Claw pole rotor for an electric machine

Abstract

A claw pole rotor (10) for an electric machine (11) is provided, the claw pole rotor (10) comprising a first claw pole part (13) having a first yoke shaft part (12) to which at least two first claw pole fingers (15) are connected and a second claw pole part (14) having a second yoke shaft part (17) to which at least two second claw pole fingers (16) are connected. Wherein the first claw pole fingers (15) extend from a first side (18) of the claw pole rotor (10) towards a second side (19) of the claw pole rotor (10), the second claw pole fingers (16) extend from the second side (19) towards the first side (18) and a magnet (20) is arranged between the first yoke shaft part (12) of the first claw pole part (13) and the second yoke shaft part (17) of the second claw pole part (14).

Description

[0001] Cross Reference to Related Applications

[0002] The present patent application claims priority to German patent application 10 2021 104 270.4, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to a claw pole rotor for an electrical machine. BACKGROUND

[0004] Generally, an electrical machine comprises a stator and a rotor which is movable relative to the stator. The electrical machine can operate as a motor which converts electrical energy into kinetic energy or as a generator which converts kinetic energy into electrical energy. In operation, a magnetic field of the rotor interacts with a magnetic field of the stator.

[0005] A claw pole rotor generally has two parts with claw pole fingers. The claw pole fingers form magnetic poles of the claw pole rotor. By means of field windings in the claw pole rotor, the magnetic flux in the rotor can be increased, resulting in an electrical machine comprising the claw pole rotor having a higher torque. This means that the electrical machine can be operated more efficiently. SUMMARY

[0006] It is an object to be achieved to provide a claw pole rotor for an electrical machine which can be operated efficiently.

[0007] According to at least one embodiment of a claw pole rotor for an electrical machine, the claw pole rotor comprises a first claw pole part having a first yoke shaft part to which at least two first claw pole fingers are connected. The first claw pole part can further comprise a first ring part. The first ring part can be connected to the first yoke shaft part. The first claw pole fingers can be connected to the first ring part. Thus, the first claw pole fingers can be connected to the first yoke shaft part by means of the first ring part. The fact that the first claw pole fingers are connected to the first yoke shaft part can mean that the first claw pole fingers are fastened to the first yoke shaft part. Further, the first claw pole fingers can be fastened to the first ring part, thereby being fixed to the first yoke shaft part. The first claw pole fingers can be integrally formed with the first yoke shaft part. Further, the first claw pole fingers can be integrally formed with the first yoke shaft part and the first ring part. Alternatively, the first claw pole fingers can each be a separate part which is connected to the first yoke shaft part.

[0008] The first yoke shaft part can comprise a rotor core. The first yoke shaft part is arranged at least partially within the claw pole rotor. The first yoke shaft part can at least partially have the shape of a hollow cylinder. The first yoke shaft part can comprise a ferromagnetic material, such as iron or steel. The first yoke shaft part can further comprise a soft magnetic powder composite.

[0009] The claw pole rotor further comprises a second claw pole part having a second yoke shaft part, to which at least two second claw pole fingers are connected. The second claw pole part can further comprise a second ring part. The second ring part can be connected to the second yoke shaft part. The second claw pole fingers can be connected to the second ring part. Thus, the second claw pole fingers can be connected to the second yoke shaft part via the second ring part. Alternatively, the second claw pole part does not have a second ring part, and the second claw pole fingers are directly connected to the second yoke shaft part. The fact that the second claw pole fingers are connected to the second yoke shaft part can mean that the second claw pole fingers are fastened to the second yoke shaft part. Further, the second claw pole fingers can be attached to the second ring part, thereby being connected to the second yoke shaft part. The second claw pole fingers can be integrally formed with the second yoke shaft part. Further, the second claw pole fingers can be integrally formed with the second yoke shaft part and the second ring part. Alternatively, the second claw pole fingers can each be a separate part connected to the second yoke shaft part.

[0010] The second yoke shaft part is at least partially arranged within the claw pole rotor. The second yoke shaft part can at least partially have the shape of a hollow cylinder. The second yoke shaft part can comprise a ferromagnetic material, such as iron or steel. Further, the second yoke shaft part can comprise a soft magnetic powder composite.

[0011] The first claw pole fingers and the second claw pole fingers can each have a substantially parallelogram shape in an outer view of the claw pole rotor. In general, each of the claw pole fingers can have a curved shape. In each case, the curved shape of the claw pole fingers extends along a circumferential direction of the claw pole rotor. Each of the claw pole fingers can extend further along a longitudinal axis of the claw pole rotor than along the circumferential direction of the claw pole rotor. The claw pole fingers can be arranged at an outer side of the claw pole rotor. The claw pole fingers can comprise the same material as the first yoke shaft part and the second yoke shaft part. That is, the claw pole fingers can comprise a ferromagnetic material, such as iron or steel. Further, the claw pole fingers can comprise a soft magnetic powder composite. The first claw pole fingers can all have the same size and shape. The second claw pole fingers can all have the same size and shape. Further, all of the claw pole fingers, i.e. the first claw pole fingers and the second claw pole fingers, can all have the same size and shape. The claw pole rotor can have as many first claw pole fingers as second claw pole fingers.

[0012] The first claw pole fingers extend from a first side of the claw pole rotor towards a second side of the claw pole rotor. The second claw pole fingers extend from the second side towards the first side. The first side of the claw pole rotor is opposite the second side of the claw pole rotor. This means that along the longitudinal axis of the claw pole rotor, the first side is arranged at one end of the claw pole rotor and the second side is arranged at the other end of the claw pole rotor. The first annular part of the first yoke shaft part can be arranged at the first side. The second yoke shaft part can be arranged at the second side. The first claw pole fingers can be connected to the first yoke shaft part at the first side. The second claw pole fingers can be connected to the second yoke shaft part at the second side. The first and second claw pole fingers can have a main extension direction parallel to the longitudinal axis of the claw pole rotor.

[0013] The first and second claw pole fingers can be arranged alternatingly along the circumferential direction of the claw pole rotor. That is, along the circumferential direction of the claw pole rotor, each first claw pole finger is arranged between two second claw pole fingers. Likewise, along the circumferential direction of the claw pole rotor, each second claw pole finger is arranged between two first claw pole fingers. In this case, each first claw pole finger is arranged spaced apart from the respective adjacent second claw pole fingers. This means that a gap is left between each first claw pole finger and the second claw pole fingers.

[0014] The first claw pole fingers can have a tapering shape from the first side to the second side. The second claw pole fingers can have a tapering shape from the second side to the first side. In each case, the extension of the claw pole fingers tapers along the circumferential direction of the claw pole rotor. Additionally or alternatively, the shape of each of the first claw pole fingers can taper such that in a cross-section through the claw pole rotor in a radial direction, the first claw pole finger has a longer extension at the first side of the claw pole rotor than at a position not located at the first side. Additionally or alternatively, the shape of each of the second claw pole fingers can taper such that in a cross-section through the claw pole rotor in a radial direction, the second claw pole finger has a longer extension at the second side of the claw pole rotor than at a position not located at the second side.

[0015] The magnet is arranged between the first yoke shaft part of the first claw pole part and the second yoke shaft part of the second claw pole part. The magnet can be a permanent magnet. Between the first yoke shaft part and the second yoke shaft part, a cavity can be partially arranged in which the magnet is arranged. The cavity can have the shape of a hollow cylinder. The cavity can extend along the longitudinal axis of the claw pole rotor. The cavity can have a shorter extension than the entire claw pole rotor. The magnet can be arranged completely within the claw pole rotor. Additionally, the magnet can partially or completely fill the cavity. The magnet can extend within the claw pole rotor to the second side. The extension of the second yoke shaft part along the longitudinal axis of the claw pole rotor can be shorter than the first yoke shaft part. The extension of the magnet along the longitudinal axis of the claw pole rotor can be longer than the second yoke shaft part.

[0016] The arrangement of the magnets in the claw pole rotor results in that the magnetic flux in the air gap of the electric machine using the claw pole rotor is amplified during operation of the electric machine. The magnets contribute to the magnetization of the first claw pole fingers and the second claw pole fingers. The claw pole fingers form the magnetic poles of the claw pole rotor. The magnets generate a magnetic flux in the claw pole rotor which results in that the first claw pole fingers are magnetized in opposite directions compared to two adjacent second claw pole fingers, respectively. The magnets thus generally increase the magnetic flux in the claw pole rotor. The increased magnetic flux results in an increased torque of the electric machine. Thus, the electric machine can be operated more efficiently.

[0017] According to at least one embodiment of the claw pole rotor, the first yoke shaft part, the magnets and the second yoke shaft part are arranged at least partially coaxially with respect to each other. This can mean that the first yoke shaft part, the magnets and the second yoke shaft part extend at least partially parallel to each other along a longitudinal axis of the claw pole rotor. For example, the second yoke shaft part at least partially forms a hollow cylinder in which the magnets and the first yoke shaft part are arranged. With this coaxial arrangement, the magnets can contribute to the amplification of the magnetic flux in the claw pole rotor.

[0018] According to at least one embodiment of the claw pole rotor, in a cross section through the claw pole rotor, the magnets are arranged at least partially between the first yoke shaft part and the second yoke shaft part in a radial direction. This can mean that, in a cross section through the claw pole rotor in the radial direction, the magnets are arranged at least partially between the first yoke shaft part and the second yoke shaft part. At least a portion of the magnets can be arranged between the first yoke shaft part and the second yoke shaft part in the cross section through the claw pole rotor in the radial direction. The claw pole rotor can generally have the shape of a cylinder. Thus, the cross section refers to a cross section in which the claw pole rotor shows a circular shape. The claw pole rotor can have a longitudinal axis. The longitudinal axis of the claw pole rotor is perpendicular to the cross section. In this cross section through the claw pole rotor, the second yoke shaft part can be arranged at least partially between the magnets on the one hand and the first claw pole fingers and the second claw pole fingers on the other hand in the radial direction. In the cross section through the claw pole rotor, the magnets can be arranged at least partially between the first yoke shaft part and the second yoke shaft part in the radial direction. With this arrangement, the magnets can contribute to the amplification of the magnetic flux in the claw pole rotor.

[0019] According to at least one embodiment of the claw pole rotor, the magnets have the shape of a hollow cylinder. The magnets can extend along a longitudinal axis of the claw pole rotor. That is, a longitudinal axis of the hollow cylinder forming the magnets can be parallel to the longitudinal axis of the claw pole rotor. The magnets in the shape of a hollow cylinder can efficiently contribute to the amplification of the magnetic flux in the claw pole rotor.

[0020] According to at least one embodiment of the claw pole rotor, the diameter of the first yoke shaft part is smaller than the diameter of the magnet, which is smaller than the diameter of the second yoke shaft part. This can mean that, if the first yoke shaft part, the magnet and the second yoke shaft part at least partly have the shape of a hollow cylinder, the three hollow cylinders have different diameters. The first yoke shaft part has the smallest diameter and is at least partly arranged within the magnet. The magnet has a smaller diameter than the second yoke shaft part and is at least partly arranged within the second yoke shaft part. With this arrangement of the magnet in the claw pole rotor, the magnet is able to efficiently contribute to the amplification of the magnetic flux in the claw pole rotor.

[0021] According to at least one embodiment of the claw pole rotor, the extension of the magnet along the longitudinal axis of the claw pole rotor is shorter than the entire extension of the claw pole rotor along the longitudinal axis. That is, the magnet does not extend along the entire length of the claw pole rotor. With this arrangement, the magnet is able to be adjacent to the first yoke shaft part and the second yoke shaft part, such that the magnet contributes to magnetizing the first claw pole fingers and the second claw pole fingers. This means that the magnet amplifies the magnetic flux in the claw pole rotor in an advantageous manner.

[0022] According to at least one embodiment of the claw pole rotor, in a cross section through the claw pole rotor, the magnetization direction of the magnet extends from the outside of the claw pole rotor towards the center of the claw pole rotor. That is, in a cross section through the claw pole rotor, the magnetization direction of the magnet extends parallel to the radial direction towards the center of the claw pole rotor. With this magnetization direction of the magnet, the magnet contributes to magnetizing the first claw pole fingers and the second claw pole fingers, thereby amplifying the magnetic flux in the claw pole rotor.

[0023] According to at least one embodiment of the claw pole rotor, in a cross section through the claw pole rotor, the magnetization direction of the magnet extends from the center of the claw pole rotor towards the outside of the claw pole rotor. That is, in a cross section through the claw pole rotor, the magnetization direction of the magnet extends parallel to the radial direction towards the outside of the claw pole rotor. With this magnetization direction of the magnet, the magnet contributes to magnetizing the first claw pole fingers and the second claw pole fingers, thereby amplifying the magnetic flux in the claw pole rotor.

[0024] According to at least one embodiment of the claw pole rotor, the first claw pole part and the second claw pole part are arranged spaced apart from each other. This can mean that a gap is left between the first claw pole part and the second claw pole part. The gap can be a cavity in which the magnet is arranged. Furthermore, a gap can be left between the first claw pole part and the second claw pole part along the longitudinal axis of the claw pole rotor. The first claw pole part and the second claw pole part do not directly contact each other. This advantageously avoids stray magnetic flux in the claw pole rotor.

[0025] According to at least one embodiment of the claw pole rotor, the magnet is in direct contact with the first yoke shaft part and the second yoke shaft part. The magnet can be in direct contact with the first yoke shaft part on one side thereof and in direct contact with the second yoke shaft part on the other side thereof. For example, the outer side of the magnet can be in direct contact with the second yoke shaft part, and the inner side of the magnet can be in direct contact with the first yoke shaft part. In those regions where the first yoke shaft part, the magnet, and the second yoke shaft part are arranged coaxially, the magnet can be in direct contact with the first yoke shaft part and the second yoke shaft part. This allows a compact design of the claw pole rotor and a magnetization of the claw pole fingers by the magnet. Furthermore, the first claw pole part and the second claw pole part can be mechanically connected to each other by the magnet.

[0026] According to at least one embodiment of the claw pole rotor, the field coil is arranged between the claw pole fingers and the second yoke shaft part. In a cross-section through the claw pole rotor in the radial direction, the field coil is arranged between the first claw pole finger and the second claw pole finger on the one hand and the second yoke shaft part on the other hand. The field coil is designed to be supplied with direct current. The field coil can have the shape of a hollow cylinder. The field coil is arranged at a distance from the first claw pole finger and the second claw pole finger. This means that a gap is left between the field coil and the first claw pole finger and the second claw pole finger. By using the field coil, it is possible to further amplify the magnetic flux in the air gap during operation of the electric machine.

[0027] According to at least one embodiment of the claw pole rotor, at least one further magnet is arranged between the first yoke shaft part and the second yoke shaft part, and the magnet and the at least one further magnet are arranged in a ring. A plurality of further magnets can be arranged between the first yoke shaft part and the second yoke shaft part, and the magnet and the further magnets are arranged in a ring. The magnet and the at least one further magnet can be distributed along the circumference of the claw pole rotor. That is, the magnet and the at least one further magnet are arranged at different positions along the circumference of the claw pole rotor. The magnet and the further magnets can be arranged spaced apart from each other. The magnet and the further magnets can extend both along the longitudinal axis of the claw pole rotor and along the circumference of the claw pole rotor. In a cross-section through the claw pole rotor, the magnetization direction of the magnet and the further magnets extends from the outside of the claw pole rotor towards the center of the claw pole rotor or from the center towards the outside. The magnet and the further magnets can be used instead of a single magnet in the shape of a hollow cylinder to amplify the magnetic flux in the claw pole rotor.

[0028] According to at least one embodiment of the claw pole rotor, a ferromagnetic material is arranged between the magnet and at least one further magnet. The magnet and the further magnet can each be in direct contact with the ferromagnetic material. The ferromagnetic material can be connected to the first claw pole part or the second claw pole part. In case the claw pole rotor has a plurality of further magnets, the ferromagnetic material is arranged between each two further magnets. The magnet together with the further magnets and the ferromagnetic material can be arranged in the shape of a hollow cylinder. This means that the magnet, the further magnets and the ferromagnetic material combine to form a hollow cylinder. Thus, the magnet and the further magnets are able to effectively amplify the magnetic flux in the claw pole rotor.

[0029] According to at least one embodiment of the claw pole rotor, at least one magnet layer is arranged between the first yoke shaft part and the second yoke shaft part. The at least one magnet layer is arranged at a different radial position than the magnet when observed in a cross section through the claw pole rotor. The magnet layer can have the same properties as the magnet. However, the dimensions of the magnet layer are different from the dimensions of the magnet. The magnet layer can be arranged coaxially to the magnet, the first yoke shaft part and the second yoke shaft part. The magnet layer can also have the shape of a hollow cylinder. The fact that the magnet layer is arranged at a different radial position than the magnet can mean that the magnet layer is arranged closer to the inside or closer to the outside in the claw pole rotor than the magnet.

[0030] According to at least one embodiment of the claw pole rotor, at least one first spacer is attached to the first claw pole part and extends at least partially parallel to the magnet and / or at least one second spacer is attached to the second claw pole part and extends at least partially parallel to the magnet. The first spacer can have the shape of a hollow cylinder. The first spacer can be arranged between the magnet and at least one magnet layer or between two magnet layers. Thus, the magnet and the magnet layer are not in direct contact. The first spacer can comprise a ferromagnetic material.

[0031] The second spacer can have the shape of a hollow cylinder. The second spacer can be provided between the magnet and at least one magnet layer or between two magnet layers. The second spacer can comprise a ferromagnetic material.

[0032] The claw pole rotor can comprise at least one first spacer or at least one second spacer to arrange the magnet and the at least one magnet layer at a distance from each other. The claw pole rotor can also have at least one first spacer and at least one second spacer. The first spacer is arranged spaced apart from the second claw pole part along a longitudinal axis of the claw pole rotor. The second spacer is arranged spaced apart from the first claw pole part along the longitudinal axis of the claw pole rotor. This reduces the stray magnetic flux in the claw pole rotor.

[0033] If magnets and at least one magnet layer are used in the claw pole rotor, the extension of the magnets and the magnet layers in the radial direction in a cross section through the claw pole rotor can be shorter compared to a case where only one magnet is used. This has the advantage that the internal resistance of the magnets and the magnet layers which extend shorter in the radial direction is smaller than the internal resistance of the magnets which extend longer in the radial direction. Thus, the magnets and the magnet layers can be used more efficiently to amplify the magnetic flux.

[0034] According to at least one embodiment of the claw pole rotor, the magnetization direction of the magnets extends in an opposite direction compared to the magnetization direction of at least one of the at least one magnet layer in a cross section through the claw pole rotor in the radial direction. This can mean that in a cross section through the claw pole rotor, the magnetization direction of the magnets extends from the center of the claw pole rotor towards the outside of the claw pole rotor, while the magnetization direction of the magnet layers extends from the outside towards the center. Alternatively, in a cross section through the claw pole rotor, the magnetization direction of the magnets can extend from the outside of the claw pole rotor towards the center of the claw pole rotor, while the magnetization direction of the magnet layers can extend from the center towards the outside. If the claw pole rotor has a plurality of magnet layers, the magnetization direction of every second magnet layer extends in the same direction. The magnetization direction in two adjacent magnet layers extends in different directions. This means that in a section through the claw pole rotor along its longitudinal axis, the magnetization direction of two adjacent magnet layers extends in opposite directions, respectively. In this way, the magnets and the magnet layers efficiently facilitate the amplification of the magnetic flux in the claw pole rotor. BRIEF DESCRIPTION OF DRAWINGS

[0035] In the following, the claw pole rotor described herein will be explained in more detail in connection with exemplary embodiments and related drawings.

[0036] Figure 1A and 1B A schematic cross section through a portion of one example of an electric machine is shown.

[0037] Figure 2A , 2B and 2C show a portion of one exemplary embodiment of a claw pole rotor.

[0038] Figure 3A , 3B , 3C, 3D and 3E describe one exemplary embodiment of a claw pole rotor.

[0039] Figure 4A and 4B A magnet for an exemplary embodiment of a claw pole rotor is shown.

[0040] Figure 5A , 5B , 5C, 5D, 5E, 5F and 5G describe another exemplary embodiment of a claw pole rotor.

[0041] Figure 6 Another exemplary embodiment of a claw pole rotor is shown.

[0042] Figure 7A 7B Another exemplary embodiment of a claw pole rotor is described in Figs. 7A and 7C.

[0043] Figure 8 Another exemplary embodiment of a claw pole rotor is shown.

[0044] Figure 9A 9B Another exemplary embodiment of a claw pole rotor is described.

[0045] Figure 10 A schematic cross section through a portion of an electric machine comprising one exemplary embodiment of a claw pole rotor is shown. DETAILED DESCRIPTION

[0046] Figure 1A A schematic cross section through a portion of one example of an electric machine 11 is shown. The electric machine 11 is not an exemplary embodiment. The electric machine 11 comprises a stator 26 and a claw pole rotor 10. The claw pole rotor 10 is not an exemplary embodiment. The stator 26 has a plurality of slots 27 in which electrical windings 28 are arranged. The claw pole rotor 10 is arranged in the stator 26. The claw pole rotor 10 has a field coil 22.

[0047] Figure 1B A portion of the claw pole rotor 10 of Figure 1A is shown. It shows that the field coil 22 is arranged between the claw pole fingers 15, 16 and the first yoke shaft member 12.

[0048] Figure 2A A portion of one exemplary embodiment of a claw pole rotor 10 for an electric machine 11 is shown. The claw pole rotor 10 comprises a first claw pole member 13 having a first yoke shaft member 12 to which at least two first claw pole fingers 15 are connected. The claw pole rotor 10 further comprises a second claw pole member 14 having a second yoke shaft member 17 to which at least two second claw pole fingers 16 are connected. In Figure 2A In, a cross section through a portion of the claw pole rotor 10 is shown in order to partially show the interior of the claw pole rotor 10. A cavity 29 is arranged within the claw pole rotor 10. The cavity 29 is arranged between the first yoke shaft member 12 and the second yoke shaft member 17. A magnet 20 is placed in the cavity 29. In order to illustrate the structure of the claw pole rotor 10 and the cavity 29, the magnet 20 is shown spaced apart from the claw pole rotor 10.

[0049] Figure 2B A portion of the claw pole rotor 10 of Figure 2A ​​part of the claw pole rotor 10. The first yoke shaft part 12, the magnet 20 and the second yoke shaft part 17 are arranged at least partially coaxially to each other. The first yoke shaft part 12, the magnet 20 and the second yoke shaft part 17 have the longitudinal axis L of the claw pole rotor 10 as a common axis of rotation. The extension of the magnet 20 along the longitudinal axis L of the claw pole rotor 10 is shorter than the entire extension of the claw pole rotor 10 along the longitudinal axis L. The magnet 20 completely fills the cavity 29. Thus, the magnet 20 is in direct contact with the first yoke shaft part 12 and the second yoke shaft part 17. However, the first claw pole part 13 and the second claw pole part 14 are spaced apart from each other. Thus, a gap is left between the second yoke shaft part 17 and the first claw pole part 13. This gap is arranged above the magnet 20.

[0050] Figure 2C A further view onto the part shown in Figure 2B is shown.

[0051] Figure 3A , 3B and 3C. This is the same exemplary embodiment, a part of which is shown in Figure 2A , 2B and 2C. In Figure 3A , the claw pole rotor 10 is shown in a disassembled state. The claw pole rotor 10 comprises the first claw pole part 13, the magnet 20 and the second claw pole part 14. The first claw pole part 13 comprises the first yoke shaft part 12, the first ring part 30 and the first claw pole fingers 15. The first claw pole part 13 comprises a total of four first claw pole fingers 15. The first claw pole fingers 15 are connected to the first ring part 30. The first ring part 30 is connected to the first yoke shaft part 12. The first yoke shaft part 12 has the shape of a hollow cylinder and is arranged at the inside of the claw pole rotor 10. The magnet 20 also has the shape of a hollow cylinder and is arranged at the inside of the claw pole rotor 10. The second claw pole part 14 comprises the second yoke shaft part 17, the second ring part 31 and the second claw pole fingers 16. The second claw pole part 14 comprises a total of four second claw pole fingers 16. The second claw pole fingers 16 are connected to the second ring part 31. The second ring part 31 is connected to the second yoke shaft part 17. The second yoke shaft part 17 has the shape of a hollow cylinder. In comparison to the first yoke shaft part 12, the second yoke shaft part 17 has a shorter extension along the longitudinal axis L of the claw pole rotor 10.

[0052] In Figure 3B , the magnet 20 in the illustration of Figure 3A is arranged at the first claw pole part 13. For the purpose of illustration, the second claw pole part 14 is also arranged spaced apart.

[0053] Figure 3CAn exemplary embodiment of the claw pole rotor 10 is shown in an assembled state. The first claw pole fingers 15 extend from a first side 18 of the claw pole rotor 10 towards a second side 19 of the claw pole rotor 10. The second claw pole fingers 16 extend from the second side 19 towards the first side 18. The magnet 20 is arranged between the first yoke shaft part 12 of the first claw pole part 13 and the second yoke shaft part 17 of the second claw pole part 14. The magnet 20 extends up to the second side 19. In a cross section through the claw pole rotor 10, the magnet 20 is arranged at least partially between the first yoke shaft part 12 and the second yoke shaft part 17 in a radial direction r. The diameter of the first yoke shaft part 12 is smaller than the diameter of the magnet 20, which is smaller than the diameter of the second yoke shaft part 17. Thus, the first yoke shaft part 12, the magnet 20 and the second yoke shaft part 17 are arranged at least partially coaxially with respect to each other. The first claw pole fingers 15 are arranged spaced apart from the second claw pole fingers 16.

[0054] Figure 3D An exemplary embodiment as shown in Figure 3C Figure 3C is shown in Fig. 5A. In contrast to the exemplary embodiment shown in Fig. 4A, the magnetization direction of the magnet 20 is shown by arrows. In a cross section through the claw pole rotor 10, the magnetization direction of the magnet 20 extends from an outer side 21 of the claw pole rotor 10 towards a center of the claw pole rotor 10.

[0055] In Figure 3E Figure 3D is shown in Fig. 5B. The only difference to the exemplary embodiment shown in Fig. 5A is that the magnetization direction of the magnet 20 extends from the center of the claw pole rotor 10 towards the outer side 21 of the claw pole rotor 10.

[0056] Figure 4A A magnet 20 for one exemplary embodiment of the claw pole rotor 10 is shown. The magnet 20 has the shape of a hollow cylinder.

[0057] In Figure 4B is shown in Fig. 6. A magnet 20 and a further magnet 23 for one exemplary embodiment of the claw pole rotor 10 are shown. The further magnet 23 can also be a permanent magnet. The further magnet 23 is arranged in the claw pole rotor 10 like the magnet 20, between the first yoke shaft part 12 and the second yoke shaft part 17. The magnet 20 and the further magnet 23 are arranged in a ring-like manner.

[0058] Figure 5A 、 5B , 5C, 5D, 5E, 5F and 5G describe another exemplary embodiment of the claw pole rotor 10. Figure 5A Another exemplary embodiment of the claw pole rotor 10 is shown. The claw pole rotor 10 has Figure 3C ​​The structure shown is simply that the claw-pole rotor 10 has a magnet 20 and seven additional magnets 23. The magnets 20 and the additional magnets 23 are arranged in a ring between the first yoke member 12 and the second yoke member 17. In this respect, ferromagnetic material 24 is arranged between the magnet 20 and adjacent additional magnets 23, and between every two additional magnets 23. Therefore, the magnets 20 and the additional magnets 23 are all arranged at a distance from each other.

[0059] exist Figure 5B For illustration purposes, the image is shown in a disassembled state. Figure 5A The exemplary embodiment shown herein illustrates that ferromagnetic material 24 is connected to the second claw pole member 14. The ferromagnetic material 24 may be formed as a web integrally formed with the second claw pole member 14. The web extends in the radial direction r in a cross-section passing through the claw pole rotor 10.

[0060] Figure 5C It shows Figure 5B The second claw pole component 14 has a magnet 20 and another magnet 23. The magnet 20 and the other magnet 23 are arranged between the ferromagnetic material 24 attached to the second claw pole component 14.

[0061] Figure 5D It shows Figure 5C Another view of the second claw pole component 14. Ferromagnetic material 24 extends along the longitudinal axis L of the claw pole rotor 10 to the magnet 20 and the additional magnet 23.

[0062] Figure 5E It shows Figure 5C The second claw pole component 14 does not have a magnet 20 and another magnet 23.

[0063] Figure 5F Shown separately Figure 5C Magnet 20 and another magnet 23.

[0064] exist Figure 5G In, it is shown separately Figure 5A The first claw pole component 13.

[0065] exist Figure 6 Another exemplary embodiment of the claw pole rotor 10 is shown in the figure. The claw pole rotor 10 has Figure 5A The structure shown is simply that the excitation coil 22 is arranged between the first and second claw pole fingers 15, 16 and the second yoke shaft component 17. The excitation coil 22 has the shape of a hollow cylinder.

[0066] Figure 7A , 7B Articles 7C and 7C describe another exemplary embodiment of the claw pole rotor 10. Figure 7AIn the shown exemplary embodiment, a part of the claw pole rotor 10 is shown. A cross section through the claw pole rotor 10 is shown. The first claw pole part 13 and the second claw pole part 14 are arranged in different radial positions in the cross section through the claw pole rotor 10. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with each other. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first yoke shaft part 12 and the second yoke shaft part 17, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first spacer 31 and the second spacer 32, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first magnet 20 and the first magnet layer 25, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the second magnet layer 26 and the third magnet layer 27, respectively. Figure 3C In the shown exemplary embodiment, a part of the claw pole rotor 10 is shown. A cross section through the claw pole rotor 10 is shown. The first claw pole part 13 and the second claw pole part 14 are arranged in different radial positions in the cross section through the claw pole rotor 10. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with each other. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first yoke shaft part 12 and the second yoke shaft part 17, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first spacer 31 and the second spacer 32, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first magnet 20 and the first magnet layer 25, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the second magnet layer 26 and the third magnet layer 27, respectively.

[0067] In the shown exemplary embodiment, a part of the claw pole rotor 10 is shown. A cross section through the claw pole rotor 10 is shown. The first claw pole part 13 and the second claw pole part 14 are arranged in different radial positions in the cross section through the claw pole rotor 10. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with each other. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first yoke shaft part 12 and the second yoke shaft part 17, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first spacer 31 and the second spacer 32, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first magnet 20 and the first magnet layer 25, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the second magnet layer 26 and the third magnet layer 27, respectively.

[0068] In the shown exemplary embodiment, a part of the claw pole rotor 10 is shown. A cross section through the claw pole rotor 10 is shown. The first claw pole part 13 and the second claw pole part 14 are arranged in different radial positions in the cross section through the claw pole rotor 10. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with each other. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first yoke shaft part 12 and the second yoke shaft part 17, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first spacer 31 and the second spacer 32, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first magnet 20 and the first magnet layer 25, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the second magnet layer 26 and the third magnet layer 27, respectively. Figure 7A In the shown exemplary embodiment, a part of the claw pole rotor 10 is shown. A cross section through the claw pole rotor 10 is shown. The first claw pole part 13 and the second claw pole part 14 are arranged in different radial positions in the cross section through the claw pole rotor 10. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with each other. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first yoke shaft part 12 and the second yoke shaft part 17, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first spacer 31 and the second spacer 32, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the first magnet 20 and the first magnet layer 25, respectively. The first claw pole part 13 and the second claw pole part 14 are arranged in direct contact with the second magnet layer 26 and the third magnet layer 27, respectively.

[0069] In a cross-section through the claw pole rotor 10 in the radial direction r, the magnetization direction of the magnets 20 extends in an opposite direction compared to the magnetization direction of the adjacent magnet layer 25. For every two adjacent magnet layers 25, the magnetization directions extend in opposite directions compared to each other in a cross-section through the claw pole rotor 10 in the radial direction. The magnetization direction is indicated by arrows in the enlarged view on the left. Figure 7A In a cross-section through the claw pole rotor 10 in the radial direction r, the magnetization direction of the magnets 20 extends in an opposite direction compared to the magnetization direction of the adjacent magnet layer 25. For every two adjacent magnet layers 25, the magnetization directions extend in opposite directions compared to each other in a cross-section through the claw pole rotor 10 in the radial direction. The magnetization direction is indicated by arrows in the enlarged view on the left.

[0070] Figure 7B A portion of the first claw pole part 13 having two first spacers 32 and the first yoke shaft part 12 is shown. Figure 7A Since only a portion is shown, the first spacers 32 both have an arcuate shape only. Overall, each first spacer 32 has the shape of a hollow cylinder.

[0071] Figure 7C A portion of the second claw pole part 14 having two second spacers 33 is shown. Figure 7A Since only a portion is shown, the second spacers 33 both have an arcuate shape only. Overall, each second spacer 33 has the shape of a hollow cylinder.

[0072] Figure 8 A portion of another exemplary embodiment of the claw pole rotor 10 is shown. The claw pole rotor 10 has the structure shown in Figure 7A Furthermore, the field coil 22 is arranged between the first and second claw pole fingers 15, 16 on the one hand and the second yoke shaft part 17 on the other hand.

[0073] Figure 9A and 9B Another exemplary embodiment of the claw pole rotor 10 is described. In Figure 9A A portion of the claw pole rotor 10 is shown. The claw pole rotor 10 has the structure shown in Figure 3C and further comprises the field coil 22 between the first and second claw pole fingers 15, 16 and the second yoke shaft part 17.

[0074] Figure 9B The entire claw pole rotor 10 according to the exemplary embodiment shown in Figure 9A is shown.

[0075] In Figure 10 a schematic cross-section through a portion of the electric machine 11 is shown, which comprises one exemplary embodiment of the claw pole rotor 10. The claw pole rotor 10 is Figure 3CThe claw pole rotor 10 is arranged in a stator 26 of an electric machine 11. The stator 26 has a plurality of slots 27 in which electric windings 28 are arranged.

[0076] Reference Signs List

[0077] 10: Claw pole rotor

[0078] 11: Electric machine

[0079] 12: First yoke shaft part

[0080] 13: First claw pole part

[0081] 14: Second claw pole part

[0082] 15: First claw pole finger

[0083] 16: Second claw pole finger

[0084] 17: Second yoke shaft part

[0085] 18: First side

[0086] 19: Second side

[0087] 20: Magnet

[0088] 21: Outer side

[0089] 22: Field coil

[0090] 23: Further magnet

[0091] 24: Ferromagnetic material

[0092] 25: Magnet layer

[0093] 26: Stator

[0094] 27: Slot

[0095] 28: Electric winding

[0096] 29: Cavity

[0097] 30: First ring part

[0098] 31: Second ring part

[0099] 32: First spacer

[0100] 33: Second spacer

[0101] L: Longitudinal axis

[0102] r: Radial direction.

Claims

1. A claw pole rotor (10) for an electric motor (11), the claw pole rotor (10) comprising: - A first claw pole component (13) having a first yoke shaft component (12), at least two first claw pole fingers (15) being connected to the first yoke shaft component, and - A second claw pole component (14) having a second yoke shaft component (17), wherein at least two second claw pole fingers (16) are connected to the second yoke shaft component, wherein - The first claw finger (15) extends from the first side (18) of the claw rotor (10) toward the second side (19) of the claw rotor (10), - The second claw finger (16) extends from the second side (19) toward the first side (18), and - A magnet (20) is arranged between the first yoke shaft member (12) of the first claw pole member (13) and the second yoke shaft member (17) of the second claw pole member (14). At least one magnet layer (25) is arranged between the first yoke member (12) and the second yoke member (17), wherein, viewed in cross-section through the claw pole rotor (10), the at least one magnet layer (25) is arranged at a different radial position than the magnet (20), and When viewed in a cross section passing through the claw pole rotor (10) in the radial direction (r), the magnetization direction of the magnet (20) extends in the opposite direction to the magnetization direction of at least one of the at least one magnet layer (25).

2. The claw pole rotor (10) according to claim 1, wherein the first yoke shaft component (12), the magnet (20) and the second yoke shaft component (17) are arranged to be at least partially coaxial with respect to each other.

3. The claw pole rotor (10) according to claim 1, wherein in a cross section through the claw pole rotor (10), the magnet (20) is arranged at least partially in the radial direction (r) between the first yoke member (12) and the second yoke member (17).

4. The claw pole rotor (10) according to claim 1, wherein the magnet (20) has the shape of a hollow cylinder.

5. The claw pole rotor (10) according to claim 1, wherein the diameter of the first yoke shaft component (12) is smaller than the diameter of the magnet (20), and the diameter of the magnet (20) is smaller than the diameter of the second yoke shaft component (17).

6. The claw pole rotor (10) according to claim 1, wherein the extension of the magnet (20) along the longitudinal axis (L) of the claw pole rotor (10) is shorter than the entire extension of the claw pole rotor (10) along the longitudinal axis (L).

7. The claw pole rotor (10) according to claim 1, wherein in a cross section through the claw pole rotor (10), the magnetization direction of the magnet (20) extends from the outer side (21) of the claw pole rotor (10) toward the center of the claw pole rotor (10).

8. The claw pole rotor (10) according to claim 1, wherein the first claw pole component (13) and the second claw pole component (14) are arranged to be spaced apart from each other.

9. The claw pole rotor (10) according to claim 1, wherein the excitation coil (22) is arranged between the claw pole fingers (15, 16) and the second yoke shaft component (17).

10. The claw pole rotor (10) according to claim 1, wherein at least one additional magnet (23) is arranged between the first yoke shaft member (12) and the second yoke shaft member (17), and the magnet (20) and the at least one additional magnet (23) are arranged in a ring.

11. The claw pole rotor (10) according to claim 10, wherein the ferromagnetic material (24) is arranged between the magnet (20) and the at least one other magnet (23).

12. The claw pole rotor (10) according to claim 1, wherein at least one first spacer (32) is attached to the first claw pole member (13) and extends at least partially parallel to the magnet (20), and / or wherein at least one second spacer (33) is attached to the second claw pole member (14) and extends at least partially parallel to the magnet (20).

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