Motor

Abstract

The invention relates to an electric machine having a permanent magnet arrangement and an electromagnet arrangement. The electromagnet arrangement has a first number of excitation coils, wherein the excitation coils are each wound around a pole core. The permanent magnet arrangement has a second number of magnet segments made of permanent magnetic material. An air gap is arranged between the electromagnet arrangement and the permanent magnet arrangement. The magnet segments have a permanent magnetization in a first magnet segment volume. At least one magnet segment has a demagnetized region in a second magnet segment volume.

Description

Technical Field

[0001] The invention relates to an electrical machine, such as a generator or a motor, comprising a permanent magnet arrangement and an electromagnet arrangement. Furthermore, the invention relates to a manufacturing method for such an electrical machine. Background Art

[0002] Such electric machines are used in various technical applications. In this case, it can be provided that the permanent magnet arrangement is assigned to the rotor and the electromagnet arrangement is assigned to the stator. Alternatively, the permanent magnet arrangement can be assigned to the stator and the electromagnet arrangement can be assigned to the rotor.

[0003] In particular, the following electric motor is known, in which the rotor has a plurality of magnet segments made of permanent magnetic material, which are fastened to the magnetic loop. The stator has a plurality of excitation coils, which are respectively wound around the pole core. In the case of such an electric motor, a certain fluctuation can be observed in the torque generated. This torque fluctuation is derived from the so-called cogging effect (Nutrasten) of the motor and can be attributed to the magnetic interaction between the stator poles and the rotor poles, and the torque fluctuation is manifested as an angle-related deviation of the torque of the motor under constant current. However, the torque fluctuation periodically superimposed on the shaft torque of the motor may have a negative impact on the speed regulation and the working process depending on the field of use of the motor. In this case, it is desirable to reduce the cogging effect and torque fluctuation in the motor. In order to achieve this, the end sections of the magnet segments can be shaped in a targeted manner. For example, the so-called pole lift (Polabhebungen) can be produced by the reasonable flattening of the end sections of the magnet segments, which can achieve a more intentional magnetic transition between the magnet segments. In the case of an arrangement with eight poles and eight segments, 16 pole lifts are provided accordingly. To further reduce torque ripple or cogging, further design measures can be taken, for example by providing additional gaps in the magnet segments between the end segments. Such an electric machine is disclosed, for example, in the publication WO 2017 / 001 159 A1.

[0004] However, due to the mechanical stability of the magnet segments, not all desirable gaps can be realized, since otherwise the permanent magnetic material is weakened in its structure, so that the magnet segments can break off. In addition, not all shapes of gaps are technically feasible. Summary of the invention

[0005] The object of the present invention is to provide an electric machine in which torque ripples and cogging are reduced without affecting the mechanical stability of the magnet segments. In addition, the object of the present invention is to provide a production method for such an electric machine.

[0006] These objects are achieved by an electric machine and a method for producing the same according to the independent patent claims. Further advantageous embodiments are described in the dependent claims.

[0007] The electric machine has a permanent magnet arrangement and an electromagnet arrangement. The electromagnet arrangement has a first number of excitation coils, each of which is wound around a pole core. The permanent magnet arrangement has a second number of magnet segments made of permanent magnetic material, wherein an air gap is arranged between the electromagnet arrangement and the permanent magnet arrangement. The magnet segments have a permanent magnetization in a first magnet segment volume. At least one magnet segment has a demagnetized region in a second magnet segment volume.

[0008] Therefore, instead of the pole raising or gaps disclosed in the prior art, the core idea of ​​the present invention is: in order to obtain the mechanical stability of the magnet segment, instead of removing the permanent magnetic material, partial areas of the permanent magnetic material are not magnetized or demagnetized, but a weaker overall magnetization area is still produced despite this. As a result, a more mechanically stable permanent magnet device can be provided. Here, the demagnetization area can be arranged so that the permanent magnet device has essentially the same magnetic field change process as the known permanent magnet device with gaps and pole raising. However, alternatively, other designs that can be realized without gaps are also conceivable.

[0009] In this case, the permanent magnetic material can include, in particular, iron, nickel or cobalt and alloys of the aforementioned metals and also hard ferrites.

[0010] In one embodiment of the electric machine, all magnet segments have demagnetized regions in the second magnet segment volume. In particular, a permanent magnet arrangement can thereby be provided whose magnetic field profile corresponds to the magnetic field profile of permanent magnet arrangements known from the prior art.

[0011] In one embodiment of the electric machine, the permanent magnet arrangement is arranged outside the electromagnet arrangement. The permanent magnet arrangement has a surrounding magnetic loop element, wherein the magnet segments are arranged at the loop element. This allows for simple production of the permanent magnet arrangement, wherein the loop element not only facilitates the guidance of the magnetic field lines of the magnetic field process of the permanent magnet arrangement, but also serves as a mechanical carrier for the magnet segments or permanent magnetic material. In this case, the loop element can also be composed of permanent magnetic material.

[0012] In one embodiment of the electric machine, a plurality of magnet segments form a magnet unit. This can further simplify the manufacturing method. The magnet unit has, for example, an even number of magnet segments, wherein the magnetic polarities of the magnet segments alternate. Alternatively, the magnet unit can have an odd number of magnet segments, wherein the magnetic polarities of the magnet segments also alternate.

[0013] In one embodiment of the electric machine, the demagnetizing region is arranged at the transition between two magnet segments of the magnet unit. Here, the demagnetizing region can have a second magnet segment volume, which extends over the two magnet segments.

[0014] In one embodiment of the electric machine, the magnet segments have permanent magnetizations that extend obliquely in the axial direction. As a result, torque ripples and cogging effects can be further reduced.

[0015] In one embodiment of the electric machine, the magnet segment has a magnet segment surface. The magnet segment surface has a transition from a first permanent magnetic field strength to a second permanent magnetic field strength due to the permanent magnetization and the demagnetization area. It can be provided that the permanent magnetization is still present in the adjacent area despite being close to the demagnetization area. The second permanent magnetic field strength is then not equal to zero, but is numerically smaller than the first permanent magnetic field strength due to the demagnetization area. In addition, the corresponding course of the first and second permanent magnetic field strengths indicates the presence of a corresponding demagnetization area.

[0016] In one embodiment of the electric machine, the permanent magnet arrangement is arranged on the rotor of the electric machine. The electromagnet arrangement is arranged on the stator of the electric machine. The magnetic field of the electromagnet arrangement is reversed by means of a reverse polarity of the field coil. The electric machine can then be realized with a small number of movable parts, thereby making a cost-effective manufacturing method possible.

[0017] In one embodiment of the electric machine, the permanent magnet arrangement is arranged on the stator of the electric machine, and the electromagnet arrangement is arranged on the rotor of the electric machine. The magnetic field of the electromagnet arrangement is reversed by means of a commutator.

[0018] The electric machine can be designed as a generator and / or as an electric motor. In particular, the electric machine can be an electric motor for a window lifter or glass roof drive, a seat adjuster, an ABS or ESP motor, a fuel pump or a coolant pump or an engine cooling fan of a vehicle. Such an electric motor can also be used in windshield wiper motors, steering motors and other actuators (e.g. gear adjusters etc.). Other applications are also conceivable.

[0019] In the method for manufacturing an electric machine, the following steps are performed:

[0020] - providing an electromagnet device having a first number of excitation coils, wherein the excitation coils are respectively wound around a pole core;

[0021] - providing a permanent magnet arrangement, wherein the permanent magnet arrangement has a second number of magnet segments consisting of permanent magnetic material, wherein the magnet segments have a permanent magnetization in a first magnet segment volume, wherein at least one magnet segment has a demagnetized region in a second magnet segment volume;

[0022] - Arranging the electromagnet arrangement and the permanent magnet arrangement such that an air gap is arranged between said electromagnet arrangement and said permanent magnet arrangement.

[0023] With this method, an electric machine according to the invention can be produced, wherein the electric machine can be designed as explained in the specific embodiments.

[0024] In one embodiment of the method, the permanent magnet arrangement is provided by first magnetizing the permanent magnet material by means of a first current in a coil arrangement to produce the magnet segments, and then producing the demagnetized region in at least one magnet segment by means of a second current in the coil arrangement or in a further coil arrangement. This enables a simple process with which the magnetization of the permanent magnet material is first produced. The magnetization produced can be partially removed again by means of a second current. Removal can also be referred to as deletion or demagnetization.

[0025] It is known in the prior art to use coil arrangements to produce magnet segments of permanent magnet arrangements. It can be provided that the permanent magnetic material has pole rises and gaps, wherein no magnetization occurs in these regions due to the lack of material. According to the invention, demagnetized regions are produced by means of a second current, so that the permanent magnetic material does not have to have gaps or pole rises and can therefore be designed to be more mechanically stable.

[0026] In one embodiment of the method, the first current comprises a half-sinusoidal current pulse. The second current comprises an oscillating current pulse with an exponentially decreasing amplitude. With such a design, the first current can lead to permanent magnetization and the second current can lead to demagnetization.

[0027] The permanent magnet arrangement comprises a plurality of magnet segments made of permanent magnetic material. The magnet segments have a permanent magnetization in a first magnet segment volume. At least one magnet segment has a demagnetized region in a second magnet segment volume. The permanent magnet arrangement may be modified according to the above-described embodiments.

[0028] In a method for producing a permanent magnet arrangement, first a permanent magnet material is provided. Then a magnet segment is produced in a coil arrangement by means of a first current, by magnetizing the permanent magnet material. Then a demagnetized region is produced in at least one magnet segment by means of a second current in the coil arrangement or in a further coil arrangement. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments of the present invention are described with reference to the following drawings. In the schematic drawings:

[0030] Figure 1 shows a cross section of the motor;

[0031] Figure 2 showing a cross section of a magnet unit;

[0032] Figure 3 A top view of a magnet unit is shown;

[0033] Figure 4 A top view showing another magnet unit;

[0034] Figure 5 A top view showing another magnet unit;

[0035] Figure 6 The process of magnetic field change is shown;

[0036] Figure 7 shows a cross section of another electric machine;

[0037] Figure 8 shows a magnet unit during a manufacturing method;

[0038] Fig. 9 The first through current variation process is shown;

[0039] Fig.10 showing the magnet unit during a later process step; and

[0040] Fig.11 A second through-current profile is shown. DETAILED DESCRIPTION

[0041] Figure 1 1 shows a cross section through an electric machine 1 having a permanent magnet arrangement 2 and an electromagnet arrangement 3. The electromagnet arrangement 2 has eight field coils 4, which are each wound around a pole core 5. For a simpler explanation, Figure 1 In the figure, only the reference numerals 4 and 5 are shown for one excitation coil 4 and one pole core 5, and other corresponding reference numerals are omitted. It is also possible to provide more or less than eight excitation coils 4 and pole cores 5, in particular to provide a first number of excitation coils 4 and pole cores 5. The pole core 5 additionally has an optional pole shoe 6, which can also be omitted. The permanent magnet arrangement 2 has twelve magnet segments 8 consisting of a permanent magnetic material 7, wherein an air gap 9 is arranged between the electromagnet arrangement 2 and the permanent magnet arrangement 3. The magnet segment 8 has a permanent magnetization portion 11 in a first magnet segment volume 10. In addition, the magnet segment 8 has a demagnetization region 12 in a second magnet segment volume 13. In Figure 1 In the embodiment, all magnet segments 8 have demagnetizing regions 12. It can be provided that only one or more of the magnet segments 8, but not all magnet segments 8, have corresponding demagnetizing regions 12. Another number of magnet segments 8, in particular a second number of magnet segments 8, can be provided.

[0042] The magnet segments 8 are arranged respectively in Figure 1. The loop element 14 is designed as a cylindrical loop. The magnet segment 8 is constructed in a shell shape and has a fan-shaped profile. However, other designs are also conceivable. The permanent magnet device 2 is arranged outside the electromagnet device 3. Alternatively, the electromagnet device 3 can also be arranged outside the permanent magnet device 3.

[0043] The permanent magnet arrangement 3 is arranged on the rotor 24 of the electric machine 1, while the electromagnet arrangement 2 is arranged on the stator 25 of the electric machine 1. The magnetic field of the electromagnet arrangement 3 can be reversed by reversing the polarity of the excitation coil 4.

[0044] The first and second quantities are Figure 1 It can also be provided that the first number and the second number are the same, for example, twelve magnet segments 8 and twelve excitation coils 4 with pole cores 5 and pole shoes 6 can be provided.

[0045] Figure 2 A cross section through three magnet segments 8 is shown, which correspond to Figure 1 The magnet segment element 8 of the embodiment of the present invention. Three magnet segments 8 constitute a magnet unit 15. It can be provided that the second number of magnet segments 8 are arranged in a third number of magnet units 15, wherein the second number is a multiple of the third number. For example, as in Figure 1 and Figure 2 As shown in , three magnet segments 8 can each constitute a magnet unit 15, and four magnet units 15 can be provided. In addition, alternatively, three magnet units 15 can be provided, each of which has four magnet segments 8. If the second number is not twelve, for example, three magnet units 15 each having six magnet segments 8 can also be provided. Here, the second number must be an even number, and the third number must be an even number only when an odd number of magnet segments 8 is provided for each magnet unit 15.

[0046] The demagnetizing region 12 is arranged at the transition 16 of two magnet segments 8. Furthermore, the demagnetizing region is arranged at the end 34 of the magnet unit 15. In this case, for example, the demagnetizing region 12 arranged at the transition 16 can be omitted. Alternatively, the demagnetizing region 12 arranged at the end 34 can be omitted. Additionally or alternatively, further demagnetizing regions (not shown) can be provided, which are arranged neither at the end 34 nor at the transition 16. The magnet segments 8 each have a magnet segment surface 18 facing inwards. Figure 1 In the electric machine 1 , the magnet segment surface 18 is therefore oriented towards the electromagnet arrangement.

[0047] Figure 3A top view of the surface of two magnet units 15 arranged next to each other is shown, each having three magnet segments 8 arranged next to each other, wherein the magnet units correspond to Figure 1 and Figure 2 The top view is compressed here. The usual illustration of the magnetic field shows which of the magnet segments 8 have a magnetic field entering the magnet segment 8 (circle with a cross located inside) and which of the magnet segments 8 have a magnetic field leaving the magnet segment 8 (circle with a dot located inside). The magnet segments 8 are arranged on two magnet units 15 in such a way that magnet segments 8 with an incoming and an outgoing magnetic field alternate. A demagnetization region 12 is again arranged at the transition 16 and at the end 34. Two further magnet units 15 can be provided in order to provide Figure 1 Permanent magnet device 2.

[0048] Figure 4 A top view of the surface of two other magnet units 15 arranged side by side is shown, which correspond to the magnet units 15 as long as no differences are described below. Figure 3 The corresponding intermediate magnet segments 8 have a permanent magnetization 17 extending axially obliquely. This means that the transition 16 between the magnet segments 8 is not parallel to the end 34, but is arranged at an angle. This makes it possible to further reduce the torque ripple and the cogging effect of the motor 1.

[0049] Figure 5 A top view of the surface of two other magnet units 15 arranged side by side is shown, which correspond to the magnet units 15 as long as no differences are described below. Figure 4 Magnet units 15 of the embodiment of the present invention. Gaps 35 are arranged between the magnet units 15, wherein the transitions 16 are guided through the gaps 35. This means that adjacent to the gaps 35 there are respectively regions 36 which are magnetized similarly to the magnet segments 8 opposite at the gaps 35 and which are separated from the magnet segments 8 which are located on the same side of the gaps 35 as the regions 36 by means of the demagnetizing regions 12.

[0050] Figure 6 A diagram showing the course of the magnetic field strength at a magnet segment surface 18, which can correspond to the magnet segment surface 18 already described. Positions 22 on the magnet segment surface 18 are plotted on an axis, wherein the positions 22 in the diagram correspond to the positions at Figures 3 to 5The position shifted to the right in the illustration of . The magnetic field strength 23 measured at the magnet segment surface 18 is plotted on the other axis. In this case, a first permanent magnetic field strength 20 can be observed in the central region of the magnet segment surface 18, while a second permanent magnetic field strength 21 can be observed in the outer region. Due to the permanent magnetization 11 and the demagnetization area 12, the magnet segment surface 18 therefore has a transition 19 from the first permanent magnetic field strength 20 to the second permanent magnetic field strength 21. Since the permanent magnetization 11 is located below the demagnetization area 12, the magnetic field strength 23 is weakened by the demagnetization area 12.

[0051] In addition, Figure 6 The diagram of shows how the magnetic field of the magnet segment surface 18 extends between a plurality of magnet segments 8. After a zero crossing 37, the magnetic field course is essentially the same, but with a negative sign. After another zero crossing 37, the magnetic field is positive again.

[0052] Figure 7 A cross section of a further electric machine 1 is shown, which corresponds to the Figure 1 The permanent device 3 is arranged on the stator 25 of the electric machine 1, while the electromagnet device 2 is arranged on the rotor 24 of the electric machine 1. The magnetic field of the electromagnet device 3 can be reversed by means of a commutator known from the prior art (not shown). In addition, each magnet unit 15 has only two magnet segments 8, so that the permanent magnet device 2 has only eight magnet segments 8 in total.

[0053] Here, Figure 1 and 7 The permanent magnet material of the electric machine 1 can include, in particular, iron, nickel or cobalt and alloys of the aforementioned metals as well as hard ferrites.

[0054] To manufacture Figure 1 An electric machine 1 of or 7, firstly, an electromagnet device 3 having a first number of excitation coils 4 is provided, wherein the excitation coils 4 are respectively wound around a pole core 5. Subsequently, a permanent magnet device 2 is provided, wherein the permanent magnet device 2 has a second number of magnet segments 8 consisting of a permanent magnetic material 7. The magnet segments 8 have a permanent magnetization portion 11 in a first magnet segment volume 10. At least one magnet segment 8 has a demagnetized region 12 in a second magnet segment volume 13. Subsequently, the electromagnet device 3 and the permanent magnet device (2) are arranged so that an air gap 9 is arranged between the electromagnet device 3 and the permanent magnet device 2.

[0055] Figure 8 The magnet unit 15 is shown during a production method. The permanent magnetic material 7 is arranged in a coil arrangement 26. In this case, the coil arrangement 26 comprises six coils, of which two coils are arranged opposite each other and the permanent magnetic material 7 is arranged between the opposite coils. Figure 83 shows a coil core 32 arranged in a coil of the coil arrangement 26, which has an optional cover 33. If a current is now generated in the coil, a magnet segment 8 can be generated in the permanent magnetic material 7. The direction of the magnetic field of the individual coils is explained with the aid of arrows, so that then similarly to Figures 1 to 7 The permanent magnetization 11 is obtained, wherein the magnet unit 15 has three magnet segments 8. If the magnet unit 15 has a different number of magnet segments 8, the coil arrangement 26 can accordingly have a different number of coils. The optional coil core 32 and the cover 33 can be used for geometric adjustment of the magnetic field, for example to generate Figure 4 and 5 The permanent magnetization portion 17 extends axially obliquely.

[0056] Fig. 9 A first current 27 in the coil arrangement 26 during the generation of the permanent magnetization is shown in a diagram, wherein the current intensity 30 is plotted over time 29. The first current 27 comprises a half-sinusoidal current pulse. Alternatively, another current pulse flowing in one direction can also be used. This current pulse can have a duration of approximately one tenth of a millisecond up to five milliseconds, for example approximately one millisecond.

[0057] Fig.10 The coil arrangement 31 is shown adjacent to another coil arrangement 31. Figure 8 The magnet device 15 can be used similarly to the other coil device. Figures 1 to 7 The embodiment described in the above embodiment produces a demagnetized region 12 in the magnet unit 15. The coil of the other coil arrangement 31 does not have a coil core and a cover plate, but the coil arrangement and the cover plate can also be similar to Figure 8 Ground setting.

[0058] Fig.11 A second current 28 in a further coil arrangement 31 during the generation of the demagnetization region 12 is shown in a diagram, wherein the current intensity 30 is plotted over time 29. The second current 28 comprises an oscillating current pulse with an exponentially decreasing amplitude. Alternatively, another oscillating current pulse can also be used. This current pulse can have a duration of approximately up to ten milliseconds.

[0059] It may be provided that a second current 28 is applied to the magnet unit 15 by means of an inner coil of the coil arrangement 26 .

[0060] Figure 8 and 10 Alternatively, the magnet unit 15 of the permanent magnet device 3 can also be arranged on the loop element 14, just like any other magnet unit 15 of the permanent magnet device 3. Figures 8 to 11 The method described produces all magnet segments 8 and demagnetized areas 12 of the permanent device 3 .

[0061] If the demagnetization area 12 is Figure 8 The coil arrangement 26 shown in FIG. 1 or in another coil arrangement 31 is produced, wherein the coil is similar to Figure 8 If the magnet unit 15 is arranged on both sides, it can then be provided that the second current 28 is also used on the outer coil in order to produce the demagnetized region 12 more easily.

[0062] Although the present invention has been described in detail by means of preferred embodiments, the present invention is not limited to the disclosed examples and other variations may be derived therefrom by a person skilled in the art without departing from the scope of protection of the present invention.

Claims

1. An electric machine (1), comprising a permanent magnet arrangement (2) and an electromagnet arrangement (3), wherein the electromagnet arrangement (3) comprises a first number of excitation coils (4), wherein the excitation coils (4) are each wound around a pole core (5), and wherein the permanent magnet arrangement (2) comprises a second number of magnet segments (8) made of permanent magnetic material (7), wherein an air gap (9) is arranged between the electromagnet arrangement (3) and the permanent magnet arrangement (2), wherein the magnet segments (8) have a permanent magnetization (11) in a first magnet segment volume (10), and wherein at least one magnet segment (8) has a demagnetized region (12) in a second magnet segment volume (13).

2. The electric machine (1) as claimed in claim 1, wherein all magnet segments (8) have a demagnetized area in the second magnet segment volume (13).

3. The electric machine (1) according to claim 1, wherein the permanent magnet arrangement (2) is arranged outside the electromagnet arrangement (3), wherein the permanent magnet arrangement (2) has a surrounding magnetic loop element (14), wherein the magnet segment (8) is arranged at the loop element (14).

4. The electric machine (1) according to any one of claims 1 to 3, wherein a plurality of magnet segments (8) form a magnet unit (15). 5 . The electric machine ( 1 ) as claimed in claim 4 , wherein the demagnetizing region ( 12 ) is arranged at a transition ( 16 ) between two magnet segments ( 8 ) of a magnet unit ( 15 ). 6 . The electric machine ( 1 ) as claimed in claim 1 , wherein the magnet segments ( 8 ) have a permanent magnetization ( 17 ) extending axially obliquely.

7. The electric machine (1) according to claim 1 , wherein the magnet segment (8) has a magnet segment surface (18), and wherein the magnet segment surface (18) has a transition (19) from a first permanent magnetic field strength (20) to a second permanent magnetic field strength (21) due to the permanent magnetization (11) and the demagnetization region (12).

8. An electric motor (1) according to any one of claims 1 to 3, wherein the permanent magnet device (2) is arranged on the rotor (24) of the electric motor (1), wherein the electromagnet device (3) is arranged on the stator (25) of the electric motor (1), wherein the magnetic field of the electromagnet device (3) is reversed by changing the polarity of the excitation coil (4).

9. An electric machine (1) according to any one of claims 1 to 3, wherein the permanent magnet device (2) is arranged on a stator (25) of the electric machine (1), wherein the electromagnet device (3) is arranged on a rotor (24) of the electric machine (1), wherein the magnetic field of the electromagnet device (3) is reversed by means of a commutator.

10. A method for producing an electric machine (1) according to any one of claims 1 to 9, the method comprising the following steps: - providing an electromagnet device (3) having a first number of excitation coils (4), wherein the excitation coils (4) are each wound around a pole core (5); - providing a permanent magnet arrangement (2), wherein the permanent magnet arrangement (2) has a second number of magnet segments (8) consisting of a permanent magnetic material (7), wherein the magnet segments (8) have a permanent magnetization (11) in a first magnet segment volume (10), and wherein at least one magnet segment (8) has a demagnetized region (12) in a second magnet segment volume (13); - The electromagnet arrangement (3) and the permanent magnet arrangement (2) are arranged such that an air gap (9) is arranged between the electromagnet arrangement (3) and the permanent magnet arrangement (2).

11. A method according to claim 10, wherein the permanent magnet arrangement (3) is provided in such a way that the permanent magnetic material (7) is first magnetized by means of a first current (27) in a coil arrangement (26) to produce the magnet segments (8), and subsequently the demagnetized region (12) is produced in at least one magnet segment (8) by means of a second current (28) in the coil arrangement (26) or in another coil arrangement (31).

12. The method according to claim 11, wherein the first current (27) comprises half-sinusoidal current pulses, and wherein the second current (28) comprises oscillating current pulses having an exponentially decreasing amplitude.

13. A permanent magnet arrangement (2) for an electric machine (1) according to any one of claims 1 to 9, comprising a plurality of magnet segments (8) consisting of a permanent magnetic material (7), wherein the magnet segments (8) have a permanent magnetization (11) in a first magnet segment volume (10), and wherein at least one magnet segment (8) has a demagnetized area (12) in a second magnet segment volume (13).

14. A method for producing a permanent magnet arrangement (2) according to claim 13, wherein first a permanent magnetic material (7) is provided, wherein subsequently magnet segments (8) are produced in a coil arrangement (26) by means of a first current (27), in that the permanent magnetic material (7) is magnetized, and subsequently a demagnetized region (12) is produced in at least one magnet segment (8) by means of a second current (28) in the coil arrangement (26) or in another coil arrangement (31).

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