Rotor for electric machine, in particular for motor vehicle, and electric machine, in particular for motor vehicle

Abstract

The invention relates to a rotor (1) for an electric machine, comprising a rotor shaft (5), a laminated core (6) arranged on the rotor shaft (5), and at least one star-shaped disc (11) which is connected to the laminated core (6) in the axial direction (7) of the rotor (1) and is arranged on the rotor shaft (5). A shaft nut (29) is provided which is connected to the star-shaped disc (11) in the axial direction (7) of the rotor (1) and which is screwed onto the rotor shaft (5), by means of which shaft nut the star-shaped disc (11) is tensioned onto the laminated core (6) in the axial direction (7) of the rotor (1).

Description

Technical Field

[0001] The present invention relates to a rotor for an electric machine, in particular for a motor vehicle, as described in the preamble of claim 1. Furthermore, the present invention relates to an electric machine, in particular for a motor vehicle, having such a rotor. Background Art

[0002] It is known from WO2020 / 099048A1 that a support device for a rotor of an externally excited inner rotor synchronous machine for an electrically drivable motor vehicle is provided, which support device has a star-shaped disk that can be arranged on the lamination stack of the rotor between the end face of the lamination stack and the winding heads protruding from the end face of the rotor winding. Furthermore, DE102018009845A1 discloses a rotor for an electric machine. US1450521 discloses an electric machine. A motor is known from DE647315C. DE102013208856A1 discloses a rotor of a flywheel energy storage device, which rotor comprises an axial stack formed by a plurality of laminated disks. Furthermore, a rotor of an electric motor is known from DE102020203483A1, in which a lamination stack is arranged on the rotor shaft of the rotor with an interference fit. Furthermore, a first clamping disk and a second clamping disk are provided, which are arranged on the rotor shaft and clamp the lamination stack axially between them and thereby fix it. Furthermore, it is known from DE102020112037A1 that a rotor for an electric machine is disclosed. Summary of the Invention

[0003] The object of the present invention is to provide a rotor for an electric machine, in particular for a motor vehicle, and an electric machine, in particular for a motor vehicle, such that in particular it is also possible to ensure particularly advantageous operation of the electric machine over a long service life of the electric machine.

[0004] This object is solved according to the invention by a rotor having the features of claim 1 and by an electric machine having the features of claim 9. Advantageous embodiments of the present invention are the technical solutions of the dependent claims.

[0005] A first aspect of the present invention relates to a rotor for an electric machine, in particular for a motor vehicle. This means that a motor vehicle, preferably configured as an automobile, in particular a sedan and also simply referred to as a vehicle, has an electric machine in its fully manufactured state and can be driven electrically, in particular purely electrically, by means of the electric machine. Thus, the motor vehicle is, for example, a hybrid vehicle or an electric vehicle, in particular a battery electric vehicle (BEV). Preferably, the electric machine is a high-voltage component, the voltage of which, in particular the operating voltage or the rated voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and particularly preferably several hundred volts. In particular, the electric machine in its fully manufactured state has a rotor and a stator, and the rotor can be driven by means of the stator and thus can be rotated relative to the stator about the rotational axis of the electric machine. In particular, the electric machine can provide a drive torque by means of its rotor, by means of which the motor vehicle can be driven electrically, in particular purely electrically.

[0006] The rotor has a rotor shaft by means of which the electric machine can, for example, provide a drive torque. In addition, the rotor has a lamination stack which is constructed separately from the rotor shaft and is arranged on the rotor shaft. In particular, the lamination stack is torsionally connected to the rotor shaft. In addition, the rotor has at least one star disk, which is also referred to as the first star disk. If the star disk is mentioned before and after, unless otherwise stated, it should be understood as the first star disk. In particular, the star disk is constructed separately from the lamination stack and separately from the rotor shaft. The star disk is arranged on the rotor shaft. In addition, the star disk is connected to the lamination stack in the axial direction of the rotor (the axial direction of the rotor coincides with the rotational axis of the electric machine). Particularly in particular, the star disk is connected to the axial end face of the lamination stack in the axial direction of the rotor, where this axial end face is also referred to as the first axial end face. If the axial end face is mentioned before and after, unless otherwise stated, it should be understood as the first axial end face. Particularly in particular, the lamination stack terminates in the axial end face in the axial direction of the rotor.

[0007] Now, in order to also ensure a particularly advantageous operation of the electric machine, especially high running smoothness, over a long service life, according to the invention, there is provided a shaft nut which is especially constructed separately from the rotor shaft, separately from the laminated core and separately from the star disk, and which is connected to the star disk in the axial direction of the rotor, especially such that the shaft nut is arranged on the side of the star disk which is axially remote from the laminated core in the direction of the rotor, i.e., on the side facing away from the laminated core, especially on the end face. The shaft nut is especially screwed directly onto the rotor shaft (which is also simply referred to as the shaft), so that the star disk is tensioned against the laminated core, especially on the first axial end face, in the axial direction of the rotor by means of the shaft nut. Preferably, the shaft nut is screwed directly onto the rotor shaft and is therefore preferably tightened directly with the shaft. For this purpose, especially the following is provided: Preferably, the shaft, especially the outer circumferential surface of the shaft, has a first thread, which is especially constructed as a first external thread. The shaft nut, especially the inner circumferential surface of the shaft nut, has a second thread corresponding to the first thread, which is preferably constructed as a first internal thread. Here, the threads are screwed directly into each other and are therefore directly tightened to each other, whereby the shaft nut is screwed onto the rotor shaft and is tightened, especially directly, in the axial direction to and therefore tensioned against the star disk, especially on the said side of the star disk. Thereby, the star disk is tensioned against the laminated core, especially on the first axial end face of the laminated core. Particularly preferably, the shaft nut abuts directly against the said side of the star disk in the axial direction of the rotor, so that the shaft nut is preferably supported directly against the said side of the star disk in the axial direction of the rotor. The present invention is especially based on the following recognition and consideration: Usually, the laminated core is compressible and thus deformable by technology, especially in the axial direction of the rotor. The deformability of the laminated core can especially lead to stresses as well as elastic and / or plastic deformations or displacements at high rotational speeds of the electric machine. This can especially lead to an imbalance during the operation of the electric machine, which can cause increased wear and / or adverse acoustic effects. For example, the rotor has at least one winding, especially a plurality of windings, where each corresponding winding is also called a rotor winding. The windings are wound around the laminated core and preferably around the star disk. For example, the windings are especially formed by a metal wire, which can therefore be formed of a metal material (such as copper) and can be constructed as a copper wire, for example. The said displacements can lead to stresses in the windings, especially in the wires, so that damage to the wires (such as breaks) can occur. The present invention now allows the star disk to be firmly tensioned against the laminated core in the axial direction by means of the shaft nut and thereby to achieve a very rigid unit block axially, which unit block at least includes the said laminated core, star disk and shaft nut. Especially, the unit block is tensioned in the axial direction by means of the shaft nut, whereby the unit block is less sensitive to elastic and plastic changes (especially caused by rotational speed and temperature) compared to traditional solutions. The axial tension caused by the shaft nut can prevent so-called "dishing warping" of individual laminations in the laminated core.In other words, it can be conceived that the stack of laminations is formed by a plurality of separately constructed lamination segments, which are, for example, connected to one another, and these lamination segments can be the above-mentioned laminations. For example, these lamination segments are successively arranged along the axial direction of the rotor and / or along the circumferential direction extending around the axial direction of the rotor. The so-called "dishing warping" (also known as "dishing effect") occurs because the laminations (also known as single laminations) are deformed unilaterally, especially by stamping and stretching and stamping and tearing, when they are hot-fitted onto the rotor shaft. If the rotor rotates relative to the stator around the axis of rotation of the electric machine during operation of the electric machine, a centrifugal force acts on the laminations, and through this centrifugal force, the laminations are erected again at high speeds of the rotor, and a changing imbalance of the rotor and possibly stresses acting in components (such as the wires of the electric machine) can occur relative to the stationary state of the electric machine (in the stationary state of the electric machine, the rotor does not rotate relative to the stator). Therefore, in particular, it can be conceived that the stack of laminations is connected to the rotor shaft by means of a press fit, that is, in particular, by means of an interference fit, whereby the stack of laminations is connected to the rotor shaft in such a way that relative rotation around the axis of rotation of the electric machine between the stack of laminations and the rotor shaft is prevented and preferably relative movement in the axial direction between the stack of laminations and the rotor shaft is prevented. In particular, the stack of laminations is torsionally connected to the rotor shaft by means of a press fit. By means of the present invention, the above-mentioned dishing warping can be avoided or at least reduced, so that overloading of the rotor and excessive imbalance or excessive change of imbalance of the rotor during operation of the electric machine can be avoided. Thereby, particularly high running smoothness of the electric machine can be ensured. In addition, excessive stresses in components (such as wires) can be avoided.

[0008] In order to be able to achieve a particularly advantageous tensioning of the stack of laminations and the star disk in the axial direction of the rotor, in one embodiment of the present invention it is provided that the star disk is connected to the first axial end face of the stack of laminations in the axial direction of the rotor.

[0009] It has proven to be particularly advantageous here that the star disk is tensioned onto the first axial end face in the axial direction of the rotor by means of an axial nut, so that the star disk can be tensioned particularly firmly onto the stack of laminations by means of the axial nut. Thereby, particularly strong tensioning of the unit block and thus particularly high rigidity can be achieved, so that overloading and excessive deformation of the stack of laminations can be avoided. Therefore, particularly high running smoothness of the electric machine and thus particularly advantageous operation can be ensured.

[0010] Another embodiment is characterized in that the star disk abuts directly against the first axial end face of the stack of laminations in the axial direction of the rotor. Thereby, particularly advantageous high rigidity of the unit block can be achieved, so that particularly high running smoothness of the electric machine and thus particularly advantageous operation can be ensured.

[0011] In another particularly advantageous embodiment of the invention, it is provided that a flange (also referred to as a collar) of the rotor shaft is provided on the second axial end face of the lamination stack which is remote from the first axial end face of the lamination stack in the axial direction of the rotor and thus remote from the star disk and the shaft nut. In particular, it is provided that the lamination stack terminates in the axial direction of the rotor at the second axial end face. Here, the lamination stack is supported at least indirectly, in particular directly, on the flange in the axial direction of the rotor. Thus, it can be conceived that the lamination stack, in particular the second axial end face of the lamination stack, is supported at least indirectly, in particular directly, on the flange in the axial direction of the rotor, so that, for example, the lamination stack, in particular the second axial end face of the lamination stack, abuts at least indirectly, in particular directly, against the flange in the axial direction of the rotor. Furthermore, it is provided that the lamination stack, in particular the second axial end face of the lamination stack, is tensioned at least indirectly, in particular directly, against the flange by means of the shaft nut in the axial direction of the rotor.

[0012] In principle, it can be conceived that another shaft nut is provided on the second axial end face of the lamination stack, which other shaft nut is in particular screwed directly onto the rotor shaft and is screwed tightly to the rotor shaft in particular directly. Here, the statements made above and below regarding the first shaft nut can also be transferred to the second shaft nut without any problems and vice versa. If a shaft nut is mentioned above and below, unless otherwise stated, it should be understood as the first shaft nut. Thus, it can be conceived that the lamination stack is supported at least indirectly on the other shaft nut in the axial direction of the rotor. However, in contrast thereto, it has proven particularly advantageous that the lamination stack is supported at least indirectly on the flange in the axial direction of the rotor and is tensioned against the flange. The flange forms a stop which can be manufactured simply and cost-effectively and is precisely and definitively positioned in the axial direction of the rotor relative to the rest of the rotor shaft. Starting from the flange, a dimension chain can be established in a simple manner and definitively, and simple manufacture of the rotor can be achieved. Furthermore, the lamination stack and the star disk can be firmly tensioned against the flange by means of the shaft nut, so that a high tension and rigidity of the unit block can be achieved. Thereby, particularly high running smoothness of the electric machine and thus particularly advantageous operation can be ensured.

[0013] Another embodiment is characterized in that a second star disk is provided between the flange and the second axial end face of the lamination stack in the axial direction of the rotor. Preferably, the second star disk is separately constructed from the rotor shaft, from the lamination stack, from the first star disk, and from the shaft nut. The lamination stack is hereby supported on the flange in the axial direction of the rotor in the case where the second star disk is provided in the middle, i.e., via the second star disk, wherein the lamination stack is tensioned onto the flange in the axial direction of the rotor in the case where the second star disk is provided in the middle and thus via the second star disk. In particular, it is conceivable that the above-mentioned unit block has the second star disk. In this way, a particularly strong axial tension extending in the axial direction of the lamination stack can be achieved, thereby ensuring a particularly favorable operation of the electric machine. In particular, it is conceivable that the winding is also wound around the second star disk.

[0014] Another embodiment is characterized in that the second star disk directly abuts against the flange on one side in the axial direction of the rotor and directly abuts against the second axial end face of the lamination stack on the other side. In particular, the second star disk has a second side face, in particular a second end face, which is away from the lamination stack, in particular away from the second axial end face of the lamination stack, away from the first star disk, and away from the shaft nut and towards the flange in the axial direction of the rotor, wherein, for example, the flange directly abuts against the second side face of the second star disk in the axial direction. Thereby, a particularly high axial tension of the unit block and thus a particularly high rigidity can be achieved, so that in particular the overloading and deformation of the lamination stack can be avoided even at high rotational speeds of the rotor. Thereby, a particularly high running smoothness of the electric machine can be ensured even at high rotational speeds of the rotor.

[0015] Finally, it has been shown to be particularly advantageous that the flange is integrally constructed with the rotor shaft. Thereby, the lamination stack can be particularly firmly tensioned onto the flange by means of the shaft nut, and the rotor can be manufactured in a time- and cost-effective manner.

[0016] For example, the winding protrudes from the first axial end face in the axial direction of the rotor, in particular such that a first length region of the winding protrudes from the first axial end face in the axial direction of the rotor and thereby forms at least one first winding head of the winding. Here, for example, the first star disk is arranged in the axial direction of the rotor between the first winding head and the lamination stack, in particular the first axial end face. Furthermore, it is conceivable that the winding protrudes from the second axial end face of the lamination stack in the axial direction of the rotor, in particular such that a second length region of the winding protrudes from the second axial end face in the axial direction of the rotor and thereby forms at least one second winding head of the winding. Here, it is conceivable that the second star disk is arranged in the axial direction of the rotor between the second winding head and the lamination stack, in particular the second axial end face. The corresponding star disk is in particular used to mechanically support the corresponding winding head when the rotor rotates to overcome high centrifugal forces. Furthermore, for example, the corresponding star disk is used so that the winding can be turned and thus wound advantageously.

[0017] A second aspect of the present invention relates to an electric machine having a stator and a rotor according to the first aspect of the present invention. The advantages and advantageous designs of the first aspect of the present invention can be regarded as the advantages and advantageous designs of the second aspect of the present invention and vice versa. In order to enable a particularly advantageous operation of the electric machine, in one embodiment of the second aspect of the present invention, it is provided that the electric machine is configured as a current-excited synchronous machine (SSM). Thereby, the use of rare earths can be avoided or advantageously reduced, the electric machine can be advantageously regulated and operated particularly efficiently. For example, a magnetic field of the rotor can be generated or produced by means of a winding, thereby enabling a particularly advantageous operation.

[0018] There is also disclosed a motor vehicle (also simply referred to as a vehicle), which is preferably configured as an automobile, in particular a sedan, and has at least one electric machine according to the second aspect of the present invention and can be electrically driven, in particular purely electrically driven, by means of the electric machine. The advantages and advantageous designs of the first and second aspects of the present invention can be regarded as the advantages and advantageous designs of the motor vehicle and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further details of the present invention result from the following description of preferred embodiments together with the drawings. Herein:

[0020] Figure 1 shows a schematic and partially cut-away side view of a rotor of an electric machine for a motor vehicle;

[0021] Figure 2 shows a schematic and perspective exploded view of the rotor; and

[0022] Figure 3 shows a schematic perspective view of the star disk of the rotor. DETAILED DESCRIPTION

[0023] In the drawings, identical or functionally identical elements are provided with the same reference numerals.

[0024] Figure 1 A rotor 1 of an electric machine for a motor vehicle (also simply referred to as a vehicle) is shown in a schematic and partially cut-away side view. This means that the motor vehicle has the electric machine in its fully manufactured state and can be electrically driven, in particular purely electrically driven, by means of the electric machine. The electric machine has a stator and a rotor 1, which can be driven by the stator and can thus rotate relative to the stator about an electric machine rotation axis 4. Herein, the rotor 1 has a rotor shaft 5, through which the electric machine can provide a drive torque for electrically driving, in particular purely electrically driving, the motor vehicle. In addition, the rotor 1 has a slip ring module 3. The electric machine is configured as a current-excited synchronous machine (SSM) in the illustrated embodiment. Herein, as combined with Figure 2Particularly clearly visible, the rotor 1 has a lamination stack 6, which is constructed separately from the rotor shaft 5 and is arranged on the rotor shaft 5. In particular, the lamination stack 6 is torsionally connected to the rotor shaft 5. Thus, the lamination stack 6 is connected to the rotor shaft 5 in such a way that relative rotation about the motor rotation axis 4 between the lamination stack 6 and the rotor shaft 5 is prevented. Particularly preferably, the lamination stack 6 (also) is connected to the rotor shaft 5 in such a way that relative movement in the axial direction of the rotor 1 and thus of the motor between the lamination stack 6 and the rotor shaft 5 is prevented. The axial direction of the rotor 1 and thus of the motor coincides overall with the motor rotation axis 4 and is shown in Figure 1 by a double arrow 7. During operation of the motor, the radial direction of which extends perpendicular to the axial direction and is shown by a double arrow 8, the rotor 1 and thus the rotor shaft 5 rotate relative to the stator about the motor rotation axis 4, whereby centrifugal forces act on the rotor 1, which centrifugal forces act particularly outward in the radial direction of the motor and thus of the rotor 1.

[0025] As can be seen particularly clearly in connection with Figure 2 the lamination stack 6 has two axially opposite end faces, i.e. end faces facing away from each other, in the axial direction, namely a first axial end face 9 and a second axial end face 10. The first star disk 11 of the rotor 1 is connected to the first axial end face 9 in the axial direction of the rotor 1 and thus to the lamination stack 6, wherein the star disk 11 is constructed separately from the lamination stack 6 and separately from the rotor shaft 5. Thus, the star disk 11 is arranged on the first axial end face 9. The second star disk 12 of the rotor 1 is connected to the second axial end face 10 in the axial direction of the rotor 1 and thus to the lamination stack 6, wherein the star disk 12 is constructed separately from the lamination stack 6, separately from the rotor shaft 5 and separately from the star disk 11. Thus, the lamination stack 6 is arranged between the star disks 11 and 12 in the axial direction of the rotor 1. Furthermore, it can be seen that the lamination stack 6 terminates on both sides in the axial direction in the axial end faces 9 and 10. The lamination stack 6 and the star disks 11 and 12 are arranged on the rotor shaft 5. In particular, it is preferred that the respective star disks 11, 12 are torsionally connected to the rotor shaft 5.

[0026] It can be seen from Figure 2 that the rotor 1 also has a winding 13, which is also referred to as the rotor winding. In particular, the motor is constructed as an internal rotor synchronous motor. In principle, it is conceivable that the lamination stack 6 is constructed as an integral iron core. In other words, it is conceivable that the lamination stack 6 is integrally constructed, i.e. formed from a single piece. It is also conceivable that the lamination stack 6 is formed from a plurality of individually constructed and interconnected single laminations, which single laminations are arranged successively, for example, in the axial direction of the rotor 1 and / or in the circumferential direction of the rotor 1 and thus of the motor extending around the motor rotation axis 4. The circumferential direction of the rotor 1 and thus of the motor extends around the motor rotation axis 4 and is shown in Figure 2 by a double arrow 14.

[0027] The stack 6 has an annular central region 15, which is also referred to as a yoke or rotor yoke. The region 15 defines a central through-hole 16 of the stack 6, through which the rotor shaft 5 passes. The magnetic poles 17 of the stack 6 project outward from the region 15 in the radial direction of the rotor 1, and the magnetic poles 17 are arranged successively and spaced apart from each other in the circumferential direction of the rotor 1 (bidirectional arrow 14), in particular such that the magnetic poles 17 are arranged uniformly in the circumferential direction of the rotor 1. Thus, a rotor slot 18 is formed between every two adjacent magnetic poles 17 in the circumferential direction of the rotor 1, so that the rotor slots 18 are arranged successively and in particular uniformly in the circumferential direction of the rotor 1. The rotor winding is wound around the magnetic poles 17 and also around the star disks 11 and 12, such that a first length region of the rotor winding extends in the rotor slots 18, a second length region of the rotor winding projects from the end face 9 in the axial direction of the rotor 1 and thus forms a first winding head of the rotor winding, and a third length region of the rotor winding projects from the end face 10 in the axial direction of the rotor 1 and forms a second winding head of the rotor winding. This means that the first winding head is arranged on the first axial end face 9 and the second winding head is arranged on the second axial end face 10. Here, the star disk 11 is arranged in the axial direction of the rotor 1 between the corresponding first winding head and the stack 6, in particular the axial end face 9, and the second star disk 12 is arranged in the axial direction of the rotor 1 between the corresponding second winding head and the stack 6, in particular the second axial end face 10.

[0028] In addition, the stack 6 has pole shoes 19, in particular such that each magnetic pole 17 is provided with a corresponding pole shoe 19, where, for example, the corresponding pole shoe 19 is connected to the corresponding magnetic pole 17, in particular to the outer end of the corresponding magnetic pole 17 facing away from the region 15 in the radial direction of the rotor 1. In other words, the pole shoe 19 is arranged on the corresponding end of the magnetic pole 17 opposite to the region 15 in the radial direction of the rotor 1, and the pole shoe 19 prevents the winding head arranged between the region 15 (rotor yoke) and the pole shoe 19 from slipping off the magnetic pole 17 when the rotor 1 rotates relative to the stator about the motor rotation axis 4. For example, a covering slider 20 is arranged in the rotor slot 18, which in particular closes the rotor slot 18 outward in the radial direction of the rotor 1 and prevents the rotor winding, in particular the first length region, from being pressed out of the rotor slot 18.

[0029] Figure 3Exemplarily, the first star disk 11 is shown, wherein the descriptions of the front and the back regarding the star disk 11 can also be transferred to the star disk 12 without problems and vice versa. In particular, the respective star disks 11, 12 provided between the respective end faces 9, 10 and the respective winding heads ensure a favorable turning of the winding wires of the rotor winding on the respective end faces 9, 10, wherein the rotor winding is formed by the winding wires. Around the respective star disks 11, 12, for example, respective tyre rings 21 are provided, which are configured, for example, as respective support rings. The respective tyre rings 21 ensure additional stability and fixation of the respective star disks 11, 12.

[0030] From Figure 3As can be seen in the example of the star disk 11, the corresponding star disks 11, 12 have a central region 22 which corresponds in particular to the region 15, which central region is also referred to as the star disk yoke and is at least substantially annular and delimits a corresponding through-hole 23, such that in particular the through-hole 23 is delimited directly by the inner circumferential surface 24 of the region 22. Here, the rotor shaft 5 passes through the through-hole 23. Star-shaped or star-like tabs 25 project outwards from the central region 22 in the radial direction of the rotor 1 (the radial direction of the rotor extends perpendicular to the axial direction and is indicated by the double arrow 8), and the tabs are arranged successively and spaced apart from one another in the circumferential direction of the rotor 1, such that in particular the tabs 25 are arranged evenly distributed in the circumferential direction of the rotor 1. In particular, a corresponding tab 25 is provided for each pole 17, such that for example the pole 17 overlaps with the corresponding tab 25 of the corresponding star disks 11, 12 in the axial direction of the rotor 1 outwards. The tabs 25 are also referred to as support teeth, and the region 22 is also referred to as the annular frame, for example. In particular, the corresponding region 22 abuts directly against the rotor yoke (region 15) in the axial direction of the rotor 1. The support teeth (tabs 25) project outwards in the radial direction of the rotor 1 from the annular frame (region 22) of the corresponding star disks 11, 12, and the support teeth are arranged overlapping with the poles 17 on the corresponding end faces 9, 10 of the lamination stack 6. The rotor winding is guided from the corresponding rotor slots 15 via the support teeth into the respectively adjacent rotor slots 15, such that the tabs 25 are arranged in the axial direction of the rotor 1 between the poles 17 and the corresponding winding heads arranged on the corresponding end faces 9, 10. In addition, the corresponding star disks 11, 12 have end pieces 26 which project axially from the tabs 25, and the end pieces can receive the centrifugal force acting on the corresponding winding heads. In other words, for example, the first winding head overlaps at least partially with the end piece 26 of the star disk 11 in the radial direction of the rotor 1 outwards, and for example the second winding head overlaps at least partially with the end piece 26 of the star disk 12 in the radial direction of the rotor 1 outwards. Thereby, the first winding head or the second winding head can be supported or can be supported outwards in the radial direction of the rotor 1 on the end piece 26 of the star disk 11 or 12. In particular, it is conceivable that the corresponding end pieces 26 project outwards in particular on both sides in the circumferential direction of the rotor 1 which extends around the axis of rotation of the electric machine and thus around the axial direction of the rotor 1, and the corresponding end pieces 26 are arranged on the ends of the corresponding tabs 25 which are opposite to the region 22 in the radial direction of the rotor 1.

[0031] In Figure 1 it, the first winding head is denoted by the reference numeral 27 and the second winding head is denoted by the reference numeral 28.

[0032] Now, in order to also ensure a particularly high running smoothness of the electric machine and thus a particularly favorable operation at high rotational speeds of the rotor 1, the rotor 1 has an axle nut 29 which is connected to the star disk 11 in the axial direction of the rotor 1 and is screwed directly onto the rotor shaft 5, by means of which the star disk 11 is tensioned in the axial direction of the rotor 1 onto the lamination stack 6, in particular onto the end face 9. As can be seen from Figure 1 the star disk 11 is connected in the axial direction of the rotor 1 to the first axial end face 9 of the lamination stack 6, wherein the star disk 11 abuts directly in the axial direction of the rotor 1 against the end face 9 and is thus directly supported on the end face 9. Here, the star disk 11 is directly tensioned in the axial direction of the rotor 1 onto the first axial end face 9 by means of the axle nut 29. The star disk 11 has a first side face 30 which faces away from the lamination stack 6 and towards the axle nut 29 in the axial direction of the rotor 1, wherein the axle nut 29 abuts directly in the axial direction of the rotor 1 against the side face 30. By screwing the axle nut 29 directly onto the rotor shaft 5, i.e., by directly tightening it with the rotor shaft 5, the axle nut 29 is directly tensioned in the axial direction of the rotor 1 onto the side face 30 of the star disk 11.

[0033] Starting from the second axial end face 10 of the lamination stack 6 which is remote from the first axial end face 9 in the axial direction of the rotor 1, the rotor shaft 5 has a flange 31 (also referred to as a collar) which is integrally formed with the rotor shaft 5, wherein the lamination stack 6 is indirectly supported on the flange 31 in the axial direction of the rotor 1 and is indirectly tensioned onto the flange 31 by means of the axle nut 29 in the axial direction of the rotor 1, such that a separate second star disk 12 is provided in the axial direction of the rotor 1 between the flange 31 and the second axial end face 10. Here, the lamination stack 6 is supported on the flange 31 in the axial direction of the rotor 1 with the second star disk 12 interposed therebetween and is tensioned onto the flange 31 by means of the axle nut 29 in the axial direction of the rotor 1 with the second star disk 12 interposed therebetween. The second star disk 12 abuts directly against the second axial end face 10 and has a second side face 32 which faces away from the end face 10 and thus away from the lamination stack 6, away from the star disk 11 and away from the axle nut 29, and this second side face abuts directly against the flange 31. In other words, the flange 31 abuts directly against the second side face 32 in the axial direction of the rotor 1.

[0034] The corresponding star disks 11, 12 are also referred to as the first components for example, and the lamination stack 6 is also referred to as the second component. It is conceivable that one of the components, in particular the corresponding star disks 11, 12, has at least one or more projections which are, for example, inserted into at least one or more corresponding recesses such that, for example, the corresponding star disks 11, 12 interact form-locked with the lamination stack 6, thereby preventing relative rotation in the circumferential direction of the rotor 1 between the corresponding star disks 11, 12 and the lamination stack 6, that is, the corresponding star disks 11, 12 and the lamination stack 6 are form-locked and torsionally resistant to each other. In Figure 1 the illustrated embodiment, for example, the star disk 11 has at least one projection 33 which is inserted into a corresponding recess 34 of the lamination stack 6, whereby the star disk 11 and the lamination stack 6 are form-locked and torsionally resistant to each other, currently preventing relative rotation between the lamination stack 6 and the star disk 11 about the electric machine axis of rotation 4 and thus in the circumferential direction of the rotor 1. Thereby, for example, it is not necessary to directly and torsionally connect the corresponding star disks 11, 12 themselves to the rotor shaft 5.

[0035] List of reference numerals

[0036] 1 Rotor

[0037] 3 Slip ring module

[0038] 4 Electric machine axis of rotation

[0039] 5 Rotor shaft

[0040] 6 Lamination stack

[0041] 7 Double-headed arrow

[0042] 8 Double-headed arrow

[0043] 9 First axial end face

[0044] 10 Second axial end face

[0045] 11 First star disk

[0046] 12 Second star disk

[0047] 13 Winding

[0048] 14 Double-headed arrow

[0049] 15 Region

[0050] 16 Through hole

[0051] 17 Magnetic pole

[0052] 18 Rotor slot

[0053] 19 Pole shoe

[0054] 20 Cover sliding member

[0055] 21 wheel tyre

[0056] 22 area

[0057] 23 through hole

[0058] 24 inner peripheral side surface

[0059] 25 tab

[0060] 26 end piece

[0061] 27 first winding head

[0062] 28 second winding head

[0063] 29 shaft nut

[0064] 30 first side surface

[0065] 31 flange

[0066] 32 second side surface

[0067] 33 protrusion

[0068] 34 recess

Claims

1. Rotor (1) for an electric machine, said rotor having a rotor shaft (5), a stack of laminations (6) arranged on the rotor shaft (5) and at least one star disk (11) which is connected to the stack of laminations (6) in the axial direction (7) of the rotor (1) and is arranged on the rotor shaft (5), characterized in that, There is a shaft nut (29) that is connected to the star disk (11) along the axial direction (7) of the rotor (1) and screwed onto the rotor shaft (5), and the star disk (11) is tensioned onto the lamination stack (6) along the axial direction (7) of the rotor (1) by means of the shaft nut.

2. The rotor (1) according to claim 1, characterized in that, The star disk (11) is connected to the first axial end face (9) of the lamination stack (6) along the axial direction (7) of the rotor (1).

3. The rotor (1) according to claim 2, characterized in that, The star disk (11) is tensioned onto the first axial end face (9) along the axial direction (7) of the rotor (1) by means of the shaft nut (29).

4. The rotor (1) according to claim 2 or 3, characterized in that, The star disk (11) directly abuts against the first axial end face (9) along the axial direction (7) of the rotor (1).

5. The rotor (1) according to any one of claims 2 to 4, characterized in that, On the second axial end face (10) of the lamination stack (6) that is away from the first axial end face (9) along the axial direction (7) of the rotor (1), there is a flange (31) of the rotor shaft (5), wherein the lamination stack (6) is at least indirectly supported on the flange (31) along the axial direction (7) of the rotor (1) and is at least indirectly tensioned onto the flange (31) along the axial direction (7) of the rotor (1) by means of the shaft nut (29).

6. The rotor (1) according to claim 5, characterized in that, A second star disk (12) is provided between the flange (31) and the second axial end face (10) along the axial direction (7) of the rotor (1), wherein the lamination stack (6) is supported on the flange (31) along the axial direction (7) of the rotor (1) with the second star disk (12) in between and is tensioned onto the flange (31) along the axial direction (7) of the rotor (1) with the second star disk (12) in between by means of the shaft nut (29).

7. The rotor (1) according to claim 6, characterized in that, The second star disk (12) directly abuts against the flange (31) on one side and directly abuts against the second axial end face (10) on the other side along the axial direction (7) of the rotor (1).

8. The rotor (1) according to any one of claims 5 to 7, characterized in that, The flange (31) is integrally formed with the rotor shaft (5).

9. An electric machine having a stator and a rotor (1) according to any one of the preceding claims.

10. The motor according to claim 9, characterized in that, The electric machine is configured as a current-excited synchronous machine.

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