Motor

Abstract

The rotor (1) comprises at least one first rotor body (3) with a first group of permanent magnets (6) and a second rotor body (4) with a second group of permanent magnets (61), the first rotor body (3) and the second rotor body (4) being rotatable relative to each other about a common axis of rotation (119) by means of a mechanical field attenuation mechanism (7) in order to overcome the influence of a first torsional stiffness member (8), the field attenuation mechanism (7) comprises a lever element (10) having a center of gravity (52) and being pivotable about a tilt axis (13). The first rotor body (3) may be coupled to a first lever section (31) of a lever element (10) and the second rotor body (4) may be coupled to a second lever section (32) of the lever element, the first lever section (31) and the second lever section (32) being arranged on opposite sides of the lever (10) such that by tilting the lever element (10), the first rotor body (3) and the second rotor body (4) may be coupled to a second lever section (32) of the lever element (10). The first rotor body (3) and the second rotor body (4) can be rotated relative to each other in a targeted manner in order to produce a desired adjustment of the mechanical field attenuation mechanism (7). The center of gravity (52) and the tilt axis (53) of the lever element (10) are spaced apart from each other when the motor (120) is in a stationary state.

Description

Technical Field

[0001] The invention relates to 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 comprises at least a 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 can be rotated relative to each other about a common rotation axis by means of a mechanical field damping mechanism to overcome the influence of a first torsional stiffness element. Background Art

[0002] Electric machines experience losses during operation due to magnetic reversals, which losses are collectively referred to as iron losses and reduce the efficiency of the machine. In mobile applications, low efficiency of the electric machine means reduced range of the vehicle or increased demand on battery capacity. Minimizing the described iron losses is therefore a constant goal, especially in mobile applications with purely electric drive.

[0003] An example of such an electric machine with iron losses, as can be used in the drive train of a hybrid or fully electric motor vehicle, 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 preferably used in the field of electric vehicles, where the available installation space is often a limiting factor. The excitation field of the machine is usually generated by permanent magnets arranged in the rotor of the machine. In a permanently excited synchronous machine, slip ring contacts, which are necessary in electrically excited synchronous machines in order to supply power to the field coils arranged on the rotor, can be omitted.

[0004] However, a disadvantage of permanent excitation is that the excitation field cannot be easily modified. In principle, a synchronous machine can be operated beyond its rated speed by controlling the so-called field decay range. In this range, the machine is operated at its maximum rated power, wherein the torque delivered by the machine decreases with increasing speed. Electrically excited synchronous machines can be operated very easily in the field decay range by reducing the excitation current. Even in the case of permanent magnet machines, there are known methods to generate an air gap magnetic field component by means of a suitable current supply to the stator of the machine in order to counteract the excitation field generated by the permanent magnets and thus weaken or attenuate the excitation field. However, such control of the machine leads to increased losses, so that the machine can only be operated with reduced efficiency in this range.

[0005] An effective method for reducing iron losses in electric machines is to intentionally weaken or attenuate the magnetic field between the stator and the rotor for operating points with high speeds, since in the case of a weak magnetic field, the losses due to high-frequency magnetic reversals are lower. There are also mechanical methods as well as electrical methods for targeted field attenuation. From patent specifications US58211710, FR2831345, EP1085644, EP11867030, DE1012011708670, DE1012016103470, CN104600929 and CN105449969, a rotor of a radial flux machine is known, 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. According to the relative rotation between the rotor disks, the rotor provides a full magnetic field in a position where the magnetic poles are aligned in the axial direction, and provides an attenuated magnetic field in a position rotated relative to this position. 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 overall engine map.

[0006] 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 part of the rotor is directly connected to the rotor shaft, the other part is connected to the rotor shaft in a torque-transmitting manner via a torsionally rigid member. The torsionally rigid member is selected so that: at low torques, the partial rotor is in a torsion position with a weakened magnetic field and at high torques, the partial rotor is in a torsion position with a full magnetic field. DE 10 12021 101 904 claims protection for a structurally designed mechanical module that can be introduced into the interior of a rotor disk equipped with permanent magnets, establishes the described connection of the partial rotor to the rotor shaft, and allows the movement characteristics to be defined via a torsionally rigid member, which is realized by means of a spring and a cam drive equipped with rollers.

[0007] All the previously mentioned passive solutions - using torque as a sensor variable to trigger the relative movement between the two partial rotors to overcome the torsional stiffness - assume that, in the case of a position where the initial magnetic field with misaligned poles is attenuated, the total electromagnetic torque generated by the stator current supply is simply distributed between the two partial rotors roughly according to their share in the total length and their respective phase positions relative to the stator field, regardless of the presence of the other partial rotors. Only in this way can the partial torque proportional to the total torque be easily directed to overcome the torsional stiffness between the partial rotor or one of the partial rotors and the rotor shaft and achieve the desired rotation by means of the increased torque to enter a position with full magnetic field and aligned poles. However, experiments and modeling by the applicant have shown that the actual situation is much more complicated.

[0008] Even in the case of a power failure, there is an interaction between the rotor disks of the two partial rotors in the form of a magnetic repulsion torque. The position with full magnetic field and aligned poles presents an unstable equilibrium in which the repulsion torque disappears. When rotating from this equilibrium position, a repulsion torque is generated, which increases with increasing rotation until the repulsion torque reaches a maximum value and then decreases again with further rotation. The trajectory of the repulsion 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 in the rotor disk. The trajectory within the electrical cycle is essentially nonlinear.

[0009] In the case of a desired effective stator current supply for different speeds, these magnetic repulsion torques increase in different ways depending on the speed, sometimes by several times. Overall, the resulting partial torques cannot in any case be easily directed to overcome the torsional stiffness between the partial rotor or one of the partial rotors and the rotor shaft in order to rotate the partial rotor into a position with a full magnetic field, since the partial torques are not directed in the correct direction for this purpose due to the high proportion of the magnetic repulsion torque. Summary of the invention

[0010] In order to represent a functional arrangement in the sense of the aforementioned passive solutions for torque-adapted field damping of a rotor of an electric machine, the object of the present invention is to provide an electric machine with an improved mechanical field damping device, which in particular also effectively converts part of the torque actually occurring on the rotor body into the desired movement and transmits this part of the torque to the rotor shaft.

[0011] This object is achieved by an electric machine, in particular for use in a drive train of a hybrid or fully electric motor vehicle, the electric machine comprising a stator and a rotor separated from the stator by an air gap, 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 can be rotated relative to each other about a common rotation axis by means of a mechanical field damping mechanism to overcome the influence of a first torsional stiffness member, wherein the field damping mechanism comprises a lever element with a center of gravity, which can be pivoted about a tilting axis, wherein the first rotor body can be coupled to a first lever section of the lever element and the second rotor body can be coupled to a second lever section of the lever element, and the first lever section and the second lever section are arranged on opposite sides of the lever, so that the first rotor body and the second rotor body can be rotated relative to each other in a targeted manner by tilting the lever element in order to achieve a desired movement of the mechanical field damping mechanism, wherein the center of gravity of the lever element and the tilting axis of the lever element are spaced apart from each other when the electric machine is at a standstill.

[0012] 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 on or in the rotor from the outside.

[0013] Under the effect of speed, the centrifugal force at the center of gravity of the lever can disturb the balance of force and torque at the lever element and thus affect the movement behavior of the lever mechanism within the engine characteristic diagram. For example, the expected pure torque-related movement behavior may be disturbed by the influence of centrifugal force. On the contrary, a movement behavior that depends on both speed and torque can be sought in order to achieve more efficient motor operation over the entire engine characteristic diagram. By adjusting the position of the center of gravity and the lever pivot axis, different movement behaviors can be explained via torque and speed (in combination with other influences that will be explained in more detail below).

[0014] The position of the center of gravity and the lever tilt axis can be specifically determined, for example, by distributing the material within the lever element in an appropriate manner, such as by means of forming, adding mass or removing material. A decisive factor for the tilt of the lever element and therefore the magnetic field strength in the associated position of the part of the rotor (rotor body) is the balance of forces and torques at the lever element, which will be discussed in more detail below.

[0015] Another aspect of the proposed mechanical field damping is, among other things, the use of levers within the rotor at at least two points around the circumference in order to transfer part of the torque of the two rotor bodies to, for example, the rotor shaft, wherein a torsional stiffness element acts simultaneously between the rotor bodies, wherein the mechanical field damping mechanism has a plurality of lever elements, each of which is pivotally arranged in a distributed manner around the circumference of the rotor shaft.

[0016] The partial torques of the two rotor bodies act on the lever via the lever section so that the sum of the torques is transmitted, for example, to the rotor shaft and, at the same time, the two rotor bodies are pivoted, for example, to a position with full magnetic field and aligned magnetic poles, by pivoting the lever, overcoming the torsional stiffness present between the two rotor bodies. The partial torque, which in the process is actually pointing in the wrong direction, is converted into the target direction by means of the lever.

[0017] First, the various elements of the claimed subject matter of the present invention will be explained in the order in which the elements are named in the claims, and thereafter particularly preferred embodiments of the claimed subject matter of the present invention will be described.

[0018] In particular, the electrical machine can be designed as a rotating machine. In the case of an electrical machine designed as a rotating machine, a distinction is made in particular between radial flux machines and axial flux machines. A radial flux machine is characterized in that the magnetic field lines extend 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 electrical machine can be configured as a radial flux machine or as an axial flux machine.

[0019] The rotor is the rotating (turning) part of the electric machine. In particular, the rotor comprises a rotor shaft and one or more rotor bodies formed by a laminated rotor core arranged in a non-rotatable manner on the rotor shaft. The rotor shaft may be hollow, which on the one hand reduces weight and on the other hand allows the supply of lubricants or coolants 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 therefore consists in particular of a laminated rotor core and magnetic elements introduced into pockets of the laminated rotor core or circumferentially fixed to the laminated rotor core and any axial covering parts present for closing the pockets.

[0021] The permanent magnets can preferably be inserted into pockets in the rotor core. Each pocket can be provided with a single larger rotor magnet designed as a bar magnet or with a plurality of smaller permanent magnet elements.

[0022] The rotor preferably has a plurality of rotor bodies. Particularly preferably, the rotor bodies are formed substantially of identical parts, in particular substantially of identical parts in the same manner. It is highly preferred that the rotor bodies are formed of identical, in particular substantially identical, rotor laminations. Therefore, the rotor body is particularly preferably formed by a laminated rotor core, which consists of a plurality of laminated individual sheets or rotor laminations, which are generally made of electrical steel, which are layered and packaged one on top of 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 of the laminated rotor core or are fixed to the laminated rotor core in the circumferential direction.

[0023] According to an advantageous embodiment of the invention, the rotor shaft can be coaxially coupled to the first rotor body and the second rotor body via a lever element in a torque-transmitting manner within the first rotor body and the second rotor body. According to a further preferred development of the invention, the lever element can be pivotally mounted on the rotor shaft. This makes it possible to achieve a particularly compact design for mechanical field damping.

[0024] In addition, according to an equally advantageous embodiment of the present invention, the lever element can extend in a radial direction into a first lever window of the first rotor body, wherein the first lever window has a first lever contact section and a second lever contact section radially spaced apart from the first lever contact section, and the lever element can extend in a radial direction into a second lever window of the second rotor body, wherein the second lever window has a first lever contact section and a second lever contact section radially spaced apart from the first lever contact section, wherein the lever element is supported against the first lever contact section of the first lever window and the second lever contact section of the second lever window in the first operating position, and is supported against the second lever contact section of the first lever window and the first lever contact section of the second lever window in the second operating position.

[0025] Therefore, in a highly preferred embodiment of the invention, the lever has three areas at different distances from the axis of rotation of the rotor, in which the lever contacts the two rotor bodies as two inputs of torque and the rotor shaft as an output of torque. This is another significant difference compared to the prior art, in which the element for transmitting partial torque to the rotor shaft always has only one input and one output. The partial torques of the two rotor bodies act on the lever via a defined lever contact section so that the sum is transmitted to the rotor shaft, and at the same time, by tilting the lever, the two rotor bodies overcome the torsional stiffness present between the two rotor bodies and pivot to a position with a full magnetic field and aligned poles, for example. This will be explained in more detail using the embodiments of the invention shown in the accompanying drawings.

[0026] According to another particularly preferred embodiment of the present invention, the first lever contact section may be arranged radially below the second lever contact section of the first lever window, and the first lever contact section may be arranged radially below the second lever contact section of the second lever window.

[0027] Furthermore, the present invention can be further improved in the following manner: the torque applied to the first lever contact section of the first lever window and the first lever contact section of the second lever window via the first lever element is greater in absolute value than the torque applied to the second lever contact section of the first lever window and the second lever window. In this respect, the partial torque actually pointing in the wrong direction of the mechanical movement process is converted into the desired direction using the lever by the partial torque which is greater in absolute value of the two partial torques, while the larger partial torque determines the direction of the total torque and acts on the lever more radially inwardly than the smaller partial torque of the two partial torques.

[0028] In a further preferred embodiment of the invention, the torsionally rigid element can be formed as a spring element, in particular as a compression spring or a curved spring.

[0029] According to another preferred embodiment of the present invention, the characteristic curve of the torsion stiffness element can be selected so that: when a specified minimum torque is exceeded, the first rotor body and the second rotor body start to rotate relative to each other from a position with maximum field attenuation, and when a specified maximum torque is reached and / or exceeded, the first rotor body and the second rotor body have completed the rotation relative to each other into a position with full magnetic field. In this context, it may be advantageous to further develop the invention so that the characteristic curve of the torsion stiffness element exhibits a bias torque.

[0030] According to an advantageous embodiment of the invention, the center of gravity of the lever element can be located below the tilting axis when the motor is at rest. Thus, in the case where the center of gravity of the lever is moved radially further inwards than the lever tilting axis, the centrifugal forces acting during operation of the motor will assist the movement process, which means that full movement can occur at higher speeds even at lower torques.

[0031] According to another preferred further development of the invention, the center of gravity of the lever element can be located above the tilting axis when the motor is at rest. In the case where the center of gravity of the lever is moved radially further outward than the lever tilting axis, centrifugal forces inhibit the movement process, which means that at higher speeds, full movement can only be achieved at higher torques.

[0032] According to another particularly preferred embodiment of the present invention, when the motor is at rest, the center of gravity of the lever can be located in a plane spanned by the rotation axis and the lever tilt axis, whereby the characteristic curves in motor operation and generator operation can achieve the same movement behavior.

[0033] Furthermore, the invention can be modified so that when the motor is at rest, the center of gravity is located outside the plane spanned by the axis of rotation and the axis of lever tilting. Thus, in the case where the center of gravity is located to the left or right of the plane spanned by the axis of rotation and the axis of lever tilting, an asymmetric movement behavior results, and in one operating mode, the torque at the start of the movement will be lower than in the other operating mode, because the influence of the radial position of the center of gravity is amplified or attenuated at the start.

[0034] All of these combinations of the center of gravity of the lever / the lever inclination axis can lead to a kinematic behavior that is advantageous in terms of machine efficiency on the engine characteristic map for motor operation and generator operation and can be used individually or in any desired combination with one another.

[0035] Finally, the invention can also advantageously be realized in such a way that the mechanical field damping mechanism has a plurality of lever elements which are each arranged pivotably in a distributed manner around the circumference of the rotor shaft, whereby a smoother and safer movement of the rotor body can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will be explained in more detail below with reference to the accompanying drawings without limiting the general inventive concept.

[0037] In the attached picture:

[0038] Figure 1 The electric machine is shown in cross section,

[0039] Figure 2A schematic block diagram shows a rotor with the mechanical field damping mechanism in a neutral position,

[0040] Figure 3 A schematic block diagram shows a rotor with the mechanical field damping mechanism in a first operating position,

[0041] Figure 4 shows a schematic block diagram of a rotor with the mechanical field damping mechanism in a second operating position,

[0042] Figure 5 shows a schematic cross-sectional view of a rotor with the mechanical field damping mechanism in a neutral position,

[0043] Figure 6 shows in schematic cross-section the rotor with the mechanical field damping mechanism in a second operating position,

[0044] Figure 7 The rotor is shown in a schematic cross-sectional view with the mechanical field damping mechanism in a first operating position.

[0045] Figure 8 The electric machine is shown in a schematic cross-sectional view,

[0046] Fig. 9 The rotor is shown in a perspective partial cross-sectional view,

[0047] Fig.10 The four operating positions of the lever element are shown in detail in cross section.

[0048] Fig.11 The lever element is shown in two perspective views, each of which is separate.

[0049] Fig.12 Two cross-sectional views of the rotor are shown,

[0050] Fig.13 The rotor with separate lever elements and fixing ring is shown in a perspective view,

[0051] Fig.14 Two axial sections through the rotor are shown,

[0052] Fig.15 A first embodiment of the lever element is shown when the motor is at rest.

[0053] Fig.16 A first embodiment of the lever element during operation of the motor is shown,

[0054] Fig.17A second embodiment of the lever element is shown when the motor is at rest,

[0055] Fig.18 A third embodiment of the lever element is shown when the motor is at rest.

[0056] Fig.19 A fourth embodiment of the lever element is shown when the motor is at rest. DETAILED DESCRIPTION

[0057] Figure 1 An electric machine 120 configured as a radial flux machine, in particular for use in a drive train of a hybrid or fully electric motor vehicle, is shown, comprising a stator 2 and a rotor 1 separated from the stator 2 by an air gap 22 .

[0058] The rotor 1 comprises at least one first rotor body 3 having a first set of permanent magnets 6 and a second rotor body 4 having a second set of permanent magnets 61. Figures 2 to 7 , which shows two rotor bodies 3, 4. The two rotor bodies 3, 4 are basically formed by the same rotor laminations, wherein the position and number of the first set of permanent magnets 6 in the rotor body 3 are the same as the position and number of the second set of permanent magnets 61 in the rotor body 4.

[0059] The first rotor body 3 and the second rotor body 4 can be rotated relative to each other about a common rotation axis 119 by means of the mechanical field damping mechanism 7 in order to overcome the influence of the first torsionally rigid element 8 .

[0060] The field damping mechanism 7 comprises a lever element 10 which can be pivoted about a pivot point, wherein the first rotor body 3 can be coupled to a first lever section 31 and the second rotor body 4 can be coupled to a second lever section 32 of the lever element 10, and the first lever section 31 and the second lever section 32 are arranged on opposite sides of the lever 10, so that the first rotor body 3 and the second rotor body 4 can be rotated relative to each other in a targeted manner by tilting the lever element 10 in order to achieve a desired movement of the mechanical field damping mechanism 7, which can also be achieved from Figures 2 to 4 This can be clearly seen in the combination of and this will be explained in more detail below.

[0061] The field damping mechanism 7 uses a lever element 10 at at least two circumferential positions of the rotor bodies 3 and 4, also referred to as lever contact sections 12, 13, 15, 16, in the rotor 1 to transfer part of the torque of the two rotor bodies 3 and 4 to the rotor shaft 5, while a torsional stiffener 8 is arranged between the rotor bodies 3 and 4, which can also be obtained from Figures 2 to 4The lever element 10 has three regions at different distances from the rotation axis 119 of the rotor 1, in which the lever element is in contact with the two rotor bodies 3, 4 as two inputs of torque and the rotor shaft 5 as the output of torque. Here, the three regions of the lever element 10 are the first lever section 31, the second lever section 32, and an unspecified contact section with the rotor shaft 5 at the radially inner end of the lever element 10.

[0062] Via these defined contact areas of the first lever section 31 and the second lever section 32, part of the torque of the two rotor bodies 3, 4 acts on the lever element 10 via the lever contact sections 12, 13, 15, 16, so that the sum is transmitted to the rotor shaft 5 via the unspecified contact section at the radially inner end of the lever element 10, and at the same time, by tilting the lever element 10, the two rotor bodies 3, 4 are rotated via the lever contact sections 12, 13, 15, 16 to a position with full magnetic field and aligned magnetic poles, as a result of overcoming the torsional stiffness piece 8 present between the two rotor bodies. Figure 3 to Figure 4 As shown in . By means of the lever element 10 , part of the torque which is actually directed in the wrong direction during the process is converted into the target direction.

[0063] exist Figures 2 to 4 The torsionally rigid element 8 is symbolically shown in FIG by means of compression springs, which are located, for example, in spring windows of the two rotor bodies 3, 4. However, the torsionally rigid element 8 can also be formed in any other known manner.

[0064] Figure 2 The field attenuation mechanism 7 is shown initially in its neutral position. The field attenuation mechanism 7 is here in the field attenuation position, wherein the magnetic poles of the first set of permanent magnets 6 are not aligned with the magnetic poles of the second set of permanent magnets 61, which can be seen from Figure 2 The rotational angular position of the two rotor bodies 3, 4 in the embodiment of FIG. 1 is easily understood. In this case, the total torque is lower than the minimum torque required to allow the rotor bodies 3, 4 to start moving relative to each other to overcome the possibly biased torsional stiffness member 8. The characteristic curve of the torsional stiffness member 8 is selected so that when a specified minimum torque is exceeded, the field attenuation mechanism 7 starts to move from the position with maximum field attenuation, and when a specified higher torque is reached and exceeded, the full movement to the position with full magnetic field has been completed, as for example with respect to FIG. Figure 3 The motor operation of the electric motor 120 is shown in FIG.

[0065] The first partial torque M1 is transmitted via the lever contact sections 12, 13 of the first rotor body 3 according to the direction of the total torque, wherein the first lever contact section 12 of the first rotor body 3 is arranged to be radially offset inwardly relative to the second lever contact section 13. Similarly, the second partial torque M2 of the second rotor body 4 is transmitted to the lever element 10 via the lever contact sections 15, 16 according to the direction of the total torque. The first lever contact section 15 of the second rotor body 4 is arranged to be radially offset inwardly relative to the second lever contact section 16.

[0066] If the direction of the total torque is changed, for example by changing the motor operation of the electric machine 120 to the generator operation, the lever sections 31, 32 of the lever element 10 can be switched sides, and in both operating states, the same relative rotation occurs between the rotor bodies 3, 4, so as to generate a decaying magnetic field or a full magnetic field, as shown in FIG. Figure 3 to Figure 4 as shown in .

[0067] exist Figure 3 In the embodiment, the mechanical field damping mechanism 7 is in an operating position with a full magnetic field and in which the magnetic poles of the permanent magnets 6, 61 are aligned, and the lever element 10 is in an inclined extreme position. In this case, for example, the total torque when driving in motor operation is greater than the minimum torque in the entire movement of the torsionally rigid member 8.

[0068] Figure 4 The mechanical field damping mechanism 7 is shown in a position with full magnetic field and in which the poles of the permanent magnets 6, 61 are aligned, and the lever element 10 is in an extreme position of reverse tilt with an oppositely acting torque. In this case, for example, the total torque during recuperation in generator mode of the electric machine 120 is greater than the minimum torque to overcome the entire movement of the torsional stiffness element 8.

[0069] As from the Figures 2 to 4 The possible designs of the shown principle are outlined Figures 5 to 7 It can be seen that the rotor shaft 5 is coaxially coupled to the first rotor body 3 and the second rotor body 4 in a torque-transmitting manner via a lever element 10 , wherein the lever element 10 is pivotably arranged on the rotor shaft 5 .

[0070] like Figures 5 to 7As shown, the lever element 10 extends in the radial direction into a first lever window 11 of the first rotor body 3 shown in a partial cross-sectional view, wherein the first lever window 11 has a first lever contact section 12 and a second lever contact section 13 radially spaced apart from the first lever contact section, which is indicated by a solid line. The lever element 10 also extends in the radial direction into a second lever window 14 of the second rotor body 3. The second lever window 14 has a first lever contact section 15 and a second lever contact section 16 radially spaced apart from the first lever contact section, which is indicated by a dotted line. Figure 7 In the illustrated first operating position 117 , the lever element 10 is supported against the first lever contact section 12 of the first lever window 11 and the second lever contact section 16 of the second lever window 14 , and Figure 6 In the second actuating position 118 shown, the lever element is supported against the second lever contact section 13 of the first lever window 11 and against the first lever contact section 15 of the second lever window 14 .

[0071] The first lever contact section 12 of the first lever window 11 is arranged to be located radially below the second lever contact section 13 of the first lever window, and the first lever contact section 15 of the second lever window 14 is arranged to be located radially below the second lever contact section 16 of the second lever window. Compared with the second lever contact section 13 of the first lever window 11 and the second lever contact section 16 of the second lever window 14, the torque transmitted via the first lever element 10 at the first lever contact section 12 of the first lever window 11 and the first lever contact section 15 of the second lever window 14 is larger.

[0072] exist Figures 5 to 7 In the embodiment, the torsion stiffness element 8 is designed as a spring element, in particular as a compression spring or an arc spring, whose characteristic curve exhibits a bias torque. Here, the characteristic curve of the torsion stiffness element 8 is also selected so that: when a specified minimum torque is exceeded, the first rotor body 3 and the second rotor body 4 start to rotate relative to each other from a position with maximum field attenuation, and when a specified maximum torque is reached and / or exceeded, the first rotor body and the second rotor body have completed the rotation relative to each other and enter a position with a full magnetic field.

[0073] exist Figures 5 to 7 In the embodiment, the field damping device 7 has two opposing, essentially identical lever elements 10 , which are each arranged so as to be pivotable in a distributed manner around the circumference of the rotor shaft 5 .

[0074] Figure 8An electric machine 120 is shown, in particular for use in a drive train of a hybrid or fully electric motor vehicle, comprising a stator 2 and a rotor 1 separated from the stator 2 by an air gap 22. The rotor 1 has a first rotor body 3 with a first set of permanent magnets 6 and a second rotor body 4 with a second set of permanent magnets 61, the second rotor body being axially spaced from the first rotor body 3, as shown in FIG. Fig. 9 It can be clearly seen in.

[0075] In the first rotor body 3 and the second rotor body 4, the rotor shaft 5 is coaxially coupled to the first rotor body 3 and the second rotor body 4 in a torque-transmitting manner. The first rotor body 3 is mounted on the rotor shaft 5 in a rotatable manner relative to the second rotor body 4 by means of a mechanical field attenuation mechanism 7 to overcome the influence of a first torsional stiffness member 8, which is designed as a compression spring or an arc spring. In order to transmit part of the torque of the two rotor bodies 3, 4 to the rotor shaft 5, a lever element 10 is used at at least two circumferential points in the rotor 1, wherein the torsional stiffness member 8 between the rotor bodies 3, 4 acts simultaneously. Referring to the following Fig.10 The mechanical field attenuation mechanism 7 is explained in more detail.

[0076] from Fig.10 It can be seen that the contour 17 of the lever element 10 that contacts the lever contact sections 12, 13, 15, 16 is designed so that: in each operating position of the mechanical field attenuation mechanism 7 on its entire movement path in a cross section perpendicular to the rotation axis 18 of the rotor 1, all contact points 19, 20, 21 between the rotor bodies 3, 4 and the lever element 10 are arranged on the straight connecting line 23 between the tilting axis 24 of the lever element 10 and the rotation axis 18 of the rotor 1.

[0077] The lever element 10, which comprises an oval base body 26, is received in a V-shaped groove 25 which points radially inwards and extends axially through the rotor shaft 5. Figure 4 The ovoid, i.e. egg-shaped, shape of the base body 26 can also be clearly seen in FIG. During operation of the mechanical field attenuation mechanism 7, the ovoid base body 26 rolls in the V-shaped groove 25. To illustrate these kinematics, Figure 3 Four operating positions of the lever element 10 are shown, in which the rotor shaft 5 moves counterclockwise relative to the rotor body 3. In order to better observe the dynamic processes during the movement of the field damping mechanism 7, Fig.11 The reference numerals in the images marked b, c, d have been omitted.

[0078] from Fig.11As can be clearly seen from the illustration in FIG, the corresponding design of the lever element 10, the lever contact sections 12, 13, 15, 16 and the V-shaped groove 25 results in a non-slip contact between the lever element 10, the rotor body 3, 4 and the rotor shaft 5. The lever element 10, the lever contact sections 12, 13, 15, 16 and the V-shaped groove are geometrically designed so that their contours roll on each other during the tilting of the lever element 10 about the tilting axis 24 and during the rotation of the rotor body 3, 4 or the rotor shaft 5 about the rotation axis 18 of the rotor 1.

[0079] For this purpose, the profile 17 of the lever element 10 is designed so that in every position of the entire intended movement of the mechanical field attenuation mechanism observed in a cross section perpendicular to the rotation axis 18, all contact points 19, 20, 21 between the rotor bodies 3, 4 and the lever element 10 are located on a straight connecting line 23 between the tilting axis 24 of the lever element 10 and the rotation axis 18 of the rotor 1.

[0080] The lever element thus has three contact areas which are radially spaced apart from one another by contact points 19, 20, 21, which are located at different distances from the axis of rotation 18 of the rotor 1, and through which the lever element is in axial contact with the two rotor bodies 3, 4 as two inputs of torque and with the rotor shaft 5 as an output of torque.

[0081] The partial torques of the two rotor bodies 3, 4 act on the lever element 10 via the limited contact area of ​​the contact points 20, 21, so that the sum is transmitted to the rotor shaft 5 via the contact area of ​​the contact point 19, and at the same time, by tilting the lever element, the two rotor bodies 3, 4 overcome the torsionally rigid piece 8 present between them and rotate into a position with a full magnetic field and in which the magnetic poles of the permanent magnets 6, 61 are aligned, which can be seen from Fig.11 The various operating positions are shown for easy understanding.

[0082] The partial torque, which is actually pointing in the wrong direction in the process, is converted into the target direction by means of the lever element 10. The decisive factor here is that the larger of the two partial torques, which determines the direction of the total torque, acts on the lever element more radially inwardly than the smaller of the two partial torques.

[0083] The rotor bodies 3, 4 provide lever contact sections 12, 13, 15, 16 at two distances from the axis of rotation 18 for contacting the lever element 10 at contact points 20, 21. Figure 5If the direction of the total torque changes during motor operation and generator operation, the contact points 20, 21 on the lever element 10 can switch sides and the same relative rotation occurs between the rotor bodies 4, 4 in both operating states to produce a decaying magnetic field or a full magnetic field.

[0084] The characteristic curve of the torsionally rigid member 8 is selected so that: when a specified minimum torque is exceeded, the mechanical field attenuation mechanism 7 starts to move from a position in which the magnetic field is at its maximum attenuation level, and when a specified higher torque is reached and exceeded, the entire movement to the position with the full magnetic field is completed. For this purpose, the characteristic curve of the torsionally rigid member 8 can have a bias torque.

[0085] exist Fig.10 The lever element 10 in its non-tilted neutral position shown in the illustration a of FIG. 1 forms a stop for a position with a magnetic field attenuated to the greatest extent by the lever element at contact points 20, 21 with the rotor bodies 3, 4 at their lever contact sections 12, 13, 15, 16, so as to overcome the magnetic repulsive torque between the rotor bodies 3, 4 and the bias torque of the torsional stiffness member 8. Figure 5 As shown, stop teeth 35, 36 acting in the circumferential direction are formed between the rotor disks 29, 30 of the rotor bodies 3, 4 and the rotor shaft 5, and these stop teeth define the rotation end position of the rotor shaft relative to the rotor disks 29, 30 or the rotor bodies 3, 4. If the torque for this position is exceeded, the lever mechanism will be bypassed by means of the stop teeth, and the increased torque will be transmitted directly from the rotor bodies 3, 4 to the rotor shaft 5.

[0086] exist Fig.11 1 shows the lever element 10 in two separate perspective views. It can be clearly seen from these illustrations that radially outwardly extending arcuate claws 27 are formed on the oval base body 26 for engaging with the radially outer lever contact sections 13, 16. Here, the circumferential orientation of the arcuate claws 27 alternates in the axial direction. The base body 26 is hollow and also has convex arcuate segments 38, 39 arranged alternately in the axial direction, wherein one set of arcuate segments 38 is assigned to the first rotor body 3 and the other set of arcuate segments 39 is assigned to the second rotor body 4.

[0087] The radially inner contact points 19 of the lever contact sections 12, 15 with the rotor bodies 3, 4 are located on the radially inner contact surfaces 41, 42 of the arcuate sections 38, 39 of the lever element 10. The radially outer contact surfaces 43, 44 on the arcuate claws 27 of the lever element 10 provide the contact points 21 with the rotor bodies 3, 4. Contact surfaces 45, 46 are formed radially between the rotor bodies on the oval base body 26, which contact surfaces form the contact points 20 with the rotor bodies 3, 4. When the lever element 10 is connected to the rotor body 3, 4, the contact points 21 are formed. Figure 4 and Fig.10 This can be clearly seen again when doing a comparison.

[0088] The claw 27 and a section of the oval base body 26 radially engage in a recess 37 provided for this purpose in the rotor body 3, 4 so as to come into contact with the rotor body, which can be seen from the Fig.12 The recess 37 has a mushroom-shaped contour with circumferentially inwardly directed opening shoulders 47 on the radially inner section. The lever contact sections 12, 15 of the rotor bodies 3, 4 are formed on these opening shoulders 47 of the recess 37. The radially outer lever contact sections 13, 16 are formed in the recess 37.

[0089] The lever element 10 is radially fixed by a fixing ring 28, which can rotate relative to the rotor 1 and coaxially with the rotor, as shown in FIG. Fig.13 The retaining ring supports the centrifugal forces of the lever element 10 in the rotor 1 and fixes the radial position of the lever element. In order to minimize the friction at the bearing points, the profile of the contact surface between the lever element 10 and the retaining ring 28 can also be designed so that the lever element and the retaining ring roll against each other. For this purpose, axially outer claws of the lever element 10 are provided, which are not shown in detail and have a design different from the arcuate claws 27, which can also be Fig.11 These axially outer claws, not shown further, engage in recesses provided for this purpose in the fixing ring 28 .

[0090] The first rotor body 3 includes a plurality of rotor disks 29, which are arranged alternately with the rotor disks 30 of the second rotor body 4 in the axial direction. The rotor disks 29 of the first rotor body 3 are connected to form a structural unit via a first connecting device 131 extending axially parallel to the rotation axis 18 of the rotor 1, and the rotor disks 30 of the second rotor body 4 are connected to form a structural unit via a second connecting device 132 extending axially parallel to the rotation axis 18 of the rotor 1, which is Fig.14 It can be clearly seen in FIG. 1 that a spacing sleeve 33 is arranged on the first connection element 131 between adjacent rotor disks 29 of the first rotor body 3 , and a spacing sleeve 34 is arranged on the second connection element 132 between adjacent rotor disks 30 of the second rotor body 4 .

[0091] The connecting means 131, 132 carry the guide element 48 for one end of the torsion rigidity piece 8 acting in the circumferential direction on the associated spacing sleeves 33, 34. The other end of the rotor rests in an unspecified recess of the corresponding rotor disk of the rotor body 3, 4. Via the torsion rigidity piece 8, the guide element 48, the spacing sleeves 33, 34 and the final connecting means 131, 132, the torsion rigidity piece 8 is formed from the two rotor bodies 3, 4 to the corresponding other rotor body 3, 4, preferably so that the two torsion rigidity pieces 8 interact in the direction of relative rotation in the form of a parallel circuit, which means a stronger magnetic field. The two rotor bodies 3, 4 are each mounted on the front rotor disk using rolling bearings or sliding bearings on the rotor shaft 5. The rotor 1 can be balanced on two front balancing disks 49, which are part of the first rotor body 3.

[0092] Figures 15 to 19 A field damping mechanism 7 is shown, which comprises a lever element 10 having a center of gravity 52 and which can be pivoted about a tilting axis 53. Figures 15 to 19 The inclined axis 53 with reference numeral 53 is provided in the Fig.10 24 in the figure. As shown in the aforementioned figures, the first rotor body 3 can be coupled to the first lever section 31 of the lever element 10, and the second rotor body 4 can be coupled to the second lever section 32 of the lever element, wherein the first lever section 31 and the second lever section 32 are arranged on opposite sides of the lever 10, so that the first rotor body 3 and the second rotor body 4 can be rotated relative to each other in a targeted manner by tilting the lever element 10 for achieving the desired movement of the mechanical field attenuation mechanism 7. In this regard, when the motor 120 is at rest, the center of gravity 52 of the lever element 10 and the tilting axis 53 are spaced apart from each other.

[0093] The position of the center of gravity 52 and the lever tilt axis 53 can be determined by distributing the material in the lever element 10 in a suitable manner, for example by means of shaping, adding mass or removing material. A decisive factor for the tilt of the lever element 10 and thus the magnetic field strength in the associated position of the rotor bodies 3, 4 is the balance of forces and torques at the lever element 10, such as Fig.16 The following factors affect this balance of forces and torques:

[0094] The forces 80 and 82 generated by the torsionally rigid piece 8 between the rotor bodies 3, 4 at the contact points of the lever element 10 and the rotor bodies 3, 4, and the electromagnetic partial torque generated on the rotor bodies 3, 4 due to the stator current supply.

[0095] the force 83 generated at the contact point of the lever element 10 and the rotor shaft 5 due to the total torque transmission,

[0096] the speed-dependent centrifugal force 81 at the center of gravity 52,

[0097] and the distance of the lines of action of all mentioned forces as lever arms to the fixed lever tilting axis 53 .

[0098] By adjusting the position of the center of gravity 52 and the lever tilt axis 53 , fundamentally different movement behaviors resulting from torque and speed can be explained in conjunction with the other mentioned influences, as will be explained in more detail below.

[0099] If the movement behavior depends only on the torque, the center of gravity 52 and the lever tilt axis 53 must coincide in their axial projection. If the center of gravity 52 is radially further inward than the lever tilt axis 53, the centrifugal force 81 will assist the movement process, which means that the full movement will occur at a higher speed even at a lower torque. This can be achieved in Fig.15 It can be seen in FIG. 1 that the center of gravity 52 of the lever element 10 is located below the tilting axis 53 when the motor 120 is at rest.

[0100] If, on the other hand, the center of gravity 52 is radially further outward than the lever tilt axis 53, the centrifugal force 81 inhibits the motion process, which means that at higher speeds, full motion can only be achieved at higher torques. Fig.17 , in which the center of gravity 52 of the lever element 10 is located above the tilting axis 53 when the motor 120 is at rest.

[0101] Fig.15 and Fig.17 An embodiment of the lever element 10 has been shown in which, when the electric machine 120 is at rest, the center of gravity 52 lies in the plane 54 spanned by the axis of rotation 119 and the lever tilting axis 53. This allows the characteristic curves in motor operation and generator operation to have the same kinematic behavior.

[0102] Figure 18 to Figure 19 A variant is shown in which, when the motor 120 is at rest, the center of gravity 52 is located outside the plane 54 spanned by the axis of rotation 119 and the lever tilt axis 53. If the center of gravity were to be to the left or to the right of the plane, an asymmetric movement behavior would result, and the torque at the start of the movement would be lower in one operating mode than in the other, since the influence of the radial position of the center of gravity is amplified or attenuated at the start.

[0103] The present invention is not limited to the embodiments shown in the accompanying drawings. Therefore, the above description should not be regarded as limiting, but rather as illustrative. The attached claims should be understood to mean that the stated features exist in at least one embodiment of the present invention. This does not exclude the existence of other features. Where the claims and the above description define a "first" feature and a "second" feature, such naming is used to distinguish between two features of the same type without defining the order of precedence.

[0104] Reference numerals list

[0105] 1 Rotor

[0106] 2 Stator

[0107] 3. First rotor body

[0108] 4 Second rotor body

[0109] 5 Rotor shaft

[0110] 6 The first set of permanent magnets

[0111] 7 Field Attenuation Mechanism

[0112] 8 Torsional stiffness parts

[0113] 10 Lever element

[0114] 11 First Lever Window

[0115] 12 Lever contact section

[0116] 13 Lever contact section

[0117] 14 Second lever window

[0118] 15 Lever contact section

[0119] 16 Lever contact section

[0120] 17 Profile

[0121] 18 Rotation axis

[0122] 19 Touchpoints

[0123] 20 touch points

[0124] 21 Touchpoints

[0125] 22 Air Gap

[0126] 23 Connection line

[0127] 24 Tilt axis

[0128] 25 grooves

[0129] 26 Basic ontology

[0130] 27 claws

[0131] 28 Fixing ring

[0132] 29 rotor disc

[0133] 30 rotor disc

[0134] 31 First lever section

[0135] 32 Second lever section

[0136] 33 Spacer sleeve

[0137] 34 Spacer sleeve

[0138] 35 Stop tooth

[0139] 36 Stop tooth

[0140] 37 Concave

[0141] 38 arc segments

[0142] 39 arc segment

[0143] 41 Contact surface

[0144] 42 Contact surface

[0145] 43 Contact surface

[0146] 44 Contact surface

[0147] 45 Contact surface

[0148] 46 Contact surface

[0149] 47 Open Shoulder

[0150] 48 Guide element

[0151] 49 Balance plate

[0152] 52 Center of Gravity

[0153] 53 Tilt axis

[0154] 54 Plane

[0155] 61 The second set of permanent magnets

[0156] 80 Strength

[0157] 81 Centrifugal force

[0158] 83 Strength

[0159] 117 Operating position

[0160] 118 Operating position

[0161] 119 Rotation axis

[0162] 120 Motor

[0163] 131 Connectors

[0164] 132 Connectors

Claims

1. An electric machine (120), in particular for use in a drive train of a hybrid or purely electric motor vehicle, comprising a stator (2) and a rotor (1) separated from the stator (2) by an air gap (22), wherein: The rotor (1) comprises at least one first rotor body (3) having a first set of permanent magnets (6) and a second rotor body (4) having a second set of permanent magnets (61), wherein the first rotor body (3) and the second rotor body (4) are rotatable relative to each other around a common rotation axis (119) by means of a mechanical field damping mechanism (7) to overcome the influence of a first torsional stiffness member (8), It is characterized in that The field attenuation mechanism (7) comprises a lever element (10) having a centre of gravity (52), the lever element being pivotable about a tilting axis (53), wherein the first rotor body (3) is connectable to a first lever section (31) of the lever element (10), and the second rotor body (4) is connectable to a second lever section (32) of the lever element, and the first lever section (31) and the second lever section (32) are arranged on opposite sides of the lever (10) so that the first rotor body (3) and the second rotor body (4) can be rotated relative to each other in a targeted manner by tilting the lever element (10) in order to achieve a desired movement of the mechanical field attenuation mechanism (7), wherein the centre of gravity (52) of the lever element (10) and the tilting axis (53) are spaced apart from each other when the motor (120) is at rest.

2. The electric machine (120) according to claim 1, It is characterized in that When the motor (120) is in a stationary state, the center of gravity (52) of the lever element (10) is located below the tilting axis (53).

3. The electric machine (120) according to claim 1, It is characterized in that When the motor (120) is in a stationary state, the center of gravity (52) of the lever element (10) is located above the tilting axis (53).

4. The electric machine (120) according to any one of the preceding claims, It is characterized in that When the motor (120) is at rest, the center of gravity (52) is located in a plane (54) spanned by the rotation axis (119) and the lever tilt axis (53).

5. The electric machine (120) according to any one of claims 1 to 3, It is characterized in that When the motor (120) is at rest, the center of gravity (52) is located outside a plane (54) spanned by the rotation axis (119) and the lever tilt axis (53).

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