Q, Q') of the at least one turn in step B in the radial direction (R) inwardly or outwardly with respect to the coil axis (A ) is shifted.

Electrical coil (1), produced by the method according to any of preceding the claims.

10. electromagnet or electric motor, preferably synchronous machine, preferably three-phase synchronous machine, with at least one coil (1) according to claim.9