WO2021003510A2

WO2021003510A2 - Stator for an axial flow machine

Info

Publication number: WO2021003510A2
Application number: PCT/AT2020/060264
Authority: WO
Inventors: Christian DORFBAUER; Dietmar Andessner; Gerold Stetina
Original assignee: Miba Sinter Austria Gmbh
Priority date: 2019-07-09
Filing date: 2020-07-08
Publication date: 2021-01-14
Also published as: AT522711A1; WO2021003510A3

Abstract

The invention relates to a stator (2) for an axial flow machine, comprising a plurality of stator teeth (7) having a tooth body (8) and a yoke element (11), and comprising multiple coil windings (10), wherein the yoke element (11) consists of a rolled lamination stack, in which recesses are arranged in which the tooth bodies (8) of the stator teeth (7) are arranged or which form the tooth bodies (8) of the stator teeth (7).

Description

- 1 -

STATOR FOR AN AXIAL FLOW MACHINE

The invention relates to a stator for an axial flux machine, comprising a plurality of stator teeth, which have a tooth body and a return element, and with several coil windings.

The invention also relates to a stator for an axial flux machine, comprising a plurality of stator teeth that have an SMC material and a tooth body made of a soft magnetic material different from the SMC material, and each having a tooth base and a tooth tip, the tooth tip has a flux collecting element, and with a plurality of coil windings.

The invention further relates to an axial flux machine comprising at least one stator and at least one rotor.

Electrical assemblies with a disk-shaped rotor and a stator arranged parallel to it are known from the prior art and are used, for example, in axial flux machines. Usually, the rotor has a plurality of permanent magnets or permanent magnet poles, which rotate past opposing electro-magnetically excitable poles of the stator separated by an air gap. The electromagnetically excitable poles are designed, for example, as stator teeth made of a soft magnetic material, as described, for example, in DE 10 2016 207 943 A1, around the tooth core of which an electrically conductive winding generates a magnetic field when energized. A torque is applied to the rotor by energizing the stator teeth, which are arranged uniformly and concentrically in the circumferential direction of the stator, or their windings, depending on the rotor position. Depending on the application, very high power and / or torque densities may be required.

The object of the present invention was to provide a stator for an improved axial flux machine.

The object of the invention is achieved in the aforementioned stator in that the return element consists of a rolled laminated core in which recesses are arranged. - 2nd

are net, in which the tooth bodies of the stator teeth are arranged, or which the Zahnkör by the stator teeth form, and / or that only the flux collecting elements are at least partially formed from the SMC material.

The object of the invention is also achieved in the axial flux machine mentioned at the outset in that the at least one stator is designed according to the invention.

The advantage here is that the rolled return element improves the flux density and the punching waste can be reduced in the manufacture of the stator. Due to the hybrid design of the stator teeth made of the SMC and the soft magnetic material, the magnetic flux density through the stator teeth or through the windings surrounding them can be increased, whereby the efficiency and the torque or the torque density of the axial flux machine can be increased depending on the design priority . Thanks to the combination of materials, the three-dimensional magnetic flux guidance achieved by the SMC material can be maintained even if the magnet utilization is significantly higher due to the increased flux density in the body of the teeth. In addition, by using the more expensive SMC materials only for the flux collecting elements, a corresponding reduction in the manufacturing costs of the stator can be achieved.

In order to further improve at least some of these effects, one embodiment of the stator can provide that the tooth bodies consist of sheet metal elements made of co-oriented sheet metal or include this. According to one embodiment of the stator, it can be provided that the flux collecting elements are positively connected to the respective tooth bodies. Due to the positive fit of the connection, the assembly of the flux collecting elements on the tooth body can be simplified and their retention on the tooth body can be improved.

According to a further embodiment variant, the tooth bodies are each formed by a laminated core, possibly rolled, whereby eddy current losses can be avoided in the tooth bodies and a higher 2D flux density can be achieved. By using a rolled sheet metal, the punching waste can be reduced in the manufacture of the stator. - 3 -

According to another embodiment of the stator, it can also be provided that the stator teeth are arranged on a return element, the return element being formed by a rolled sheet metal. Due to the rolled stator yoke, the punching waste can be reduced compared to the “layered” yoke. According to a further embodiment of the stator, it can be provided that the return element and the tooth bodies are formed integrally with one another, with which better contact between the return element and the tooth bodies can be achieved. In addition, the number of individual parts for assembling the stator can be reduced. The entire unit comprising the return element and the tooth bodies can thus be made from a one-piece, rolled sheet metal.

In order to reduce the necessary machine room and to further simplify the installation, the coil windings can be a plugged concentrated coil windings in another variant of the stator. The advantage of an increased fill factor in the groove can thus also be achieved. It is also possible, however, for the coil windings to be inserted, distributed coil windings, with which an increased fill factor can also be achieved. In addition, a reduction in the harmonic component of the induced voltage can be achieved.

According to one variant of the stator, it can be provided that the laminated core is composed of several individual laminated cores. In a further embodiment variant of the stator it can be provided that the sheet-metal package or the sheet-metal packages have / have sheet-metal lamellae which are connected to one another. By connecting the sheet metal lamellas, the machine handling of the sheet metal stacks can be improved.

The sheet metal lamellas are preferably connected to one another without short-circuits, for example glued to one another or baked with a baking varnish. But it is also possible for the sheet metal lamellas to be welded to one another, in particular spot-welded, caulked or jammed. - 4 -

The one-piece laminated core consisting of the return element and the tooth bodies can be fixed via punched holes in another variant of the stator. With this design variant, the stator can be better exposed to increased mechanical requirements (e.g. vibrations). In addition, expensive bonding or potting processes can be dispensed with.

According to one variant of the stator, it can be provided that the one-piece laminated core consisting of the return element and the tooth bodies is screwed axially into a stator housing, whereby a simple and also cost-reducing variant of the stator can be achieved. The stator can be prefabricated to a high degree and then assembled so that it can be dismantled. This variant is particularly advantageous for large axial flow machines.

According to other design variants of the stator it can be provided that free spaces are formed under the winding heads on the side facing away from the air gap, in which at least one cooling element and / or an interconnection of the coil windings and / or at least one fastening element is arranged, whereby the Machine room of the axial flow machine can be reduced. In addition, the cooling can thus be arranged very close to the heat source, whereby the efficiency of the cooling can be improved.

According to another embodiment variant of the stator, it can also be provided that electrical insulation is arranged between connection points of two adjacent laminated cores, whereby eddy currents can be better prevented.

According to a preferred embodiment of the axial flux machine, this has two stators to increase the power density, a rotor being arranged between the two stators in the axial direction.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They each show in a simplified, schematic representation:

1 shows a first variant embodiment of an axial flow machine;

2 shows a further embodiment variant of an axial flow machine; - 5 -

3 shows a stator in an oblique view seen from the air gap and with partially removed

River collecting elements;

4 shows a first variant embodiment of a flow collecting element in an oblique view;

5 shows a variant of a stator in an oblique view seen from the air gap and with partially removed flux collecting elements;

6 shows a second embodiment variant of a flow collecting element in an oblique view;

7 shows a rolled return element in an oblique view;

8 shows a detail from a rolled yoke element formed in one piece with the tooth bodies of the stator teeth;

9 shows a detail of design variants of the stator;

10 shows a detail of another embodiment variant of the stator.

At the outset, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, whereby the disclosures contained in the entire description can be applied to the same parts with the same reference numerals or the same component names. The position details chosen in the description, such as above, below, side, etc., also relate to the figure immediately described and shown and these position details must be transferred to the new position in the event of a change in position.

1 shows a first embodiment variant of an axial flux machine 1 comprising at least one stator 2 and at least one rotor 3. The axial flux machine 1 can, for example, have two rotors 3 between which the stator 2 is arranged. However, the variant embodiment shown in FIG. 1 with only one stator 2 and only one rotor 3 is possible.

Magnets 4, for example permanent magnets, are arranged on the rotor 3 or the rotors 3. The at least one stator 2 and the at least one rotor 3 can be arranged in an optionally present housing 5, as is indicated by dashed lines in FIG.

A plurality of stators 3 can also be arranged. In this case, all stators 3 are preferably designed in the same way, so that the following statements also apply to the possible 6th

further existing stators 3 can be used. For example, FIG. 2 shows an embodiment variant of the axial flow machine 1 in which only one rotor 3 is arranged. The rotor 3 is - viewed in the axial direction - arranged between two stators 2 which are designed according to the invention. The rotor 3 is equipped on both sides with several magnets 4 (permanent magnets). The two stators 2 are arranged so that Flusssam melelemente 6 are each arranged on the side of the stator 2 facing away from the rotor 3, ie on the outside.

3 shows a first variant of the stator 2 for the axial flux machine 1. The stator 2 has several stator teeth 7. The stator teeth 7 each have a tooth body 8. Furthermore, the stator teeth 7 have opposite end sections in an axial direction 9, which form a tooth head and a tooth foot. The stator teeth 7 are each wrapped with a coil winding 10 (only indicated schematically in FIG. 3). The tooth bodies 8 rest in the axial direction 7 on an, in particular plate-shaped, return element 11 or are at least partially inserted into the return element 11, for which purpose it can have corresponding recesses in which the tooth bodies 8 are preferably received in a form-fitting manner. The return element 11 is preferably formed in one piece.

At least between the coil winding 10 and the tooth body 8, an electrical insulation not further presented is arranged. The number of stator teeth 7 shown in the figures is not to be understood as limiting. Rather, their number depends on the respective conditions in the use of the stator 2 or the axial flux machine 1 or their desired performance features.

The stator teeth 7 are evenly distributed over the circumference of the stator 2. In particular, viewed in the direction of the axial direction 9, they have an at least approximately trapezoidal cross-sectional area.

In FIG. 3, a flux collecting element 6 has been removed in order to enable a better view of the stator teeth 7. - 7 -

The in particular ring-shaped and preferably plate-shaped return element 11 of the stator 2 can consist of a material customary for this purpose.

The flux collecting elements 6 (also referred to as pole shoes) consist of a so-called SMC material (Soft Magnetic Composite). They are preferably manufactured using powder metallurgy and enable low-loss, three-dimensional magnetic flux guidance. Since such powder metallurgy processes are known per se, further explanations are not necessary.

SMC materials have been known for a long time. It is a powder made of soft magnetic material whose surface is coated with an electrically insulating layer. These powders are consolidated into soft magnetic components by pressing. The SMC powder has particles which comprise a core which is surrounded by an insulating layer or a plurality of insulating layers, or consists of the core and the at least one insulating layer. If necessary, a binder layer can be applied to the outside of the insulating layer, with which the individual particles can be connected to one another. The core of the SMC powder particles can contain or consist of pure iron. However, other magnetizable materials or alloys can also be used as the core, such as iron alloys, which are usually used for the production of electrical steel sheets.

This core is completely surrounded by the at least one insulating layer. The at least one insulating layer can be organic, e.g. a silicone varnish, or metal-organic or inorganic in nature, e.g. an oxide layer, a silicate layer, a phosphate layer. In the case of several insulating layers, these can also be made of different materials, for example selected from the materials mentioned.

The insulating layer or the insulating layers can have an average layer thickness (arithmetic mean of at least ten individual values) between 0.01 μm and 800 μm.

The binder layer, if present, can be a polymer layer, e.g. PTFE, wax, etc.

In principle, this structure of SMC powders is also known from the prior art, so that further explanations are unnecessary. 8th

The SMC material is used in the stator 2 exclusively for the flux collecting elements 6.

The tooth bodies 8 of the stator teeth 7, however, are formed from an iron-based material that is different from the SMC material or comprise this. For example, an electrical sheet can be used, as is known for electrical machines and magnetic circuits with alternating magnetic fields.

For the arrangement of the flux collecting elements 6 on the tooth bodies 8, in the embodiment variant shown in FIG. 3 they each have a depression 12 or recess. In contrast, the flux collecting elements 6 have a projection 13, as can be seen from FIG. 4. The projection 13 can have a height which is between 5% and 100% of a total height 15 of the flow collecting element 6 in the same direction.

The flux collecting elements 6 are arranged on the tooth bodies 8 in such a way that the jumps 13 of the flux collecting elements 6 are taken up from the recesses 12 in the tooth bodies 8. As can be seen from FIGS. 5 and 6, the reverse design is also possible. The

FIG. 5 shows a variant embodiment of the stator 2, a flux collecting element 6 again having been removed in order to have a better view of the tooth body 8. As can be seen from FIG. 5, the tooth body 8 has an elevation 16. Accordingly, the flux collecting element 6 has a recess 17, which is designed in particular as an opening through the flux collecting element 6, as can be seen from FIG. The elevations 16 of the tooth bodies 8 can have a height 18 which corresponds to between 5% and 100% of the total height 15 of the flux collecting element 6.

The flux collecting elements 6 are arranged on the tooth bodies 8 in such a way that their elevations 16 are received by the recesses 17 in the flux collecting elements 6. In both of the described embodiment variants of the stator 2, the Flusssammelele elements 6, viewed in plan view, have an at least approximately circular segment-shaped shape. But they can also have a different shape, for example be trapezoidal ausgebil det. - 9 -

Furthermore, in both of the embodiments of the stator 2 described, at least one bearing surface 19 is provided on the tooth bodies 8, on which the flux collecting elements 6 rest. The flux collecting elements 6 have a larger area than the tooth bodies 8, again viewed in plan view. It is further preferred if the flux collecting elements 6 rest exclusively on these bearing surfaces 19 on the tooth bodies 8. The geometric dimensions of the depressions 12 or elevations 16 of the tooth bodies 8 are accordingly adapted to the geometric dimensions of the projections 13 and the recesses 17 of the flow collecting elements 6 in order to make this possible. These support surfaces 19 can only be formed on one side of the tooth body 8, for example only radially inward or radially outward, or on several sides, for example radially inward and radially outward.

The bearing surfaces 19 are preferably formed circumferentially around the tooth body 8 (viewed from above on the tooth body 8 from the direction of the air gap). A width 20 of these bearing surfaces 19 can be selected from a range of 5% to 30% of a radially outer length 21 of the circular arc segment of the tooth body 8 in a circumferential direction 22. The bearing surfaces 19 are therefore essentially strip-shaped or in the case of a circumferential bearing surface 19 substantially frame-shaped.

It should be pointed out at this point that the tooth bodies 8 preferably fill the space enclosed by the coil windings 10 to at least 90%, in particular between 90% and 100%. The tooth bodies 8 are not hollow bodies. According to another, not shown, variant embodiment of the stator 2, however, there is also the possibility that the end surfaces of the tooth bodies 8 are completely covered with the flux collecting elements 6 and are connected to them. The tooth body 8 can be free of recesses 12 or elevations 16 and the Flusssammelele elements 6 free of recesses 17 of the flux collecting elements 6 in this embodiment. According to a further embodiment of the stator 2 it can be provided that the

Flux collecting elements 6 are positively connected to the respective tooth body 8, as FIG. 5 shows and FIG. 3 indicates with broken lines. In order to achieve this, the shapes and geometric dimensions of the depressions 12 or elevations 16 of the Zahnkör can be adapted accordingly to the shapes and geometric dimensions of the projections 13 and the recesses 17 of the flow collecting elements 6. 10

According to a preferred embodiment of the stator 2, it can be provided that the tooth body 8 is entirely formed by a laminated core made of several sheet metal lamellas 23, as can be seen from FIG. 8. Known electrical steel sheets can be used for this purpose, for example non-oriented magnetic steel sheets. According to a further variant, grain-oriented magnetic (steel) sheets can be used to increase performance. Grain-oriented sheets per se are known from the prior art, so reference is made to them. The crystallographic orientation of these sheets is formed when used for the stator teeth 6 in the axial direction.

The sheet metal lamellas 23 preferably have a thickness selected from a range from 0.05 mm to 0.5 mm. A width and a length of the metal sheets for producing the sheet metal lamellae 23 is usually significantly greater than their thickness.

The sheet metal lamellas 23 are arranged running perpendicular to the return path element 11. They are therefore arranged upright, as can be seen from FIG. Furthermore, the surface of the sheet metal lamellae 23 defined by the length and width is preferably arranged vertically in a radial direction 24 through the stator tooth 7, oriented in the stator tooth 7 or in the stator 2, as shown in FIG. The lateral end faces of the metal sheets 15 therefore point approximately in the circumferential direction 22 of the stator 2. By “approximately” it is meant that the annular design of the stator 2 must be taken into account.

According to one embodiment variant, it can be provided that the laminated core is made from a rolled sheet metal. For this purpose, a metal sheet is wound onto a dome.

It should be mentioned at this point that the terms “wound” and “rolled” are used synonymously with regard to a sheet-metal package made from a metal strip.

The winding of the metal strip creates a laminated core consisting of the laminated laminations 23 arranged one above the other in the radial direction (immediately after the winding, the laminated laminations are still connected due to the winding of the belt). For better handling of the wound laminated core, the sheet metal lamellas 23 can be connected to one another. The connection can, for example, by means of a punch packet, caulking the sheet metal lamellae together, generally by clamping the sheet metal lamellae together, etc., he follows. In addition to this type of connection, the sheet metal lamellas 23 can also be connected exclusively due to the friction between the sheet metal lamellas 23. This can do 11

Metal tape can be wound under tension. In addition to the form-fitting or frictional connection types, the sheet metal lamellas 23 can also be materially connected, for example by spot welding, gluing, baking, etc .. For baking, a so-called baking varnish is applied to at least one side of the metal band and then the connection at elevated temperature can be produced via the paint. At the same time, the paint can form electrical insulation between the sheet metal lamellas 23. In general, however, it is also possible to arrange electrical insulation between the sheet metal lamellas 23, for example in the form of a strip, it being possible for the strip to be wound along with the metal strip.

The corresponding shape of the laminated cores for the tooth bodies can be produced from the rolled laminated cores using a conventional cutting process.

The explanations for connecting the sheet metal lamellas 23 with one another and for insulation ge against one another can generally be applied to said laminated cores in the context of this description. Furthermore, these explanations can also be applied to the connection of the tooth bodies 8 with the respective flow collecting element 6, so that the flow collecting elements 6 can also be connected to the tooth bodies 8 in a material and / or force-locking manner in addition or as an alternative to the above-mentioned positive connection .

In addition to the rolled variant for the production of the sheet metal stacks, these can also be made from a larger sheet metal by Stan zen or cutting the individual lamellae. The (ring-shaped) return element 11 can be designed as a compact plate. According to one embodiment of the stator 2, which is shown in FIG. 7, it can be provided that the return element 11 is designed as a rolled sheet metal, i.e. as a rolled sheet metal strip 25. The return element 11 can be made from just a single sheet metal strip 25.

The sheet thickness of the rolled sheet metal strip 25 can be between 0.05 mm and 0.5 mm. With this embodiment variant, the punching waste for the production of the return element 11 can be significantly reduced or almost eliminated. In addition, an anisotropic material can also be used for the return element 11, in particular in order to be able to better utilize the potential in terms of power density and efficiency. The use of an isotropic material is also possible. 12

According to an embodiment of the stator 2, it can be provided that the return element 11 is formed from a rolled, grain-oriented electrical sheet, the preferred crystallographic direction being formed in the tangential direction.

As indicated in FIG. 7, the stator teeth 7 can simply be placed on the return element 11 (or inserted into a corresponding groove in this) and connected to it, e.g. glued.

It is possible that an anisotropic material is also used for the sheet metal lamellae 23 and for the return element 11, i.e. in particular the sheet metal strip 25. The use of an isotropic material is also possible. According to a preferred embodiment of the stator 2, which is shown in Fig. 8, there is the possibility that the return element 11 and the tooth body 8 are integrally formed. The return element 11 is also made of a (single) rolled sheet metal strip 25 here. In this case, an isotropic material is used in particular for the return element 11 and the Blechla fins 23 of the tooth body 8. In this case, the sheet metal strip 25 has a greater width in order to be able to manufacture the tooth bodies 8 from the sheet metal core using a separating process, for example by punching or cutting, after winding.

In the figures, the coil windings 10 are shown as plugged-in concentrated coil windings 10. However, there is also the possibility that the coil windings 10 are inserted, distributed coil windings 10.

According to a further embodiment variant of the stator 2, it can be provided that the one piece laminated core consisting of the return element 11 and the toothed bodies 8 is screwed axially into a stator housing 26, as shown in FIG. 9.

9 shows yet another variant of the stator 2. There is namely the possibility of the laminated core being composed of several individual laminated cores 27, 28. In the embodiment variant shown in FIG. 9, the laminated core consists of two single sheet metal stacks 27, 28, which in particular each extend over 180 °. The laminated core can also be composed of more than two individual laminated cores 27, 28, for example three, four, five, six, eight, etc. - 13 -

The division plane of the laminated core for forming the individual laminated core 27, 28 preferably runs through toothed bodies 8.

Instead of, or in addition to, the axial screw connection of the laminated core consisting of the return element 11 and the tooth bodies 8, this laminated core can also be fixed or secured radially, as shown in FIG. 10. For this purpose, one or more fastening means, such as screws, rods, rivets, etc., can be guided through openings in the stator housing 26 and in the laminated core, for example in the return element 11 and / or in at least individual tooth bodies 8. The openings in the laminated core or in the stator housing 26 can also be designed as blind holes. According to a further embodiment of the stator 2 it can be provided that the one piece laminated core consisting of the return element and the tooth bodies is fixed via punched holes.

According to another variant, it is also possible to form free spaces under the winding heads on the side facing away from the air gap, in which at least one cooling element and / or an interconnection of the coil windings and / or at least one fastening element is arranged.

For the sake of completeness, it should be noted that in the case of the return element 11, which consists of a rolled laminated core, the tooth bodies 8 can also consist of separate laminated cores. It is preferred here if all of the laminated cores, that is to say the laminated cores for the return element 11 and / or the laminated cores for the tooth bodies 8, are made from a grain-oriented laminated core.

The stator 2 according to the invention can be used, for example, in a traction machine for motor vehicles or aircraft.

The exemplary embodiments show possible design variants of the stator 2, details of the design variant shown or described or also combinations of the individual design variants with one another being possible. Thus, a stator 2 for an axial flux machine, comprising a plurality of stator teeth 7, which have a tooth body 8 and a return element 11, and which has a plurality of coil windings 10, can be a - 14 - be an independent invention if the return element 11 consists of a rolled Blechpa ket, in which recesses are arranged in which the tooth body 8 of the

Stator teeth 7 are arranged. Of course, this invention can also be combined with the other design variants of the stator 2 mentioned in the description, in particular with those design variants of the stator 2 described in the claims.

For the sake of clarity, it should finally be pointed out that for a better understanding of the structure of the axial flux machine 1, the stator 2 and the stator tooth 7, they are not necessarily shown to scale.

15th

List of reference symbols

1 axial flow machine

2 stator

3 rotor

4 magnet

5 housing

6 river collector

7 stator tooth

8 tooth bodies

9 axial direction

10 coil winding

11 Inference element

12 deepening

13 advantage

14 height

15 total height

16 survey

17 recess

18 height

19 support surface

20 width

21 length

22 circumferential direction

23 sheet metal lamella

24 radial direction

25 metal strips

26 stator housing

27 single sheet package

28 single sheet package

Claims

- 16 -

P a t e n t a n s p r ü c h e

1. Stator (2) for an axial flux machine, comprising a plurality of stator teeth (7) which have a tooth body (8) and a return element (11) and with several coil windings (10), characterized in that the return element (11) consists of a rolled laminated core in which recesses are arranged in which the tooth bodies (8) of the stator teeth (7) are arranged or which form the tooth bodies (8) of the stator teeth (7).

2. Stator (2) for an axial flux machine, comprising a plurality of stator teeth (7) which have an SMC material and a tooth body (8) made of a soft magnetic material different from the SMC material, the tooth tip having a flux collecting element (6), and with a plurality of coil windings (10), characterized in that only the flux collecting elements (6) are at least partially formed from the SMC material. 3. Stator according to claim 2, characterized in that the tooth body consists of

Sheet metal elements consist of grain-oriented sheet metal or include this.

4. stator (2) according to claim 2 or 3, characterized in that the Flusssam melelemente (6) are positively connected to the respective tooth body (8).

5. stator (2) according to claim 1 to 3, characterized in that the tooth body (8) are each formed by a laminated core, optionally rolled.

6. stator (2) according to one of claims 2 to 5, characterized in that the stator teeth (8) are arranged on a return element (11), wherein the return element (11) is formed by a rolled sheet metal.

7. stator (2) according to claim 1 or 6, characterized in that the rear-end element (11) is formed in one piece with the tooth bodies (8). - 17 -

8. Stator (2) according to one of claims 1 to 7, characterized in that the coil windings (10) are plugged concentrated coil windings (10).

9. stator (2) according to any one of claims 1 to 7, characterized in that the coil windings (10) are inserted distributed coil windings (10). 10. stator (2) according to any one of claims 1 to 9, characterized in that the

Laminated core is composed of several individual laminated cores (27, 28).

11. stator (2) according to any one of claims 1 to 10, characterized in that the

The laminated core or the laminated core has / have interconnected sheet metal lamellas (23). 12. stator (2) according to claim 11, characterized in that the sheet metal lamellas

(23) are welded or glued in places or baked with a baking varnish or caulked or jammed.

13. Stator (2) according to one of claims 7 to 9, characterized in that the one-piece laminated core from the return element (11) and the tooth bodies (8) is screwed axially into a stator housing.

14. Stator (2) according to one of claims 7 to 9, characterized in that the one-piece laminated core from the return element (11) and the tooth bodies (8) is fixed via punched holes.

15. Stator (2) according to one of claims 1 to 14, characterized in that free spaces are formed under the winding heads on the side facing away from the air gap, in which at least one cooling element and / or an interconnection of the coil windings and / or the at least one fastening element is arranged.

16. Stator (2) according to one of claims 11 to 15, characterized in that an electrical insulation is arranged between the sheet metal lamellas (23). - 18 -

17. Axial flux machine (1) comprising a stator (2) or several stators (2) and at least one rotor (3), characterized in that the stator (2) or the stators (2) is designed according to one of claims 1 to 16 or are.

18. Axial flux machine (1) according to claim 17, characterized in that it comprises two stators (2), with one between the two stators (2) in the axial direction

Rotor (3) is arranged.