Circular ring segment-shaped rotor segment formed from an electric sheet metal, laminated core assembly, segmented rotor and electric machine

Abstract

The invention relates to a circular ring segment-shaped rotor segment (1) that is formed from an electric sheet metal and is suitable for a segmented, continuously excited rotor (2) of an electric machine (3). The rotor segment (1) comprises a plurality of magnet pockets (4) for receiving permanent magnets (5). The rotor segment (1) has at least one first opening (6) with two tangential tabs (8) that lie opposite one another in the tangential direction (7) and can be pivoted axially, and at least one second opening (9) with two radial tabs (11) that lie opposite one another in the radial direction (10) and can be pivoted axially. A plurality of such rotor segments (1) form a laminated core arrangement of the continuously excited rotor (2) by means of an offset arrangement, wherein a first opening (6) of a first rotor segment lies above or below an aligned second opening (9) of a second rotor segment and all tangential and radial tabs (8, 11) are bent in an axial direction.

Description

[0001] Circular segment-shaped rotor segment formed from an electrical sheet, laminated core arrangement, segmented rotor and electrical machine

[0002] The present invention relates to a rotor segment in the shape of a circular ring, formed from an electrical steel sheet, for forming a segmented, permanently excited rotor of an electrical machine, comprising a plurality of magnetic pockets formed in the rotor segment for accommodating permanent magnets. The invention further relates to a laminated core assembly, a segmented rotor, and an electrical machine.

[0003] In the field of electrical machines, especially those used in highly dynamic applications such as electric vehicles or industrial applications, the rotor design plays a crucial role. Segmented rotors have emerged as a promising alternative to conventional solid-ring rotors, addressing specific challenges related to manufacturing, efficiency, and adaptability.

[0004] Segmented rotors, due to their modular design, offer the advantage of enabling precise arrangement of the permanent magnets and optimal magnetic flux control. This can lead to increased efficiency of the electric machine. The ability to manufacture and assemble the rotor segments separately facilitates the production of complex rotor structures and can reduce production costs.

[0005] Despite these advantages, segmented rotors pose several challenges to the state of the art. A key problem is ensuring precise alignment and secure connection of the individual rotor segments, as any deviation can impair the efficiency and operating behavior of the machine. Misalignment of the rotor segments can lead to, among other things, vibrations, acoustic noise, and uneven wear, which reduces the service life and reliability of the rotor. Another problem is the assembly of the segmented rotors. A precise and stable design is required to ensure a permanently reliable mechanical structure. In this context, the thermal integrity of the rotor segments is also important, as different thermal expansions of the segments can lead to stresses in the material and a reduction in mechanical strength.

[0006] The manufacturing and stacking of the individual segments can also be complex, as each step must be performed with high precision to avoid assembly errors. Furthermore, each additional manufacturing step increases the risk of irregularities and defects. The use of fixation materials is also a critical issue, as these hold the rotor segments securely in place but can also be a source of mechanical weaknesses if not properly designed and implemented.

[0007] The production of lamination stacks or individual laminations is inherently associated with considerable material costs. Options for reducing costs include increasing the rotor's power density to achieve greater efficiency while maintaining the same material usage. Another option is to optimize the raw sheet material through clever cutting. One approach to this is the aforementioned segmentation of rotors or their laminations. However, segmenting rotor laminations requires even greater mitigation of centrifugal forces that occur at higher speeds.

[0008] To solve this problem, there are, among other things, bandages, such as those made of fiber-reinforced plastic, the realization of a positive connection between individual segments or segments and the rotor carrier, or even the transfer of centrifugal forces to elements located outside the active length.

[0009] Different design approaches for the formation of the laminated cores and their fixation are known.For example, DE102012013836A1 discloses a connecting arrangement of a first ring segment, which has at least one first form-locking element of a form-locking arrangement, with at least one second ring segment, which has at least one second form-locking element of the form-locking arrangement, of a ring element for an electrical machine, in which the ring segments are positively connected to one another in the tangential direction via the form-locking elements which interact with one another and each have at least two form-locking regions which follow one another in the tangential direction of the ring element to form a respective form-locking connection of the form-locking arrangement, wherein at least one further form-locking connection of the ring segments is provided in the radial direction at least on the outside of the form-locking arrangement, by means of which one of the ring segments is covered outwards in the radial direction by the other ring segment to support the form-locking arrangement.Puzzle-piece-like form-locking elements are used that can interlock with each other.

[0010] US2012126658 A1 discloses that a rotor core for a rotating electrical machine comprises a plurality of annular core plates. The core plates are formed by joining arcuate segments. The core plate segments each include a protruding portion formed on one surface of each of the segments and having an arcuate end in the tangential direction, and a depressed portion formed on the other surface and having an end. The tangential direction is arcuate, and the protruding portion of the core plate segment of another layer is adapted to it when the core plates are laminated. An interference fit is provided in the radial direction between the width of the protruding portion of the core plates and the depressed portion of the core plates, and a loose fit is provided in the tangential direction.Furthermore, each of the core plate segments is provided with a plurality of magnet insertion holes into which permanent magnets, such as neodymium magnets, are inserted. A plurality of fastening portions are provided for fastening the plurality of stacked core plates. The magnet insertion holes and the fastening portions are formed in the tangential direction of the core plate segment. The fastening portions are respectively provided on the inner circumferential sides of the two end portions of each magnet insertion hole. The fastening portions are fastened after the core plates are temporarily assembled, so that the overall configuration of the core plates can be maintained in the rotor core without falling apart. The fastening portions each include a protruding portion, such as a dowel.

[0011] US2016094098 A1 discloses a rotor with a rotor core and permanent magnets. The rotor core comprises annular bodies stacked in a stacking direction and each consisting of core segments arranged along a tangential direction. The number of core segments in each of the annular bodies is determined based on k, where k is the number of magnetic poles formed by the permanent magnets. The rotor core has n through-holes, where n^k. The rotor further comprises n fastening elements, each extending in the stacking direction through a corresponding through-hole of the rotor core. A gap is formed between each tangentially adjacent pair of core segments, which gap is larger than a distance provided between the through-holes of the rotor core and the fastening elements.At least one of the annular bodies is offset in the tangential direction by an integer multiple of a magnetic pole relative to another annular body. Furthermore, this document teaches the use of puzzle-piece-like end sections of the segments. The fastening elements used can be rivets or pins.

[0012] Based on these considerations, the state of the art aims to find improved solutions that enable efficient, precise and cost-effective production of segmented rotors, as well as to develop assembly methods that ensure a reliable and permanently stable connection of the rotor segments.

[0013] The object of this invention is therefore to create a rotor segment design for permanent magnet rotors that enables improved assembly and handling and increases the precision and mechanical stability of the rotor within the electrical machine. The object of the invention is further to create an improved laminated core assembly using a segmented rotor stack that can structurally transmit both the rotor torque to the shaft and the acting centrifugal forces. It is also the object of the invention to realize an optimized segmented rotor and an improved electrical machine.

[0014] This object is achieved by a rotor segment in the shape of a circular ring section, formed from an electrical steel sheet for forming a segmented, permanently excited rotor of an electrical machine, comprising a plurality of magnetic pockets formed in the rotor segment for receiving permanent magnets, wherein the rotor segment has a first opening with tangential tabs opposite one another in the tangential direction and pivotally formed on the rotor segment, and a second opening with radial tabs opposite one another in the radial direction and pivotally formed on the rotor segment, wherein the rotor segments can be stacked alternately in the axial direction offset from one another by an angle in the tangential direction, and the first opening and the second opening are designed such that they can be positioned flush with one another when the rotor segments are stacked.

[0015] The invention thus relates to the design of a rotor segment in which special tabs are provided in the region of the rotor segment, preferably in an area that is less magnetically relevant. This enables optimal use of the magnetic field, while simultaneously providing structural components for the assembly and integrity of the rotor. This design offers the advantages that the annular rotor segment, formed from an electrical steel sheet, is structurally optimized for a segmented, permanently excited rotor of an electrical machine, enabling efficient assembly and configuration of the rotor.Furthermore, the pivoting tangential and radial tabs allow for flexible handling and simplified assembly by adapting the parts to each other. This not only simplifies production but also reduces manufacturing errors and increases overall precision. The tab geometry is preferably divided into radially distributed pairs and tangentially distributed pairs per punch. This arrangement of the tabs contributes to the transmission of forces and enables a force-locking and / or positive connection within the segment assembly and throughout the stack structure.

[0016] According to the invention, the first and second openings are designed so that they can be positioned in alignment with each other when stacking the rotor segments. This achieves high precision in the alignment of the segments, which in turn contributes to improved performance and efficiency of the electric machine by minimizing mechanical imbalances and magnetic field disturbances.

[0017] For the purposes of this patent application, a rotor segment is a circular ring-shaped component formed from electrical steel sheet and intended for the construction of a segmented, permanently excited rotor of an electrical machine. The rotor segment is characterized by having a plurality of magnetic pockets specifically designed to accommodate permanent magnets. The shape, configuration, and arrangement of the magnetic pockets in the rotor segment are designed to optimize the desired magnetic field distribution for rotor operation and ensure high magnetic efficiency.

[0018] The function of the rotor segment in an electric machine is to work with the stator to generate torque, which is created by the interaction of the permanent magnets with the rotating magnetic field generated by the stator. Each rotor segment contributes a portion of the magnetic flux and is designed so that multiple segments can be combined to form a complete rotor. This allows for customized rotor configurations with different diameters and performance characteristics to be created using individual segments.

[0019] Inventive features were incorporated into the rotor segment design to enhance assembly and mechanical strength. These include pivoting tangential and radial tabs that allow the rotor segment to be flexibly positioned, mounted, and connected to other segments. Such tabs can also serve as supports for fastening elements and, due to their pivoting nature, allow for a certain degree of tolerance compensation during rotor assembly.

[0020] The rotor segments can be coated or treated to improve their corrosion resistance and thermal stability. The specific design of the magnetic pockets can be adapted to different types of permanent magnets. The geometric arrangement of the magnetic pockets, as well as their number and dimensions, can also be varied to accommodate different requirements for the magnetic field profile and mechanical load. Furthermore, the rotor segments can have features that support the stacking and alignment of the segments into lamination stacks, such as precision-formed openings that facilitate aligned positioning of the segments.

[0021] For the purposes of this patent application, a tangential link is a component that is part of the rotor segment of an electric machine and is designed to pivot in the tangential direction of the rotor segment. The tangential link is arranged at a first opening of the rotor segment and serves to facilitate and enhance assembly and connectivity between adjacent rotor segments.

[0022] The function of the tangential link is to create a flexible connection option that allows the rotor segments to be precisely aligned and mechanically connected during assembly or during operation of the electrical machine. The pivoting ability of the tangential links allows tolerances between individual rotor segments to be compensated and installation time to be shortened. Furthermore, the tangential links enable efficient power transmission between the individual segments and contribute to increasing the stability of the entire rotor core. Preferred embodiments of the tangential link can vary in terms of their geometric shape, size, and the material used. The tangential links are preferably made of the same material as the rotor segment to ensure uniform thermal expansion and magnetic properties.They can also be formed using various manufacturing processes such as punching, bending, or laser cutting, and their shape can be adapted to specific requirements. Furthermore, it is conceivable that the tangential plates could be provided with additional functional elements such as holes or serrations to enable improved mechanical connection. Depending on the application, the tangential plates could also be surface treated or coated to improve corrosion resistance or thermal conductivity.

[0023] For the purposes of this patent application, a radial link is a structural element of the rotor segment of an electrical machine that is pivotably mounted in the radial direction of the rotor segment. The radial link is part of a second opening in the rotor segment and is designed to improve the functional and structural properties of the rotor segment by enabling a connection to adjacent rotor segments or providing support during assembly.

[0024] The function of the radial link extends to providing a point of contact for the mechanical strengthening of the segment-to-segment connection. It contributes to the precise alignment of the rotor segments both during assembly and operation. Due to their pivoting nature, the radial links can help compensate for existing tolerances in the assembly of the rotor core. This contributes to increasing the mechanical integrity of the rotating part of the machine, which is crucial for the smooth and low-vibration operation of the electric machine.

[0025] Radial tabs are preferably made from the same electrical steel material as the rotor segment itself to ensure homogeneous material characteristics across the entire component. This serves to harmonize thermal expansion coefficients and magnetic properties. Various geometric designs of the radial tabs are possible to ensure optimal fit and functionality depending on the application. The machining and shaping of the radial tabs can be precisely tailored to automated manufacturing processes using methods such as stamping, bending, or laser cutting.

[0026] Further embodiments may include surface finishes or coatings that protect the radial links from corrosion or modify their thermal properties. Furthermore, additional structural features such as serrations, recesses, or stiffening grooves can be integrated into the radial links to increase mechanical robustness and provide connection options for additional components or assembly aids.

[0027] According to a further preferred development of the invention, the rotor segment can also have a first group of magnetic pockets aligned in a V-shape relative to one another, with the tips of the V-shaped magnetic pockets of the first group pointing radially inward. This arrangement improves the magnetic efficiency of the rotor, since the special arrangement of the permanent magnets results in an optimized magnetic flux pattern.

[0028] Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the rotor segment has a second group of magnetic pockets that are aligned in a V-shape relative to one another, wherein the tip of the V-shaped magnetic pockets of the second group points radially inward. By implementing a second group of V-shaped magnetic pockets, which also point radially inward, the symmetry and balance of the magnetic field in the rotor is further increased. This can result in an increase in efficiency and a reduction in vibrations, thereby extending the service life of the machine and reducing noise. According to a further particularly preferred embodiment of the invention, it can be provided that the first opening and / or the second opening are / is formed radially below the first group of magnetic pockets and / or radially below the second group.This design offers the advantage that the openings are positioned radially below the magnet pocket groups, outside the magnetic flux of the magnet arrangement in the rotor. This allows for particularly high magnetic efficiency of the rotor. Greater rigidity can also be achieved, reducing rotor expansion at speed.

[0029] Furthermore, the invention can also be further developed such that two first openings are formed radially below the first group of magnetic pockets and two second openings are formed radially below the second group of magnetic pockets. This arrangement can further optimize the magnetic efficiency of the rotor, which overall contributes to a further increase in performance.

[0030] The object of the invention is further achieved by a laminated core assembly for a rotor of an electrical machine, comprising a plurality of stacked rotor segments according to one of the preceding claims 1-5, wherein the rotor segments can be stacked alternately in the axial direction offset from one another by an angle in the tangential direction, and the first opening and the second opening of the rotor segments are positioned in alignment with one another, and the tangential tabs and the radial tabs of the rotor segments are bent in a common axial direction. A significant advantage of this laminated core assembly is that a structural unit is created which has tabs bent in the axial and tangential directions, which strengthens the connection of the rotor segments and increases the strength of the assembly overall. This also facilitates the assembly and balancing of the rotor.

[0031] The tabs on the rotor segments can be formed in radial and tangential directions during the stamping process itself or subsequently. To ensure a robust connection between the rotor segments, a positive or non-positive fit can be achieved by inserting a fixing agent or using transfer molding. This joining technique ensures the necessary mechanical strength and precision in the alignment of the segments, thus ensuring the integrity of the entire rotor.

[0032] A characteristic feature of the design is a mechanical overlap created by the aforementioned tabs. This overlap is crucial for the power transmission between the rotor segments and ensures a frictional and positive connection, which is important for the mechanical stability and function of the rotor.

[0033] Because the tabs must be bent, a bending radius is created, necessitating alternating geometry. This means that in the axial stacking of the laminated cores, plates with the two different tabs must alternate to achieve a uniform structure. Bending the tabs creates a specific angle, typically around 60 degrees, between the tabs, allowing for overlap across multiple segments. This overlap creates a larger contact area and consequently a stronger and more reliable connection.

[0034] Due to the lack of any further adjacent structure, the last sheet in the stack can preferably be fixed by an additional component or a special filling to ensure the necessary stability and integrity of the rotor end.

[0035] Furthermore, it is advantageous that the axial ends of the rotor are also appropriately fixed and stabilized. This can be achieved with additional components that ensure precise alignment and reliable connection of the laminated cores.

[0036] Optionally, it is possible to design the tabs in a three-dimensional forming process, either during the punching process or in a subsequent step, so that they serve as joining and centering aids for the assembly or stacking of the rotor segments. This additional functionality of the tabs facilitates component assembly and contributes to further improving the precision and reliability of the entire rotor structure. According to the invention, the rotor segments are stacked alternately in the axial direction, offset from one another by an angle in the tangential direction, resulting in the formation of a so-called brickwall.

[0037] The laminated core arrangement thus comprises a brickwall. For the purposes of this patent application, a brickwall is a stacking pattern for rotor segments of an electrical machine in which adjacent rotor segments are arranged offset in the tangential direction to create an overlapping and offset structure resembling the pattern of a brick wall.

[0038] The function of the brickwall is to increase the structural strength of the lamination stack by multiplying the force transmission points between the rotor segments. This leads to a reduction in localized loads and a more even distribution of mechanical forces. Furthermore, the brickwall pattern can reduce the noise generated by the machine during operation, as vibrations and resonances are dampened by the irregular structure.

[0039] The brickwall's design is characterized by the rotor segments being arranged not in a continuous line, but rather in alternating, staggered configurations. The rotor segments can be designed to have special notches or tabs that support this staggered stacking.

[0040] Preferred embodiments of the brickwall could feature various variations in the geometric configuration of the rotor segments. Examples of design variations include the insertion of grooves or projections on the lateral edges of the rotor segments, which promote interlocking of the rotor segments, or the use of additional connecting elements inserted into the stack structure and holding the rotor segments in the desired offset orientation. The choice of materials for the rotor segments can further influence the efficiency of the brickwall pattern. Materials with high mechanical strength and good magnetic conductivity, as well as thermal expansion compatible with the operating temperatures of the machine, are preferred.In addition, the rotor segments can receive surface treatments or coatings to prevent corrosion or to optimize specific magnetic properties.

[0041] According to a further preferred embodiment of the subject matter of the invention, it can be provided that the first openings and / or the second openings are each penetrated by a fixing means, and the tangential tabs and / or the radial tabs rest against the fixing means. The passage of fixing means through the openings and the contact of the tabs against the fixing means contribute to securing the individual rotor segments and thus establish a robust and reliable connection. This is particularly advantageous for applications with high operating speeds and changing loads, as the mechanical integrity and stability of the rotor are increased.

[0042] For the purposes of this patent application, a fixing means is an element or device that serves to secure the stacked rotor segments in their positional relationship to one another. The fixing means penetrates the stacked rotor segments and ensures their stable and permanent connection, increasing the operational reliability and functionality of the electrical machine.

[0043] One function of a fixing device is to prevent the tabs in the individual laminations from deforming backwards. The fixing devices can also participate in the torque and / or force transmission, but this is not necessary. Therefore, it is fundamentally conceivable for a fixing device to be made of a comparatively low-strength material, such as a plastic. However, it must be ensured that if the axial preload of the rotor or the laminated core arrangement is to be assumed via a fixing device, the latter is sufficiently strong for this purpose. A further, optional function of the fixing device can also be the reliable fixation of the positioned rotor segments within the laminated core. It then prevents their axial and radial displacement both during operation and under the influence of vibrations and other mechanical loads.

[0044] The fixing element can take various forms depending on the design and requirements of the electrical machine. It could be screws, bolts, pins, clamps, or other suitable mechanical fasteners. A design that allows for easy assembly and disassembly, offers strength and reliability, and is compatible with the material properties of the rotor segments is preferred.

[0045] The fixative can also be introduced into the openings using a transfer molding process, for example. The clamping ring can then preferably be directly molded into the transfer molding process.

[0046] The fixing device can be realized in various materials, such as plastic, steel, stainless steel, aluminum, or other metallic alloys that retain their mechanical properties even under changing temperature and load conditions. Furthermore, the fixing devices can be designed to provide favorable force distribution and support within the laminated core assembly through precisely fitting heads, threads, or notches that interact with corresponding receiving elements of the rotor segments or the clamping ring.

[0047] Finally, the invention can also be advantageously designed such that a first clamping ring rests on the first end face of the laminated core arrangement, from which one of the fixing means extends in the axial direction through the first opening or the second opening, and / or a second clamping ring rests on the second end face of the laminated core arrangement, from which one of the fixing means extends in the axial direction through the first opening or the second opening. The use of clamping rings on the end faces of the laminated core arrangement, from which fixing means extend and penetrate the openings, represents an additional reinforcement of the overall assembly. This configuration enables a uniform axial clamping distribution, which leads to a further increase in mechanical strength and improved vibration damping, thereby reducing noise generation.

[0048] For the purposes of this patent application, a clamping ring is a ring-shaped component that serves to engage the end face of a laminated core assembly of the rotor of an electrical machine and exert an axial clamping force. The clamping ring interacts with the stacked rotor segments to press them tightly together, thus increasing the mechanical stability of the rotor.

[0049] The function of the clamping ring is to apply a preload to the laminated core, which both fixes the individual rotor segments in their position and secures them against displacement and vibration, thereby strengthening the structural integrity of the entire laminated core.

[0050] The clamping ring can be constructed from various wear-resistant and stable materials that can withstand the mechanical stress requirements. Preferably, the clamping ring is made of a metal or metal alloy that offers high strength and resistance to environmental influences.

[0051] The clamping ring can be designed as a simple ring with a smooth surface, for example, or it can include special features such as grooves, recesses, or attachment points for assembly tools. These elements serve to facilitate installation and enable a precise fit and secure anchoring in the rotor.

[0052] The clamping rings can also be provided with a coating to increase corrosion resistance or to adjust thermal expansion properties. The object of the invention is further achieved by a segmented, permanently excited rotor of an electrical machine comprising a laminated core assembly according to any one of claims 7-10. Finally, the object of the invention can also be achieved by an electrical machine, in particular for a drive train of a motor vehicle, comprising a stator and a segmented, permanently excited rotor according to claim 11.

[0053] Combining the laminated core assembly into a segmented, permanently excited rotor creates further advantages in the modularity and scalability of the rotor assembly, allowing for the efficient production of different rotor sizes for electric machines. Particularly for automotive powertrains, this can lead to reduced manufacturing costs and adaptability to different vehicle types and performance requirements.

[0054] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0055] It shows:

[0056] Figure 1 shows a rotor segment with tabs not yet deformed in a top view,

[0057] Figure 2 shows the rotor segment known from Figure 1 with tabs projecting from the rotor segment in a common axial direction in a perspective view,

[0058] Figure 3 shows a rotor formed from rotor segments in a plan view,

[0059] Figure 4 is a perspective axial sectional view of the openings and bent tabs in a laminated core assembly formed from the rotor segments, Figure 5 is an axial sectional view of the openings and bent tabs in a laminated core assembly formed from the rotor segments with a fixing means inserted into the openings,

[0060] Figure 6 a clamping ring in a perspective view,

[0061] Figure 7 shows a fixing means in a perspective view,

[0062] Figure 8 shows a rotor in three different assembly states, each in a top view,

[0063] Figure 9 shows a first sheet metal circular ring made of rotor segments and a sheet metal circular ring made of rotor segments rotated by 45° in the tangential direction, each in a top view,

[0064] Figure 10 shows an electrical machine in a schematic axial section,

[0065] Figure 11 shows a motor vehicle with an electric machine in a schematic representation.

[0066] Figure 1 shows a rotor segment 1 in the form of a circular ring section, formed from an electrical sheet, for forming a segmented, permanently excited rotor 2 of an electrical machine 3, as is also sketched, for example, in Figure 3.

[0067] The rotor segment 1 comprises a plurality of V-shaped magnet pockets 4 formed in the rotor segment 1 for receiving permanent magnets 5.

[0068] Furthermore, the rotor segment 1 has a first opening 6 with

[0069] Tangential tabs 8, which are opposite one another in the tangential direction 7 and are designed to be pivotable on the rotor segment 1, and a second opening 9 with radial tabs 11, which are opposite one another in the radial direction 10 and are designed to be pivotable on the rotor segment 1. As can be clearly seen from Figure 1, the first opening 6 and the second opening 9 each have an H-shaped contour in the undeformed state of the tangential tabs 8 and the radial tabs 11. The parallel legs of the H-shaped first opening 6 extend in the tangential direction 7, and the parallel legs of the H-shaped second opening 9 extend in the radial direction 10. It can also be seen that the H-shaped first opening 6 has a thinner contour than the H-shaped second opening 9.The geometry of opening 9, with the geometry of opening 6 remaining fixed, has only limited degrees of freedom, such as the width of the gap (i.e., the H-shape) between the two tabs (extension of the gap in the radial direction). This degree of freedom is used to increase the gap to a level where the choice of punch is no longer a concern.

[0070] The rotor segment 1 further comprises a first group 12 of magnetic pockets 4, which are aligned in a V-shape relative to one another, with the tip 13 of the V-shaped magnetic pockets 4 of the first group 12 pointing radially inward. Furthermore, the rotor segment 1 comprises a second group 14 of magnetic pockets 4, which are aligned in a V-shape relative to one another, with the tip 15 of the V-shaped magnetic pockets 4 of the second group 14 also pointing radially inward. The first opening 6 and the second opening 9 are formed radially below the first group 12 of magnetic pockets 4 and radially below the second group 14, and thus outside the areas of the rotor 2 that are important for the magnetic flux.

[0071] As can be seen from Figure 2, the radial tabs 11 are subsequently bent around an axis running in the tangential direction 7, so that they exhibit a deformation out of the sheet plane. Analogously, the tangential tabs 8 are also bent around an axis extending in the radial direction 10, so that they also exhibit a deformation out of the sheet plane. This deformation is shown in Figure 2 in the individual sheet, as this is the best way to illustrate it in isolation. However, the forming of the tangential tabs 8 and the radial tabs 11 can also be carried out, for example, within the punch on an individual sheet, as shown in Figure 2.It would also be conceivable for individual sheets to be joined together to form a laminated core without any deformation of the tabs, and for the radial tabs 11 and the tangential tabs 8 to be deformed later in the laminated core arrangement 25 by tool parts or by the fixing means 26 that later remain in the laminated core arrangement 25. It is also possible to provide a certain amount of pre-deformation in the punch, followed by deformation into the final state in the laminated core arrangement 25 by tool parts or by the fixing means 26 that later remain in the laminated core arrangement 25. Another possibility for forming the tabs is for the individual sheets to initially remain undeformed, for a certain amount of pre-deformation to be carried out by tool parts in the laminated core arrangement 25, followed by deformation into the final state by the fixing means 26 that later remain in the laminated core arrangement 25.

[0072] Two first openings 6 are formed radially below the first group 12 of magnetic pockets 4, and two second openings 9 are formed radially below the second group 14 of magnetic pockets 4. In other words, the tangential tabs 8 are positioned radially below the first group 12 of magnetic pockets 4, and the radial tabs 11 are positioned radially below the second group 14 of magnetic pockets 4.

[0073] Figures 1-2 also show that the first opening 6 and the second opening 9 are designed such that they can be positioned flush with one another when stacking the rotor segments 1. The openings 6, 9 and the magnetic pockets 4 are arranged and designed such that the rotor segments 1 can be stacked in various configurations, but in particular in a brickwall.

[0074] The rotor segments 1 with two poles, which are known from Figure 1 and have a circumferentially sweeping angle of 90°, are axially stacked, each offset by 45° to one another in the tangential direction 7 (which corresponds to an offset of one pole), which also results in a first opening 6 being arranged alternately above a second opening 9 in the axial direction. This configuration leads to the formation of a brickwall, in which axially adjacent rotor segments 1 are arranged offset in the tangential direction in order to create an overlapping and offset structure that resembles the pattern of a brick wall. In the context of this invention, a laminated core arrangement 25 with a brickwall stacking of the rotor segments 1 is preferable. Such a configuration can also be clearly seen in Figure 9. In figure a, a first laminated ring can be seen, which is composed of four rotor segments 1.Figure b shows a second lamination ring, also formed from four of the rotor segments 1, but positioned tangentially rotated by 45° (corresponding to one pole) relative to the first lamination ring. Alternating axial stacking of these lamination rings results in the aforementioned brickwall stacking pattern.

[0075] It would also be conceivable, when adapting the openings 6, 9 and the tabs, to stack the rotor segments 1 alternately rotated by 180° about their axis of symmetry 16, so that a first opening 6 is then arranged alternately above a second opening 9 in the axial direction, as can also be seen in Figures 4-5, for example.

[0076] Figures 4-5 show detailed views through an axially sectioned laminated core assembly 25, with the aid of which the function of the radial tabs 11 and tangential tabs 8 will be explained in more detail below. The laminated core assembly 25 for the rotor 2 comprises a plurality of stacked rotor segments 1, as known from Figure 1. In the laminated core assembly 25, the first opening 6 and the second opening 9 of the rotor segments 1 are positioned in alignment with one another, and the tangential tabs 8 and the radial tabs 11 of the rotor segments 1 are bent in a common axial direction.

[0077] It can be seen that the radial tabs 11 and the tangential tabs 8 each have a uniform deformation angle of approximately 60°, which, in combination with the alternating geometry of the rotor segments 1 resulting from the stacking, ensures that the openings 6, 9 are filled, as shown in Figures 4-5. It can be clearly seen that a force can be transferred from one tab of one rotor segment 1 to at least two tabs of the axially adjacent rotor segment 1. Within the tabs, the absorbed force is then transferred as a shear force in the tab up to the level of the respective rotor segment 1.

[0078] Fundamentally, with such laminated core arrangements 25, there is a risk of unwanted three-dimensional deformation of the tangential links 8 and the radial links 11. In an "ideal", tolerance-free system, this phenomenon would not be a problem, since the links that could deform three-dimensionally would each be supported on the other side by another link. With tolerances, however, a (small) gap is to be expected on the force-free side. Therefore, it may be advantageous to prevent three-dimensional deformation of a link by other means. For example, it may be advantageous to address this phenomenon either by rigid clamping rings 18, 20 on both end faces 17, 19 of the rotor 2 or by head deformation of the fixing means 26 under axial preload of the laminated core arrangement 25.

[0079] As can be seen in Figure 5, the first openings 6 and the second openings 9 are each penetrated by a fixing means 26, and the tangential tabs 8 and the radial tabs 11 rest against the fixing means 26. The fixing means 26 can be made of plastic, aluminum, or steel, for example. Figure 7 shows an example of a fixing means 26. The final shape of the fixing means is shown.

[0080] 26 in a state inserted in the rotor 2. At least one of the two heads

[0081] 27 must not exist in its original state, but may only be deformed after the insertion process, as otherwise axial insertion is impossible. One of the heads 27 of the fixing means 26 can, of course, be preformed. The fixing means 26 has a pin 28 located axially between the heads 27, which extends through the openings 6, 9 of the laminated core arrangement 25. The cross-sectional contour of the pin 28 essentially corresponds to the cross-sectional contour of the openings 6, 9, which is rectangular in the illustrated embodiment. The fixing means 26 accordingly remains in the rotor 2.

[0082] A first clamping ring 18 can be arranged on the first end face 17 of the laminated core assembly 25, from which one of the fixing means 26 extends in the axial direction through the first opening 6 or the second opening 9. Similarly, a second clamping ring 20 can also be arranged on the second end face 19 of the laminated core assembly 25, from which one of the fixing means 26 extends in the axial direction through the first opening 6 or the second opening 9.

[0083] Such a clamping ring 18, 20 is shown in Figure 6. It has openings 24 that can be aligned with the openings 6, 9 of the rotor segments 1. These clamping rings 18, 20 can also help prevent unwanted three-dimensional deformation of the rotor segments 1, and especially of the tangential tabs and the radial tabs 11, on both axial end faces 17, 19. In principle, it would be conceivable to dispense with the clamping rings 18, 20 and simply use the fixing means 26, in which case the axial preload of the laminated core arrangement 25 is absorbed by the heads 27 of the fixing means 26.

[0084] The clamping rings 18, 20 can have additional recesses into which parts of the laminated core arrangement 25, in particular tangential tabs 8 or radial tabs 11, can engage.

[0085] Figure 8 shows a possible assembly method for a laminated core assembly 25 with clamping rings 18, 20 and fixing means 26. First, the laminated core assembly 25 is formed by the rotor segments 1, resulting in a cylindrical ring-like rotor 2 that is closed in the tangential direction. This is shown in Figure a. Subsequently, a clamping ring 18, 20 is placed on each of the end faces 17, 19 of the rotor 2, with the openings 24 of the clamping rings 18, 20 aligned with the openings 6, 9 of the rotor 2. The fixing means 26 are then pushed through the openings 24 of the clamping rings 18, 20 and through the openings 6, 9 of the rotor 2 until one of their heads 27 rests on one of the clamping rings 18, 20. Finally, the head 27 is formed on the still free end of the pin 28 of the fixing means 26, for example, by riveting. This final assembly state is shown in Figure 8 (c).

[0086] Figure 10 shows an electric machine 3 for a drive train 21 of a motor vehicle 22, as is also depicted in Figure 11. The electric machine 3, configured as a radial flux machine, comprises a stator 23 and a segmented, permanently excited rotor 2, as described with reference to Figures 1-9. This segmented, permanently excited rotor 2 therefore has a laminated core arrangement 25, as explained above. The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be regarded as limiting, but as explanatory. The following patent claims are to be understood such that a named feature is present in at least one embodiment of the invention. This does not exclude the presence of further features.Where the patent claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority. The terms "radial," "axial," and "tangential direction" always refer to the rotor's axis of rotation within the scope of the present invention.

[0087] List of reference symbols

[0088] 1 rotor segment

[0089] 2 rotors

[0090] 3 electric machine

[0091] 4 magnetic pockets

[0092] 5 permanent magnets

[0093] 6 Opening

[0094] 7 Tangential direction

[0095] 8 tangential tabs

[0096] 9 Opening

[0097] 10 Radial direction

[0098] 11 radial tabs

[0099] 12 Group

[0100] 13 lace

[0101] 14 Group

[0102] 15 lace

[0103] 16 axis of symmetry

[0104] 17 Front side

[0105] 18 clamping ring

[0106] 19 Front side

[0107] 20 clamping ring

[0108] 21 Drivetrain

[0109] 22 Motor vehicle

[0110] 23 Stator

[0111] 24 Opening

[0112] 25 Laminated core arrangement

[0113] 26 Fixatives

[0114] 27 heads

[0115] 28 pin

Claims

Claims 1. Circular ring section-shaped, formed from an electrical sheet Rotor segment (1) for forming a segmented, permanently excited rotor (2) of an electrical machine (3) comprising a plurality of magnetic pockets (4) formed in the rotor segment (1) for receiving permanent magnets (5), characterized in that the rotor segment (1) • a first opening (6) with tangential tabs (8) opposite one another in the tangential direction (7) and pivotable on the rotor segment (1) and • a second opening (9) with radial tabs (11) opposite one another in the radial direction (10) and pivotably formed on the rotor segment (1), and • the rotor segments (1) can be stacked alternately in the axial direction offset by an angle in the tangential direction, whereby • the first opening (6) and the second opening (9) are designed such that they can be positioned flush with one another when the rotor segments (1) are stacked.

2. Rotor segment (1) according to claim 1, characterized in that the rotor segment (1) has a first group (12) of magnetic pockets (4) which are aligned in a V-shape with respect to one another, the tip (13) of the V-shaped magnetic pockets (4) of the first group (12) pointing radially inwards.

3. Rotor segment (1) according to one of the preceding claims, characterized in that the rotor segment (1) has a second group (14) of magnetic pockets (4) which are aligned in a V-shape with respect to one another, wherein the tip (15) the V-shaped magnetic pockets (4) of the second group (14) point radially inwards.

4. Rotor segment (1) according to claim 2 or 3, characterized in that the first opening (6) and / or the second opening (9) are / is formed radially below the first group (12) of magnetic pockets (4) and / or radially below the second group (14).

5. Rotor segment (1) according to one of claims 2-4, characterized in that two first openings (6) are formed radially below the first group (12) of magnetic pockets (4) and two second openings (9) are formed radially below the second group (14) of magnetic pockets (4).

6. Laminated core arrangement (25) for a rotor (2) of an electrical machine (3), comprising a plurality of stacked rotor segments (1) according to one of the preceding claims 1 - 5, wherein the rotor segments (1) can be stacked alternately in the axial direction offset from one another by an angle in the tangential direction, and the first opening (6) and the second opening (9) of the rotor segments (1) are positioned in alignment with one another and the tangential tabs (8) and the radial tabs (11) of the rotor segments (1) are bent in a common axial direction.

7. Laminated core arrangement (25) according to claim 6, characterized in that the first openings (6) and / or the second openings (9) are each penetrated by a fixing means (26) and the tangential tabs (8) and / or the radial tabs (11) bear against the fixing means (26).

8. Laminated core arrangement (25) according to one of claims 6 to 7, characterized in that a first clamping ring (18) bears against the first end face (17) of the laminated core arrangement (25), from which one of the fixing means (26) extends in the axial direction through the first opening (6) or the second opening (9), and / or a second clamping ring (20) bears against the second end face (19) of the laminated core arrangement (25), from which one of the fixing means (26) extends in the axial direction through the first opening (6) or the second opening (9).

9. Segmented, permanently excited rotor (2) of an electrical machine (3) comprising a laminated core arrangement (25) according to one of claims 7-8.

10. Electrical machine (3), in particular for a drive train (21) of a motor vehicle (22), comprising a stator (23) and a segmented, permanently excited rotor (2) according to claim 9.

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