Rotor with a rotational axis for an electric drive machine

Abstract

The invention relates to a rotor (1) with a rotational axis (2) for an electric drive machine (3), having at least the following components: - a plurality of rotor groups (4), each comprising a plurality of lamination groups (5) and a number of magnets (7) corresponding to a pole pair arrangement (6); and - a rotor shaft (8), on which the rotor groups (4) are fixed. The rotor is primarily characterized in that the rotor groups (4) are arranged on the rotor shaft (8) in an orientation-consistent manner in terms of their end face runout (9) taking into account the pole pair arrangement (6). With the rotor presented here, the imbalance changes caused by heat can be significantly reduced.

Description

Technical Field

[0001] The invention relates to a rotor having an axis of rotation for an electric drive machine, a method for assembling such a rotor, a drive machine for a powertrain, a motor vehicle having such a drive machine, a computer program, and a computer program product having such a computer program for executing the assembly method. Background Art

[0002] Electric drive machines are known from the prior art, which include a stator and a rotor for converting electrical energy into torque (or vice versa in generator operation). In such electric drive machines, the rotor shaft is typically provided with a large number of magnetically insulated laminations, which are packaged into a lamination stack. In permanently excited synchronous machines (PSMs), the lamination stack is equipped with permanent magnets (e.g., containing neodymium, iron, and boron, or samarium and cobalt). The lamination stack is pre-assembled or placed on the rotor shaft without magnets. The concentricity (or eccentricity) of the lamination stack is measured beforehand. Eccentricity is the deviation between the center axis of the inner diameter (i.e., the seat on the rotor shaft) and the outer diameter of the lamination stack. To minimize imbalance, the lamination stack is then arranged in an optimized manner, for example, so that it is positioned and fixed on the rotor shaft in a mutually compensating manner.

[0003] It has been found that when the temperature rises to operating temperatures of, for example, 120°C (one hundred and twenty degrees Celsius) to 160°C, the thermal expansion of the laminated core leads to bending moments on the rotor shaft. In the case of elastic deformation, this can lead to reversible imbalance within the operating temperature range. However, plasticization can also occur on the rotor shaft and / or the laminated core, resulting in irreversible imbalance. In the best case, this effect occurs during in-line commissioning (i.e., during the start-up of the production line), allowing it to be compensated with the help of balancing. However, this effect often also occurs during commissioning at the customer's site, affecting the operating performance of the rotor. Summary of the Invention

[0004] Starting from this, the basic object of the present invention is to at least partially overcome the disadvantages known from the prior art. The features of the invention are apparent from the following description, and advantageous embodiments thereof are illustrated in the following preferred embodiments. The features of the invention can be combined in any technically appropriate manner and method, and for this purpose, the explanations from the following description and the features from the accompanying drawings, which include supplementary embodiments of the invention, can also be used.

[0005] The invention relates to a rotor having a rotation axis for an electrically driven machine, the rotor comprising at least the following components:

[0006] - a plurality of rotor groups, each of the plurality of rotor groups comprising a plurality of lamination stacks and a number of magnets corresponding to the pole pair arrangement; and

[0007] A rotor shaft, to which the rotor assembly is fastened.

[0008] This rotor is characterized essentially in that the rotor components are arranged on the rotor shaft in a uniformly oriented manner according to their end face runout, taking into account the pole pair arrangement.

[0009] In the following text, if the axial direction, radial direction, or circumferential direction and the corresponding terms are used without explicit indication otherwise, reference is made to the axis of rotation mentioned. Unless explicitly stated otherwise, the ordinal numbers used in the above and below descriptions are used only for clarity and do not reflect any order or sequence of the components referred to. An ordinal number greater than one does not necessarily mean that another such component must be present.

[0010] The rotor can be placed in a conventional manner in an electric drive machine (i.e., a PSM), for example, in a conventional manner. The rotor shaft can rotate about its axis of rotation, wherein, due to tolerances, there are imbalances relative to the axis of rotation that are to be minimized, for example, imbalances due to concentricity deviations (eccentricity). In one embodiment, the rotor shaft is designed as a single piece and / or includes one or more pinions for transmitting the torque of the rotor shaft to a transmission. The eccentricity is a measure from the geometric center of the outer circumference (here, the shaft seat that accommodates the rotor assembly) to the actual axis of rotation, wherein in the context considered here, the axis of rotation generated by the bearing seat is defined as the basic measure.

[0011] The respective rotor stack is a laminated core with magnets arranged according to the desired number of poles or pole pairs. This does not necessarily mean that each rotor stack has its own set of magnets. In one embodiment, multiple laminated cores are equipped with shared magnets, i.e., magnets with a longer axial extension than one of the multiple laminated cores. In an advantageous embodiment, each laminated core is equipped with its own magnets, so that each rotor stack is designed to be self-sufficient relative to the other rotor stacks.

[0012] Each lamination stack consists of a plurality of (axially) stacked (preferably conventionally) rotor laminations. Each rotor lamination includes an insertion receptacle for a magnet and a central shaft receptacle. The lamination stack has this larger axial extension. The lamination stack is typically a purchased part. This lamination stack has an axis of rotation that, ideally, coincides with the rotor shaft's axis of rotation after assembly. In practice, deviations due to tolerances, both internal and due to assembly tolerances, can occur.

[0013] The rotor comprises a plurality of rotor groups, for example 3 [three] to 8 [eight], which are fastened to the rotor shaft, for example, by means of a press fit.

[0014] It has been determined that the aforementioned effects of thermally induced bending moments on the rotor shaft are at least largely caused by the end face runout of the lamination stack. End face runout is the inclination of the plane of the lamination stack or rotor stack relative to its (own) central axis of rotation or the axis of rotation of the rotor shaft. For example, if, in an extreme case, two rotor stacks are arranged side by side with opposite end face runouts (i.e., tilted toward each other), the two rotor stacks will repel each other only or primarily on the side of their contacting (outer) edges due to their thermal expansion, thus exerting a lever effect on the rotor shaft due to their radial expansion. This can cause bending moments. This end face runout can be as high as 0.3 mm (three-tenths of a millimeter), for example, with disk diameters of 120 mm (one hundred and twenty millimeters) to 160 mm.

[0015] It is now proposed that the rotor assembly be assembled with its end face runout in a manner that is as uniformly oriented as possible. Ideally, the rotor assembly is positioned and fixed so that the individual lamination stacks rest parallel to one another on the rotor shaft. Rotor assembly mounted with uniform end face runout thus exhibits uniformly oriented inclinations relative to the respective (parallel) axes in a plane oriented orthogonally to the axis of rotation. This avoids leverage effects caused by thermal expansion. Due to the pole pair arrangement and the requirement that the individual orientations of the rotor assembly (with minimal angular tolerances relative to the axis of rotation) must be uniform, the ideal uniformity of the end face runout is limited. For example, with three pole pairs, only three angular orientations (rotated 120° relative to one another) are possible. In the extreme case of two rotor assembly oriented in opposite directions (i.e., with the largest end face runout), assuming an ideally flat end face runout (i.e., a linear transition), the leverage effects caused by thermal expansion can be reduced by at least approximately 66% through a relative angular rotation of 120°. In contrast to the ideal orientation consistency of the end face runout, "orientationally consistent" should be understood to mean at least polarity-adaptive orientation consistency, i.e., a pole deflection angle that is less than a fraction of one full revolution [360°; numerator] divided by the number of pole pairs (i.e., half the number of (polarity-effective) magnets). This means, in the example above, less than 120°. Preferably, the lamination stack or rotor stack is preselected and arranged in such a way that the polarity-adaptive orientation consistency is less than 60°, particularly preferably less than 30°.

[0016] It should also be noted that with such a rotor the duration required for online commissioning can be shortened or even omitted, thus saving a considerable amount of time in the production of the rotor.

[0017] According to another aspect, a method for assembling the rotor according to the above embodiment is provided, the method comprising the following steps:

[0018] a. Provide lamination pack;

[0019] b. measuring the lamination stack;

[0020] c. Provide a magnet;

[0021] d. Each of the lamination stacks is connected to a corresponding number of magnets to form a rotor group having a corresponding pole pair arrangement;

[0022] e. Provide rotor shaft;

[0023] f. positioning the rotor shaft and the rotor assembly relative to each other; and

[0024] g. Fixing the rotor shaft and the rotor assembly to each other to form a rotor.

[0025] In step f., the rotor assembly is mounted on the rotor shaft in a uniformly oriented manner according to its end face runout determined in step b., taking into account the pole pair arrangement.

[0026] This illustrates an advantageous assembly method for a rotor according to the previously described method, and without loss of generality, reference is made to the description therein. It should be noted that the steps can be performed in any order, as long as they do not build upon one another. For example, steps a, c, and e can be performed independently of one another, as needed (e.g., in a kanban system), or simultaneously. For example, step b can be performed after step d. Steps a through c or d can, for example, be performed at a separate location (e.g., at a supplier), where the measurement data for the respective lamination stack or rotor stack is stored. Steps a through d are repeated (for each additional rotor stack) until the desired number of rotor stacks is available for assembly. Step f (and possibly step g) is repeated a corresponding number of times, or the desired number of rotor stacks are placed on the rotor shaft at once (and then secured in step g).

[0027] For the execution of step f., steps a. to c. and step e. need to be completed, but step d. can also be performed only after step g., for example. Preferably, step d. is performed before step f., wherein it is particularly preferred that the rotor groups are each self-sufficient relative to each other, that is, comprise magnets that are independent of each other. It should also be noted that steps f. and g. are performed repeatedly for each rotor group. For example, when a press-fit connection is performed, steps f. and g. are smoothly combined (for example, when assembly is performed using thermal expansion and appropriate temperature control). In one embodiment, steps a. to g. can be integrated into conventional assembly methods, or even each can be performed separately in a conventional manner. In an advantageous embodiment, all or most of the steps (for example, at least steps a., c. and e. and / or steps d. and f.) are performed using automated transport tools and / or robots.

[0028] In this case, the end face runout determined in step b. is now taken into account in step f. In one embodiment, step b. is performed immediately before step f. In step f., the installation also includes orienting the rotor assembly according to its end face runout. In one embodiment, the end face runout is not the only tolerance to be taken into account when installing in step f. As mentioned above, the orientation consistency of the end face runout is always secondary to the pole pair arrangement, that is, it can only be approximate. In a preferred embodiment, the orientation consistency of the end face runout takes precedence over other measures for compensating tolerances, such as those that lead to imbalance.

[0029] In one embodiment, the assembly method is followed by a (preferably shortened) online commissioning. In one embodiment, the online commissioning is performed based on the degree of alignment of the end face runout of the rotor assembly fixed to the rotor shaft. This decision is based on experience, for example.

[0030] In an advantageous embodiment of the assembly method, it is further provided that before step f., a plurality of laminated cores and / or rotor cores are arranged according to their respective end face runouts and in step f. the arranged rotor cores are each placed on the rotor shaft.

[0031] It is proposed that a buffer storage bin with a lamination stack and / or rotor assembly be reserved, in which the lamination stack and / or rotor assembly are arranged in such a way that they can be mounted on the rotor shaft in a uniformly oriented manner in particularly close proximity to one another. Preferably, the relative eccentricity of the rotor shaft relative to the rotor assembly is also taken into account, with compensation being sought. The criteria for the arrangement are the angular orientation of the end face runout, the tolerance value of the end face runout, and possibly also the eccentricity. Depending on the variety of events or the combination of tolerances, a corresponding number of buffer storage bins should be reserved for each rotor or each rotor shaft. In this case, apart from a longer startup phase during the assembly operation, no or only reduced time delays are to be expected.

[0032] In an advantageous embodiment of the assembly method, it is further provided that in step f., the rotor assembly is assembled according to its eccentricity determined in step b.

[0033] And preferably, the rotor assembly is tilted according to its end face,

[0034] Oriented and / or mounted in a corresponding sequence on the rotor shaft.

[0035] For example, to minimize dynamic imbalance, the rotor assemblies are arranged in such a way that rotor assemblies with poor concentricity (i.e., high eccentricity) are positioned axially outward on the rotor shaft, while rotor assemblies with better concentricity are positioned axially in the center of the rotor shaft. This means that the primary imbalance contributors are positioned close to or directly adjacent to the (optional) balancing disk, thereby reducing the effects of deformation on the rotor shaft and / or adjacent rotor assemblies. Similarly, rotor assemblies with larger end face runout tolerance values ​​are preferably positioned further outward than rotor assemblies with lower tolerance values, thereby achieving the most compact axial stacking possible on the rotor shaft.

[0036] In one embodiment, an optimal orientation (i.e., relative angular position) about the rotation axis of the rotor shaft is determined based on the eccentricity and the end face runout. For example, better orientation consistency is sacrificed for end face runout in order to achieve improved unbalance quality. Preferably, better unbalance quality is sacrificed for improved orientation consistency for end face runout.

[0037] In an advantageous embodiment of the assembly method, it is further provided that, in a further step h., at least one balancing disk is placed on the rotor shaft, and in a step i., the at least one balancing disk is processed depending on the measured imbalance.

[0038] Step h. proposed here is performed before, simultaneously with, or after step g. Subsequently, as is known per se, the at least one balancing disk (preferably one at each end of the rotor assembly) is treated, for example, iteratively, to minimize the imbalance. In a preferred embodiment, before treating the at least one balancing disk, the imbalance and / or bending moments caused by thermal expansion of the rotor assembly are recorded and registered as experience with the orientation and sequence of the rotor assembly and the quality of the rotor assembly, for example, stored in a computer.

[0039] In an advantageous embodiment of the assembly method, it is further provided that the rotor is measured and the measurement data of the rotor are integrated into the machine learning model in a manner associated with the measurement data of the rotor assembly fixed to the rotor shaft and the rotor shaft, as well as the relative position of the rotor assembly.

[0040] In this embodiment, a learning algorithm (machine learning model) is integrated in which large amounts of data can be taken into account and used to improve the control results. Such learning algorithms (also called deep learning algorithms) are already known in the field of speech recognition or speech processing and face recognition, which are characterized in that these fields are based on amounts of data that cannot be adequately controlled by humans and / or are based only on rules that are inadequate or not known at all. Compared to finite element algorithms, such deep learning algorithms are trivial in the smallest details, but due to the complexity (in this case mainly the amount of associated measurement data), the task is unsolvable for humans or can only be solved with an unreasonable expenditure of time. Known deep learning algorithms or available program libraries are, for example, Keras and Cognitive Toolkit.

[0041] Not all effects caused by imbalance changes during operation (i.e., during service life or after premature replacement) or during online commissioning can be fully explained by the eccentricity and end runout described here. Since measurements of the laminated stack or rotor assembly are always available (step b.), modeling using machine learning (machine learning model) is proposed here. This means that effects that are difficult or impossible to describe analytically can also be reproduced. To do this, domain knowledge that can be described analytically is first integrated into the machine learning model.

[0042] It is therefore proposed here to use a machine learning model to further improve the solution to the complex task described herein. Particularly preferably, the method is performed together with assembly on an assembly line in a factory, wherein the measurement results (e.g., quality control) are incorporated into the decision-making for the selection and / or placement of the rotor group for the rotor. For example, a selection and / or arrangement of a rotor group that is not or is subjected to online debugging and is considered just sufficient may achieve better results than a selection and / or arrangement of a rotor group that is considered more optimized for another rotor. The decision is then changed accordingly with the aid of a machine learning model. In this embodiment of the assembly method, a very large number of different measured values ​​are preferably recorded, which makes manual analysis and decision-making almost impossible due to the resulting complexity.

[0043] In one advantageous embodiment of the assembly method, the measurement results of the laminated stack in step b. are input as a machine-readable code on the laminated stack or on a carrier of the transport tool and read out in step f. for placement or for loading the buffer storage bin. In one embodiment, the measurement results are stored in a corresponding computer in order to form an experience set or data source for the machine learning model.

[0044] The machine learning model is preferably started during ongoing production, enabling further quality improvements based on analytical assembly quality without the need to interrupt assembly for complex test series.

[0045] According to another aspect, a drive machine for a powertrain is proposed, the drive machine having at least the following components:

[0046] - a rotor according to the above embodiment;

[0047] - a stator corresponding to the rotor; and

[0048] - a shaft bearing for a rotor shaft,

[0049] Preferably, the rotor is assembled according to the assembly method of the above embodiment.

[0050] The electric drive machine is a so-called permanently excited synchronous machine [PSM], which can be used as a torque source (engine operation) and / or an energy source (generator operation). The rotor is designed in the manner described above. The stator operates in a conventional manner, so that the torque of the electric drive machine can be generated and controlled in a conventional manner, and is designed, for example, in a conventional manner. The rotor shaft or rotor is supported by means of shaft bearings, such as fixed bearings and floating bearings, preferably rolling bearings. The shaft bearings are integrated into the engine housing or are at least partially arranged in the (integrated) transmission housing. In the latter case, for example, the electric drive machine is assembled solely in the transmission housing. Preferably, the rotor is assembled according to the assembly method of the above-described embodiment.

[0051] The rotors of electrically driven machines are particularly well balanced and only experience negligible or small temperature-induced imbalance changes. This results in very smooth operation and a long service life in all operating states.

[0052] According to another aspect, a motor vehicle is proposed, comprising: at least one drive wheel; a drive machine according to the above embodiment, which propels the motor vehicle via the at least one drive wheel; and a traction battery, which provides an electrical voltage for the electric drive machine.

[0053] It is now proposed that a motor vehicle includes a drive machine in which the electrical voltage required for propulsion of the motor vehicle is provided by a traction battery. The traction battery is electrically connected to the drive machine and supplies the required electrical voltage to the drive machine based on propulsion requirements (e.g., based on the position of the accelerator pedal). Torque (generated in the electric drive machine) can be transmitted to at least one drive wheel via a rotor shaft (preferably via a transmission gear and / or a differential). The drive wheel transmits the torque to the ground, thereby propelling the motor vehicle forward.

[0054] The rotors of electric drive machines are particularly well balanced and experience only negligible or small temperature-induced imbalance changes. This results in very smooth operation and a long service life in all operating states. This also increases the power efficiency of the propulsion.

[0055] According to another aspect, a computer program is provided, the computer program comprising:

[0056] Computer program code, wherein the computer program code is executable on at least one computer so as to cause the at least one computer to perform the assembly method according to the above embodiment, wherein at least one of the computers:

[0057] - integrated into an edge device of an assembly station, preferably as an assembly computer or a component of an assembly computer; and / or

[0058] - configured to communicate with a cloud which preferably provides computer program code.

[0059] It should be noted that the assembly method is physically performed by one or more assembly stations, and the computer program merely commands the devices used and, in some cases, instructs the personnel involved accordingly. The computer program is a superior or specialized supplement to the subroutines that (e.g., at the machine code level) output actual executable commands (e.g., movements of a robot arm) or outputs on a human-machine interface (e.g., a screen). Preferably, the subroutines are executed in a conventional manner or are configured to be executed and / or operated in a conventional manner by the corresponding automated devices.

[0060] The computer includes one or more processors, such as a general-purpose processor (CPU) or a microprocessor, a RISC processor, a GPU and / or a DSP. For example, the computer has additional elements such as a memory interface. Alternatively or additionally, the term refers to a device that can preferably use a standardized programming language (such as C++, JavaScript or Python) to execute a provided or packaged program and / or control and / or access data storage devices and / or other devices (such as input interfaces and output interfaces). The term "computer" also refers to a plurality of processors or a plurality of (sub) computers that are interconnected and / or otherwise communicatively connected and that may use one or more other resources (such as a memory) in common.

[0061] The (data) memory is, for example, a hard disk (HDD, SSD, HHD) or (non-volatile) solid-state memory, such as ROM memory or flash memory (EEPROM). The memory typically consists of multiple separate physical units or is distributed across a large number of individual devices, allowing access via (data) communication (e.g., packet data services). The latter is a decentralized solution in which the memory and processors of multiple independent computing units are used instead of or in addition to a (single, modular) central onboard computer.

[0062] According to another aspect, a computer program product having a computer program code stored thereon is provided, wherein the computer program code is executable on at least one computer so as to cause the at least one computer to perform the assembly method according to the above-described embodiment, wherein at least one of the computers:

[0063] - integrated into an edge device of an assembly station, preferably as an assembly computer or a component of an assembly computer; and / or

[0064] - configured to communicate with a cloud which preferably provides computer program code.

[0065] The computer program product with the computer program code is, for example, a medium such as RAM, ROM, SD card, memory card, flash memory card or optical disc. Alternatively, the computer program product is stored on a server and can be downloaded. Once the computer program is made readable by a reading unit (e.g. a drive and / or an installation program), the computer program code contained therein and the method contained therein can be executed by a computer or in a manner communicating with a plurality of computer-aided devices, as described above.

[0066] The edge device corresponds to a local server that is arranged at an assembly station, assembly line, or production site and is provided in a dedicated manner with the smallest possible distance and as little other (interfering) data transmission as possible. It contains all the necessary components of a computer, and preferably, the edge device is physically separated from the rest of the data processing and is configured only for the tasks of the machine learning model.

[0067] In terms of their tasks, the cloud corresponds to edge devices, but in contrast, it is a collection of remote or at least widely available servers or computers. In some cases, this can offer greater computing power and / or lower initial costs compared to edge devices. However, the downsides often lie in data congestion due to the diverse nature of queries, as well as data security. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The invention will be described in detail below, starting from the relevant technical background and referring to the accompanying drawings showing preferred designs. The invention is not limited in any way by the purely schematic drawings, wherein it should be noted that the drawings are not accurate in size and are not suitable for defining dimensional ratios. In the drawings:

[0069] Figure 1 : shows a perspective view of the rotor;

[0070] Figure 2 : shows a schematic cross-sectional view of a conventional rotor having a rotor shaft with two rotor groups;

[0071] Figure 3 :Shows the heating state according to Figure 2 Conventional rotor;

[0072] Figure 4 : shows a schematic cross-sectional view of a rotor having a rotor shaft with two aligned rotor groups;

[0073] Figure 5 : A diagram showing the assembly method;

[0074] Figure 6 : shows a schematic front view of the rotor assembly; and

[0075] Figure 7 : Shows a top view of a motor vehicle with an electric drive machine. DETAILED DESCRIPTION

[0076] exist Figure 11 shows a perspective view of a rotor 1. The rotor 1 is rotatable about a central axis of rotation 2 and comprises a rotor shaft 8 (here with a pinion 24 at one end) with a first bearing seat 25 and a second bearing seat 26. The rotor 1 comprises a shaft seat 27 between the bearing seats 25, 26 (see Figures 2 to 4 ) on the (purely optional six) rotor groups 4. Balancing disks 11, 12 are arranged on each end side of the rotor shaft 8, i.e. a first balancing disk 11 on the pinion side of the rotor group 4 and a second balancing disk 12 on the illustrated side of the rotor group 4. Each rotor group 4 includes a laminated core 5 and a number of magnets 7 corresponding to the desired pole pair arrangement 6.

[0077] (See e.g. Figure 6 ). For example, the rotor 1 has the size and / or functionality of a conventional rotor 28.

[0078] exist Figure 2 , a schematic cross-sectional view of a conventional rotor 28 is shown with a rotor shaft 8 having two end-side bearing seats 25, 26 and two rotor assemblies 4 on an axially central shaft seat 27. The rotor shaft 8 and the two rotor assemblies 4 are, for example, designed in a conventional manner. The end face runout 9, i.e., the inclination of the plane of the rotor assembly 4 relative to the axis of rotation 2 (either its own or that of the rotor shaft 8), is shown exaggerated here for easier understanding. Again, for simplicity, the axis of rotation 2 is shown precisely in the center of the rotor shaft 8. Here, for example, the two rotor assemblies 4 are mounted on the rotor shaft 8 in such a way that they rest against each other with their end face runouts 9 oriented in opposite directions. The rotor assemblies 4 are thus tilted toward each other.

[0079] exist Figure 3 In the figure, the heat state is shown according to Figure 2 Conventional rotor 28. In the heated state shown here (e.g., at operating temperatures in the range of 120°C to 160°C), rotor core 4 expands. The thermal expansion of rotor core 4, combined with the oppositely directed end face runout 9 of rotor core 4, results in a bending moment on rotor shaft 8 (about an axis perpendicular to the plane of the drawing). The bending moment of the laminated core 5 thus causes an imbalance 13 of rotor 1 about the axis of rotation 2. For easier understanding, the imbalance 13 of rotor 1 about the axis of rotation 2 is shown exaggerated. This is reversible, i.e., it is compensated as the temperature of rotor core 4 decreases and the thermal expansion recedes, or plastic deformation of rotor shaft 8 and / or plastic deformation of at least one of rotor core 4 remains.

[0080] exist Figure 4 1 shows a schematic cross-sectional view of a rotor 1 having a rotor shaft 8 with two aligned rotor groups 4. Without loss of generality, purely for the sake of clarity, the rotor 1 is shown with Figure 2The embodiment shown is essentially identical, so reference is made to the description therein to some extent. In this embodiment, the rotor stacks 4 are mounted on the rotor shaft 8 with (purely optional, equal in magnitude and) aligned end face runouts 9, so that, in the event of thermal expansion of the two rotor stacks 4, no bending moments (at least no bending moments caused by the end face runouts 9) act on the rotor shaft 8. Due to the aligned alignment of the end face runouts 9 of the laminated core 5, the rotor 1 thus experiences no or only very slight imbalance changes.

[0081] exist Figure 5 For the description of the rotor 1 and its components herein, reference is made purely by way of example to the Figure 1 . In a first step a., a lamination stack 5 is provided. In step b., the end face runout 9 of the lamination stack 5 and preferably the eccentricity 10 of the lamination stack are measured. In this case, the (first) measurement data are optionally stored for subsequent correlation. Providing magnets 7 in a subsequent step c. is purely optional. In step d., one of the lamination stacks 5 is connected to a corresponding number of magnets 7 (for example, by means of adhesive bonding in a permanently loose manner) to form a rotor stack 4. It should be noted that the magnets 7 are arranged in the lamination stack 5 in such a way that their polarity is aligned in a pole pair arrangement 6.

[0082] In a further step e., a rotor shaft 8 is provided, and in step j., at least its concentricity is measured. The rotor shaft 8 is configured to receive a plurality of rotor assemblies 4 and at least one balancing disk 11, 12. In a subsequent step f., the rotor shaft 8 and the rotor assembly 4 are positioned relative to each other in an assembly station 22 (based on the first measurement data from step b.). Then, in step g., the rotor assembly 4 is secured to the rotor shaft 8, for example, by shrink-fitting. It is purely optional to place and secure (for example, two) balancing disks 11, 12 to the rotor shaft 8 in step h. simultaneously with steps f. and g. In a subsequent step i., the balancing disks 11, 12 are processed (for example, iteratively) based on the measured imbalance 13. Optionally, at least the initial (preferably all) measurements are stored as (second) measurement data. Optionally, step i. also includes online commissioning.

[0083] The measurement data of the rotor 1 determined in step i. are correlated together with the measurement data of the rotor assembly 4 attached to the rotor shaft 8 and of the rotor shaft 8 itself, as well as the relative position of the rotor assembly 4. Optionally, the correlated measurement data are stored and / or processed in the edge device 21 or the cloud 23 and integrated into a machine learning model in such a way that the continuous improvement of the arrangement and / or orientation of the rotor assembly 4 is set as the goal of the machine learning model.

[0084] exist Figure 6 , a schematic front view of a rotor core 4 is shown. The rotor core 4 comprises a laminated core 5 with a plurality of magnets 7 (here six), which are arranged in a 120° pole pair arrangement 6 within the laminated core 5. The axis of rotation 2 is shown in the center. Due to production-related reasons, the laminated core 5 (and therefore the rotor core 4) has a concentricity deviation (eccentricity 10) with respect to the axis of rotation 2, which leads to an imbalance 13. The laminated core 5 also has an end face runout 9, i.e. an inclination of the plane of the laminated core 5 relative to the (own) axis of rotation 2 or relative to the axis of rotation 2 of the rotor shaft 8 (see Figure 4 The angular position of the end face runout 9 is determined with the aid of the pole deflection angle 29. This pole deflection angle represents the uncompensable deviation of the uniformly oriented end face runout 9, assuming that the end face runout 9 of the other rotor group 4 has a zero pole deflection angle 29.

[0085] exist Figure 7 shows a purely schematic top view of a motor vehicle 17 having an electric drive machine 3. The drive train 14 has (purely optional) two drive machines 3, one of which is configured, for example, as a rear drive and the other as a front drive. The drive machines 3 are torque-transmittingly connected to left-hand and right-hand drive wheels 18, 19 of a common axle. For example, the drive train 14 of the motor vehicle 17 can be propelled in an all-wheel drive configuration or solely by means of the rear drive or the front drive. Both drive machines 3 include a rotor 1, which is configured to rotate within a respective stator 15. The rotor 1 is supported on an axle bearing 16. To supply voltage to the (electric) drive machines 3, a traction battery 20 is provided, which is arranged, for example, in the floor of the motor vehicle 17. Preferably, at least one of the electric drive machines 3 is configured to recover deceleration energy (braking) alone or in addition, thereby charging the traction battery 20.

[0086] With the rotor proposed here, thermally induced imbalance changes can be significantly reduced.

Claims

1. A rotor (1) having an axis of rotation (2) for an electrically driven machine (3), the rotor comprising at least the following components: - a plurality of rotor groups (4), each of which comprises a plurality of lamination stacks (5) and a number of magnets (7) corresponding to the pole pair arrangement (6), wherein: The lamination stack (5) has an eccentricity (10) and an end face runout (9) relative to the rotation axis (2); and - a rotor shaft (8), the rotor group (4) being fixed on the rotor shaft, the rotor shaft (8) having an axial outer side and an axial center, wherein the rotor group (4) having a large eccentricity (10) is arranged on the axial outer side of the rotor shaft (8), and the rotor group (4) having a small eccentricity (10) is arranged at the axial center of the rotor shaft (8), It is characterized by: The rotor assembly (4) is mounted on the rotor shaft (8) in an aligned manner according to its end face runout (9) while taking into account the pole pair arrangement (6).

2. A method for assembling a rotor (1) according to claim 1, comprising the following steps: a. Providing the lamination stack (5); b. measuring the lamination stack (5) to determine the eccentricity (10) and end face runout (9) of the lamination stack (5) relative to the axis of rotation (2) of the rotor (1); c. providing the magnet (7); d. connecting one of the lamination stacks (5) to a corresponding number of magnets (7) to form a rotor group (4) having a corresponding pole pair arrangement (6); e. Providing the rotor shaft (8), wherein The rotor shaft (8) has an axial outer side and an axial center; f. arranging the rotor shaft (8) and the rotor group (4) relative to each other so that the rotor group (4) with a large eccentricity (10) is arranged axially outside the rotor shaft (8), and the rotor group (4) with a small eccentricity (10) is arranged at the axial center of the rotor shaft (8); and g. fixing the rotor shaft (8) and the rotor assembly (4) to each other to form a rotor (1), In step f., the rotor assembly (4) is mounted on the rotor shaft (8) in a uniformly oriented manner according to its end face runout (9) determined in step b., taking into account the pole pair arrangement (6).

3. The assembly method according to claim 2, wherein Prior to step f., a plurality of laminated cores (5) and / or rotor cores (4) are arranged according to their respective end face runouts (9), and in step f., the arranged rotor cores (4) are respectively placed on the rotor shaft (8).

4. The assembly method according to claim 2 or 3, wherein In step f., the rotor assembly (4) is adjusted according to its eccentricity (10) determined in step b. and the rotor assembly (4) is tilted according to its end face (9), Oriented and / or mounted in a corresponding sequence on the rotor shaft (8).

5. The assembly method according to any one of claims 2 or 3, wherein Furthermore, in step h., at least one balancing disk (11, 12) is placed on the rotor shaft (8), and in step i., the at least one balancing disk is processed according to the measured imbalance (13).

6. The assembly method according to claim 2 or 3, wherein The rotor (1) is measured, and the measurement data of the rotor (1) is integrated into a machine learning model in a manner associated with the measurement data of a rotor assembly (4) fixed to the rotor shaft (8) and the rotor shaft (8), as well as the relative position of the rotor assembly (4).

7. A drive machine (3) for a powertrain (14), the drive machine having at least the following components: - a rotor (1) according to claim 1; - a stator (15) corresponding to said rotor (1); and - a shaft bearing (16) for the rotor shaft (8).

8. The drive machine (3) according to claim 7, wherein The rotor (1) is assembled according to the assembly method according to any one of claims 2 to 6.

9. A motor vehicle (17) comprising: at least one drive wheel (18, 19); a drive machine (3) according to claim 7 or 8, which propels the motor vehicle (17) via the at least one drive wheel (18, 19); and a traction battery (20) which provides an electrical voltage for the electric drive machine (3).

10. A computer program product having a computer program code stored thereon, wherein the computer program code is executable on at least one computer to cause the at least one computer to perform the assembly method according to any one of claims 2 to 6, wherein at least one of the computers: - integrated into an edge device (21) of an assembly station (22); and / or - configured to communicate with the cloud (23).

11. The computer program product of claim 10, wherein At least one of the computers serves as an assembled computer or a component of an assembled computer.

12. The computer program product of claim 10, wherein The cloud (23) provides the computer program code.

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