Rotor, electric machine, motor vehicle and method

Abstract

A rotor (10; 40; 60) for an electric machine (2), comprising: a hollow shaft (11; 41); and an electronics carrier (49; 61a, 61b) for rectifying an exciter current, the electronics carrier (49; 61a, 61b) being arranged in the hollow shaft (11; 41) along an axis of rotation of the hollow shaft (11; 41).

Description

[0001] Rotor, electric machine, motor vehicle and method

[0002] The invention generally relates to a rotor, an electric machine, a motor vehicle and a method.

[0003] Separately excited synchronous electric machines are generally known. An excitation current can be inductively transmitted to a rotor of a separately excited synchronous electric machine. The inductive current transmission can operate with alternating current. The rotor can include a rectifier circuit for rectifying the excitation current.

[0004] Although separately excited synchronous electric machines are generally known, it is an object of the present invention to provide an improved rotor, an improved electric machine, an improved motor vehicle and an improved method.

[0005] The object is achieved by the rotor according to claim 1, by the electric machine according to claim 8, by the motor vehicle according to claim 9 and by the method according to claim 10.

[0006] Further embodiments emerge from the subclaims, the drawing and the following description.

[0007] Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0008] Fig. 1 shows an embodiment of a motor vehicle;

[0009] Fig. 2 shows an embodiment of a rotor for an electrical machine;

[0010] Fig. 3 shows different arrangements of diodes;

[0011] Fig. 4 shows an embodiment of a rotor with a printed circuit board;

[0012] Fig. 5 shows an embodiment of an arrangement of a circuit board and an oil lance in a hollow shaft; Fig. 6 shows an embodiment of a rotor with a circuit board and a plugged-on air coil;

[0013] Fig. 7 shows an embodiment of a rotor with two circuit boards;

[0014] Fig. 8 shows an embodiment of a rectifier circuit with four rectifier diodes;

[0015] Fig. 9 shows an embodiment of a rectifier circuit with two rectifier diodes;

[0016] Fig. 10 shows an embodiment of a method for manufacturing a rotor; Fig. 11 shows an embodiment of a positive connection of circuit boards between guide points and a diametrical curvature of an inner wall of a hollow shaft;

[0017] Fig. 12 shows an embodiment of a positive connection of printed circuit boards between guide points;

[0018] Fig. 13 shows an embodiment of a positive connection of printed circuit boards between guide points with a heat sink as a spacer;

[0019] Fig. 14 shows an embodiment of a positive connection of printed circuit boards between guide points with spacers;

[0020] Fig. 15 shows an embodiment of a positive connection of printed circuit boards between guide points with screws;

[0021] Fig. 16 shows an embodiment of a positive connection of printed circuit boards by axial fixing with slots; and

[0022] Fig. 17 shows an embodiment of a positive connection of printed circuit boards by guide points with additional material connection.

[0023] As mentioned at the beginning, an excitation current can be inductively transmitted to a rotor of a separately excited synchronous machine (SESM). The inductive current transmission can operate with alternating current. The rotor can comprise a rectifier circuit for rectifying the excitation current. The rotor can also comprise a rotor winding through which the rectified excitation current can flow and which can therefore generate a magnetic field. The magnetic field generated by the rotor winding can cause the rotor to align with a magnetic field that can be generated by current-carrying stator windings of the SESM. The rotor can be set in rotation by controlling a current in the stator windings.

[0024] Due to the inductive transmission of the excitation current to the rotor, slip rings and brushes (e.g., copper brushes, carbon brushes, or the like) can be dispensed with in some embodiments. By omitting brushes, the SESM can contain fewer wearing parts. By omitting brushes, it is also possible to prevent the transmission of the excitation current to the rotor from being disrupted by cooling oil getting between the brushes and slip rings. Furthermore, by omitting brushes, it is possible to prevent abrasion from the brushes from reaching other parts of the SESM and causing, for example, a short circuit. Consequently, it may also be possible to dispense with a sealing chamber in which a slip ring and brushes are arranged.

[0025] In some embodiments, an inductively excited SESM rotor is integrated into the system package of a permanent-magnet electric machine in a space-neutral manner. For this purpose, a transformer for inductively transmitting the excitation current to the rotor and one or more circuit boards for rectifying the excitation current can be arranged within a hollow rotor shaft of the rotor. The arrangement of a rectifier assembly can also be selected such that fewer space restrictions exist for components than with a conventional SESM with a rotor with a slip-ring system.

[0026] As mentioned, the inductive current transfer of the excitation current to the rotor can operate with alternating current. The excitation current can be rectified to operate the rotor windings with direct current.

[0027] In addition to a rectifier circuit for rectifying the excitation current, the rotor can include additional circuits or components, e.g., to reduce voltage spikes and / or high induced voltages that could, for example, damage the rectifier diodes. These additional circuits or components may require additional installation space. An electronic assembly, which may include the rectifier circuit and the additional circuits or components, can be arranged in the rotor hollow shaft, can be blindly pluggable, and / or can provide contact elements for connecting an output side of a rotary transformer, which can inductively receive the excitation voltage, as well as rotor windings.

[0028] In some embodiments, the rotor, including a transformer assembly with the rotary transformer and the electronics assembly, must be able to withstand vehicle-typical loads caused by vibrations and / or a speed of the rotor shaft.

[0029] It may be necessary to cool the power semiconductors of the electronic assembly well due to the high power density of the electronic assembly.

[0030] Cooling oil can also be transported past the electronics assembly toward the rotary transformer to cool it. This can occur relatively close to the rotational axis of the rotor shaft, since, in some embodiments, oil that has reached a radially outer region within the hollow shaft can no longer be pumped further inward against centrifugal force and is therefore no longer available for cooling the electronics and / or transformer assembly. Consequently, a space conflict can arise between an oil guide and the electronics assembly.

[0031] In some solutions presented so far, electronic components are arranged in a disk-shaped installation space distributed around the circumference between an oil guide lance and a hollow rotor shaft. This can result in relatively limited installation space for conductor tracks. Furthermore, an additional distance may be necessary between a stationary oil lance and a circuit board rotating with a hollow rotor shaft to prevent contact between the oil lance and the circuit board. Therefore, in some embodiments, a circuit board arrangement is chosen that provides the necessary circuits and components in the electronics assembly between an output of the rotary transformer and an input of the rotor winding(s).

[0032] In some embodiments, a solution is provided which allows the electronic assembly (e.g., printed circuit boards) to be securely mounted, positioned, and fixed for corresponding speed and vibration requirements, taking into account an assembly process and good accessibility for cooling oil.

[0033] Fig. 1 shows an embodiment of a motor vehicle 1. The motor vehicle 1 comprises an electric machine 2 and a battery 3. The motor vehicle 1 can comprise a passenger car, a truck, a motorcycle, a rail vehicle (e.g., a locomotive, a railcar), a construction machine (e.g., an excavator, a road roller, a forklift, etc.), or the like. The electric machine 2 is designed as an inductively excited SESM, provides traction torque for the motor vehicle 1, and draws electrical energy from the battery 3.

[0034] However, the disclosure is not limited to motor vehicles with a rechargeable battery. For example, the electric machine 2 can draw electrical energy from a fuel cell, a photovoltaic cell, an overhead line, and / or a generator, which can be driven, for example, by an internal combustion engine. The electric machine 2 can also drive a ship, a boat, a submarine, an aircraft, a helicopter, a multicopter, a robot, or the like. The electric machine 2 can also be used in mobile or stationary applications as a generator and / or motor, e.g., in a crane, a saw, a compressor, an emergency power generator, a pump, a blower, or the like.

[0035] Fig. 2 shows an embodiment of a rotor 10 for the electric machine 2 from Fig. 1 . As shown in A of Fig. 2, a rotor shaft 11 of the rotor 10 is designed as a hollow shaft and has a cavity 12. A star-shaped rotor core stack 13 is arranged around the rotor shaft 11. Several prefabricated air-core coils 14 are plugged onto the star-shaped rotor core stack 13. The plugged-on air-core coils 14 are an example of a rotor winding 14.

[0036] As shown in B of Fig. 2, another cylindrical laminated core 15 is pressed over the air coils 14 to absorb a centrifugal force.

[0037] A transformer for transmitting an excitation current to the rotor 10 is arranged in the cavity 12. Furthermore, a rectifier circuit is arranged in the cavity 12, which rectifies the excitation current so that the rotor winding 14 can be operated with the rectified excitation current. The rectifier circuit includes diodes.

[0038] Fig. 3 shows different arrangements of diodes.

[0039] A first arrangement 20 comprises a hollow shaft 21. Diodes 22 are arranged horizontally in the hollow shaft 21. An oil lance 23 is located centrally in the hollow shaft 21.

[0040] A second arrangement 24 comprises a radially arranged circuit board 25 on which diodes 26 are arranged. The second arrangement 24 also comprises an intermediate contact element 27 with further circuits.

[0041] A third arrangement 28 comprises a radially arranged circuit board 29 on which diodes 30 are arranged. The third arrangement 28 also comprises plug connections 31.

[0042] Some embodiments have advantages over the arrangements of Fig. 3. Some embodiments relate to a rotor for an electric machine. The rotor comprises a hollow shaft and an electronics carrier for rectifying an excitation current, wherein the electronics carrier is arranged in the hollow shaft along a rotational axis of the hollow shaft.

[0043] The rotor can be designed similarly to rotor 10 in Fig. 2, but is not limited to the configuration of rotor 10 in Fig. 2. The rotor can comprise one, two, three, or more pole pairs. Rotor windings of the rotor can be plugged on, as shown in Fig. 2, or wound. The rotor windings can be arranged radially outward on the hollow shaft of the rotor.

[0044] The rotor can be rotatably mounted, for example via ball bearings and / or magnetic bearings, which can be arranged at predefined axial positions of the hollow shaft so that the hollow shaft (and thus the rotor) can rotate about the axis of rotation. The hollow shaft can have a cavity that can be located radially inward in the hollow shaft. The cavity can comprise a section penetrated by the axis of rotation of the hollow shaft. The cavity can extend outwards from the axis of rotation up to a predefined radius so that the hollow shaft can delimit the cavity as a lateral surface. The cavity can be continuous from one axial end of the hollow shaft to an opposite axial end of the hollow shaft. In some embodiments, one axial end of the hollow shaft is closed, whereby the cavity can remain accessible through the opposite axial end.The cavity may be cylindrical or may have variable dimensions in the axial and / or radial direction.

[0045] The electronics carrier can comprise one or more electronic circuits. The electronics carrier can be embodied as a printed circuit board. The electronics carrier can comprise, for example, epoxy resin and / or fiberglass fabric and can comply with the FR4 specification. The electronics carrier can be embodied as an insulated metal surface (IMS) printed circuit board and can contain a metallic material, e.g., aluminum and / or copper. The electronics carrier can comprise, for example, a rectifier circuit for rectifying the excitation current. Furthermore, the electronics carrier can comprise an additional circuit, e.g., a protection circuit for protecting the electronic circuits from voltage spikes and / or high induced voltages. The additional circuit can also comprise a smoothing circuit for smoothing the rectified excitation current. The electronic circuits can comprise semiconductor components.The semiconductor components can be based on silicon (Si), silicon carbide (SiC), gallium nitride (GaN), or the like. The semiconductor components can comprise, for example, a diode, a capacitor, a resistor, or the like. Examples of the semiconductor components can include: one or more rectifier diodes for the rectifier circuit, an RC snubber for damping oscillations and / or overvoltage spikes for the auxiliary circuit, and a TVS (transient voltage suppressor) diode and / or a varistor for protecting the electronic circuits from voltage spikes and / or high induced overvoltages.

[0046] The rotor may further include a secondary coil for inductively receiving the excitation current from a primary coil. The rectifier circuit may receive and rectify the excitation current from the secondary coil.

[0047] The rectifier circuit can be implemented as a half-wave rectifier, a bridge rectifier, a center-wave rectifier, or the like. The rectifier circuit can comprise a thyristor, an insulated-gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), a gate turn-off (GTO) thyristor, or the like.

[0048] The electronics carrier can be arranged in the cavity of the hollow shaft in the axial direction. For example, the electronics carrier can extend from a first axial position to a second axial position in the cavity. The electronics carrier can be electrically connected to the secondary coil (and / or to an intermediate contact element between the secondary coil and the electronics carrier) so that excitation current, which the secondary coil receives inductively, can be conducted into the electronics carrier and rectified, for example, by the rectifier circuit. The electronics carrier can be electrically connected to the rotor winding(s) of the rotor so that the rectified excitation current can flow through the rotor winding(s) and generate a magnetic field there.

[0049] The electronics carrier can be flat. For example, the electronics carrier can be arranged as a strip in the axial direction in the cavity. The electronics carrier can also be bent around the axis of rotation of the hollow shaft. For example, the electronics carrier can be bent with a radius that is greater than the distance between the electronics carrier and the axis of rotation. This can provide a larger area for electronic circuits on the electronics carrier, and / or the distance between the electronics carrier and the axis of rotation can be increased while maintaining the same area. For example, the electronics carrier can be bent with a radius that corresponds to the distance between the electronics carrier and the axis of rotation. For example, the electronics carrier can be arranged on a predefined circular arc around the axis of rotation.The electronics carrier can surround the rotational axis, for example, in a range of 90°, 120°, 180°, or 360° (although the disclosure is not limited to these values). As a result, an area of ​​the electronics carrier can be increased for a given distance from the rotational axis and / or from an inner wall of the hollow shaft, and / or a number of electrical contact elements (e.g., for an electrical connection to the secondary coil and / or to the rotor winding(s)) can be reduced.

[0050] In some embodiments, the electronics carrier has a predefined distance from the axis of rotation.

[0051] The electronics carrier can be arranged so that it does not touch the rotation axis. For example, the electronics carrier can be arranged so that it orbits the rotation axis when the rotor rotates. A space (e.g., cylindrical, or generally rotationally symmetrical) can remain free around the rotation axis, into which the electronics carrier does not penetrate. The radius of the free space can correspond to the predefined distance of the electronics carrier from the rotation axis.

[0052] The remaining space can be used for a cooling oil guide to cool the electronics carrier and / or the secondary coil. For example, an oil lance can be arranged in the remaining space, which can guide cooling oil to the electronics carrier and / or the secondary coil. The oil lance can have one or more openings (e.g., radial or axial) through which cooling oil can escape from the oil lance and reach the electronics carrier and / or the secondary coil for cooling. For example, the oil lance can have an opening at an axial position at which the electronics carrier can have a power diode (and / or another semiconductor component) that can heat up considerably during operation of the electric machine. The oil lance can, for example, protrude from an axial end of the hollow shaft into the hollow space in a manner fixed to the stator. For example, the oil lance can be arranged concentrically to the axis of rotation of the hollow shaft.

[0053] In some embodiments, the rotor has a further electronics carrier for rectifying the excitation current, wherein the further electronics carrier is arranged in the hollow shaft along the axis of rotation and has a predefined distance from the axis of rotation.

[0054] The additional electronics carrier can be designed similarly to the electronics carrier. For example, the rectifier circuit and / or the additional circuit can be distributed between the electronics carrier and the additional electronics carrier. For example, the electronics carrier and the additional electronics carrier can each comprise a rectifier circuit and an additional circuit and can supply different rotor windings (e.g., different pole pairs) with excitation current or can be connected in parallel.

[0055] The additional electronics carrier can, for example, be arranged in the same axial section of the hollow shaft as the electronics carrier. For example, a first axial end of the electronics carrier can be arranged at the same axial position of the hollow shaft as a first axial end of the additional electronics carrier, and a second axial end of the electronics carrier can be arranged at the same axial position of the hollow shaft as a second axial end of the additional electronics carrier.

[0056] The present technology is not limited to one additional electronics carrier. For example, the rotor may include three or four electronics carriers (although the disclosure is not limited to these numbers).

[0057] The additional electronics carrier (or several additional electronics carriers) can provide a larger area for the rectifier circuit and / or for the additional circuit, so that semiconductor components can be arranged at a greater distance from one another. This can facilitate heat dissipation and / or compliance with required air and creepage distances. In some cases, the electronics carrier and each additional electronics carrier each contain a rectifier circuit and thus supply different rotor windings or are connected in parallel. This allows the excitation current to be distributed among the several electronics carriers, so that the rectifier circuits can be based on smaller semiconductor components and / or heat dissipation can be facilitated.

[0058] The electronics carriers can be arranged in such a way that imbalance is avoided during rotation of the hollow shaft or the rotor or does not exceed a predetermined value. For example, the electronics carriers (or their centers of gravity) can be arranged symmetrically around the axis of rotation. With two electronics carriers, the two electronics carriers (e.g. their centers of gravity) can be arranged at radially opposite positions around the axis of rotation (e.g. offset by 180° from each other). With three electronics carriers, the three electronics carriers (e.g. their centers of gravity) can be arranged offset by 120° from each other around the axis of rotation, for example. With four electronics carriers, the four electronics carriers (e.g. their centers of gravity) can be arranged at intervals of 90° around the axis of rotation, for example. The person skilled in the art can find further advantageous arrangements of multiple electronics carriers.The distance of the additional electronics carrier from the rotational axis can (within specified manufacturing tolerances) correspond to the distance of the electronics carrier from the rotational axis, so that, for example, the oil lance can be arranged concentrically to the rotational axis (between the electronics carrier and the additional electronics carrier). The distance of the additional electronics carrier from the rotational axis can also differ from the distance of the electronics carrier, for example, to compensate for mass differences between the electronics carrier and the additional electronics carrier (e.g., if the electronics carrier contains a different circuit than the additional electronics carrier).

[0059] In some embodiments, the electronics carrier has a first rectifier diode for supplying a rotor winding with a positive half-wave of the excitation current, and the further electronics carrier has a second rectifier diode for supplying the rotor winding with a negative half-wave of the excitation current.

[0060] For example, the secondary coil may comprise two windings connected in series and connected at a center of the secondary coil. The two windings of the secondary coil may be arranged concentrically and may (within manufacturing tolerances) have the same radius and the same number of turns. The first rectifier diode may electrically connect a first end of the secondary coil to a first end of the rotor winding, and the second rectifier diode may electrically connect a second end of the secondary coil to the first end of the rotor winding. A second end of the rotor winding may be electrically connected to the center of the secondary coil (where the two windings are connected) via a center tap.Alternatively, instead of the center tap, a first line can electrically connect the second end of the rotor winding to one of the two windings and a second line can electrically connect the second end of the rotor winding to the other of the two windings.

[0061] The first and second rectifier diodes may be arranged such that the positive half-wave of the excitation current flows in the forward direction of the first rectifier diode and in the reverse direction of the second rectifier diode, and that the negative half-wave of the excitation current flows in the forward direction of the second rectifier diode and in the reverse direction of the first rectifier diode.

[0062] The rectifier assembly, which comprises the first and the second rectifier diode, can thus comprise a center point rectifier distributed between the electronics carrier and the further electronics carrier.

[0063] This allows a single rectifier diode to be required per electronics carrier, allowing for increased clearance and creepage distances and / or facilitating heat dissipation. In some cases, larger rectifier diodes can also be selected, as more space can be available for the rectifier diodes while maintaining the same size of the electronics carrier.

[0064] In some embodiments, an electrical connection between a secondary coil for inductive reception of the excitation current and the electronics carrier is designed as a plug connection that can be plugged in the axial direction.

[0065] The secondary coil can also be arranged in the hollow shaft and axially adjacent to the electronics carrier. An intermediate contact element can also be arranged in the hollow shaft, which can be electrically connected to the secondary coil and axially adjacent to the electronics carrier. The secondary coil or the intermediate contact element can have plug contacts, and the electronics carrier can have plug contacts that can correspond to the plug contacts of the secondary coil or the intermediate contact element.

[0066] For example, the plug connection can be closed by axially bringing together the secondary coil or the intermediate contact element and the electronics carrier.

[0067] This makes assembly of the rotor easier because the electrical connection can be closed during axial joining, thus eliminating the need for an additional work step for electrical connection.

[0068] In some embodiments, the plug connection between the secondary coil and the electronics carrier can be blindly plugged.

[0069] The plug connection can be designed so that, apart from axial alignment, no further steps are required to establish the electrical connection. For example, separate locking, screwing, soldering, connecting cables, etc., can be eliminated.

[0070] For example, electrical contacts of the plug contacts can be connected to each other during axial joining by clamping, e.g. based on a clamping spring and / or on a clamping profile.

[0071] For example, the plug connection can be held after joining by positive locking and / or by force locking (e.g. by a plug lock).

[0072] For example, the plug connection can comprise a guide aid which supports a suitable alignment when axially joining the electronics carrier with the secondary coil or with the intermediate contact element, so that plug contacts on both sides of the plug connection are aligned with each other when joined together in such a way that the electrical connection is established when further joined together.

[0073] The expert can find other suitable designs for a blind plug-in connector.

[0074] In some embodiments, the electronics carrier further comprises a plug contact for supplying a rotor winding with the excitation current. The hollow shaft has a recess, and the plug contact can be inserted through the recess from outside the hollow shaft. The recess can be arranged in the hollow shaft in such a way that the plug contact on the electronics carrier can be reached from outside the hollow shaft.

[0075] For example, the rotor winding can be plugged radially onto a laminated core of the rotor, as shown in Fig. 2 for the air-core coils 14. The rotor winding (e.g., the air-core coils 14) can have a contact element (sword) that can correspond to the plug contact of the electronics carrier, so that when the rotor winding is plugged onto the rotor (e.g., onto the laminated core), an electrical connection can be established between the contact element of the rotor winding and the plug contact of the electronics carrier.

[0076] The plug contact of the electronics carrier and the contact element of the rotor winding can provide a plug connection which can be designed similarly to the plug connection between the electronics carrier and the secondary coil or the intermediate contact element.

[0077] The plug connection between the electronics carrier and the rotor winding can, for example, be designed to be blindly pluggable, so that further work steps for establishing an electrical connection between the electronics carrier and the rotor winding can be omitted after the rotor winding has been plugged onto the rotor.

[0078] The plug connection between the electronics carrier and the rotor winding can fix the electronics carrier in an axial direction. For example, it can prevent the electronics carrier from slipping axially, thereby ensuring an electrical connection between the electronics carrier and the secondary coil or the intermediate contact element.

[0079] Some embodiments relate to an electric machine. The electric machine comprises the rotor, as described above, and an oil lance for cooling the electronics carrier, wherein the oil lance is arranged radially further inward than the electronics carrier in the hollow shaft along the rotational axis of the hollow shaft. The electric machine can be designed as described for the electric machine 2 in Fig. 1. The rotor of the electric machine can be configured as described above. Each feature described above for the rotor can represent a corresponding feature of the electric machine.

[0080] The oil lance can be rigidly connected to a stator of the electrical machine and extend from outside the hollow shaft of the electrical machine into the hollow shaft coaxially to the axis of rotation of the hollow shaft. To cool the electrical machine (e.g. a transformer circuit with the secondary coil and / or the electronics carrier(s) with the rectifier diode(s)), oil can be pumped into the oil lance. The oil lance can guide the cooling oil into the rotor of the electrical machine and release it through openings at predefined positions. The electronics carrier(s) can be arranged in the hollow shaft at a predefined distance from the axis of rotation of the hollow shaft so that the electronics carrier(s) orbit(s) the oil lance during operation of the electrical machine without touching the oil lance.

[0081] Some embodiments relate to a motor vehicle comprising the electric machine described above, wherein the electric machine is configured to provide a traction torque of the motor vehicle.

[0082] The motor vehicle can be designed as described for motor vehicle 1 in Fig. 1. The motor vehicle can include the electric machine and / or the rotor described above. Each feature described above for the rotor and / or for the electric machine can represent a corresponding feature of the motor vehicle.

[0083] The electric machine can be designed as a traction motor of the motor vehicle and, in motor mode, can provide a traction torque for the propulsion of the motor vehicle. For example, the traction torque can be transferred to wheels of the motor vehicle. In generator mode, the electric machine can also provide a deceleration torque for the motor vehicle. For example, the electric machine can be driven by a rotational movement of the wheels of the motor vehicle and convert the rotational movement into electrical energy. The electrical energy thus generated can be stored (e.g., in the accumulator 3 of Fig. 1) and can later be used in motor mode to drive the electric machine.

[0084] Some embodiments relate to a method for manufacturing the rotor described above. The method comprises:

[0085] Inserting the electronics carrier in the axial direction into the hollow shaft; and inserting a secondary coil for inductively receiving the excitation current in the axial direction into the hollow shaft; wherein the electronics carrier and the secondary coil are electrically connected to one another by a plug connection upon insertion of the electronics carrier and / or the secondary coil.

[0086] The electronics carrier and the secondary coil can be inserted into the hollow shaft (e.g., in a predefined sequence) from the same axial end of the rotor's hollow shaft. The electronics carrier and the secondary coil can also be inserted into the hollow shaft from different axial ends of the hollow shaft.

[0087] The secondary coil may, for example, be arranged in a transformer unit, so that the insertion of the secondary coil may comprise an insertion of the transformer unit.

[0088] An electrical connection between the secondary coil and the electronics carrier can be established via an intermediate contact element. The intermediate contact element can, for example, be inserted between the electronics carrier and the secondary coil in the axial direction into the cavity of the hollow shaft. The intermediate contact element can be connected to the secondary coil or to the transmitter unit before being inserted into the hollow shaft and can then be inserted into the hollow shaft together with the secondary coil or transmitter unit, wherein an electrical connection can be established between the intermediate contact element and the electronics carrier during insertion. The intermediate contact element can be connected to the electronics carrier before being inserted into the hollow shaft and can then be inserted into the hollow shaft together with the electronics carrier, wherein an electrical connection can be established between the intermediate contact element and the secondary coil or transmitter unit during insertion.the transmitter unit can be manufactured.

[0089] The rotor can comprise multiple electronics carriers. The multiple electronics carriers can be inserted one after the other in the axial direction into the hollow shaft. Each of the multiple electronics carriers can be electrically connected to the secondary coil or the intermediate contact element via a plug connection when inserted into the hollow shaft. The multiple electronics carriers can also be inserted into the hollow shaft simultaneously in the axial direction, and an electrical connection between the multiple electronics carriers and the secondary coil or the intermediate contact element can be established simultaneously (e.g., in a single work step). For example, the multiple electronics carriers can be connected or held together by one or more spacers before being inserted into the hollow shaft, and thus inserted into the hollow shaft as a single unit.

[0090] By establishing an electrical connection between the electronics carrier(s) and the secondary coil when inserting the electronics carrier(s) and / or the secondary coil, an additional work step can be saved in the manufacture of the rotor or the electrical machine.

[0091] The features of the rotor, the electric machine, the motor vehicle and / or the method can be combined in a suitable manner.

[0092] Fig. 4 shows an embodiment of a rotor 40 with a circuit board 49. The

[0093] Rotor 40 is designed as a rotor for an electrical machine that is configured as a separately excited synchronous machine. Rotor 40 is an example of rotor 10 in Fig. 2 and of a rotor of electrical machine 2 in Fig. 1.

[0094] The rotor 40 comprises a hollow shaft 41, which has a cavity 42 around its rotational axis. A star-shaped laminated core 43 for accommodating an air-core coil is arranged radially outside the hollow shaft 41. A transformer assembly 44 and a rectifier assembly 45 are arranged in the cavity 42 of the hollow shaft 41.

[0095] The transformer assembly 44 comprises a primary ferrite with a primary coil 46, which is fixed to the stator, and a secondary ferrite with a secondary coil 47, which is rigidly connected to the hollow shaft 41. The primary ferrite and the primary coil 46 are pre-assembled with bearings and bolts. The primary coil 46 and the secondary coil 47 are arranged concentrically at the same axial position in the hollow shaft 41 and are rotatable relative to each other about the rotational axis of the hollow shaft 41. Excitation current is fed into the primary coil 46 as alternating current via cable 48, so that the primary coil 46 generates an alternating magnetic field. The alternating magnetic field generates an alternating current in the secondary coil 47 through induction. The secondary coil 47 can thus receive the excitation current inductively, and the excitation current can be transmitted to the rotor 40 without the need for brushes. The transformer assembly 44 further comprises an intermediate contact element 48 which is electrically connected to the secondary coil 47.

[0096] The rectifier assembly 45 comprises a printed circuit board 49. The printed circuit board 49 is an example of an electronics carrier and is arranged in the hollow shaft 41 along the rotational axis of the hollow shaft 41. A rectifier diode circuit 50 for rectifying the excitation current and an additional circuit 51 are arranged on the printed circuit board 49. The printed circuit board 49 has plug contacts 52 for (blind) contacting at an end facing the transformer assembly 44. The plug contacts 52 are plugged into corresponding plug contacts of the intermediate contact element 48 such that a plug connection is closed between the printed circuit board 49 and the intermediate contact element 48. The plug contacts 52 thus enable insertion in the axial direction to establish the electrical connection between the transformer assembly 44 and the printed circuit board 49. The plug connection can be plugged in the axial direction and blindly.

[0097] The plug connection provides an electrical connection between the circuit board 49 and the intermediate contact element 48 (and thus the secondary coil 47).

[0098] The circuit board 49 receives the excitation current from the secondary coil 47 via the plug connection. The rectifier diode circuit 50 comprises several power diodes that rectify the excitation current so that it is present as direct current. The auxiliary circuit 51 includes RC snubbers, TVS diodes, and varistors to dampen oscillations in the excitation current, as well as voltage spikes and high induced voltages.

[0099] The circuit board 49 also has a plug contact 53 for supplying a rotor winding with the rectified excitation current. The hollow shaft 41 has a recess 54. The recess 54 is arranged such that the plug contact 53 can be inserted through the recess 54 from outside the hollow shaft 41.

[0100] Concentric to the rotational axis of the hollow shaft 41, an oil lance 55 of the electric machine penetrates the cavity 42 of the hollow shaft 41 from the right side. The oil lance 55 is rigidly connected to a stator (fixed to the stator) and serves to cool the circuit board 49 and the transformer assembly 44. The oil lance 55 carries cooling oil and introduces it into the hollow shaft 41. The oil lance 55's task is to transport the cooling oil near the rotational axis into the area of ​​the transformer assembly 44. For this purpose, the oil lance 55 overlaps the circuit board 49 in the axial direction.

[0101] In some embodiments, it is necessary to arrange the oil lance 55 centrally, e.g., coaxially to the axis of rotation. Oil introduced into a radially outer region of the cavity 42 in the hollow shaft 41 can, in some cases, no longer reach components in a more inner region of the cavity 42 due to the centrifugal force to which it may be subject in the rotating shaft 41. In some embodiments, completely filling the hollow shaft 41 with oil is to be avoided due to increased drag losses. Fig. 5 shows an embodiment of an arrangement of the circuit board 48 and the oil lance 55 in the hollow shaft 41. The circuit board 48 is arranged eccentrically in the hollow shaft 41 and has a predefined distance x from the axis of rotation of the hollow shaft 41.

[0102] The oil lance 55 is arranged in the hollow shaft 41 along the axis of rotation of the hollow shaft radially further inward than the circuit board 48 and concentrically to the axis of rotation of the hollow shaft 41.

[0103] Thus, the circuit board 48 also has a distance (which is based on the predefined distance x) from the oil lance 55, so that the circuit board 48 orbits the oil lance 55 during operation of the electric machine without touching it.

[0104] The arrangement shown in Fig. 5 resolves a space conflict between the oil lance 55 and the rectifier assembly 45 by arranging the printed circuit board 49, which includes, among other things, the rectifier circuit 50, eccentrically in the hollow shaft 41.

[0105] Fig. 6 shows an embodiment of the rotor 40 from Fig. 5 with the circuit board 49 and a plugged-on air-core coil 56. The air-core coil 56 is plugged onto the star-shaped laminated core 43, as described with reference to Fig. 2. The air-core coil 56 is an example of a rotor winding. The air-core coil 56 has a contact element 57 that penetrates through the recess 54 into the cavity 42 and contacts the plug-in contact 53.

[0106] The plug contact 53 is arranged on the printed circuit board 49 on an output side of the circuits 50 and 51 in an axial region of a winding head of the rotor winding and is closed in the radial direction. In the rotor concept considered here, the rotor winding comprises several individual air-core coils 56 (as described with reference to Fig. 2), which are plugged radially from the outside onto the star-shaped rotor core 43. When plugging in two opposing coils 56, each of which has a corresponding contact element 57 (blade) at one end of its winding, contact is thus simultaneously established between the coils 56 and an output of a secondary electronics unit (secondary coil 47) of the transformer assembly 44.

[0107] Fig. 7 shows an embodiment of a rotor 60 with two circuit boards 61a and 61b. Apart from the differences described below, the rotor 60 has the features of the rotor 40 from Figs. 4 to 6. The rotor 60 is designed as a rotor for an electrical machine (e.g., for the electrical machine 2 from Fig. 1) that is configured as a separately excited synchronous machine. The rotor 60 is an example of the rotor 10 from Fig. 2. The circuit boards 61a and 61b are examples of electronics carriers.

[0108] The rotor 60 has a first circuit board 61a for rectifying the excitation current and a second circuit board 61b for rectifying the excitation current. The first circuit board 61a and the second circuit board 61a are arranged in the hollow shaft 41 along the rotational axis of the hollow shaft 41 and are spaced a predefined distance from the rotational axis. The first circuit board 61a and the second circuit board 61b are arranged on radially opposite sides of the rotational axis.

[0109] The first circuit board 61a comprises a first power diode 62a, a first additional circuit 63a, a plug contact 64a, and a plug contact 65a. The plug contact 64a is designed similarly to the plug contact 52 from Figs. 4 and 6 and provides an electrical connection between the first circuit board 61a and the intermediate contact element 48 (and thus the secondary coil 47) so that the first circuit board 61a can receive the excitation current from the secondary coil 47. The first power diode 62a rectifies the excitation current. The first additional circuit 63a is designed similarly to the additional circuit 51 from Figs. 4 and 6. The plug contact 65a is designed similarly to the plug contact 52 from Figs. 4 and 6 and serves to transmit the excitation current rectified by the first power diode 62a to a first rotor winding 66a. The first rotor winding 66a is plugged onto the star-shaped laminated core 43, as shown in Fig.2, and comprises a contact element 67a, which contacts the plug contact 65a through the recess 54. The second circuit board 61b comprises a second power diode 62b, a second additional circuit 63b, a plug contact 64b, and a plug contact 65b. The plug contact 64b is configured similarly to the plug contact 52 from FIGS. 4 and 6 and provides an electrical connection between the second circuit board 61b and the intermediate contact element 48 (and thus the secondary coil 47), so that the second circuit board 61b can receive the excitation current from the secondary coil 47. The second power diode 62b rectifies the excitation current. The second additional circuit 63b is designed similarly to the additional circuit 51 from Fig. 4 and 6. The plug contact 65b is designed similarly to the plug contact 52 from Fig. 4 and 6 and serves to transmit the excitation current rectified by the second power diode 62b to a second rotor winding 66b.The second rotor winding 66b is plugged onto the star-shaped laminated core 43, as shown in Fig. 2, and comprises a contact element 67b, which contacts the plug contact 65b through the recess 54.

[0110] The first circuit board 61a has the first rectifier diode 62a for supplying the first rotor winding 66a with a positive half-wave of the excitation current, and the second circuit board 61b has the second rectifier diode 62b for supplying the second rotor winding 66b with a negative half-wave of the excitation current.

[0111] The embodiment of Fig. 7 represents an expansion option for an eccentric circuit board arrangement, wherein several circuit boards 61a and 61b are arranged eccentrically around the oil lance 55. In some embodiments, this increases the available area for electronic circuits and components.

[0112] To interconnect the circuit boards 61a and 61b, appropriate additional conductors and plug contacts can be provided on the intermediate contact element 48. Separate "board-to-board" connectors according to the state of the art are also possible.

[0113] Fig. 7 shows a division into two opposing circuit boards 61a and 61b, with each circuit board 61a and 61b contacting and supplying power to one half of the rotor windings 66a and 66b (circuit board 61a contacts the first rotor winding 66a, and circuit board 61b contacts the second rotor winding 66b). Fig. 7 shows a circuit in which each of the two circuit boards 61a and 61b carries only one rectifier diode 62a and 62b, respectively. This can halve the required number of power diodes compared to a conventional bridge circuit with four diodes.

[0114] With the rotor concept presented here, dividing the rotor windings into two groups can be easily achieved, since the rotor windings are already composed of individually prefabricated air-core coils (see Fig. 2), which only need to be connected accordingly. The first circuit board 61a, with its single diode 62a, can then only pass a positive half-wave of the transmitted alternating voltage (the excitation current) to a coil group contacted with it, and the second circuit board 61b can only supply a negative half-wave to a coil group contacted with it.

[0115] Fig. 8 shows an embodiment of a rectifier circuit 70 with four rectifier diodes. The rectifier circuit 70 can be implemented, for example, in the rotor 40 shown in Figs. 4 and 6.

[0116] The rectifier circuit 70 comprises a secondary coil 71 (e.g., the secondary coil 47 of Figs. 4 and 6), four rectifier diodes 72, 73, 74 and 75 (e.g., the rectifier assembly 44 of Figs. 4 and 6) and a rotor winding 76 (e.g., the rotor winding 56 of Fig. 6).

[0117] The rectifier circuit 70 represents a bridge rectifier and supplies the rotor winding 76 with rectified excitation current, regardless of the direction of flow of the excitation current in the secondary coil 71. In some cases, the rectifier circuit 70 also includes an additional circuit (e.g., the additional circuit 51) at a suitable location. Fig. 9 shows an embodiment of a rectifier circuit 80 with two rectifier diodes. The rectifier circuit 80 can be implemented, for example, in the rotor 60 of Fig. 7.

[0118] The rectifier circuit 80 comprises a secondary coil 81 (e.g., the secondary coil 47 from Fig. 7), two rectifier diodes 82 and 83 (e.g., the rectifier diodes 62a and 62b from Fig. 7), and a rotor winding 84 (e.g., the first rotor winding 66a and / or the second rotor winding 66b from Fig. 7). The secondary coil 81 comprises two series-connected windings 81a and 81b. The two rectifier diodes 82 and 83 each connect one end of the secondary coil 81 to a first end of the rotor winding 84. A center tap 85 connects a second end of the rotor winding 84 to a center of the secondary coil 81, where the two windings 81a and 81b are connected to one another.

[0119] The rectifier circuit 80 represents a center-point rectifier and supplies the rotor winding 84 with rectified excitation current, regardless of the direction of flow of the excitation current in the secondary coil 81. In some embodiments, the center tap 85 is also implemented by two lines, each connecting the second end of the rotor winding 84 to one of the two windings 81a and 81b. In some cases, the rectifier circuit 80 also includes an additional circuit (e.g., the additional circuit 63a and / or 63b) at a suitable location.

[0120] The rectifier circuit 80 comprises two fewer rectifier diodes than the rectifier circuit 70 of Fig. 8. Thus, in the case of the rectifier circuit 80, more space can be available for each rectifier diode so that, for example, air and creepage distances can be increased and / or heat dissipation can be facilitated.

[0121] Fig. 10 shows an embodiment of a method 90 for manufacturing a rotor. The method 90 can be used, for example, in the assembly of the rotor 10 of Fig. 2, the rotor 40 of Figs. 4 to 6, and / or the rotor 60 of Fig. 7.

[0122] The method 90 comprises inserting 91 an electronics carrier (e.g. the circuit board 49 from Fig. 4 to 6 and / or the circuit board(s) 61 a and / or 61 b ​​from Fig. 7) in the axial direction into a hollow shaft of the rotor (e.g. the hollow shaft 11 from Fig. 2 and / or the hollow shaft 41 from Fig. 4 to 7).

[0123] The method 90 further comprises inserting 92 a secondary coil (e.g., the secondary coil 47 of Fig. 4, 6 or 7) for inductively receiving an excitation current in the axial direction into the hollow shaft.

[0124] The electronics carrier and the secondary coil are electrically connected to one another by a plug connection 93 when the electronics carrier is inserted 91 and when the secondary coil is inserted 92.

[0125] The method 90 is not limited to a specific sequence. In some embodiments, the electronics carrier is inserted 91 first, followed by the secondary coil is inserted 92. In some embodiments, the secondary coil is inserted 92 first, followed by the electronics carrier 91. In some embodiments, the electronics carrier is inserted 91 and the secondary coil is inserted 92 simultaneously.

[0126] In some embodiments, the electronics carrier and the secondary coil are electrically connected to one another by the plug connection 93 during insertion 92 of the secondary coil, but not during insertion 91 of the electronics carrier. In some embodiments, the electronics carrier and the secondary coil are electrically connected to one another by the plug connection 93 during insertion 91 of the electronics carrier, but not during insertion 92 of the secondary coil. In some embodiments, the electronics carrier and the secondary coil are electrically connected to one another both during insertion 91 of the electronics carrier and during insertion 92 of the secondary coil (e.g., when the electronics carrier and the secondary coil are inserted simultaneously).

[0127] The secondary coil may be installed into a transformer assembly (e.g., transformer assembly 44 of Fig. 4) prior to insertion 92 and inserted together with the transformer assembly during insertion 92. The transformer assembly may include a secondary ferrite, an intermediate contact element (e.g., intermediate contact element 48 of Fig. 4, 6, or 7), and / or a primary ferrite and a primary coil.

[0128] Some embodiments relate to a rotor for an electric machine. The rotor comprises a hollow shaft and an electronics carrier arranged in a hollow space of the hollow shaft along a rotational axis of the hollow shaft. The electronics carrier is fixed transversely to the rotational axis of the hollow shaft by means of a positive connection.

[0129] The rotor can be configured as described above and can include features described above for the rotor, the electric machine, the hollow shaft, and / or the electronics carrier. Examples of the rotor include rotor 10 from Fig. 2, rotor 40 from Figs. 4 to 6, and rotor 60 from Fig. 7. The rotor can be configured as a rotor for a separately excited synchronous machine (e.g., for electric machine 2 from Fig. 1).

[0130] Semiconductor components on the electronics carrier (e.g. for a rectifier circuit and / or for an additional circuit) can be arranged on a side of the electronics carrier facing the rotational axis of the hollow shaft and / or on a side facing away from the rotational axis of the hollow shaft.

[0131] The positive connection can limit movement of the electronics carrier in a radial direction relative to the hollow shaft (e.g., toward or away from the rotational axis of the hollow shaft) and / or in a circumferential direction relative to the hollow shaft (e.g., along a rotational angle of the hollow shaft). The electronics carrier can be fixed in such a way that its freedom of movement transverse to the rotational axis can be restricted. For example, movement of the electronics carrier transverse to the rotational axis can be prevented or limited to a negligible extent (e.g., within the scope of manufacturing tolerances).The positive connection can also be designed in such a way that a predefined pressure is exerted on the electronics carrier (for example based on an elasticity of the electronics carrier and / or a spacer), so that the pressure on the electronics carrier prevents movement of the electronics carrier in opposite directions and the electronics carrier can thus be fixed.

[0132] If the rotor comprises more than one electronics carrier (as shown, for example, in Fig. 7 and 11 to 17), then each additional electronics carrier can be fixed in a similar manner transversely to the axis of rotation of the hollow shaft by means of a positive connection.

[0133] In some embodiments, the rotor comprises a plurality of guide points for the positive connection of the electronics carrier, wherein the guide points are formed by elevations on an inner wall of the cavity.

[0134] The guide points can be arranged at one or more predefined axial positions. For example, at the predefined axial position(s), elevations can protrude from the inner wall of the cavity into the cavity. The elevations can form the guide points by having contact surfaces for contacting the electronics carrier at the predefined axial position(s). The elevations can overlap with the electronics carrier in the radial direction to prevent or restrict movement of the electronics carrier transverse to the axis of rotation (e.g., in the radial direction and / or in the circumferential direction).

[0135] The elevations can, for example, be arranged radially further inward than the electronics carrier and touch a side of the electronics carrier facing the rotation axis to prevent or limit movement of the electronics carrier in the direction of the rotation axis. The elevations can, for example, be arranged radially further outward than the electronics carrier and touch a side of the electronics carrier facing away from the rotation axis to prevent or limit movement of the electronics carrier away from the rotation axis.

[0136] In some embodiments, the rotor further comprises a further electronics carrier arranged in the hollow space of the hollow shaft along the rotational axis of the hollow shaft, and a spacer. The electronics carrier and the further electronics carrier are offset radially outward in different directions from the rotational axis of the hollow shaft, and the spacer is arranged between the electronics carrier and the further electronics carrier and is configured to press the electronics carrier and the further electronics carrier against the guide points.

[0137] The additional electronics carrier can be configured similarly to the electronics carrier and can axially overlap with the electronics carrier. For example, a first axial end of the additional electronics carrier can be arranged at the same axial position on the hollow shaft as a first axial end of the electronics carrier, and a second axial end of the additional electronics carrier can be arranged at the same axial position on the hollow shaft as a second axial end of the electronics carrier.

[0138] The electronics carrier and the additional electronics carrier can be arranged symmetrically to each other. For example, the electronics carrier and the additional electronics carrier can be arranged parallel and symmetrically with respect to the rotational axis. For example, the electronics carrier and the additional electronics carrier can be arranged around the rotational axis in such a way that an imbalance during rotation of the hollow shaft around the rotational axis is prevented or limited to a predefined level.

[0139] The electronics carrier and the further electronics carrier can, for example, be arranged opposite one another with respect to the axis of rotation, as shown in Fig. 7 and 11 to 17. The spacer can press the electronics carrier and the further electronics carrier apart. For example, dimensions of the spacer can be selected such that a thickness of the spacer together with a thickness of the electronics carrier and with a thickness of the further electronics carrier exceeds a distance between guide points for the electronics carrier and guide points for the further electronics carrier (before installation of the spacer in the hollow shaft) by a predefined amount, so that the spacer presses the electronics carrier and the further electronics carrier apart (after installation of the spacer in the hollow shaft) and thus presses the electronics carrier and the further electronics carrier against the corresponding guide points.In this case, the elasticity of the spacer, the electronics carrier, the further electronics carrier and / or the guide points can be exploited.

[0140] The rotor can comprise more than two electronics carriers, which can, for example, be arranged regularly around the axis of rotation and / or can be arranged around the axis of rotation in such a way that imbalance during rotation of the hollow shaft around the axis of rotation is prevented or limited to a predefined level. The spacer can be arranged between the electronics carriers and be designed to push the electronics carriers apart (e.g., radially outward) and against corresponding guide points.

[0141] The spacer can be made of plastic and / or metal. For example, the spacer can contain epoxy resin, fiberglass, carbon fiber, thermoset, aluminum, titanium, steel, copper, or the like. However, the spacer is not limited to the materials mentioned and can also be made of other suitable materials.

[0142] The rotor may also have a plurality of spacers, which may, for example, be arranged at a plurality of axial positions.

[0143] In some embodiments, the spacer is configured as a heat sink for cooling the electronics carrier and / or the further electronics carrier. For example, the spacer may contain a material that has high thermal conductivity, e.g., copper, aluminum, and / or silver. A side of the spacer facing the electronics carrier or the further electronics carrier may directly abut the (further) electronics carrier and / or semiconductor components arranged thereon (e.g., power diodes), such that heat can be transferred from the (further) electronics carrier and / or from the semiconductor components to the spacer. A thermally conductive agent may be applied to the spacer between the spacer and the (further) electronics carrier or the semiconductor components for improved heat transfer.

[0144] A surface of the spacer that is not in contact with the (further) electronics carrier and / or semiconductor components arranged thereon can have a surface structure that supports heat transfer from the spacer to a cooling medium (e.g., ambient air and / or cooling oil). For example, the surface can be roughened and / or have fins, grooves, waves, scales, teeth, pins, or the like, so that a contact area with the cooling medium can be enlarged.

[0145] By designing the spacer as a heat sink, heat dissipation from the (other) electronics carrier (e.g. from a rectifier circuit and / or power diodes) can be improved and the risk of overheating can be reduced.

[0146] In some embodiments, the spacer has an opening for an axial cooling oil guide.

[0147] The opening can, for example, be arranged around the axis of rotation. A size (e.g., diameter, clear width) of the opening can be selected such that an oil lance can penetrate axially through the opening. A boundary of the opening can have a safety distance from the oil lance so that contact between the spacer and the oil lance can be prevented during rotation of the hollow shaft. In some embodiments, the plurality of guide points comprise inner guide points designed to limit an inward radial movement of the electronics carrier, and the plurality of guide points comprise outer guide points designed to limit an outward radial movement of the electronics carrier. The inner guide points are arranged at a different axial position in the hollow shaft than the outer guide points.

[0148] For example, the inner guide points may be arranged at a first and a second axial position in the hollow shaft, and the outer guide points may be arranged at a third axial position in the hollow shaft, wherein the third axial position may be between the first and the second axial position. The first, second, and third axial positions may be distributed evenly or in another suitable manner over a length (in the axial direction) of the electronics carrier. Alternatively, the outer guide points may be arranged at the first and the second axial position instead of the third axial position, and the inner guide points may be arranged at the third axial position instead of the first and the second axial position.

[0149] This allows the guide points to limit radial movement of the electronics carrier both inwards and outwards.

[0150] The inner and outer guide points can each be located on both circumferentially opposite sides of the electronics carrier. Thus, the guide points can also prevent or limit tilting of the electronics carrier and / or movement of the electronics carrier in the circumferential direction.

[0151] In some embodiments, the electronics carrier is attached to at least one of the guide points with a fastening means.

[0152] The fastening means may, for example, comprise a screw, a rivet, a dowel, a bolt, or the like. The fastening means may (at least partially) penetrate the electronics carrier and / or the guide point. The fastening means may prevent the electronics carrier from moving through positive locking and / or frictional locking. For example, the fastening means may limit or prevent movement of the electronics carrier in the radial direction, the circumferential direction, and the axial direction.

[0153] The fastener can be inserted from outside the hollow shaft (for example, through a designated opening in the hollow shaft). For example, the hollow shaft can have a hole for a screw, rivet, or the like.

[0154] The electronics carrier can, for example, be attached to several guide points, each with a fastening device.

[0155] In some embodiments, the positive connection of the electronics carrier is based on a diametrical curvature of an inner wall of the cavity.

[0156] For example, the electronics carrier can be fixed (restricted in its freedom of movement) in the circumferential direction and / or in the radial direction outward by the inner wall of the cavity. The inner wall can be curved, whereby a radius of curvature of the inner wall can correspond to a distance of the inner wall from the rotational axis of the hollow shaft.

[0157] For example, the electronics carrier can be fixed radially inward by guide points, and radially outward and circumferentially by the diametrical curvature of the inner wall. This allows a positive connection of the electronics carrier to be achieved even if guide points are only arranged radially inside the electronics carrier.

[0158] One side of the electronics carrier in the circumferential direction can be rounded according to the radius of curvature of the inner wall (e.g., with a radius of curvature that corresponds to the radius of curvature of the inner wall), so that the side of the electronics carrier can come into contact with the inner wall. In some embodiments, the positive connection of the electronics carrier is based on a groove for receiving an axial end of the electronics carrier.

[0159] The groove can, for example, be arranged in a side part of the hollow shaft, which can close the hollow shaft in the axial direction and which can be tapered.

[0160] The groove can, for example, be arranged on a side of a transformer assembly (e.g. an intermediate contact element) of the rotor facing the electronics carrier, wherein the transformer assembly can be arranged in the cavity of the hollow shaft.

[0161] The groove can be arranged and designed so that the electronics carrier can be inserted (e.g., plugged) into the groove in the axial direction and that the groove can accommodate the electronics carrier (at least partially). The height of the groove can correspond to the thickness of the electronics carrier.

[0162] The groove can prevent or limit movement of the electronics carrier in the radial and circumferential directions. Furthermore, the groove can prevent or limit movement of the electronics carrier in the axial direction (in the direction of the groove, e.g., toward the transformer assembly).

[0163] In some embodiments, the electronics carrier has a plug contact for electrically contacting the electronics carrier, and the plug contact is designed to limit an axial movement of the electronics carrier.

[0164] The plug contact can be inserted into a corresponding plug contact of a transformer assembly (e.g., a secondary coil and / or an intermediate contact element) to establish a plug connection for electrically contacting the electronics carrier, allowing the electronics carrier to receive excitation current from the secondary coil. The plug connection can be established by inserting the plug contact in the axial direction and can, for example, prevent or limit movement of the electronics carrier toward the transformer assembly.

[0165] The plug contact can be designed to accommodate a corresponding contact element of a rotor winding, so that a rectified excitation current can flow from the electronics carrier via the plug contact into the rotor winding. The contact element can, for example, be plugged onto the plug contact from outside the hollow shaft through a recess in the hollow shaft, as described with reference to Fig. 6. A plugging direction of the contact element into the plug contact can, for example, be oriented perpendicular to the rotational axis of the hollow shaft or can have a component perpendicular to the rotational axis. Thus, a plug connection between the plug contact and the contact element can prevent and / or limit axial movement of the electronics carrier.

[0166] In some embodiments, a portion of the cavity is cast between an inner wall of the cavity and a side of the electronics carrier facing away from the axis of rotation of the hollow shaft.

[0167] The cavity section can be filled with synthetic resin, epoxy, polyester, polyurethane, silicone, or similar materials. Contact elements (e.g., plug contacts) for electrically connecting the electronics carrier (e.g., to a transformer assembly and / or a rotor winding) can be left out during the filling process, leaving the plug contacts accessible for contacting. Alternatively, the filling process can be performed after the plug contacts have been contacted, allowing the corresponding plug connections to be secured by the filling process.

[0168] By casting, a material bond can be created between the electronics carrier and the hollow shaft. In this way, movement of the electronics carrier in the radial, circumferential, and / or axial directions can be prevented or limited. In some embodiments, an inner wall of the hollow shaft cavity is formed by a sleeve that is inserted into the hollow shaft.

[0169] The sleeve can be made of plastic and / or metal. For example, the sleeve can contain epoxy resin, fiberglass, carbon fiber, thermosets, aluminum, titanium, steel, copper, or the like.

[0170] The sleeve can be inserted axially into the cavity. For example, the electronics carrier can be inserted into the sleeve (e.g., inserted, pushed, placed, etc.) before the sleeve is inserted into the cavity.

[0171] The sleeve can be positioned in the hollow shaft using pins. The sleeve can be pressed axially against a (e.g., continuous) shoulder on the inner wall of the hollow shaft. The sleeve can be held in the hollow shaft at a predefined angle using a tongue and groove system. The sleeve can be secured in the hollow shaft with one or more locking screws. A specialist can find other ways to position and / or secure the sleeve in the hollow shaft.

[0172] The sleeve can be designed as a single part. For example, the sleeve can be open at at least one axial end, and the electronics carrier can be inserted axially through the open end into the sleeve. The sleeve can also be designed to be assembled from multiple parts. For example, the electronics carrier can be inserted, pushed, and / or placed into one part of the sleeve, and another part of the sleeve can be attached to one part of the sleeve such that the electronics carrier is fixed in the sleeve.

[0173] The sleeve may have guide points on an inner side.

[0174] Some embodiments relate to an electric machine. The electric machine comprises the rotor described above and an oil lance for guiding the cooling oil. The oil lance is arranged radially further inward in the hollow shaft along the axis of rotation of the hollow shaft than the electronics carrier. The electric machine and the oil lance can be designed as described above. For example, the electric machine can be designed as described for the electric machine 2 in Fig. 1. For example, the electric machine can be designed as a separately excited synchronous machine. For example, the oil lance can introduce cooling oil for cooling the electronics carrier and / or a transformer assembly of the rotor into the cavity of the hollow shaft.

[0175] The rotor can be configured as described above. The electronics carrier can be arranged and fixed in the hollow shaft cavity in one of the ways described herein. Each feature described above for the rotor can represent a corresponding feature of the electric machine.

[0176] Some embodiments relate to a motor vehicle comprising the electric machine described above. The electric machine is configured to provide traction torque to the motor vehicle.

[0177] The motor vehicle can be designed as described for motor vehicle 1 in Fig. 1. The motor vehicle can include the electric machine and / or the rotor described above. Each feature described above for the rotor and / or for the electric machine can represent a corresponding feature of the motor vehicle.

[0178] Fig. 11 shows an embodiment of a positive connection of printed circuit boards 101 and 102 between guide points 103 and a diametrical curvature of an inner wall of a hollow shaft 100. The hollow shaft 100 is an example of a hollow shaft of a rotor (for example for the hollow shaft 41 of the rotor 60 from Fig. 7) of an electrical machine (for example the electrical machine 2 from Fig. 1).

[0179] A of Fig. 11 shows the hollow shaft 100 in an axial view, and B of Fig. 11 shows a section through the hollow shaft 100 in the radial direction. The circuit boards 101 and 102 are arranged in a cavity of the hollow shaft 100 along a rotational axis of the hollow shaft 100. The circuit boards 101 and 102 are examples of electronics carriers and of the circuit boards 61a and 61b from Fig. 7.

[0180] The circuit boards 101 and 102 are fixed by guide points 103 and a diametrical curvature of an inner wall of the cavity of the hollow shaft 100 by means of a positive connection transverse to a rotational axis of the hollow shaft 100. Thus, the positive connection of the electronics carriers 101 and 102 is based on the diametrical curvature of the inner wall of the cavity in the hollow shaft 100. The guide points 103 are formed by elevations 103 on the inner wall of the hollow shaft 100.

[0181] Sides of the electronics carriers 101 and 102 in the circumferential direction are rounded according to a radius of curvature of the inner wall of the hollow shaft 100, so that the sides of the electronics carriers 101 and 102 can come into contact with the inner wall in a flat manner.

[0182] The circuit boards 101 and 102 can be designed as FR4 circuit boards or as IMS circuit boards. The circuit boards 101 and 102 include an interposer terminal 104 and 105, respectively (examples of the plug contacts 64a and 64b from Fig. 7) for electrically contacting the circuit boards 101 and 102 with an interposer board (e.g., the interposer contact element 48 from Fig. 7) for receiving an excitation current. The circuit boards 101 and 102 also have rectifier diodes 106 and 107 for rectifying the excitation current and an additional circuit 108 and 109 (e.g., the additional circuit 63a and 63b from Fig. 7) comprising TVS diodes. Furthermore, the circuit boards 101 and 102 have plug contacts 110 and 111 (examples of the plug contacts 65a and 65b from Fig. 7) for electrically contacting the circuit boards 101 and 102 with rotor windings for transmitting a rectified excitation current to the rotor windings.The plug contacts 104, 105, 110 and 111 are further designed to limit axial movement of the circuit boards 101 and 102.

[0183] The circuit boards 101 and 102 are pushed directly axially into the hollow shaft 100 of the rotor. In some embodiments, the circuit boards 101 and 102 are pushed into a plastic sleeve arranged radially between the circuit boards 101 and 102 and the hollow shaft 100, with the guide points 103 protruding from the plastic sleeve into the cavity of the hollow shaft 100.

[0184] The circuit boards 101 and 102 are captured and held radially inward by the guide points 103 (on the inner wall of the hollow shaft 100 or a plastic sleeve) and radially outward by the diametrical curvature. The axial fixation of the circuit boards 101 and 102 is achieved by connecting plugs (plug contacts 104 and 105 to the intermediate board and plug contacts 110 and 111 to the rotor winding).

[0185] The rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 can be arranged radially inward and / or radially outward on the circuit boards 101 and 102. If the rectifier diodes 106 and 107 and / or the TVS diodes of the additional circuit 108 and 109 are arranged radially inward on the circuit boards 101 and 102, then the circuit boards 101 and 102 can, in some embodiments, be arranged radially further outward (with less distance from the inner wall of the hollow shaft 120 and with more distance from the oil lance), and the diodes arranged inward can be more easily accessible for cooling with cooling oil from the oil lance. In addition, the circuit boards 101 and 102 can then withstand higher rotational speeds of the hollow shaft 100 because the diodes arranged inside can be pressed onto the circuit boards 101 and 102 by a centrifugal force instead of being lifted off the circuit boards 101 and 102.If, however, the rectifier diodes 106 and 107 and / or the TVS diodes of the additional circuit 108 and 109 are arranged radially outward on the circuit boards 101 and 102, then the circuit boards 101 and 102 can, in some embodiments, be arranged radially further inward (with greater distance from the inner wall of the hollow shaft 120 and with less distance from the oil lance), and a surface of the circuit boards 101 and 102 can be more easily accessible for cooling with cooling oil from the oil lance (particularly if the circuit boards 101 and 102 are designed as IMS circuit boards). Fig. 12 shows an embodiment of a positive connection of circuit boards 121 and 122 between guide points 123 and 124. The guide points 123 and 124 are arranged on an inner wall of a hollow shaft 120. The hollow shaft 120 is an example of a hollow shaft of a rotor (for example, the hollow shaft 41 of the rotor 60 from Fig.7) an electrical machine (for example the electrical machine 2 from Fig. 1 ).

[0186] A of Fig. 12 shows the hollow shaft 120 in an axial view, and B of Fig. 12 shows a section through the hollow shaft 120 in the radial direction. The circuit boards 121 and 122 are arranged in a cavity of the hollow shaft 120 along a rotational axis of the hollow shaft 120. The circuit boards 121 and 122 are examples of electronics carriers and of the circuit boards 61a and 61b from Fig. 7.

[0187] The circuit boards 121 and 122 are fixed by inner guide points 123 and outer guide points 124. The inner guide points 123 limit inward radial movement of the circuit boards 121 and 122, and the outer guide points 124 limit outward radial movement of the circuit boards 121 and 122. The inner guide points 123 are arranged at a different axial position in the hollow shaft 120 than the outer guide points 124. In this way, the circuit boards 121 and 122 are fixed by means of a positive connection transverse to a rotational axis of the hollow shaft 120. The guide points 123 and 124 are formed by elevations 123 and 124 on an inner wall of the hollow shaft 120. The inner wall of the cavity of the hollow shaft 120 is formed by a plastic sleeve 125 that is inserted into the hollow shaft 120. The guide points 123 and 124 protrude from the plastic sleeve 125 into the cavity of the hollow shaft 120.

[0188] As described for circuit boards 101 and 102 in Fig. 11, circuit boards 121 and 122 can be designed as FR4 circuit boards or as IMS circuit boards. Circuit boards 121 and 122 include inter-board terminals 104 and 105, respectively, rectifier diodes 106 and 107, auxiliary circuits 108 and 109, and plug-in contacts 110 and 111. Plug-in contacts 104, 105, 110, and 111 are further configured to limit axial movement of circuit boards 121 and 122.

[0189] The circuit boards 121 and 122 are pushed into the plastic sleeve 125, which is arranged radially between the circuit boards 121 and 122 and the hollow shaft 120. In some embodiments, the circuit boards 121 and 122 are pushed directly axially into the hollow shaft 120 of the rotor, with the guide points 123 and 124 protruding from the hollow shaft 120 into the cavity of the hollow shaft 120.

[0190] The circuit boards 121 and 122 are fixed radially inward by the inner guide points 123 and radially outward by the outer guide points 124 (on an inner wall of the hollow shaft 120 or the plastic sleeve 125). The axial fixation of the circuit boards 121 and 122 is achieved by connecting plugs (plug contacts 104 and 105 to the intermediate board and plug contacts 110 and 111 to the rotor winding).

[0191] The rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 can be arranged radially inward and / or radially outward on the circuit boards 121 and 122, as described for the circuit boards 101 and 102 in Fig. 11.

[0192] Fig. 13 shows an embodiment of a positive connection of printed circuit boards 131 and 132 between guide points 133 with a heat sink as a spacer 134. The guide points 133 are arranged on an inner wall of a hollow shaft 130. The hollow shaft 130 is an example of a hollow shaft of a rotor (for example, for the hollow shaft 41 of the rotor 60 from Fig. 7) of an electrical machine (for example, the electrical machine 2 from Fig. 1).

[0193] A of Fig. 13 shows the hollow shaft 130 in an axial view, and B of Fig. 13 shows a section through the hollow shaft 130 in the radial direction. The circuit boards 131 and 132 are arranged in a cavity of the hollow shaft 130 along a rotational axis of the hollow shaft 130. The circuit boards 131 and 132 are examples of electronics carriers and of the circuit boards 61a and 61b from Fig. 7. The circuit boards 131 and 132 are fixed by guide points 133, which limit any radially outward movement of the circuit boards 131 and 132. The guide points 133 are formed by elevations 133 on an inner wall of the hollow shaft 130. The hollow shaft 130 further comprises a spacer 134, which is designed as a heat sink 134 for cooling the circuit boards 131 and 132. The circuit boards 131 and 132 are offset radially outward in different (in this case opposite) directions from the axis of rotation of the hollow shaft 130.The spacer 134 is arranged between the circuit boards 131 and 132 and presses the circuit boards 131 and 132 against the guide points 133. In this way, the circuit boards 131 and 132 are fixed by means of a positive connection transverse to a rotation axis of the hollow shaft 130.

[0194] The spacer 134 has an opening 135 for an axial cooling oil guide, for example for the oil lance 55 from Fig. 7. The opening 135 is designed as a bore. However, the opening 135 is not limited to a bore and, in some embodiments, is implemented in a manner other than drilling (e.g., by milling, by laser cutting, by casting into a corresponding mold, and / or by assembling from correspondingly shaped parts). The spacer 134 is made of aluminum. However, the spacer 134 is not limited to aluminum and, in some embodiments, is made of a different material. In some cases, the spacer 134 is designed as a plastic body (e.g., when a cooling effect of the spacer 134 is not required).

[0195] As described for circuit boards 101 and 102 in Fig. 11 and for circuit boards 121 and 122 in Fig. 12, circuit boards 131 and 132 can be designed as FR4 circuit boards or as IMS circuit boards. Circuit boards 131 and 132 have inter-board terminals 104 and 105, respectively, rectifier diodes 106 and 107, auxiliary circuits 108 and 109, and plug-in contacts 110 and 111. Plug-in contacts 104, 105, 110, and 111 are further configured to limit axial movement of circuit boards 131 and 132. Circuit boards 131 and 132 are pushed directly axially into hollow shaft 130 of the rotor. In some embodiments, the circuit boards 131 and 132 are pushed into a plastic sleeve which is arranged radially between the circuit boards 131 and 132 and the hollow shaft 130, wherein the guide points 133 protrude from the plastic sleeve into the cavity of the hollow shaft 130.

[0196] The circuit boards 131 and 132 are fixed radially outward by the guide points 133 (on an inner wall of the hollow shaft 130 or a plastic sleeve) and radially inward by the spacer 134. For this purpose, an aluminum heat sink 134 or a plastic body with an oversize (relative to the distance between the circuit boards 131 and 132) is placed between the circuit boards 131 and 132. The circuit boards 131 and 132 are held radially outward by the guide points 133. In some embodiments, this oversize ensures secure radial engagement. The plastic body / aluminum heat sink 134 also has a bore 135 for conducting cooling oil.

[0197] The axial fixation of the circuit boards 131 and 132 is achieved by connecting plugs (plug contacts 104 and 105 to the intermediate board and plug contacts 110 and 111 to the rotor winding).

[0198] The rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 can be arranged radially inward and / or radially outward on the circuit boards 131 and 132, as described for the circuit boards 101 and 102 in Fig. 11.

[0199] Fig. 14 shows an embodiment of a positive connection of printed circuit boards 141 and 142 between guide points 143 with spacers 144. The guide points 143 are arranged on an inner wall of a hollow shaft 140. The hollow shaft 140 is an example of a hollow shaft of a rotor (for example, for the hollow shaft 41 of the rotor 60 from Fig. 7) of an electrical machine (for example, the electrical machine 2 from Fig. 1). A of Fig. 14 shows the hollow shaft 140 in an axial view, and B of Fig. 14 shows a section through the hollow shaft 140 in the radial direction. C of Fig. 14 shows the printed circuit boards 141 and 142 with the spacers 144 in a perspective view. D of Fig. 14 shows the hollow shaft 140 with the circuit board 141 in a rotor 146, and E of Fig. 14 shows the rotor 146 in perspective. The circuit boards 141 and 142 are arranged in a cavity of the hollow shaft 140 along a rotational axis of the hollow shaft 140.The circuit boards 141 and 142 are examples of electronics carriers and of the circuit boards 61a and 61b from Fig. 7. The rotor 146 is an example of the rotor 60 from Fig. 7.

[0200] The circuit boards 141 and 142 are fixed by guide points 143, which limit radially outward movement of the circuit boards 141 and 142. The guide points 143 are formed by elevations 143 on an inner wall of the hollow shaft 140. The hollow shaft 140 further comprises two spacers 144. The circuit boards 141 and 142 are offset radially outward in different directions from the rotational axis of the hollow shaft 140. The spacers 144 are arranged between the circuit boards 141 and 142 and press the circuit boards 141 and 142 against the guide points 143. In this way, the circuit boards 141 and 142 are fixed by means of a positive connection transverse to a rotational axis of the hollow shaft 140.

[0201] The spacers 144 have an opening 145 for axial cooling oil guidance, for example, for the oil lance 55 from Fig. 7. The opening 145 is designed as a bore. However, the opening 145 is not limited to a bore and, in some embodiments, is implemented in a manner other than drilling (e.g., by milling, by laser cutting, by casting into a corresponding mold, and / or by assembling from correspondingly shaped parts). The spacers 144 are made of plastic. However, the spacers 144 are not limited to plastic and, in some embodiments, are made of a different material, e.g., aluminum, titanium, steel, or the like. As described for the circuit boards 101 and 102 of Fig. 11, for the circuit boards 121 and 122 of Fig. 12 and for the circuit boards 131 and 132 of Fig. 13, the circuit boards 141 and 142 can be designed as Fr4 circuit boards or as IMS circuit boards.The circuit boards 141 and 142 have the inter-board connection 104 and 105, respectively, the rectifier diodes 106 and 107, the additional circuit 108 and 109, and the plug contacts 110 and 111. The plug contacts 104, 105, 110, and 111 are further configured to limit axial movement of the circuit boards 141 and 142.

[0202] The circuit boards 141 and 142 are assembled with the spacers 144 to form a rectifier assembly, as shown in C of Fig. 14.

[0203] The circuit boards 141 and 142 (assembled with the spacers 144 to form the rectifier assembly) are pushed directly axially into the hollow shaft 140 of the rotor. In some embodiments, the circuit boards 141 and 142 are pushed into a plastic sleeve arranged radially between the circuit boards 141 and 142 and the hollow shaft 140, with the guide points 143 protruding from the plastic sleeve into the cavity of the hollow shaft 140.

[0204] The circuit boards 141 and 142 are fixed radially outward by the guide points 143 (on an inner wall of the hollow shaft 140 or a plastic sleeve) and radially inward by the spacers 144.

[0205] For this purpose, spacers 144 are placed between circuit boards 141 and 142 with an oversize (relative to the distance between circuit boards 141 and 142). Circuit boards 141 and 142 are held radially outward by guide points 143. In some embodiments, this oversize ensures secure radially outward contact. Spacers 144 also have a bore 135 for guiding the cooling oil.

[0206] The axial fixation of the circuit boards 141 and 142 is achieved by connecting plugs (plug contacts 104 and 105 to the intermediate board and plug contacts 110 and 111 to the rotor winding). In Fig. 14, the rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 are arranged radially inward on the circuit boards 141 and 142. In some embodiments, the rectifier diodes 106 and 107 and / or the TVS diodes of the additional circuit 108 and 109 can also be arranged radially outward on the circuit boards 141 and 142.

[0207] Fig. 15 shows an embodiment of a positive connection of printed circuit boards 151 and 152 between guide points 153 with screws 154. The guide points 153 are arranged on an inner wall of a hollow shaft 150. The hollow shaft 150 is an example of a hollow shaft of a rotor (for example, the hollow shaft 41 of the rotor 60 from Fig. 7) of an electrical machine (for example, the electrical machine 2 from Fig. 1).

[0208] A of Fig. 15 shows the hollow shaft 150 in an axial view, B of Fig. 15 shows the hollow shaft 150 with the circuit boards 151 and 152 in a perspective view, and C of Fig. 15 shows the circuit boards 151 and 152 with the screws 154 in a perspective view. The circuit boards 151 and 152 are arranged in a cavity of the hollow shaft 150 along a rotational axis of the hollow shaft 150. The circuit boards 151 and 152 are examples of electronics carriers and of the circuit boards 61a and 61b from Fig. 7.

[0209] The circuit boards 151 and 152 are fixed by guide points 153, which limit any radially outward movement of the circuit boards 151 and 152. The guide points 153 are formed by elevations 153 on an inner wall of the hollow shaft 150. The circuit boards 151 and 152 are offset radially outward in different directions from the axis of rotation of the hollow shaft 140. The circuit boards 151 and 152 are fastened to the guide points 153 with screws 154. The screws 154 are an example of a fastening means. The screws 154 are screwed from the outside into the circuit boards 151 and 152 through corresponding holes in the hollow shaft 150 and the guide points 153. In this way, the circuit boards 151 and 152 are fixed by means of a positive connection transverse to a rotational axis of the hollow shaft 150. As for the circuit boards 101 and 102 of Fig. 11, for the circuit boards 121 and 122 of Fig. 12, for the circuit boards 131 and 132 of Fig.As described in Figure 13 and for circuit boards 141 and 142 in Figure 14, circuit boards 151 and 152 can be designed as FR4 circuit boards or as IMS circuit boards. Circuit boards 151 and 152 have the interposer terminal 104 and 105, respectively, the rectifier diodes 106 and 107, the additional circuit 108 and 109, and the plug contacts 110 and 111.

[0210] The circuit boards 151 and 152 are pushed directly axially into the hollow shaft 150 of the rotor. In some embodiments, the circuit boards 151 and 152 are pushed into a plastic sleeve arranged radially between the circuit boards 151 and 152 and the hollow shaft 150, with the guide points 153 protruding from the plastic sleeve into the cavity of the hollow shaft 150.

[0211] The circuit boards 151 and 152 are held radially outward by the guide points 153 (on an inner wall of the hollow shaft 150 or a plastic sleeve). The circuit boards 151 and 152 are tightened and fixed radially inward and axially by screwing them with screws 154 to the guide points 153.

[0212] The rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 can be arranged radially inward and / or radially outward on the circuit boards 151 and 152, as described for the circuit boards 101 and 102 of Fig. 11.

[0213] Fig. 16 shows an embodiment of a positive connection of printed circuit boards 161 and 162 by axial fixation with slots 163. The slots 163 are arranged on an inner wall of a hollow shaft 160. The hollow shaft 160 is an example of a hollow shaft of a rotor (for example, for the hollow shaft 41 of the rotor 60 from Fig. 7) of an electrical machine (for example, the electrical machine 2 from Fig. 1).

[0214] A of Fig. 16 shows the hollow shaft 160 in an axial view, B of Fig. 16 shows a section through the hollow shaft 160 in the radial direction, and C of Fig. 16 shows a side part 165 of the hollow shaft 160. The circuit boards 161 and 162 are arranged in a cavity of the hollow shaft 160 along a rotational axis of the hollow shaft 160. The circuit boards 161 and 162 are examples of electronics carriers and of the circuit boards 61a and 61b from Fig. 7.

[0215] The circuit boards 161 and 162 are offset radially outward in different directions from the rotational axis of the hollow shaft 160 and are fixed by slots 163, which limit radially outward, radially inward, and axial movement of the circuit boards 161 and 162. The slots 163 are arranged in plastic bodies 164. The plastic bodies 164 at one axial end of the circuit boards 161 and 162 are arranged on a transformer assembly (exciter system, e.g., the transformer assembly 44 from Fig. 4). The plastic bodies 164 at an axial end of the circuit boards 161 and 162 opposite the transformer assembly are fastened to the hollow shaft 160. The slots 163 are designed to accommodate the circuit boards 161 and 162 in the axial direction.

[0216] In some embodiments, the slots 163 are arranged in the side part 165 of the hollow shaft 160, as shown in C of Fig. 16. The side part 165 is arranged at an axial end of the hollow shaft 160 and is tapered relative to a central part of the hollow shaft 160, in which the circuit boards 161 and 162 are arranged. For example, the slots 163 can be arranged at an axial end of the circuit boards 161 and 162 on the transformer assembly facing the transformer assembly, and the slots 163 can be arranged in the side part 165 at an axial end of the circuit boards 161 and 162 facing away from the transformer assembly.

[0217] Thus, the circuit boards 161 and 162 are positioned and retained in the slots 163 (e.g., on the transformer assembly and / or on the side panel 165). In this way, the circuit boards 161 and 162 are fixed by means of a positive connection transverse to a rotational axis and along the rotational axis of the hollow shaft 160. The slots 163 are examples of a groove. The positive connection of the circuit boards 161 and 162 is thus based on a groove for receiving an axial end of the circuit boards 161 and 162, respectively. As described for the circuit boards 101 and 102 from Fig. 11, for the circuit boards 121 and 122 from Fig. 12, for the circuit boards 131 and 132 from Fig. 13, for the circuit boards 141 and 142 from Fig. 14, and for the circuit boards 151 and 152 from Fig. 15, the circuit boards 161 and 162 can be designed as Fr4 circuit boards or as IMS circuit boards. The circuit boards 161 and 162 have the intermediate board connection 104 and105, the rectifier diodes 106 and 107, the additional circuit 108 and 109 and the plug contacts 110 and 111.

[0218] The circuit boards 161 and 162 are pushed directly axially into the hollow shaft 160 of the rotor (e.g., from an axial end of the hollow shaft 160 opposite the side part 165). In some embodiments, the circuit boards 161 and 162 are pushed into a plastic sleeve arranged radially between the circuit boards 161 and 162 and the hollow shaft 160.

[0219] The rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 can be arranged radially inward and / or radially outward on the circuit boards 161 and 162, as described for the circuit boards 101 and 102 in Fig. 11.

[0220] Fig. 17 shows an embodiment of a positive connection of printed circuit boards 171 and 172 by means of guide points 173 with additional material bonding. The positive connection is based on guide points 173 arranged on an inner wall of a hollow shaft 170. The hollow shaft 170 is an example of a hollow shaft of a rotor (for example, the hollow shaft 41 of the rotor 60 from Fig. 7) of an electrical machine (for example, the electrical machine 2 from Fig. 1).

[0221] A of Fig. 17 shows the hollow shaft 170 in an axial view, and B of Fig. 17 shows a section through the hollow shaft 170 in the radial direction. The printed circuit boards 171 and 172 are arranged in a cavity of the hollow shaft 170 along a rotational axis of the hollow shaft 170. The printed circuit boards 171 and 172 are examples of electronics carriers and of the printed circuit boards 61a and 61b from Fig. 7. The hollow shaft 170 from Fig. 17 corresponds to the hollow shaft 100 from Fig. 11, wherein a section of the cavity of the hollow shaft 170 between the inner wall of the hollow shaft 170 and a side of the printed circuit boards 171 and 172 facing away from the rotational axis of the hollow shaft 170 is filled with epoxy resin 174. The rectifier diodes 106 and 107 as well as the TVS diodes of the additional circuit 108 and 109 are arranged radially outward on the circuit boards 171 and 172 and thus embedded in the epoxy resin 174.The plug contacts 104, 105, 110 and 111 are left out of the epoxy resin 174 so that closing and opening of plug connections on the plug contacts 104, 105, 110 and 111 remains possible even after pouring. The remaining features described for the hollow shaft 100, the circuit boards 101 and 102, the guide points 103, the plug contacts 104 and 105, the rectifier diodes 106 and 107, the additional circuit 108 and 109 and the plug contacts 110 and 111 from Fig. 11 are implemented accordingly in the hollow shaft 170, the circuit boards 171 and 172, the guide points 173, the plug contacts 104 and 105, the rectifier diodes 106 and 107, the additional circuit 108 and 109 and the plug contacts 110 and 111 from Fig. 17.

[0222] The circuit boards 171 and 172 are pushed directly axially into the hollow shaft 170 of the rotor. In some embodiments, the circuit boards 171 and 172 are pushed into a plastic sleeve arranged radially between the circuit boards 171 and 172 and the hollow shaft 170, with the guide points 173 protruding from the plastic sleeve into the cavity of the hollow shaft 170.

[0223] The circuit boards 171 and 172 are supported radially inward by guide points 173 (on the inner wall of the hollow shaft 170 or a plastic sleeve). In the area of ​​the rectifier diodes 106 and 107, as well as the TVS diodes of the additional circuit 108 and 109, the hollow shaft 170 (or sleeve) is cast. Both the diodes 106, 107, 108, and 109, as well as the circuit boards 171 and 172, are thus also secured by a material bond. The connections to the intermediate board and rotor winding are left unfinished. The embodiments of Figs. 4 to 17 can be implemented in an electric machine (e.g., the electric machine 2 from Fig. 1), wherein the electric machine can comprise the rotor from one of Figs. 4 to 17 and an oil lance for guiding the cooling oil, wherein the oil lance can be arranged in the hollow shaft of the rotor along a rotational axis of the hollow shaft radially further inward than the circuit board. The electric machine can be implemented in a motor vehicle (e.g.,The system may be included in the motor vehicle 1 of Fig. 1 and may be configured to provide traction torque to the motor vehicle. The exemplary embodiments of Figs. 4 to 17 may also be combined in a suitable manner.

[0224] In summary, the present disclosure describes various possible arrangements of a printed circuit board within a hollow rotor shaft of a separately excited synchronous machine (SESM) as well as various solutions for positioning and fixing printed circuit boards within a hollow rotor shaft SESM.

[0225] In some embodiments, the circuit board or circuit boards serve to accommodate electronic circuits and components which rectify an alternating current transmitted to the rotor by an inductive rotary transformer and, in particular, smooth or cut off current and voltage peaks.

[0226] Some embodiments are based on a concept of a “built” rotor for a SESM, which has a rotor lamination section with a closed pole head ring.

[0227] Reference symbol

[0228] Motor vehicle electrical machine

[0229] accumulator

[0230] rotor

[0231] rotor shaft

[0232] cavity star-shaped rotor lamination package

[0233] Air coils / rotor winding further, cylindrical laminated core first arrangement

[0234] hollow shaft

[0235] Diodes

[0236] Oil lance second arrangement

[0237] circuit board

[0238] Diodes

[0239] Intermediate contact element third arrangement

[0240] circuit board

[0241] Diodes

[0242] Plug connections

[0243] rotor

[0244] hollow shaft

[0245] cavity star-shaped laminated core

[0246] Transformer assembly

[0247] Rectifier assembly

[0248] primary coil

[0249] secondary coil

[0250] Intermediate contact element

[0251] Printed circuit board Rectifier diode circuit Additional circuit Plug-in contacts Plug-in contact Recess Oil lance Air coil Contact element Rotor a first printed circuit board b second printed circuit board a first power diode b second power diode a Additional circuit b Additional circuit a Plug-in contact b Plug-in contact a Plug-in contact b Plug-in contact a first rotor winding b second rotor winding a Contact element b Contact element Rectifier circuit Secondary coil up to 75 rectifier diodes Rotor winding Rectifier circuit Secondary coil a Winding b Winding and 83 rectifier diodes Rotor winding Center tap

[0252] Proceedings

[0253] Inserting an electronics carrier

[0254] Inserting a secondary coil

[0255] Plug connection

[0256] hollow shaft

[0257] circuit board

[0258] circuit board

[0259] Leadership points

[0260] Intermediate board connection

[0261] Intermediate board connection

[0262] Rectifier diode

[0263] Rectifier diode

[0264] Additional circuit

[0265] Additional circuit

[0266] plug contact

[0267] plug contact

[0268] hollow shaft

[0269] circuit board

[0270] PCB inner guide points outer guide points

[0271] plastic sleeve

[0272] hollow shaft

[0273] circuit board

[0274] circuit board

[0275] Leadership points

[0276] spacers

[0277] opening

[0278] hollow shaft

[0279] circuit board

[0280] circuit board

[0281] Guide points spacer opening rotor

[0282] Hollow shaft PCB PCB guide points Screws Hollow shaft PCB PCB slot Plastic body Side part Hollow shaft PCB PCB guide points Epoxy resin

Claims

Patent claims 1. A rotor for an electrical machine (2), comprising: a hollow shaft (11; 41); and an electronics carrier (49; 61a, 61b) for rectifying an excitation current, wherein the electronics carrier (49; 61a, 61b) is arranged in the hollow shaft (11; 41) along a rotational axis of the hollow shaft (11; 41).

2. Rotor according to claim 1, wherein the electronics carrier (49; 61 a, 61 b) has a predefined distance from the axis of rotation.

3. Rotor according to claim 1 or 2, comprising a further electronics carrier (61 a, 61 b) for rectifying the excitation current; wherein the further electronics carrier (61 a, 61 b) is arranged in the hollow shaft (1 1 ; 41 ) along the axis of rotation and has a predefined distance from the axis of rotation.

4. Rotor according to claim 3, wherein the electronics carrier (61a, 61b) has a first rectifier diode (62a, 62b; 82, 83) for supplying a rotor winding (66a, 66b; 84) with a positive half-wave of the excitation current; and wherein the further electronics carrier (61b, 61a) has a second rectifier diode (62b, 62a; 83, 82) for supplying the rotor winding (66a, 66b; 84) with a negative half-wave of the excitation current.

5. Rotor according to one of the preceding claims, wherein an electrical connection between a secondary coil (47) for inductively receiving the excitation current and the electronics carrier (49; 61 a, 61 b) is designed as a plug connection which can be plugged in the axial direction.

6. Rotor according to claim 5, wherein the plug connection between the secondary coil (47) and the electronics carrier (49; 61 a, 61 b) is blindly pluggable.

7. Rotor according to one of the preceding claims, wherein the electronics carrier (49; 61a, 61b) further comprises a plug-in contact (53; 65a, 65b) for supplying a rotor winding (56; 66a, 66b) with the excitation current; wherein the hollow shaft (41) has a recess (54); and wherein the plug-in contact (53; 65a, 65b) can be inserted from outside the hollow shaft (41) through the recess (54).

8. An electrical machine comprising: the rotor (10; 40; 60) according to any one of the preceding claims; and an oil lance (55) for cooling the electronics carrier (49; 61 a, 61 b); wherein the oil lance (55) is arranged in the hollow shaft (11; 41) along the rotational axis of the hollow shaft radially further inward than the electronics carrier (49; 61 a, 61 b).

9. Motor vehicle comprising the electric machine (2) according to claim 8, wherein the electric machine (2) is configured to provide a traction torque of the motor vehicle (1).

10. A method for manufacturing the rotor (10; 40, 60) according to any one of claims 1 to 7, comprising: Inserting (91) the electronics carrier (49; 61 a, 61 b) in the axial direction into the hollow shaft (11; 41); and Inserting (92) a secondary coil (47) for inductively receiving the excitation current in the axial direction into the hollow shaft (11; 41); wherein the electronics carrier (49; 61a, 61b) and the secondary coil (47) are electrically connected to one another by a plug connection (93) upon insertion of the electronics carrier (49; 61a, 61b) and / or the secondary coil (47).

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