Rotor for an electrical machine of a motor vehicle, and electrical machine for a motor vehicle

Abstract

The invention relates to a rotor (1) for an electrical machine of a motor vehicle, comprising a rotor shaft (2), comprising at least one excitation winding which is rotatable together with the rotor shaft (2) and which can be supplied with electrical energy, and comprising at least one rolling bearing (3) which has a bearing inner ring (4) connected to the rotor shaft (2) for conjoint rotation. A first contact element (9) for transmitting the electrical energy runs within the rotor shaft (2) from a first side (S1) of the bearing inner ring (4) to a second side (S2) of the bearing inner ring (4) facing away from the first side (S1) in the axial direction of the rotor shaft (2) and is electrically connected to the excitation winding. A second contact element (10) is arranged at least partially outside the rotor shaft (2), is electrically connected to the first contact element (9), is electrically connected to the excitation winding, is provided for transmitting the electrical energy, and is used to electrically connect the first contact element (9) to the excitation winding.

Description

[0001] Rotor for an electric machine of a motor vehicle as well as electric machine for a motor vehicle

[0002] The invention relates to a rotor for an electric machine of a motor vehicle according to the preamble of claim 1. Furthermore, the invention relates to an electric machine for a motor vehicle.

[0003] JP 4265571 B2 discloses an AC generator for a vehicle, with slip rings attached to a rotating shaft and rotatable together with the shaft. JP 6597705 B2 discloses a rotating electric machine. DE 10 2007 008 229 B4 discloses a rotating electric machine.

[0004] DE 10 2020 129444 A1 discloses an electric machine for a motor vehicle as already known. Furthermore, WO 2013 / 110581 A2 discloses an electric machine.

[0005] The object of the present invention is to create a rotor for an electric machine of a motor vehicle and an electric machine for a motor vehicle, such that the rotor can be manufactured in a particularly advantageous way.

[0006] This problem is solved according to the invention by a rotor with the features of claim 1 and by an electric machine with the features of claim 10. Advantageous embodiments of the invention are the subject of the dependent claims.

[0007] A first aspect of the invention relates to a rotor of an electric machine of a motor vehicle, which can also simply be called a vehicle. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, in its fully manufactured state, has the electric machine and thus the rotor, and can be driven by means of the electric machine, in particular purely electrically. In its fully manufactured state, the electric machine has a rotor and a stator, wherein the rotor is rotatable about an axis of rotation, also referred to as the machine axis, relative to the stator.

[0008] In particular, the rotor can be driven by means of the stator and thus rotated about the axis of rotation relative to the stator. For example, the electric machine can provide drive torques via its rotor to propel the motor vehicle. Most preferably, the electric machine is a high-voltage component whose electrical voltage, in particular its operating or rated voltage, is preferably greater than 50 volts, more preferably greater than 60 volts, and most preferably several hundred volts.

[0009] The rotor has at least one excitation winding, also called a winding or rotor winding. The excitation winding can be supplied with electrical energy. For example, by supplying the excitation winding with electrical energy, a magnetic field can be generated, which drives the rotor and allows it to rotate around its axis of rotation relative to the stator.

[0010] The rotor also has a rotor shaft. The rotor shaft is thus rotatable about the axis of rotation relative to the stator. The excitation winding can rotate with the rotor shaft about the axis of rotation relative to the stator, so that the excitation winding can also rotate about the axis of rotation relative to the stator. In particular, the excitation winding is designed separately from the rotor shaft and is at least indirectly rotationally fixed to the rotor shaft and thus can rotate with the rotor shaft. For example, the rotor has a laminated core, which can be designed separately from the rotor shaft and separately from the excitation winding. The laminated core is rotationally fixed to the rotor shaft. The excitation winding is attached to the laminated core and thus supported by the laminated core, in particular by the fact that the excitation winding is wound around at least a portion of the laminated core. Thus, for example, the excitation winding is rotationally fixed to the rotor shaft via the laminated core.

[0011] In particular, the electric machine can provide the drive torques via the rotor shaft.

[0012] The rotor also has at least one rolling bearing, which is also simply referred to as a bearing. The rolling bearing can be, for example, a ball bearing or another type of rolling bearing. The rolling bearing has an inner bearing ring that is non-rotatably connected to the rotor shaft; this is also referred to as the inner bearing ring or first inner bearing ring. When the inner bearing ring or first inner bearing ring is mentioned before and below, this refers to the inner bearing ring unless otherwise specified. In particular, the inner bearing ring is separate from the rotor shaft and non-rotatably connected to the rotor shaft, especially by being pressed onto the rotor shaft. For example, the rolling bearing has rolling elements, which, particularly if the rolling bearing is a ball bearing, can be balls.For example, the inner bearing ring has a raceway, also known as the first raceway, for the rolling elements. When the rotor, and thus the rotor shaft and the inner bearing ring, rotate around the axis of rotation relative to the stator, the rolling elements roll, in particular directly, on the first raceway of the inner bearing ring.

[0013] The rolling bearing, for example, has an outer bearing ring, which is also referred to as the second bearing ring. The outer bearing ring is, for example, a component of the stator, allowing the rotor shaft, and thus the inner bearing ring, to rotate around the axis of rotation relative to the outer bearing ring. The outer bearing ring forms, for example, a second raceway for the rolling elements. When the rotor shaft, and thus the inner bearing ring, rotates around the axis of rotation relative to the stator and therefore relative to the outer bearing ring, the rolling elements roll, in particular directly, against the first raceway and against the second raceway. This enables a particularly low-friction bearing arrangement of the rotor on the stator, thus enabling highly efficient operation of the electric machine.

[0014] For example, the stator can provide the electrical energy, which can be transferred between the stator and the rotor either via sliding contacts (i.e., contact) or inductively (i.e., without contact). It is particularly important to understand that the electrical energy provided by the stator can be transferred to the rotor and, in particular, to the excitation winding, thus supplying it with electrical energy. Furthermore, the rotor, especially after the excitation winding has been supplied with electrical energy, can provide the electrical energy that can be transferred from the rotor to the stator and thereby dissipated from the rotor (dictation pause) and the excitation winding.Supplying the excitation winding with electrical energy and removing the electrical energy from the excitation winding, i.e., transferring the electrical energy from the stator to the rotor and transferring the electrical energy from the rotor back to the stator, is conventionally very complex or leads to a complex manufacturing of the rotor.

[0015] In order to manufacture the rotor particularly advantageously, and especially in a particularly simple and thus time- and cost-effective manner, the invention provides that the rotor has a first contact element for transmitting electrical energy, which is formed separately from the rotor shaft and, in particular, separately from the inner bearing ring. The first contact element extends within the rotor shaft from a first side of the bearing groove ring to a second side of the inner bearing ring, which faces away from the first side in the axial direction of the rotor shaft. Furthermore, the contact element, which is formed separately from the excitation winding, is electrically connected to the excitation winding. The feature that electrical energy can be transmitted by means of the first contact element, i.e.,The term "can be transferred" means, for example, that the excitation winding can be supplied with electrical energy via the contact element, or that electrical energy can be drawn from the excitation winding via the contact element.

[0016] The rotor also has a second contact element, which is formed separately from the rotor shaft, the inner bearing ring, and the first contact element. This second contact element is located at least partially, and in particular at least predominantly, and thus at least more than halfway or even completely, outside the rotor shaft. The second contact element is electrically connected to the first contact element. Furthermore, the second contact element is electrically connected to the excitation winding, so that the first contact element is electrically connected to the excitation winding via the second contact element. Electrical energy can be transmitted via the second contact element. This means, for example, that the excitation winding can be supplied with electrical energy via the second contact element and the first contact element.The electrical energy can be supplied to the excitation winding, or it can be dissipated from the excitation winding via the first and second contact elements. For example, if the contact elements are used to supply the excitation winding with electrical energy, so that during operation of the electric machine the electrical energy flows to the excitation winding via the contact elements, then the second contact element is arranged upstream of the excitation winding and downstream of the first contact element. If the contact elements are used to dissipate the electrical energy from the excitation winding via the contact elements, so that, for example, during the aforementioned operation of the electric machine the electrical energy is dissipated from the excitation winding via the contact elements and flows through them, then the second contact element is arranged upstream of the first contact element and downstream of the excitation winding.

[0017] According to the invention, a screw element is also provided, which is formed separately from the rotor shaft, the inner bearing ring, and the contact elements, and is arranged on the second side of the inner bearing ring. The contact elements are connected to one another by means of the screw element. In particular, the contact elements are at least mechanically connected to one another by means of the screw element, so that relative movements between the contact elements are at least limited or prevented by means of the screw element. Furthermore, it would be conceivable that the contact elements are electrically connected to one another by means of the screw element, i.e., at least via the screw element or exclusively via the screw element. The invention makes it possible to mount the first contact element in a particularly simple and therefore also in a particularly time- and cost-effective manner.Furthermore, the invention enables the contact elements to be connected to each other in a particularly simple manner. Specifically, it is possible to mount the first contact element and connect the contact elements to each other using the screw after the rotor, i.e., at least a portion of the rotor, has been potted with a potting compound, for example, a resin.

[0018] The invention is based in particular on the realization that, in conventional solutions, when two separately formed contact elements are connected to transmit electrical energy, these contact elements are joined at least at one connection point, for example by welding or crimping. This joining usually takes place before the rotor is potted with a potting compound, and the connection point is typically potted with the compound and thus lies within the potting compound in the fully manufactured state of the rotor. In this case, the connection point is no longer accessible. The invention makes it possible to arrange the screw element, in particular completely, outside the potting compound, so that the screw element can be mounted after the rotor has been potted with the potting compound, thereby connecting the contact elements to each other by means of the screw element.The screw element remains accessible even after the rotor has been potted and can be loosened, for example, to separate the contact elements from each other without damaging them.

[0019] Thus, for example, in the fully manufactured state of the rotor according to the invention, the contact elements are connected to one another non-destructively by means of the screw element, so that, for example, in the fully manufactured state of the rotor, the screw element and subsequently the contact elements can be separated from one another without damaging or destroying the rotor. Furthermore, the invention makes it possible to advantageously position the first contact element, and thus a passage of the rotor shaft in which the first contact element extends, at a considerable distance from the inner bearing ring, particularly in the radial direction of the rotor shaft. This is particularly advantageous when the inner bearing ring is connected to the rotor shaft in such a rotationally fixed manner that the inner bearing ring is connected to the rotor shaft by means of an interference fit.This prevents excessive deformation of the bearing inner ring and shaft caused by the press fit, thus ensuring a secure fit of the bearing inner ring on the rotor shaft and favorable noise characteristics of the electric machine, even over a long service life. The rotor shaft is inserted into the laminated core, for example, by heating the core and / or cooling the rotor shaft, for example, using liquid nitrogen. Due to this intense cooling, certain components, particularly those made of plastic, may only be installed after the rotor shaft has been inserted into the laminated core. If maintenance of such components is required or desired, the use of a non-destructively detachable connection is then disadvantageous. These problems and disadvantages can also be avoided by the invention.

[0020] In order to manufacture the rotor particularly advantageously, one embodiment of the invention provides that the first contact element has an internal thread into which an external thread of the screw element, preferably designed as a screw, is screwed, in particular directly, so that the screw element is screwed into the internal thread. This connects the contact elements to each other.

[0021] Another embodiment is characterized by the provision of a sleeve, formed separately from the contact elements and, in particular, separately from the screw element, and penetrated by the screw element. This sleeve directly contacts the contact elements, thereby electrically connecting the sleeve to the contact elements and the first contact element to the second contact element via the sleeve. This allows the contact elements to be connected to each other particularly advantageously, thus enabling the rotor to be manufactured with particular efficiency.

[0022] Another embodiment is characterized in that the sleeve penetrates a corresponding opening in the rotor shaft. This allows the sleeve to be contacted particularly advantageously with the second contact element, thus enabling a particularly advantageous manufacturing of the rotor.

[0023] In a further, particularly advantageous embodiment of the invention, the sleeve is surrounded by an insulating element, also referred to as the first insulating element, by means of which the sleeve is electrically insulated from the shaft. For example, the first insulating element is made of a plastic. In particular, the first insulating element is a non-conductor. Within the scope of the present disclosure, a non-conductor is understood to be an element whose electrical conductivity is less than 10⁻⁸ S*cm⁻¹. This allows for a particularly advantageous rotor design, enabling the rotor to be manufactured advantageously.

[0024] To enable particularly advantageous manufacturing of the rotor, a further embodiment of the invention provides that the first contact element is at least partially embedded in an insulating element, also referred to as a second insulating element, by means of which the first contact element is electrically insulated from the shaft. For example, the second insulating element is made of a plastic. Furthermore, the second insulating element is preferably a non-conductor.

[0025] To enable particularly advantageous manufacturing of the rotor, a further embodiment of the invention provides that the screw element is arranged entirely outside of a potting compound with which at least a portion of the rotor is potted. Thus, in a method for manufacturing the rotor, it is possible, for example, to pot at least the portion of the rotor with the potting compound, which may consist of a resin, and only after potting is the screw element at least partially mounted with the potting compound, thereby connecting the contact elements to one another. The screw element is thus accessible even after the rotor has been potted and can, for example, be loosened to subsequently separate the contact elements from each other without damage.In other words, the screw element creates a non-destructively detachable connection between the contact elements, whereby the contact elements are connected to each other in a non-destructively detachable manner. The connection between the contact elements can be made after the rotor has been potted and can also be disconnected after the rotor has been potted, in order to, for example, separate the contact elements from each other, i.e., to disassemble them.

[0026] In a further, particularly advantageous embodiment of the invention, the rotor has a transmission element configured to form a sliding contact, also known as a slip ring, with the stator, through which electrical energy can be transmitted between the stator and the rotor. The transmission element is, for example, a slip ring. This allows for a simple and cost-effective rotor design.

[0027] To manufacture the rotor particularly advantageously and to operate the electric machine particularly efficiently, a further embodiment of the invention provides that the rotor has a transmission element designed to transmit the electrical energy inductively and thus without contact between the stator and the rotor. For example, a rotary transmitter, also known as an exciter, is provided by means of which the electrical energy can be transmitted inductively and thus without contact between the stator and the rotor.

[0028] A second aspect of the invention relates to an electric machine for a motor vehicle. The electric machine according to the second aspect of the invention comprises a stator and a rotor according to the invention, which is rotatable about an axis of rotation relative to the stator. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0029] Further details of the invention will become apparent from the following description of a preferred embodiment with the accompanying drawings. These show:

[0030] Fig. 1 shows a schematic and cutaway perspective view of a rotor for an electric machine of a motor vehicle;

[0031] Fig. 2 shows a schematic and partially cutaway perspective view of a module of the rotor;

[0032] Fig. 3 shows a further schematic and partially cutaway perspective view of the rotor; Fig. 4 shows a further schematic and partially cutaway perspective view of the rotor; and

[0033] Fig. 5 shows a schematic and cutaway side view of the rotor.

[0034] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0035] Fig. 1 shows a partial schematic and cutaway perspective view of a rotor 1 for an electric machine of a motor vehicle, also referred to simply as a vehicle. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, in its fully manufactured state, has the electric machine and can be driven by means of the electric machine, in particular purely electrically. In its fully manufactured state, the electric machine has the rotor 1 and a stator (not shown in the figures), wherein the rotor 1 is rotatable about an axis of rotation, also referred to as the machine axis of rotation, relative to the stator. The electric machine can provide drive torques for propelling the motor vehicle via the rotor 1.

[0036] The rotor 1 has a rotor shaft 2, via which the rotor 1 can provide the respective drive torque. The rotor 1 also has at least one excitation winding, not shown in the figures, which is also simply referred to as a winding or rotor winding. The excitation winding can be supplied with electrical energy. By supplying the excitation winding with electrical energy, a magnetic field can be generated, for example, by means of which the rotor 1, and thus the rotor shaft 2, can be driven and thereby rotated about the axis of rotation relative to the stator.

[0037] The rotor 1 also has at least one rolling bearing 3 by means of which the rotor 1 is rotatably mounted on the stator about the axis of rotation relative to the stator. In particular, the rotor 1 is supported in the radial direction of the rotor shaft 2 and thus of the rotor 1 via the rolling bearing 3 on the stator and is thereby rotatably mounted.

[0038] The rolling bearing 3 has an inner bearing ring 4 as the first bearing ring and a

[0039] The outer bearing ring 5 serves as the second bearing ring. The rolling bearing 3 also includes rolling elements 6. The inner bearing ring 4 is separate from the rotor shaft 2 and is rotatably connected to the rotor shaft 2. The stator of the electric machine is partially visible in Fig. 1 and is labelled 7.

[0040] The outer bearing ring 5 is a component of the stator 7. A component 8 of the stator 7 is visible in Fig. 1. It can be seen that the outer bearing ring 5 is formed separately from the component 8 and is rotatably connected to the component 8. Thus, the inner bearing ring 4 is rotatable about the axis of rotation relative to the outer bearing ring 5. Each bearing ring has a raceway for the rolling elements 6. When the rotor 1, and thus the rotor shaft 2 and the inner bearing ring 4, rotate about the axis of rotation relative to the stator 7 and thus relative to the outer bearing ring 5, the rolling elements 6 roll, in particular directly, on the raceways.

[0041] In order to manufacture the rotor 1 particularly advantageously, the rotor 1 has a first contact element 9 extending within the rotor shaft 2 from a first side S1 of the inner bearing ring 4 to a second side S2 of the inner bearing ring 4, which is located axially opposite the first side S1 and is electrically connected to the excitation winding. The electrical energy can be transmitted or is transmitted by means of this first contact element 9. The first contact element 9 is separate from the rotor shaft 2 and separate from the rolling bearing 3, and thus from the bearing rings and the rolling elements 6.

[0042] Furthermore, the rotor 1 has a second contact element 10, which is arranged at least partially, and in this case completely, outside the rotor shaft 2 and is electrically connected to the first contact element 9 and to the excitation winding. The contact element 9 is electrically connected to the excitation winding via this second contact element 10. Electrical energy can be transmitted or is transmitted by means of the contact element 10. Thus, for example, if the excitation winding is supplied with electrical energy via the contact elements 9 and 10, the electrical energy flows to the excitation winding via the contact elements 9 and 10, passing through them. The contact element 10 is arranged downstream of the first contact element 9 and upstream of the excitation winding.For example, if contact elements 9 and 10 are used to conduct electrical energy away from the excitation winding, the electrical energy flows away from the excitation winding via contact elements 9 and 10, with the electrical energy flowing through contact elements 9 and 10. Contact element 10 is arranged upstream of contact element 9 and downstream of the excitation winding. In the embodiment shown in the figures, contact elements 9 and 10 are used to supply the excitation winding with electrical energy, i.e., to supply the electrical energy to the excitation winding. The second contact element 10 is designed separately from the rotor shaft 2, separately from the inner bearing ring 4, and separately from the first contact element 9.

[0043] The second contact element 10 is formed separately from the rotor shaft 2 and separately from the inner bearing ring 4 and separately from the first contact element 9.

[0044] The rotor 1 also has a screw element arranged on the second side S2 of the inner bearing ring 4 and designed in this case as a screw 11, by means of which the contact elements 9 and 10 are connected to each other.

[0045] It is particularly evident from Fig. 2 that the contact element 9 has an internal thread 12. The screw 11 has an external thread 13 corresponding to the internal thread 12, with the external thread 13, and thus the screw 11, being screwed directly into the internal thread 12 and thus into the contact element 9. Furthermore, the screw 11 has a screw head 27 which, because the external thread 13 is screwed directly into the internal thread 12, is at least indirectly, in this case directly, clamped against the contact element 10. This clamps the contact element 10 at least indirectly against the contact element 9, thereby connecting the contact elements 9 and 10.

[0046] In the embodiment shown in the figures, a sleeve 14, particularly clearly visible in Figures 1, 3, and 4, is provided, separate from the contact elements 9 and 10, the screw 11, and the rotor shaft 2. The screw 11 penetrates the sleeve 14, in particular completely. The sleeve 14 directly contacts the contact element 9 on one side and the contact element 10 on the other, thus electrically connecting the sleeve 14 to the contact elements 9 and 10. The contact elements 9 and 10 are therefore electrically connected to each other via the sleeve 14. The sleeve 14 penetrates an opening 15 in the rotor shaft 2. The opening 15 opens at one end into a region located within the rotor shaft 2, in which the contact element 9 is located. At the other end, the opening 15 opens into the surrounding area of ​​the rotor shaft 2. Both the sleeve 14 and the screw 11 penetrate the opening 15, in particular completely.

[0047] A first insulating element 16 is associated with the sleeve 14 and surrounds the sleeve 14. Furthermore, the insulating element 16 is arranged in the opening 15, in this case such that the insulating element 16 penetrates the opening 15, in particular completely. The insulating element 16 electrically insulates the sleeve 14 from the rotor shaft 2.

[0048] The contact element 9 is at least partially embedded in a second insulating element 17, by means of which the contact element 9 is electrically isolated from the rotor shaft 2.

[0049] Figure 2 shows that the contact element 9 and, in this case, also the insulating element 17 are components of a module 18 of the rotor 1. The module 18 is independent of the rotor shaft 2 and can therefore be pre-assembled independently or is already pre-assembled. After its pre-assembly, particularly complete pre-assembly, it can be mounted on the rotor shaft 2, whereupon, for example, the screw 11 can be mounted and thus screwed into the internal thread 12 via the external thread 13, thereby connecting the contact elements 9 and 10.

[0050] Module 18, for example, has a third contact element 19, which is formed separately from contact elements 9 and 10 and separately from rotor shaft 2, and which is electrically connected to contact element 9, in particular by the fact that contact element 19 and contact element 9 directly touch.

[0051] The electric machine has a transmission device 20 through which electrical energy can be transferred between the rotor 1 and the stator 7. In the embodiment shown in the figures, the transmission device 20 is used to transfer the electrical energy provided by the stator to the rotor 1 and thereby supply it to the carrier winding. In the embodiment shown in the figures, the electrical energy can be transferred inductively and thus contactlessly from the stator 7 to the rotor 1 by means of the transmission device 20. For this purpose, the transmission device 20 has a first transmission element 21, which is a component of the stator 7. The electrical energy can be provided inductively by means of the first transmission element 21. The transmission device 20 also has a second transmission element 22, which is a component of the rotor 1.This allows the transmission element 22 to rotate about the axis of rotation relative to the stator 7 and thus relative to the transmission element 21 along with the rotor shaft 2. The transmission element 22 can inductively and thus contactlessly receive the electrical energy provided by the transmission element 21, in particular inductively and thus without contact, so that the electrical energy can be inductively and thus contactlessly transferred from the transmission element 21 to the transmission element 22. The transmission element 22 is electrically connected to the contact element 19.This allows the electrical energy provided by the transmission element 21 and received by the transmission element 22 to be transferred from the transmission element 22, particularly conductively, to the contact element 19 and from there, particularly conductively, to the contact element 9, from which the electrical energy can be transferred to the contact element 10 and via this to the excitation winding. The transmission device 20 is thus, for example, designed as a rotary transmitter in the embodiment shown in the figures. Alternatively, a slip ring module can be used, for example, by means of which a sliding contact, also referred to as a sliding contact, can be formed between the rotor 1 and the stator 7, whereby the electrical energy can be transferred via the sliding contact and thus, for example, conductively.

[0052] The contact element 10 is electrically connected to a contact tab 23, which is electrically connected to the excitation winding, so that electrical energy can be transferred from the contact element 10 to the excitation winding via the contact tab 23.

[0053] Figure 5 shows that, for example, the contact element 10 and the contact tab 23 are components of a contact assembly 24, which is rotatable about the axis of rotation relative to the stator. Figure 5 also shows an end disk 25 of the rotor 1, such that the end disk can rotate with the rotor 1 about the axis of rotation relative to the stator 7. A sealing element 26 is provided by means of which the contact assembly 24 is sealed against the end disk 25. For example, the sealing element 26 is fixedly connected to the contact assembly 24 and is therefore rotatable with the rotor 1 about the axis of rotation.

[0054] It is particularly evident from Fig. 3 that the contact element 10 has a through-opening 28, which is penetrated by the screw 11, in particular by its shank. It is also apparent that the contact element 9 is or has a nut, which forms the internal thread 12. In order to screw the screw 11 via the external threads 13 into the internal thread 12 and thus into the nut, and thereby screw it together, allowing the contact elements 9 and 10 to be connected, the screw 11 is rotated about a straight axis relative to the contact elements 9 and 10. This axis runs radially along the rotor shaft 2, so that the screw 11 forms a radial screw connection, extending radially along the rotor shaft 2, by means of which the contact elements 9 and 10 are connected.The screw 11 and thus the screw connection are positioned axially, i.e. in the axial direction of the rotor shaft 2 and thus of the rotor 1 as a whole, such that the screw connection and the screw 11 are arranged on the first side S1 of the inner bearing ring 4.

[0055] For example, rotor 1, or at least a portion of rotor 1, is encased in a potting compound, thus filling any unwanted cavities. This allows rotor 1 to withstand very high centrifugal forces, such as those resulting from high rotational speeds, without causing undesirable relative movements of rotor components. The potting compound is applied to the portion of rotor 1, or at least that portion, in such a way that it is completely encased. The screw connection, and therefore screw 11, is located entirely outside the potting compound, i.e., outside the portion of rotor 1 encased in the compound, so that screw 11 remains accessible even after the rotor 1 has been encased. Consequently, the screw connection can be disassembled without damage. In other words, the contact elements 9 and 10 are connected to each other by means of the screw connection in a way that allows for non-destructive disassembly.This means that the screw 11 can be loosened from the contact elements 9 and 10 even after the partial area of ​​the rotor 1 has been potted, so that, for example, even after the rotor 1 has been potted, the module 18 and thus the contact element 9 can be loosened from the contact element 10 and from the rotor shaft 2.

[0056] For example, the contact device 24 is guided through the end plate 25, also referred to as the end wall or forming an end wall, and sealed against the end plate 25 by means of the sealing element 26. This prevents, for example, the potting compound from reaching and flowing into the through-opening 28 when the rotor 1 is potted with the potting compound. In other words, the potting compound keeps the through-opening 28 away from the through-opening 28 and prevents it from flowing through the through-opening 28 and into the sleeve 14, so that after the rotor 1 has been potted with the potting compound, the screw 11 can be mounted and tightened. (Reference numeral list)

[0057] rotor

[0058] Rotor shaft, rolling bearing, inner bearing ring, outer bearing ring, rolling elements

[0059] stator

[0060] Component first contact element second contact element screw

[0061] Internal thread, external thread, sleeve

[0062] Opening first insulating element second insulating element module third contact element transmission device first transmission element second transmission element contact tab contact device end washer sealing element screw head first side second side

Claims

Patent claims 1. Rotor (1) for an electric machine of a motor vehicle, comprising a rotor shaft (2), with at least one excitation winding rotatable with the rotor shaft (2), which can be supplied with electrical energy, and with at least one rolling bearing (3), which has a bearing inner ring (4) connected to the rotor shaft (2) in a rotationally fixed manner, characterized by: - within the rotor shaft (2) from a first side (S1) of the bearing channel ring (4) first contact element (9) extending in the axial direction of the rotor shaft (2) away from the first side (S1) of the inner bearing ring (4) and electrically connected to the excitation winding for transmitting the electrical energy; - a second contact element (10) arranged at least partially outside the rotor shaft (2), electrically connected to the first contact element (9) and electrically connected to the excitation winding, and intended for transmitting electrical energy, via which the first contact element (9) is electrically connected to the excitation winding; and - a screw element (11) arranged on the second side (S2) of the inner bearing ring (4), by means of which the contact elements (9, 10) are connected to each other.

2. Rotor (1) according to claim 1, characterized in that an internal thread (12) is provided on the first contact element (9), into which an external thread (13) of the screw element (11) is screwed, whereby the contact elements (9, 10) are connected to each other.

3. Rotor (1) according to claim 1 or 2, characterized by a sleeve (14) formed separately from the contact elements (9, 10) and penetrated by the screw element (11), which directly contacts the contact elements (9, 10), whereby the sleeve (14) is in contact with the contact elements (9, 10) and the first contact element (9) is electrically connected to the second contact element (10) via the sleeve (14).

4. Rotor (1) according to claim 3, characterized in that the sleeve (14) penetrates a corresponding opening (15) of the rotor shaft (2).

5. Rotor (1) according to claim 3 or 4, characterized in that the sleeve (14) is surrounded by an insulating element (16) by means of which the sleeve (14) is electrically insulated from the rotor shaft (2).

6. Rotor (1) according to one of the preceding claims, characterized in that the first contact element (9) is at least partially embedded in an insulating element (17) by means of which the first contact element (9) is electrically insulated from the rotor shaft (2).

7. Rotor (1) according to one of the preceding claims, characterized in that the screw element (11) is arranged completely outside of a potting compound with which at least a partial area of ​​the rotor (1) is potted.

8. Rotor (1) according to one of the preceding claims, characterized by a transmission element which is designed to form a sliding contact with the stator (7) via which the electrical energy can be transmitted between a stator (7) of the electrical machine and the rotor (1) rotatable about an axis of rotation relative to the stator (7).

9. Rotor (1) according to one of claims 1 to 7, characterized by a transmission element (22) which is designed to inductively transmit the electrical energy between a stator (7) of the electrical machine and the rotor (1) rotatable about an axis of rotation relative to the stator (7).

10. Electric machine for a motor vehicle, comprising a stator (7) and a rotor (1) rotatable about an axis of rotation relative to the stator (7) according to one of the preceding claims.

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