AT522826A1 - rotor - Google Patents

Abstract

The invention relates to a rotor (3) for an axial flux machine (1), comprising a metallic rotor core (4) and several permanent magnets (5) which are arranged on the rotor core (4), the rotor core (4) having recesses such as pockets (8), in which the permanent magnets (5) are arranged.

Description

Rotor core are arranged.

The invention further relates to an electrical axial flux machine, comprising a rotor and a stator.

In addition, the invention relates to a method for producing a rotor for an electrical axial flow machine, according to which a metallic rotor core is provided

and several permanent magnets are arranged on the rotor core.

Electrical machines with a disk-shaped rotor or electrical disk armature machines enable high torques and power densities in short axial installation spaces. A stator generates an axially aligned magnetic flux that is superimposed on the rotor flux and runs through permanent magnets of a rotor.

As a result of efforts to reduce greenhouse gases, electrical machines are increasingly becoming the focus of research on drives for vehicles. There are many different designs of such electrical machines. For example, they can have a stator next to a rotor, a rotor between two stators or a stator between two rotors. The rotor usually has a disc-shaped rotor core,

on which is equipped with permanent magnets. The connection of the permanent magnets with the rotor core can also

be trained differently. For example, it is known from WO 01/11755 A1 that

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th and form-fitting with the surrounding plastic.

DE 10 2015 220 845 A1 describes a rotor in which the permanent magnets in axial openings of the rotor disk via spring elements in the axial direction

are maintained.

A wide variety of designs are also described with regard to increasing the performance of such electrical machines. For example, DE 10 2017 127 157 A1 describes a rotor for an axial flux motor with an axis of rotation extending along an axial direction, the rotor extending annularly and having a plurality of permanent magnets along a circumferential direction, the magnetization of which is each oriented in the circumferential direction , the permanent magnets being arranged at a distance from one another along the circumferential direction, a first material at least comprising a soft magnetic composite being arranged between the permanent magnets.

The present invention is based on the object of providing an improved electrical

cal axial flow machine available.

The object of the invention is achieved in the above-mentioned electrical axial flux machine in that the rotor core has recesses, for example pockets or grooves, and that the permanent magnets are in the

are arranged.

The object of the invention is also achieved with the axial flow machine mentioned at the outset, in which the rotor is designed according to the invention.

In addition, the object of the invention is achieved in the above-mentioned method in that recesses are created in the rotor core and the per-

manentmagneten are arranged in the recesses. The advantage here is that the rotor can be built relatively flat, so that the

axial length of the axial flow machine can be reduced. In addition, the

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be protected.

In order to further increase the performance of the axial flux machine, it can be provided in the rotor according to one embodiment that the recesses with

the permanent magnets are arranged on both sides of the rotor core.

In the preferred embodiment, the rotor core consists of a rolled electrical sheet or is produced by rolling up an electrical sheet. Due to different magnetic inductances in and across the magnetic direction, the reluctance term can be used in the field weakening range. This is advantageous, for example, for the use of the electrical axial flux machine provided with the rotor in a traction machine. In addition, eddy current losses in the rotor yoke can also be reduced. The permanent magnets of the rotor are preferred in the axial direction.

direction of the rotor magnetized.

For this purpose, according to one embodiment variant of the invention, the individual layers of the rotor core arranged one above the other in the radial direction are preferably connected to one another from the spirally rolled electrical steel sheet in order to

To give recesses a higher stability.

According to a further embodiment variant of the invention, it can be provided that the permanent magnets are arranged within the rotor core. Although the formation of the recesses can be more difficult, this variant has the advantage that the aforementioned effects are further reduced.

can be improved.

According to a preferred embodiment variant, the recesses in the rotor core for receiving the permanent magnets are already produced during the winding up, whereby

the manufacture of which can be simplified since the rolled-up rotor core follows

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GOT TO.

According to a preferred embodiment variant of the method, it can be provided that the recesses in the rotor core are produced by punching the electrical steel sheet on one or both sides. The procedural

can be shortened to manufacture the rotor core.

For better fixation of the permanent magnets in the recesses, it can be provided according to a further variant of the method that the permanent magnets are provided on the outside in the radial direction with a, in particular, me-

metallic, cover to be covered.

According to one embodiment of the invention, the cover can be made from the electrical sheet, so that the cover can be easily

roll of the electrical steel sheet to the rotor core can also be produced.

According to a further embodiment variant, it can also be provided that the cover is made from a stainless steel strip, the stainless steel strip also being able to be connected to the electrical steel sheet according to an embodiment variant of the method. The stainless steel strip has a higher tensile strength than normal electrical steel. In addition, it can be advantageous to use a stainless steel which is not or hardly at all magnetically conductive.

According to another variant of the invention, the cover can also be produced by pressing a ring onto the rotor core, which simplifies the introduction of the permanent magnets, since the ring can be pressed on in a separate production station. The ring can be made from metal or from fiber composite materials. This means that design variants with a lower weight can be made available. These have a lower mass moment of inertia

ment and can therefore have better dynamics.

For a better understanding of the invention, it will be based on the following

Figures explained in more detail.

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2 shows a first embodiment variant of a rotor for an electric axial flow machine in an oblique view;

3 shows a detail of the first embodiment variant of the rotor in a view of its end face;

4 shows a further embodiment variant of a rotor for an electric axial flow machine in an oblique view;

5 shows another embodiment of a rotor for an electrical axial flow machine in an oblique view.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference symbols or the same component designations, whereby the disclosures contained in the entire description can be transferred accordingly to the same parts with the same reference symbols or the same component names. The position details chosen in the description, e.g. above, below, to the side, etc., refer to the figure immediately described and shown and these position details are to be transferred to the new position in the event of a change in position.

1 shows schematic design variants of an electrical axial flux machine 1, comprising a stator 2 and a rotor 3. The axial flux machine 1 can, for example, also have two stators 2, between which the rotor 3 is arranged, as shown by the second stator 2 shown in dashed lines in FIG 1 is shown. However, a variant of the electrical axial flux machine 1 with only one stator 2, which is arranged between two rotors 3, is also possible. In the event that the electric axial flux machine 1 has a plurality of rotors 3, all rotors 3 are preferably designed in the same way, so that the following explanations can be applied to all rotors 3.

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In all variants of the invention, the rotor 3 has a rotor core 4 on which a plurality of permanent magnets 5 are arranged and attached to the rotor core 3, as can also be seen from FIGS. 2 and 3, which show a first variant of the rotor 3 .

The rotor core 4 can have the shape of an at least approximately annular disk. In addition, the rotor core 4 can be arranged on a shaft, for example directly or on a hub 7 of the shaft 6.

The rotor core 4 has pockets 8. In particular, a pocket 8 is provided in the rotor core 4 for each permanent magnet 5, so that a permanent magnet 5 is received in each pocket 8. In general, recesses can be arranged for receiving the permanent magnets 5, for example also grooves. Therefore, if in the following only reference is made to pockets 8, then these statements are also generally to recesses for receiving the

Permanent magnets 5 can be transferred and these recesses can therefore also be read.

In the embodiment variant of the rotor 3 according to FIGS. 2 and 3, the pockets 8 are arranged inside the rotor 3 and are designed to be open in a lateral surface 9 of the rotor core 4. Thus, the permanent magnets 5 can radially into the Ta-

between 8 are inserted.

Web 10 made of the material of the rotor core 4 are formed between the pockets 8. Furthermore, the permanent magnets 5 are also made of the material of the rotor due to the pocket formation mentioned on both axial end faces 11

core 4 covered.

The pockets 8 can extend in the radial direction over an entire radial height 12 of the rotor core 4, or only over a partial area of this radial height 12, in which case the pockets 8 can also be designed like a blind hole.

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The recesses 16, 17 can, for example, have a T-shaped cross section

have, as can be seen from FIGS. 2 and 3.

The recesses 16, 17 taper the rotor core 4 and a thin, soft magnetic web 10 is thus formed, which can be more easily saturated by the permanent magnets 5. It can thus reduce the loss of the

Magnetic effect can be achieved by this "short circuit" in the magnetic circuit.

In principle, the rotor core 4 can be produced from or consist of a solid material. In the preferred embodiment of the rotor 3 or the axial flux machine 1, however, the rotor core 4 consists of a laminated core made of electrical steel 18. In terms of process technology, however, it is simpler if a sheet metal strip is wound spirally from the electrical sheet 18, that is to say the rotor core 4 consists of a rolled, band-shaped electrical sheet 18, as can be seen in particular in FIG. The laminated core thus has several layers 19 made of electrical steel 18. The axial width of the layers 19 corresponds to the axial width of the strip-shaped electrical sheet 18. The electrical sheet 18 is thus after being rolled up to form the laminated core in the axial direction.

tion not further shared.

The layers 19 of the laminated core are preferably connected to one another, in particular by means of radial connection techniques on the wound electrical steel strip. For example, the layers 19 by one or both sides on the one or the axia-

len end face (s) of the rotor core 4 be welded together, for example

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The laminated core can also have layers 19 connected by punching, caulking or generally by clamping. The punch packet per se is known from the prior art, so that further explanations are available

superfluous. The layers 19 can also be connected to one another by spokes.

Furthermore, the layers 19 can be rolled under tension to form the laminated core, so that an (additional) frictional connection exists between the layers 19

can. The layers 19 can also be glued together.

Of course, other suitable connection techniques for connecting the layers 19 can also be used.

The rotor core 4 can also be connected to the hub 7.

The electrical sheet 18 can be an electrical sheet 18 corresponding to the prior art for this purpose. Sheet metal grades with high mechanical strengths are preferred, especially for higher speeds.

The layers 19 of the laminated core are perpendicular to the end faces 11 of the perma-

nentmagnete 5 arranged to run.

As can be seen from FIGS. 2 and 3, the pockets 8 are preferably designed such that the rotor core 4 rests directly on the permanent magnets 5 on both sides.

In the axial flux machine 1 (Fig. 1), the permanent magnets 5 preferably have a magnetization in the axial direction, i.e. in the direction of the axis of rotation of the shaft 6.

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FIGS. 4 and 5 show further and possibly independent design variants of the rotor 3, the same reference numerals or component designations being used for the same parts as in the preceding FIGS. 1 to 3. In order to avoid unnecessary repetitions, reference is made to the detailed description of the preceding FIGS. 1 to 3 or

Referenced.

In contrast to the variant of the rotor 3 according to FIGS. 2 and 3, the pockets 8 (e.g. FIG. 3) in the variant of the rotor 3 according to FIG. 4 are also covered on the radially outer lateral surface 9 (FIG. 2). For this purpose, a cover 22 can be arranged on this lateral surface 9, which covers the openings of the pockets 8. The cover 22 is preferably made of a metallic material. However, it can also consist of another suitable material, for example a plastic such as a thermoplastic or a thermosetting plastic.

According to one embodiment of the invention, it can be provided that the cover 22 is produced from the electrical sheet 18 itself. For this purpose, after the permanent magnets 5 have been inserted, the electrical sheet 18 can be wound further into the pockets 8 of the rotor core 4 until the pockets 8 are also covered on the radially outer circumference. For this purpose, one or more additional layers 19 of the strip-shaped electrical steel sheet 18 can be wound up.

For the sake of completeness, it should be mentioned at this point that the terms “wound” and “rolled” are used synonymously with regard to a sheet metal package produced from a strip-shaped electrical sheet 18.

Instead of the electrical sheet 18, a

Stainless steel band is used that around the radially outer jacket surface of the

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Rotor core 4 is wound. The stainless steel strip can optionally be connected to the strip-shaped electrical sheet 18, for example welded, so that the cover 22 in this embodiment variant with the different materials for the laminated core and the cover 22 is also produced by further winding as part of the winding of the electrical sheet 18 to the rotor core 4

can be.

According to a further embodiment of the rotor 3, it can be provided that the cover 22 is made from a ring that is placed on the rotor core 4

is pressed on.

5 shows a variant of the rotor 3 in which the pockets 8 are not arranged or formed within the rotor core 4, but rather as depressions in at least one, preferably in both, axial end faces 23, 24 of the rotor core 4 Permanent magnets 5 are arranged on one or both sides of the rotor core 4, only the two-sided variant being shown in FIG. 5.

In the circumferential direction 13, the permanent magnets 5 are again separated from one another by the radially extending webs 10. In the embodiment variant with the arrangement of the permanent magnets 5 on both sides, webs 24 are additionally formed in the axial direction.

In contrast to the preceding variant embodiment of the rotor 3 according to FIGS. 2 and 3, the permanent magnets 5 also bear (directly) on the side walls 14, 15 of the pockets 8.

Furthermore, the permanent magnets 5 preferably extend over the entire radial height 12 of the rotor core 4. In this embodiment variant, the rotor core 4 also preferably consists of the electrical sheet 18, as is indicated in FIG. 5 with the aid of a web 10.

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In all embodiment variants of the rotor 3, the permanent magnets 5, viewed in the direction of the axial direction, preferably have an at least approximately circular segment-shaped shape. But they can also have a different shape.

sen, for example, be trapezoidal.

The pockets 8 in the rotor core 4 can be formed after the rotor core 4 has been manufactured. In the preferred embodiment of the invention, however, the pockets 8 are already formed during the manufacture of the rotor core 4. In particular, this takes place when the electrical steel sheet 18 is rolled up to the rotor core 4, in that openings are created in the electrical steel sheet at the points where the pockets 8 are to be formed, which then lie one above the other in the radial direction after the electrical steel sheet has been wound up and form the pockets 8. The openings are particularly preferably produced by punching.

After the circumferential lengths of the layers 19 of the electrical steel sheet 18 in the rotor core increase from the inside to the outside and the pockets also preferably widen from the inside to the outside (as viewed in the direction of the axial direction), the punchings in the strip-shaped electrical steel sheet 18 are preferably made with variable spacing.

stood to each other and carried out variable width.

The exemplary embodiments show and describe possible embodiment variants of the invention, it being noted at this point that combinations of the

individual design variants are possible with one another.

For the sake of clarity, it should finally be pointed out that for a better understanding of the structure, the electrical axial flux machine 1 and the rotor 3 are not necessarily shown to scale.

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Axial flux machine stator

rotor

Rotor core permanent magnet shaft

hub

Pocket outer surface of the web

Face

Height in circumferential direction side wall side wall recess recess electrical sheet position

arrow

arrow

cover

Face

12

List of reference symbols

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Claims (18)

Claims 1. Rotor (3) for an axial flow machine (1), comprising a metallic rotor core (4) and several permanent magnets (5) which are arranged on the rotor core (4), characterized in that the rotor core (4) has recesses, such as Pockets (8), and that the permanent magnets (5) are arranged in the recesses. 2. Rotor (3) according to claim 1, characterized in that the recesses with the permanent magnets (5) are arranged on both sides of the rotor core (4). 3. rotor (3) according to claim 1 or 2, characterized in that the rotor core (4) consists of a rolled electrical sheet (18). 4. rotor (3) according to claim 3, characterized in that the individual layers (19) of the rotor core (4) from the rolled electrical sheet (18) in addition are connected to each other. 5. rotor (3) according to one of claims 1 to 3, characterized in that that the permanent magnets (5) are arranged within the rotor core (4). 6. Electric axial flux machine (1), comprising a rotor (3) and a stator (2), characterized in that the rotor (3) is formed according to one of claims 1 to 5. 7. Electric axial flux machine (1) according to claim 6, characterized in that the permanent magnets of the rotor (3) are magnetized in the axial direction of the rotor (3). N2019 / 19600-AT-00 8. A method for producing a rotor (3) for an electrical axial flow machine (1), according to which a metallic rotor core (4) is provided and several permanent magnets (5) are arranged on the rotor core (4), characterized in that the rotor core ( 4) Recesses, such as pockets (8), are created and the permanent magnets (5) are placed in the recesses. be arranged. 9. The method according to claim 8, characterized in that the rotor core (4) from an electrical sheet (18) by rolling up the electrical sheet (18) herge- will provide. 10. The method according to claim 9, characterized in that the recesses in the rotor core (4) are produced when the electrical sheet (18) is rolled up. 11. The method according to claim 9 or 10, characterized in that the recesses in the rotor core (4) are produced by punching the electrical steel sheet (18) on one or both sides. 12. The method according to any one of claims 9 to 11, characterized in that by rolling up the electrical steel sheet (18), a spiral-shaped laminated core with several layers (19) lying one above the other in the radial direction is produced from the sheet metal, the individual layers (19) are also connected to each other. 13. The method according to any one of claims 8 to 12, characterized in that the permanent magnets (5) are arranged within the rotor core (4) become. N2019 / 19600-AT-00 14. The method according to any one of claims 8 to 13, characterized in that the permanent magnets (5) are covered in the radial direction on the outside with an, in particular metallic, cover (22). 15. The method according to claim 14, characterized in that the cover (22) is made from the electrical sheet (18). 16. The method according to claim 14, characterized in that the cover (22) is made from a stainless steel strip. 17. The method according to claim 16, characterized in that the stainless steel strip is connected to the electrical sheet (18). 18. The method according to claim 14, characterized in that the cover (22) is produced by pressing a ring onto the rotor core (4) becomes. N2019 / 19600-AT-00