Rotor and motor

Abstract

The invention relates to an electric machine (1), in particular for use in a drive train of a hybrid or all-electric motor vehicle. The machine comprises a stator (2) and a rotor (4) spaced apart from the stator (2) by an air gap (3) wherein the rotor (4) comprises at least one first rotor body (5) with a first set of permanent magnets (6) and a second rotor body (7) with a second set of permanent magnets (8), wherein: the first rotor body (5) and the second rotor body (7) can be rotated relative to each other about a common axis of rotation (10) by means of the mechanical field attenuation means (11) in order to overcome the influence of the first torsional stiffness means (9); the first torsional stiffness mechanism (9) is designed as a first torsion spring arrangement (12) having a first torsion spring (13), which is arranged coaxially with respect to the axis of rotation (10) and is arranged between the first rotor body (5) and the second rotor body (7) or between one of the rotor bodies (5, 7) and the rotor shaft (16), the first torsion spring (13) is arranged such that a torsion of one of the rotor bodies (5, 7) as a result of the adjustment of the field attenuation mechanism (11) results in an opening or closing actuation of the first torsion spring (13).

Description

Technical Field

[0001] The present invention relates to a rotor for an electric machine, in particular for use in the drive train of a hybrid or fully electric motor vehicle, wherein the rotor comprises at least one first rotor body having a first set of permanent magnets and a second rotor body having a second set of permanent magnets, wherein the first rotor body and the second rotor body are rotatable relative to each other about a common rotation axis by means of a mechanical field damping mechanism in order to overcome the influence of a first torsional stiffness mechanism. The invention also relates to an electric machine. Background Art

[0002] Electric motors are increasingly being used to drive motor vehicles in order to create an alternative to fossil fuel-intensive internal combustion engines. Considerable effort has been made to improve the suitability of electric drives for everyday use while also providing users with the driving comfort they are accustomed to.

[0003] Perhaps the closest prior art is a detailed description of an electric drive in the article "Highly Integrative and Flexible Electric Drive Unit for Electric Vehicles" (Hochintegrativ und flexibel–Elektrische Antriebseinheit für E-Fahrzeuge) by Erik Schneider, Frank Fickl, Bernd Cebulski, and Jens Liebold, published in the German automotive magazine ATZ, Volume 113, May 2011, pages 360–365. This article describes a drive unit for a vehicle axle that includes an electric motor arranged coaxially with a bevel gear differential. Such a drive unit is also referred to as an electric axle or an electrically operable drivetrain.

[0004] Electric motors experience losses during operation due to magnetic reversals. These losses are collectively referred to as iron losses and reduce the machine's efficiency. In mobile applications, low motor efficiency leads to reduced vehicle range or increased demands on battery capacity. Minimizing these iron losses is therefore a constant goal, particularly in mobile applications with purely electric drives.

[0005] An example of an electric machine with iron losses, such as that used in the drivetrains of hybrid or fully electric motor vehicles, is a so-called permanently excited synchronous machine. Due to their higher power density compared to other types of machines, permanently excited synchronous machines are particularly preferred for use in electric vehicles, where available installation space is often a limiting factor. The machine's excitation field is typically generated by permanent magnets arranged in the machine's rotor. In permanently excited synchronous machines, the slip ring contacts required in electrically excited synchronous machines to supply power to the field coils arranged on the rotor can be omitted.

[0006] However, a disadvantage of permanent excitation is that the excitation field cannot be easily modified. In principle, by controlling the so-called field decay range, a synchronous machine can be operated beyond its rated speed. Within this range, the machine operates at its maximum rated power, with the torque delivered by the machine decreasing as speed increases. Electrically excited synchronous machines can be very easily operated within the field decay range by reducing the excitation current. Even in the case of permanently excited machines, there are known methods for generating an air gap field component by supplying a suitable current to the machine's stator. This counteracts the excitation field generated by the permanent magnets and thus weakens the excitation field. However, this type of machine control leads to increased losses, so that the machine can only operate at reduced efficiency within this range.

[0007] An effective method for reducing iron losses in electric machines is to intentionally weaken the magnetic field between the stator and the rotor for operating points with high speeds, because the losses due to high-frequency magnetic reversals are lower when the magnetic field is weak. In addition to electrical methods, there are also mechanical methods for targeted field attenuation. Patent applications US58211710, FR2831345, EP1085644, EP11867030, DE1012011708670, DE1012016103470, CN104600929, and CN105449969 disclose a rotor for a radial flux machine, which is divided into several rotor disks equipped with permanent magnets in a manner perpendicular to the axis of rotation and which can rotate relative to each other. The rotor provides a full magnetic field in a position where the magnetic poles are aligned in the axial direction, and a weakened magnetic field in a position rotated relative to this position, depending on the relative rotation between the rotor disks. An active or passive mechanism is described which is said to be able to switch between these two positions depending on rotor speed or torque and which therefore enables the electric machine to operate more efficiently with respect to the entire motor map.

[0008] DE 10 12021 101 898 describes a device in which the rotor of a radial flux machine is divided into two partial rotors, the individual rotor disks of which alternate in the axial direction. One partial rotor is directly connected to the rotor shaft, while the other partial rotor is connected to the rotor shaft in a torque-transmitting and rotatable manner via a torsional stiffness mechanism. The torsional stiffness mechanism is selected such that, at low torques, the partial rotors are in a torsional position with a weakened magnetic field, and at high torques, the partial rotors are in a torsional position with a full magnetic field. DE 10 12021 101 904 claims a structurally designed mechanical module that can be introduced into the interior of a rotor disk equipped with permanent magnets, establishes the described connection between the partial rotors and the rotor shaft, and allows the control characteristics to be defined via the torsional stiffness mechanism, which is implemented using a spring and a cam drive equipped with rollers.

[0009] All of the aforementioned passive solutions—which use torque as a sensor variable to trigger the relative movement between the two rotor segments to overcome the torsional stiffness mechanisms—assume that, in the initial field-weakened position with misaligned poles, the total electromagnetic torque generated by the stator current supply is simply distributed between the two rotor segments, roughly according to their share of the total length and their respective phase positions relative to the stator field, regardless of the presence of the other rotor segments. Only in this way can the partial torques, which are proportional to the total torque, be easily directed to overcome the torsional stiffness mechanisms between the rotor segments, or one of the rotor segments, and the rotor shaft, and achieve the desired rotation by means of the increased torque into a position with full magnetic field and aligned poles. However, the applicant's tests and modeling have shown that the actual situation is much more complex.

[0010] Even in the de-energized state, an interaction in the form of a magnetic repulsive torque exists between the rotor disks of the two partial rotors. The position with full magnetic field and aligned poles represents an unstable equilibrium in which the repulsive torque disappears. When rotating from this equilibrium position, a repulsive torque is generated that increases with increasing rotation until it reaches a maximum value and then decreases again with further rotation. The trajectory of the repulsive torque over the rotation angle within the electrical cycle, the height of the maximum value, and the rotation angle at which the maximum value occurs depend largely on the selected arrangement of the permanent magnets within the rotor disks. The trajectory within the electrical cycle is essentially nonlinear.

[0011] Given the desired effective stator current supply for different speeds, these magnetic repulsive moments increase in different ways depending on the speed, sometimes by many times. Overall, the resulting partial moments cannot be easily directed to overcome the torsional stiffness between the partial rotors or one of the partial rotors and the rotor shaft, and thus cannot rotate the partial rotors into a position with a full magnetic field, because the partial moments are not directed in the correct direction for this purpose due to the high proportion of the magnetic repulsive moment.

[0012] To ensure reliable control behavior, it is necessary, among other things, that the control characteristic of the mechanical field damping on the motor characteristic diagram neither undergoes undesirable changes nor exhibits excessive hysteresis. However, at the speeds of traction machines in today's automotive industry, the effects of centrifugal forces, particularly on existing torsional stiffness mechanisms, which can be designed as compression springs, can lead to an undesirably high shift of the control characteristic toward higher torques. Increased friction on the guide elements of the torsional stiffness mechanism can also lead to excessive hysteresis in the control characteristic. Summary of the Invention

[0013] In order to provide a functional arrangement in the sense of the aforementioned passive solutions for torque-adaptive field damping of a rotor of an electric machine, it is an object of the present invention to provide an electric machine with improved mechanical field damping.

[0014] This object is achieved by a rotor for an electric machine, in particular for an electric machine for use in a drive train of a hybrid or fully electric motor vehicle, wherein the rotor comprises at least one first rotor body with a first set of permanent magnets and a second rotor body with a second set of permanent magnets, wherein the first rotor body and the second rotor body are rotatable relative to each other about a common rotation axis by means of a mechanical field damping mechanism in order to overcome the influence of a first torsional stiffness mechanism, wherein the first torsional stiffness mechanism is designed as a first torsional spring arrangement with a first torsional spring, which is arranged coaxially with respect to the rotation axis and is arranged between the first rotor body and the second rotor body or between one of the rotor bodies and the rotor shaft, so that a torsion of one of the rotor bodies as a result of adjustment of the field damping mechanism leads to an opening actuation and a closing actuation of the first torsional spring.

[0015] This offers the advantage that the electric machine can be implemented with a purely mechanical field damping device which adjusts the position of the permanent magnets required for field damping in the rotor as required, depending on the operating conditions of torque and speed, in a reliable and cost-effective manner. Thus, in principle, the invention also avoids the need for actuators intervening externally on or in the rotor.

[0016] Designing the torsional stiffness means as a torsion spring arrangement for defining the control characteristic for damping the magnetic field by relative rotation of the rotor bodies allows in particular to reduce the influence of centrifugal forces on the control characteristic and its hysteresis.

[0017] Another advantage of this design is the relatively small number of individual components required to provide a torsional stiffness mechanism and the associated simplified assembly. Furthermore, the torsion spring allows a particularly compact design of the mechanical field damping mechanism.

[0018] In particular, the electric machine can be designed as a rotating machine. In the case of an electric machine designed as a rotating machine, a distinction is made between radial flux machines and axial flux machines. A radial flux machine is characterized by the magnetic field lines extending in the radial direction in the air gap formed between the rotor and the stator, while in the case of an axial flux machine, the magnetic field lines extend in the axial direction in the air gap formed between the rotor and the stator. In the context of the present invention, the electric machine can be configured as a radial flux machine or an axial flux machine.

[0019] The rotor is the rotating (rotating) part of the electric machine. Specifically, it comprises a rotor shaft and one or more rotor bodies formed by a laminated rotor core arranged non-rotatably on the rotor shaft. The rotor shaft can be hollow, which reduces weight and allows lubricant or coolant to be supplied to the rotor bodies.

[0020] For the purposes of the present invention, a rotor body is understood to mean a rotor without a rotor shaft. The rotor body is thus made in particular of a laminated rotor core and permanent magnets inserted into pockets in the laminated rotor core or fixed to its circumference, as well as any axial covering parts for closing the pockets.

[0021] The permanent magnets can preferably be inserted into the pockets of the laminated rotor core. In this respect, a single larger rotor magnet designed as a bar magnet or a plurality of smaller permanent magnetic elements can be provided for each pocket.

[0022] The rotor has a plurality of rotor bodies. Particularly preferably, the rotor bodies have substantially the same design, in particular substantially the same design. It is highly preferred that the rotor bodies are formed from rotor laminations of the same design, in particular substantially the same rotor laminations. Therefore, the rotor bodies are particularly preferably formed from a laminated rotor core, which consists of a plurality of laminated individual sheets or rotor laminations, which are typically made of electrical steel, and which are layered and packaged one above the other to form a stack, which is referred to as a laminated rotor core. The individual sheets can be held together in the laminated rotor core by gluing, welding or screwing. In particular, the laminated rotor core can also have permanent magnets, which are inserted into recesses in the laminated rotor core or are fixed circumferentially to the laminated rotor core.

[0023] Mechanical field attenuation mechanisms are generally known from the prior art. Particularly preferred mechanical field attenuation mechanisms relevant to the present invention are described in the as yet unpublished patent publications DE 10 20 22 10 69 44 and DE 10 20 22 10 69 45 as well as DE 10 20 21 10 19 04 B3, DE 10 20 21 10 18 98 A1 and DE 10 20 21 10 19 00 A1, which are hereby incorporated by reference into the disclosure of the present application.

[0024] According to an advantageous embodiment of the invention, the first torsion spring arrangement can include a second torsion spring that is arranged coaxially with respect to the rotor's axis of rotation and is arranged between the first and second rotor bodies or between one of the rotor bodies and the rotor shaft, such that a torsion of one of the rotor bodies as a result of adjusting the field damping mechanism results in the activation of the second torsion spring oriented in the same direction as the first torsion spring. This embodiment has the advantage that the second torsion spring enables modeling and precise adjustment of the adjustment characteristic. The torsion springs can be designed essentially identically or differently, depending on the requirements of the specific application to be achieved by the desired adjustment characteristic. The torsion springs can be connected in series or in parallel with one another.

[0025] According to another preferred embodiment of the present invention, it can be provided that the first torsion spring has a first spring leg extending radially into the first rotor body and / or a second spring leg extending radially into the second rotor body.

[0026] and / or the first torsion spring may have a first spring leg extending axially into the first rotor body and / or a second spring leg extending axially into the second rotor body, and / or

[0027] The second torsion spring may have a first spring leg extending radially into the first rotor body and / or a second spring leg extending radially into the second rotor body,

[0028] And / or the second torsion spring can have a first spring leg extending axially into the first rotor body and / or a second spring leg extending axially into the second rotor body. This makes it possible to achieve a particularly compact radial or axial torsional stiffness mechanism based on the given installation space conditions.

[0029] Furthermore, according to an equally advantageous embodiment of the invention, the first and second torsion springs can be of substantially identical design and arranged to rotate relative to one another about the axis of rotation, such that the first and second spring legs of the first torsion spring are oriented in a common radial and / or axial direction, and the first and second spring legs of the second torsion spring are oriented in a radial and / or axial direction opposite to the first and second spring legs of the first torsion spring. This embodiment advantageously prevents or at least mitigates lateral forces generated during actuation of the torsion springs and structural imbalances in the rotating rotor. For example, a housing can be formed with two identical opening and closing torsion springs, wherein the first and second torsion springs are screwed into one another and then rotated relative to one another by a corresponding winding distance. The torsion springs preferably have a winding distance that is slightly greater than the wire thickness of the torsion spring in the axial direction.

[0030] The ends of the torsion springs are preferably opposite each other in pairs, which helps to further reduce imbalances in the rotor.In principle, the torsion springs can have any number of windings, wherein preferably the torsion springs have the same number of windings.

[0031] According to another particularly preferred embodiment of the present invention, the electric machine can include a second torsional stiffness mechanism, which is designed as a second torsional spring arrangement with a third torsional spring. The third torsional spring is arranged coaxially with respect to the axis of rotation and between the third and fourth rotor bodies or between one of these rotor bodies and the rotor shaft, such that a twisting of one of the rotor bodies as a result of adjustment of the field damping mechanism results in an opening or closing actuation of the third torsional spring. The third and second rotor bodies are preferably arranged axially adjacent to each other in the rotor, and the first and second torsional spring arrangements have different actuation orientations. This makes it possible, in particular, to compensate for the influence of centrifugal forces occurring during operation on the adjustment characteristics of the mechanical field damping mechanism. Furthermore, the fact that the torsional stiffness mechanism opens and closes to the same degree can also be used to compensate for axial forces.

[0032] It should be noted that the specified coaxiality may shift slightly as the rotor is operated, so that the specified coaxiality herein always refers to when the rotor is at rest.

[0033] Furthermore, the first and second torsion spring arrangements are preferably arranged rotated about 90° relative to each other about the axis of rotation, which makes it possible to compensate for imbalances, which in particular allows the rotor to be operated at high speeds, eg >15,000 rpm.

[0034] Furthermore, the invention can be further developed so that the torsion springs of the first torsion spring arrangement and the second torsion spring arrangement have the same winding direction for both actuation orientations. It must then be ensured, for example via a corresponding connection of the torsion spring arrangements to the rotor body, that the two torsion spring arrangements have opposite actuation directions, so that when one torsion spring arrangement is open, the other torsion spring arrangement is closed, and vice versa.

[0035] Alternatively, the torsion springs of the first and second torsion spring arrangements can have opposite winding directions for the two actuation orientations. Here, too, it must be ensured, for example via a corresponding connection of the torsion spring arrangements to the rotor body, that the two torsion spring arrangements have opposite actuation directions, so that when one torsion spring arrangement is open, the other torsion spring arrangement is closed, and vice versa.

[0036] In a likewise preferred embodiment of the invention, it can be provided that at least one torsion spring, preferably all torsion springs, are wound from a spring wire having a substantially rectangular cross section.

[0037] This makes it possible to increase the energy content of the torsion spring in its installation space and promotes the transmission of bending moments and the lateral unforced suspension of the spring ends in the recess of the disk, which are designed as legs and form a structural unit with a part of the rotor or the rotor shaft for transmitting torque.

[0038] It may also be advantageous to further develop the invention so that at least one torsion spring, and preferably all torsion springs, are installed in a preloaded state. This has the advantage that the torque at which the adjustment process should begin can be defined. To this end, the torsion springs in the arrangement can then be installed preloaded, for example, by a specific rotation angle.

[0039] According to another preferred embodiment of the subject matter of the present invention, it can be provided that the torsion springs have essentially the same design. This allows the torsion springs to be manufactured in a particularly cost-effective manner. Furthermore, production and assembly are facilitated by increasing the degree of component commonality.

[0040] Finally, the invention can also advantageously be developed so that the rotor bodies each consist of two parts, namely an inner annular disk and an outer annular disk coupled to the inner annular disk in a torque-transmitting manner, wherein the permanent magnets are arranged only in the outer annular disk.

[0041] This has the advantage that, in particular, the mechanical field damping mechanism can thus be produced independently of the magnetic region of the rotor body, which can increase the flexibility in the design and production of the electrical machine.

[0042] The object of the invention is also achieved by an electric machine, in particular for use in a drive train of a hybrid or fully electric motor vehicle, comprising a stator and a rotor separated from the stator by an air gap, wherein the rotor is designed according to any one of claims 1 to 10. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The invention is explained in more detail below with reference to the accompanying drawings without limiting the general idea of ​​the invention.

[0044] In the attached figure:

[0045] Figure 1 The motor is shown in cross section,

[0046] Figure 2 shows a schematic block circuit diagram of a rotor with a mechanical field damping mechanism,

[0047] Figure 3 A first embodiment of a torsional stiffness mechanism is shown in a perspective view,

[0048] Figure 4 A second embodiment of the torsional stiffness mechanism is shown in perspective,

[0049] Figure 5 The rotor is shown in cross section,

[0050] Figure 6 A detailed view of the rotor is shown in cross section,

[0051] Figure 7 A first embodiment of a torsion spring arrangement with two rotor bodies is shown in an exploded perspective view.

[0052] Figure 8 A first embodiment of a torsion spring arrangement with two rotor bodies in the assembled state is shown in a perspective view,

[0053] Figure 9 The rotor body with the torsion spring arrangement fastened to the rotor body is shown in enlarged detail. DETAILED DESCRIPTION

[0054] Figure 1An electric machine 1 is shown, in particular for use in the drive train of a hybrid or fully electric motor vehicle. The electric machine 1, which is designed as a radial flux machine, comprises a stator 2 and a rotor 4 separated from the stator 2 by an air gap 3, wherein the rotor 4 has at least one first rotor body 5 with a first set of permanent magnets 6 and a second rotor body 7 with a second set of permanent magnets 8, which are Figure 1 and Figure 2 It is easy to see in the summary.

[0055] The first rotor body 5 and the second rotor body 7 can be rotated relative to each other about a common rotation axis 10 by means of a mechanical field damping mechanism 11 to overcome the influence of the first torsional stiffness mechanism 9. The two rotor bodies 5, 7 are essentially formed from identical rotor laminations, wherein the position and number of the first set of permanent magnets 6 in the rotor body 5 are identical to the position and number of the second set of permanent magnets 8 in the rotor body 7.

[0056] Figure 2 The field damping mechanism 11, shown by way of example in FIG, comprises a lever element (not shown in detail) that can be pivoted about a pivot point, wherein the first rotor body 5 can be coupled to a first lever section, and the second rotor body 7 can be coupled to a second lever section of the lever element. The first and second lever sections are arranged on opposite sides of the lever, so that by tilting the lever element, the first and second rotor bodies 5, 7 can be rotated relative to each other in a targeted manner for the desired adjustment of the mechanical field damping mechanism 11. This field damping mechanism 11 is described in detail in DE 10 20 22 10 69 44 and DE 10 20 22 10 69 45, so reference is made here to avoid repetition.

[0057] The first torsional stiffness mechanism 9 is designed as a first torsion spring arrangement 12 with a first torsion spring 13 which is arranged coaxially with respect to the axis of rotation 10 and between the first rotor body 5 and the second rotor body 7 so that a torsion of one of the rotor bodies 5, 7 as a result of the adjustment of the field damping mechanism 11 results in an opening or closing actuation of the first torsion spring 13. Figures 2 to 3 Not shown in FIG, it is also possible that the first torsion spring 13 is arranged in a torque-transmitting manner between one of the rotor bodies 5 , 7 and the rotor shaft 16 .

[0058] The first torsion spring arrangement 12 has a second torsion spring 14 which is arranged coaxially with respect to the rotation axis 15 of the rotor 4 and between the first rotor body 5 and the second rotor body 7 such that a torsion of one of the rotor bodies 5, 7 as a result of adjustment of the field damping mechanism 11 results in an opening or closing actuation of the second torsion spring 14. Figure 1As shown in the figure, the first torsion spring 13 and the second torsion spring 14 have essentially the same design and are arranged to rotate relative to each other about the rotation axis 10 so that the first spring leg 17 and the second spring leg 18 of the first torsion spring 13 point in a common radial direction and the first spring leg 19 and the second spring leg 20 of the second torsion spring 14 are oriented in opposite radial directions.

[0059] In this case, the first torsion spring 13 has a first spring leg 17 extending radially into the first rotor body 5 and a second spring leg 18 extending radially into the second rotor body 7. Similarly, the second torsion spring 14 also has a first spring leg 19 extending radially into the first rotor body 5 and a second spring leg 20 extending radially into the second rotor body 7.

[0060] Figure 3 It is also shown that the electric machine 1 in the embodiment shown has a second torsion spring arrangement 21, which is designed as a second torsion spring arrangement 22 with a third torsion spring 23, which is arranged coaxially with respect to the rotation axis 10 and between the third rotor body 25 and the fourth rotor body 27, so that a torsion of one of the rotor bodies 25, 27 as a result of adjustment of the field damping mechanism 11 leads to an opening or closing actuation of the third torsion spring 23. In this respect, the first torsion spring arrangement 12 and the second torsion spring arrangement 22 are rotated relative to each other by approximately 90° about the rotation axis 10.

[0061] Here, the third rotor body 25 and the second rotor body 7 are arranged axially adjacent to each other in the rotor 4. It is also conceivable that the second rotor body 7 and the third rotor body 25 are formed in one piece. Figure 4 In the configuration shown, the first torsion spring arrangement 12 and the second torsion spring arrangement 22 have different actuation orientations from each other, which are also determined by Figure 3 Indicated by the arrows in . Here, the first torsion spring arrangement 12 is actuated closed, while the second torsion spring arrangement 22 is actuated open, which contributes to speed neutrality with respect to torque.

[0062] The spring ends of the torsion springs 13 , 14 , 23 can be designed as radially or axially extending legs by means of corresponding bends. Figure 3 An embodiment with radially extending legs is shown and Figure 4 An embodiment is shown having axially extending legs.

[0063] exist Figure 3 In the embodiment shown in FIG, the ends of the torsion spring engage in a positively locking manner and essentially without play in radial grooves 26 provided for this purpose.

[0064] and Figure 3 compared to, Figure 4 The first torsion spring 13 in the embodiment shown in FIG has a first spring leg 17 extending axially into the first rotor body 5 and a second spring leg 18 extending axially into the second rotor body 7. Similarly, the second torsion spring 14 also has a first spring leg 19 extending axially into the first rotor body 5 and a second spring leg 20 extending axially into the second rotor body 7. Figure 4 In the embodiment shown in FIG, the ends of the torsion springs then engage in a form-fitting and essentially play-free manner in axial grooves 24 provided for this purpose. The essentially identically designed rotor bodies 5, 7, 25, 27 have a total of four identical axial grooves 24 distributed equidistantly around the circumference.

[0065] from Figures 3 and 4 What can also be seen in is that all torsion springs 13,14,23 are wound by the spring wire with substantially rectangular cross section and have substantially identical design.In addition, all torsion springs 13,14,23 are installed with the state of preload.

[0066] Finally, from Figures 1 to 4 It is further apparent from the overview that the rotor bodies 5 , 7 , 25 , 27 each consist of two parts, namely an inner annular disk 28 and an outer annular disk 29 coupled to the inner annular disk 28 in a torque-transmitting manner, wherein the permanent magnets 6 , 8 are arranged only in the outer annular disk 29 .

[0067] like Figure 1 As already indicated in , the rotor bodies 5, 7 each consist of two parts, comprising an inner annular disk 28 connected to the rotor shaft 16 in a torque-transmitting manner and an outer annular disk 29 coupled in a torque-transmitting manner to the inner annular disk 28, wherein the permanent magnets 6, 8 are arranged only in the outer annular disk 29 formed from electrical steel sheet. The inner annular disk 28 is made of steel, in particular hardened steel.

[0068] Figure 5 An embodiment is shown in which the inner annular disk 28 and the outer annular disk 29 are connected to each other in a form-fitting and torque-transmitting manner. To this end, the inner annular disk 28 has an external toothing 51 on its outer lateral surface 50, which engages with a corresponding internal toothing 52 on the inner lateral surface 53 of the outer annular disk 29. In this exemplary embodiment, the outer toothing 51 and the inner toothing 52 are designed as plug-in toothings. To facilitate the connection of these plug-in toothings, the outer toothing 51 and / or the inner toothing 52 can have chamfers.

[0069] from Figure 6As can be seen in the detailed illustration, the teeth 54 of the outer toothing 51 each have a first undercut 55, and the teeth 56 of the inner toothing 52 also have a second undercut 57. The first and second undercuts 55, 57 are designed to enable force transmission in the radial direction between the meshing inner and outer toothings 52, 51. To achieve this, the teeth 54 of the outer toothing 51 and the teeth 56 of the inner toothing 52 are designed with a dovetail-shaped cross-section. The two annular disks 28, 29 contact only on the inclined sides of the dovetail-shaped teeth 54, 56. Therefore, the high precision of the tooth shape for a positive fit is limited to the inclined sides. This also allows for the use of larger radii in the tooth bases of the annular disks 28, 29. This reduces local stresses and enables faster and more cost-effective manufacturing of the toothings 51, 52, for example, by selecting a milling cutter with a larger diameter. The undercuts 55, 57 are thus generated by the inclined sides of the teeth 54, 56. In this shape, the openings of the tooth gaps in the annular disks 28 , 29 are wider, which makes it easier and more cost-effective to manufacture the toothing, for example by broaching, forming or milling.

[0070] Furthermore, the outer toothing 51 has a groove 58 with a groove base 59 between every two teeth 54 adjacent in the circumferential direction, into which the teeth 56 of the inner toothing 52 engage with tooth heads 60, wherein the tooth heads 60 are subject to play relative to the groove base 59, which can be easily removed. Figure 4 In this design, an overlap can be provided in particular in the tooth flanks of the meshing teeth 54 , 56 , which results in an inward preloading of the inner and outer annular disks 28 , 29 during assembly and thus further reduces the stresses in the annular disks 28 , 29 at speed.

[0071] The permanent magnets 6 and 8 are arranged opposite each other in a V-formation, as shown in cross section, and are distributed over the circumference of the outer annular disk 29, wherein the free legs 61 of the V-shaped arrangement extend radially inwards and the V-shaped arrangement has a radially extending mirror axis 62, which extends coaxially with the radially extending mirror axis 63 of the teeth 54 and 56 of the inner toothing 52 or the outer toothing 51. At the same time, a radially extending mirror axis 64 is defined between two adjacent V-shaped arrangements in the circumferential direction, which extends coaxially with the radially extending mirror axis 65 of the teeth 56 of the inner toothing 52 or the outer toothing 51. In this case, Figure 4 It is also clearly shown that the meshing teeth 54 of the external toothing 51, through which the mirror axes 62, 63 extend, are designed to be wider in the circumferential direction than the adjacent teeth 54 of the external toothing 51. The same applies to the meshing teeth 56 of the internal toothing 52, through which the mirror axes 64, 65 extend. This means that the high centrifugal forces caused by the V-shaped arrangement of the permanent magnets 6, 8 in these areas can be better absorbed.

[0072] The first rotor body 5 and the second rotor body 7 can be rotated relative to each other about a common rotation axis 10 by means of a mechanical field damping mechanism 11 to overcome the influence of the first torsional stiffness mechanism 9. Figure 7 Let's explain this in more detail again. Figure 7 As can be seen in FIG, the first torsional stiffness mechanism 9 is designed as a first torsion spring arrangement 12 having a first torsion spring 13, which is arranged coaxially with respect to the rotation axis 10 and between the first rotor body 5 and the second rotor body 7, so that a torsion of one of the rotor bodies 5, 7 as a result of adjustment of the field damping mechanism 11 leads to an opening or closing actuation of the first torsion spring 13. Even though not shown in the figures, the first torsion spring 13 can also be arranged in a torque-transmitting manner between one of the rotor bodies 5, 7 and the rotor shaft 16.

[0073] The first torsion spring arrangement 12 has a second torsion spring 14 which is arranged coaxially with respect to the axis of rotation 10 of the rotor 4 and between the first rotor body 5 and the second rotor body 7 such that a torsion of one of the rotor bodies 5, 7 as a result of adjustment of the field damping mechanism 11 results in an opening or closing actuation of the second torsion spring 14. Figure 5 and Figure 7 As shown in the figure, the first torsion spring 13 and the second torsion spring 14 have essentially the same design and are arranged to be rotated relative to each other about the rotation axis 10, so that the first spring leg 17 and the second spring leg 18 of the first torsion spring 13 are directed to be offset radially outward by 90° in the circumferential direction, and the first spring leg 19 and the second spring leg 20 of the second torsion spring 14 are also directed to be offset radially outward by 90° in the circumferential direction.

[0074] In this case, the first torsion spring 13 has a first spring leg 17 extending radially into the first rotor body 5 and a second spring leg 18 extending radially into the second rotor body 7. Similarly, the second torsion spring 14 also has a first spring leg 19 extending radially into the first rotor body 5 and a second spring leg 20 extending radially into the second rotor body 7.

[0075] In this regard, the first spring leg 17 of the first torsion spring 13 is held in the first receiving shoe 30, which is in turn received in the first receiving pocket 31 of the first rotor body 5 and fixed to the first rotor body 5, so that the first spring leg 17 of the first torsion spring 13 is coupled to the first rotor body in the axial direction and the circumferential direction without any play relative to the first rotor body 5. Here, the first receiving shoe 30 can be inserted into the first receiving pocket 31 while being subject to play.

[0076] also, Figure 7 It is shown that the first receiving shoe 30 has a first receiving groove 32 , in which the first spring leg 17 of the first torsion spring 13 is arranged without play, for example by means of an interference fit.

[0077] The first spring leg 17 of the first torsion spring 13 protrudes from the first receiving groove 32, wherein the section 33 protruding from the first receiving groove 32 rests against the wall 34 of the first receiving groove 31, which can also be easily removed from the Figure 9 This allows a portion of the shoe load to be received by the rotor body 5. The wall 34 of the first receiving pocket 31 has a convex profile that projects into the first receiving pocket 31, which can also be seen from Figure 7 This ensures, for example, that the position of the spring leg 17 can also be adjusted in the direction of rotation.

[0078] also, Figure 9 It is shown that the first receiving shoe 30 has a first opening 35 through which a first fastening device 36 passes and by means of which the first receiving shoe 30 is fixed to the first rotor body 5 .

[0079] Figure 7 It is also shown that the second spring leg 18 of the first torsion spring 13 is retained in the second receiving shoe 37, which in turn is received in the second receiving pocket 38 of the second rotor body 7 and is fixed to the first rotor body 7, so that the second spring leg 18 of the first torsion spring 13 is coupled to the second rotor body in the axial direction and in the circumferential direction without play relative to the second rotor body 7.

[0080] The first spring leg 19 of the second torsion spring 14 is also held in a similar manner in the third receiving shoe 39, which in turn is received in the third receiving pocket of the first rotor body 5 and fixed to the first rotor body 5, so that the first spring leg 19 of the second torsion spring 14 is coupled to the first rotor body in the axial direction and the circumferential direction without play relative to the first rotor body 5.

[0081] Finally, the second spring leg 20 of the second torsion spring 14 is also held in the fourth receiving shoe 41, which in turn is received in the fourth receiving pocket 42 of the second rotor body 7 and fixed to the second rotor body 7, so that the second spring leg 20 of the second torsion spring 14 is coupled to the second rotor body in the axial direction and the circumferential direction without play relative to the second rotor body 7.

[0082] Figure 7 It is also shown that the first receiving shoe 30 , the second receiving shoe 37 , the third receiving shoe 39 and the fourth receiving shoe 41 have the same design.

[0083] By means of the receiving shoes 30, 37, 39, 41, an element is thus arranged between the spring legs 17, 18, 19, 20 and the rotor body 5, which can be adjusted and fixed in position within the receiving pockets 31, 38, 42. The receiving shoes 30, 37, 39, 41 are pressed onto the spring legs 17, 18, 19, 20, for example, by a corresponding interference fit, so that the receiving shoes are fixed relative to each other without play. The spring legs 17, 18, 19, 20 with the preassembled receiving shoes 30, 37, 39, 41 can be positioned in the rotor body 5, 7 using an assembly tool (not shown). Because a gap is formed between the receiving recesses 31, 38, 42 and the receiving shoes 30, 37, 39, 41, that is, the receiving shoes 30, 37, 39, 41 engage in the receiving recesses 31, 38, 42 with some play, the position of the receiving shoes 30, 37, 39, 41 in the receiving recesses 31, 38, 42 can be adjusted. The receiving shoes 30, 37, 39, 41 positioned in the receiving recesses 31, 38, 42 can then be fixed in place by the fastening device 36. The fastening device is shown as a screw in the figure. However, the fastening device can also be designed as a rivet, or the fastening device 36 can be a brazed connection or a welded connection.

[0084] Figure 8 Shown from Figure 7 The arrangement structure in the assembled state is known from FIG.

[0085] The present invention is not limited to the embodiments shown in the accompanying drawings. Therefore, the above description should not be regarded as restrictive, but rather as illustrative. The appended claims should be understood to mean that the recited features are present in at least one embodiment of the present invention. This does not exclude the presence of other features. Where the claims and the above description define a “first” feature and a “second” feature, such designation is used to distinguish between two features of the same type and does not define an order of precedence.

[0086] Reference Signs List

[0087] 1 motor

[0088] 2 stator

[0089] 3 Air gap

[0090] 4 rotors

[0091] 5. Rotor body

[0092] 6 permanent magnets

[0093] 7 Rotor body

[0094] 8 permanent magnets

[0095] 9 Torsional stiffness mechanism

[0096] 10 Axis of rotation

[0097] 11 Field attenuation mechanism

[0098] 12 Torsion spring arrangement

[0099] 13 Torsion spring

[0100] 14 Torsion spring

[0101] 15 Rotation axis

[0102] 16 Rotor shaft

[0103] 17 Spring Leg

[0104] 18 Spring Legs

[0105] 19 Spring Leg

[0106] 20 Spring Legs

[0107] 21 Torsional stiffness mechanism

[0108] 22 Torsion spring arrangement

[0109] 23 Torsion spring

[0110] 24 Axial groove

[0111] 25 rotor body

[0112] 26 radial grooves

[0113] 27 rotor body

[0114] 28 annular disk

[0115] 29 annular disk

[0116] 30 Acceptance Hoof

[0117] 31 Receiving pocket

[0118] 32 receiving grooves

[0119] 33 sections

[0120] 34 wall

[0121] 35 Opening

[0122] 36 Fastening device

[0123] 37 Acceptance Hoof

[0124] 38 receiving pockets

[0125] 39 Acceptance Hoof

[0126] 41 Acceptance Hoof

[0127] 42 receiving pockets

[0128] 50 lateral surface

[0129] 51 external teeth

[0130] 52 internal teeth

[0131] 53 lateral surface

[0132] 54 teeth

[0133] 55 undercut

[0134] 56 teeth

[0135] 57 Undercut

[0136] 58 grooves

[0137] 59 groove base

[0138] 60 tooth head

[0139] 61 Legs

[0140] 62 mirror axis

[0141] 63 mirror axis

[0142] 64 mirror axes

[0143] 65 mirror axis

Claims

1. A rotor (4) for an electric machine (1), in particular for use in a drive train of a hybrid or fully electric motor vehicle, wherein: The rotor (4) comprises at least one first rotor body (5) having a first set of permanent magnets (6) and a second rotor body (7) having a second set of permanent magnets (8), wherein the first rotor body (5) and the second rotor body (7) are rotatable relative to each other about a common rotation axis (10) by means of a mechanical field damping mechanism (11) to overcome the influence of a first torsional stiffness mechanism (9), It is characterized in that The first torsional stiffness mechanism (9) is designed as a first torsion spring arrangement (12) having a first torsion spring (13), which is arranged coaxially with respect to the rotation axis (10) and is arranged between the first rotor body (5) and the second rotor body (7) or between one of the rotor bodies (5, 7) and the rotor shaft (16), so that a torsion of one of the rotor bodies (5, 7) as a result of adjustment of the field damping mechanism (11) leads to an opening actuation or a closing actuation of the first torsion spring (13).

2. The rotor (4) according to claim 1, It is characterized by: The first torsion spring arrangement (12) has a second torsion spring (14) which is arranged coaxially with respect to the axis of rotation (15) of the rotor (4) and is arranged between the first rotor body (5) and the second rotor body (7) or between one of the rotor bodies (5, 7) and the rotor shaft (16), such that Torsion of one of the rotor bodies (5, 7) as a result of adjustment of the field damping mechanism (11) results in actuation of the second torsion spring (14) oriented in the same direction as the first torsion spring (13).

3. The rotor (4) according to claim 1 or 2, It is characterized by: The first torsion spring (13) has a first spring leg (17) extending radially into the first rotor body (5) and / or a second spring leg (18) extending radially into the second rotor body (7), and / or The first torsion spring (13) has a first spring leg (17) extending axially into the first rotor body (5) and / or a second spring leg (18) extending axially into the second rotor body (7), and / or The second torsion spring (14) has a first spring leg (19) extending radially into the first rotor body (5) and / or a second spring leg (20) extending radially into the second rotor body (7), and / or The second torsion spring (14) has a first spring leg (19) extending axially into the first rotor body (5) and / or a second spring leg (20) extending axially into the second rotor body (7).

4. The rotor (4) according to claim 2 or 3, It is characterized in that The first torsion spring (13) and the second torsion spring (14) are of substantially the same design and are arranged to rotate relative to each other about the rotation axis (10) such that the first spring leg (17) and the second spring leg (18) of the first torsion spring (13) are directed in a common radial direction and / or axial direction, and the first spring leg (19) and the second spring leg (20) of the second torsion spring (14) are oriented in a radial direction and / or axial direction opposite to the first spring leg and the second spring leg of the first torsion spring.

5. A rotor (4) according to any one of the preceding claims, It is characterized in that The electric motor (1) has a second torsional stiffness mechanism (21) designed as a second torsional spring arrangement (22) with a third torsional spring (23), which is arranged coaxially with respect to the axis of rotation (10) and is arranged between a third rotor body (25) and a fourth rotor body (27) or between one of these rotor bodies (25, 27) and the rotor shaft (16), so that a torsion of one of these rotor bodies (25, 27) as a result of adjustment of the field damping mechanism (11) leads to an opening actuation or a closing actuation of the third torsional spring (23), wherein the third rotor body (25) and the second rotor body (7) are preferably arranged axially adjacent to each other in the rotor (4), and the first torsional spring arrangement (12) and the second torsional spring arrangement (22) have different actuation orientations from one another.

6. The rotor (4) according to claim 5, It is characterized by: The torsion springs (13, 14, 23) of the first torsion spring arrangement (12) and the second torsion spring arrangement (22) have the same winding direction for both actuation orientations, or The torsion springs (13, 14, 23) of the first torsion spring arrangement (12) and the second torsion spring arrangement (22) have opposite winding directions for two actuation orientations.

7. A rotor (4) according to any one of the preceding claims, It is characterized by: At least one, preferably all, torsion springs (13, 14, 23) are wound from a spring wire having a substantially rectangular cross section.

8. A rotor (4) according to any one of the preceding claims, It is characterized by: At least one, preferably all, torsion springs (13, 14, 23) are installed in a preloaded state.

9. Rotor (4) according to any one of the preceding claims 5 to 8, It is characterized in that The torsion springs (13, 14, 23) are essentially of the same design.

10. A rotor (4) according to any one of the preceding claims, It is characterized by: The rotor bodies (5, 7, 25, 27) each consist of two parts, namely an inner annular disk (28) and an outer annular disk (29) coupled to the inner annular disk (28) in a torque-transmitting manner, wherein the permanent magnets (6, 8) are arranged only in the outer annular disk (29).

11. An electric machine (1), in particular for use in a drive train of a hybrid or fully electric motor vehicle, comprising a stator (2) and a rotor (4), the rotor being separated from the stator (2) by an air gap (3), characterised in that The rotor (4) is designed according to any one of the preceding claims.

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