Rotor device for an electric asynchronous machine, rotor and asynchronous machine

Abstract

Rotor device (2) for an electric asynchronous machine (1) comprising a laminated core (17) which has a plurality of bar recesses (5a, 5b) distributed around an axis of rotation of the laminated core for a plurality of rotor bars (5) and for at least some of the bar recesses (5a, 5b) has a recess for field guidance (7a, 7b) which is arranged between an outer end (9) of the respective bar recess (5a, 5b) and an outer edge (10) of the laminated core (17).

Description

[0001] The present invention relates to a rotor device for an electric asynchronous machine, in particular a three-phase asynchronous motor, comprising a laminated core having a plurality of bar recesses distributed around the axis of rotation of the core for a plurality of rotor bars. The invention further relates to a rotor for an electric asynchronous machine with such a rotor device and to a corresponding asynchronous machine with such a rotor.

[0002] In an electric asynchronous machine, the course of the electromagnetic field lines between the stator windings and the rotor, in particular the electrically conductive rotor bars in the bar recesses, or the corresponding density and / or homogeneity of the electromagnetic field in the rotor or the laminated core, is of great importance for scattering effects and associated electrical losses during the operation of the asynchronous machine.

[0003] Document DE 10 2011 114 161 A1 describes an electric machine in which the stator or rotor of the electric machine has teeth distributed around its circumference, such that the air gap width and / or magnetic conductance of the teeth are uneven around the circumference of the electric machine. This is intended to suppress harmonics in the air gap induction more effectively.

[0004] Document WO 2023 168915 A1 describes a rotor of an induction motor with alternating rotor teeth and rotor slots, which have a plurality of grooves provided at one end of the rotor teeth. This is intended to reduce the radial force of the stator.

[0005] Document JPH 08-140319A describes a rotor of an induction motor with a grid-shaped conductor cast from aluminium or an aluminium alloy.

[0006] It is an object of the present invention to provide an optimized guidance of the electromagnetic field in the laminated core of the rotor in order to reduce losses.

[0007] This problem is solved by the subject matter of the independent claim. Preferred embodiments and further developments are the subject matter of the dependent claims.

[0008] The invention is based on the idea of ​​providing a recess for field guidance between the rod recesses and the outer radial edge of the sheet metal stack.

[0009] According to one aspect of the invention, a rotor device for an electric asynchronous machine, also referred to as a three-phase asynchronous motor or induction motor, is specified. The rotor device comprises a laminated core with a plurality of bar recesses distributed around the axis of rotation of the laminated core. For at least some of the bar recesses, for example, for each bar recess of the plurality of bar recesses, the laminated core has a recess for field guidance, which is arranged between an outer end, in particular a radial outer end, of the respective bar recess and an outer edge, in particular a radial outer edge, of the laminated core.

[0010] The laminated core can be understood, in particular, as a stack of individual sheets, also called laminations, stacked on top of each other and firmly connected to one another. The individual sheets are made, in particular, of electrical steel, especially an iron-silicon alloy, or of another material known for electrical machines, especially asynchronous machines. The individual sheets of the laminated core are, in particular, congruent with each other and aligned accordingly.

[0011] Here and in the following, a recess, in particular the bar recesses and the recesses for field guidance, as well as any other specified recesses, can be understood as follows. A recess denotes an area of ​​the respective laminations of the laminated core where no sheet material is present. This can be achieved, for example, by milling or punching out the corresponding areas. Unless otherwise stated, a recess is present in all laminations of the laminated core, so that the respective recess extends axially through the entire laminated core with respect to the rotor's axis of rotation. The recess can be filled with air or, if it is not a bar recess, with another material, in particular a non-magnetic one.In the case of a bar recess, each of the bar recesses in the finished rotor contains an electrically conductive rotor bar that extends axially through the rotor stack. These rotor bars are short-circuited at the axial ends of the lamination stack, for example by corresponding rings or similar devices.

[0012] Here and in the following, the rotor assembly does not include the rotor bars. A rotor, on the other hand, includes both the rotor assembly and the rotor bars arranged in the bar recesses. The rotor bars can have a circular cross-section or can be shaped differently, for example, elongated with a radial extension relative to the rotor's axis of rotation.

[0013] The rotor bars can be made of materials such as aluminum or an aluminum alloy, copper or a copper alloy, silver or a silver alloy, brass, or any of the aforementioned materials, or another electrically conductive material reinforced with a carbon-based material, such as carbon nanotubes, graphite, and / or graphene. The rotor bars can be cast, for example.

[0014] The radial outer edge of the laminated core can be understood as being located, along a straight line extending radially outward through the center or axis of rotation of the rotor or rotor assembly, at the point where the laminated material ends. In other words, the radial outer edge of the laminated core in the resulting induction machine forms the rotor-side boundary of the air gap between the rotor and stator. The outer edge can always be the same distance from the axis of rotation in any radial direction, meaning the laminated core has a constant outer radius. Alternatively, however, this outer radius, or the aforementioned distance, can be modulated depending on the angle.

[0015] When an air gap between the stator and rotor is mentioned here and in the following, it can actually be completely filled with air or can be partially filled with another non-magnetic material.

[0016] The recess for field guidance forms, in particular, an inner sheet metal web between the outer end of the respective bar recess and the recess for field guidance. Furthermore, an outer sheet metal web is formed between the recess for field guidance and the outer edge of the sheet metal stack.

[0017] In particular, the inner sheet metal web borders directly on the bar recess and directly on the recess for the field guide in the radial direction. The outer sheet metal web borders directly on the recess for the field guide, as well as on the outer edge of the sheet metal stack, particularly in the radial direction.

[0018] The inner and outer sheet metal webs, which can also be referred to as scattering webs, allow the electromagnetic field to reach the corresponding rotor rod by forming corresponding field lines around the recess for field guidance.

[0019] In the rotor device according to the invention, the corresponding recess for field guidance is located between the outer end of the respective bar recess and the outer edge of the lamination stack, at least for some of the bar recesses. In other words, for an angle in the plane perpendicular to the axis of rotation, there exists a straight line that runs from the axis of rotation through the bar recess, then through the inner lamination web between the bar recess and the recess for field guidance, then through the recess for field guidance, and then through the outer lamination web that is formed between the recess for field guidance and the outer edge of the lamination stack.

[0020] In this way, the electromagnetic field lines from the stator windings do not travel the shortest, most direct path from the outer edge of the laminated core to the outer end of the corresponding rotor bar, but instead take a detour around the field guide recess. This allows the magnitude of the electromagnetic field to be reduced locally between the bar recess or rotor bar and the outer end of the laminated core, which in turn leads to lower losses. In particular, this can increase the efficiency, torque, and / or power output of the asynchronous machine.

[0021] The effect of the recess for field guidance is therefore different than would be the case, for example, with a recess between adjacent rotor bars or bar recesses, since the recess for field guidance provided according to the invention is arranged in the critical area between the rotor bar and the outer end of the laminated core, i.e., between the rotor bar and the stator winding, when the latter is located exactly above the rotor bar and the maximum field strength is accordingly present.

[0022] The sheet metal package has a first further recess for field guidance between two adjacent bar recesses of the plurality of bar recesses, which extends radially outwards from the outer end of the adjacent bar recess.

[0023] In some embodiments, the first further recess for field guidance can extend to the outer edge of the sheet metal stack, but this is not necessarily required.

[0024] The first additional cutout for field guidance allows for further reduction of variations and more precise field guidance, which contributes to increasing the efficiency, torque and / or power of the asynchronous machine, as well as reducing the acoustic signature of the asynchronous machine during operation.

[0025] Unlike the field guidance recess, the first additional field guidance recess directs the electromagnetic field from a gap between adjacent rotor bars towards the rotor bars themselves. In combination with the field guidance recess and its effect described above, losses can be reduced particularly effectively. A particularly positive aspect is that field lines, or a portion thereof, guided from the area between the bar recesses towards the rotor bars by the first additional field guidance recess are further guided through the field guidance recess, thus further optimizing the local field density around the rotor bars.

[0026] In some embodiments, a first further recess for field guidance as described is provided between several adjacent pairs of bar recesses or between all adjacent pairs of the plurality of bar recesses.

[0027] The first further recess for field guidance forms another outer sheet metal web between the first further recess for field guidance and the outer edge of the sheet metal stack.

[0028] Accordingly, the outer edge of the lamination stack can still be circular. This further reduces the acoustic signature of the asynchronous machine.

[0029] According to at least one embodiment, the recess for field guidance extends in the tangential direction over at least 50 percent of a width, in particular an outer width, of the respective bar recess.

[0030] The width, or outer width, of the bar recess can be defined, for example, by dropping a perpendicular from a straight line running centrally through the bar recess from the axis of rotation. The width of the bar recess at its outer end in the direction of this perpendicular is then considered the outer width of the bar recess. Similarly, an inner width can be defined, whereby, in the case of a circular cross-section of the bar recess, the inner and outer widths correspond to the diameter of the circular bar recess.

[0031] Similarly, the width of the recess for field guidance can also be understood as the maximum width along the aforementioned perpendicular.

[0032] By ensuring that the field guidance recess covers at least 50 percent of the outer width of the bar recess, it is achieved that the field guidance recess shields at least 50 percent of the outer end of the bar recess from a direct radial inward path of electromagnetic field lines from the outer edge of the laminated core. This results in a particularly good reduction of losses.

[0033] According to at least one embodiment, the width of the recess for field guidance is at least 50 percent of the width of the respective bar recess, in particular the outer width of the respective bar recess, and at most 120 percent of the width of the respective bar recess.

[0034] At 100 percent of the width of the respective rod recess, all direct paths for electromagnetic field lines can nominally be blocked by the field-guiding recess. However, at the edges, especially the tangential edges, of the field-guiding recess, there is a comparatively short distance between the field-guiding recess and the rod recess. Therefore, embodiments with a field-guiding recess width greater than the outer width of the rod recess can be particularly advantageous. By limiting the width to 120 percent, excessive influence from the field-guiding recess in areas between adjacent rotor rods can be avoided.

[0035] According to at least one embodiment, the height of the inner sheet web is at least 50 percent of the sheet thickness of the individual sheets of the sheet stack and / or at most 200 percent of the sheet thickness of the sheets.

[0036] The height of the inner sheet metal web can be understood in particular as the radial distance or maximum radial distance or minimum radial distance or mean radial distance or radial distance at a defined point between the recess for field guidance and the respective bar recess.

[0037] It has been shown that this can further optimize the reduction of losses.

[0038] According to at least one embodiment, the height of the recess for field guidance is at least 200 percent of the sheet thickness of the sheets and / or at most 500 percent of the sheet thickness of the sheets.

[0039] The height of the recess can be understood analogously as the maximum, minimum or mean radial distance or radial distance at a defined point between an inner contour of the recess facing the bar recess for field guidance and an outer contour of the recess facing away from the bar recess for field guidance.

[0040] It has been shown that this can further optimize the reduction of losses.

[0041] In some embodiments, the inner contour of the recess for field guidance is adapted to a radially outer contour of the bar recess, such that the height of the inner sheet web is constant or substantially constant over the radial angular range covered by the bar recess. Alternatively or additionally, the outer contour of the recess for field guidance is adapted to the outer edge of the sheet stack, such that the height of the outer sheet web is constant or substantially constant over the radial angular range covered by the bar recess.

[0042] It has been shown that this can further optimize the reduction of losses.

[0043] According to at least one design, the first further recess for field guidance is designed as a notch in the outer edge of the sheet metal package.

[0044] In other words, the first further recess for field guidance in the corresponding area forms the outer edge of the sheet metal stack.

[0045] According to at least one embodiment, the sheet metal stack has a second further recess for field guidance between the two adjacent bar recesses, which is offset inwards relative to the first further recess for field guidance, i.e., in particular, radially inwards. Thus, a further inner sheet metal web is formed in the radial direction between the second further recess for field guidance and the first further recess for field guidance.

[0046] The additional inner sheet metal web can be referred to as an additional scattering web and can further optimize the guidance of the electromagnetic field lines from the area between the two rod recesses in the direction of the rod recesses or in the direction of the inner sheet metal web and the outer sheet metal web around the recess for field guidance.

[0047] According to at least one embodiment, the recess for field guidance is filled with a non-magnetic material.

[0048] As mentioned above, this can alternatively or additionally apply to other exemptions, in particular the first further exemption for field management and / or the second further exemption for field management.

[0049] This allows the guidance of the field lines to be further standardized.

[0050] The non-magnetic material can be, for example, a ceramic material, gypsum, a non-magnetic anisotropic steel, or the like.

[0051] According to at least one embodiment, a radius of the laminated core, which defines an outer contour of the laminated core, is periodically modulated, wherein one period of the modulation corresponds to a distance between the bar recesses. For example, the modulation can be sinusoidal. The distance can be understood, in particular, as an arc length.

[0052] The resulting periodic modulation of the air gap between stator and rotor can further improve the efficiency of the asynchronous machine.

[0053] The form of the modulation, in particular the sinusoidal form of the modulation, can be understood as relating to a hypothetical situation in which the rotor is linearly unwound. This results in a periodic modulation in the direction of rotation of the rotor, which, however, closes in a circle in the two-dimensional plane.

[0054] According to at least one embodiment, the sheet metal stack is surrounded on its outer contour by a non-magnetic material, for example one of the materials mentioned above for filling the recesses.

[0055] In other words, the air gap in the resulting asynchronous machine is at least partially filled by the non-magnetic material. This allows the efficiency of the asynchronous machine to be further improved.

[0056] In particular, in some embodiments this can also achieve a circular outer contour for the combination of the laminated core and the adjacent non-magnetic material, even if the outer contour of the laminated core itself is not circular, for example due to the periodic modulation and / or the first further recess for field guidance.

[0057] According to a further aspect of the invention, another rotor device for an electric asynchronous machine is specified. This further rotor device comprises a laminated core with a plurality of bar recesses distributed around an axis of rotation of the core for a plurality of rotor bars. A radius of the laminated core, defining an outer contour of the core, is periodically modulated, with one period of modulation corresponding to a distance between the bar recesses.

[0058] Further embodiments of the additional rotor device according to the invention follow directly from the various configurations of the rotor device according to the invention, and vice versa. In particular, individual features and corresponding explanations as well as advantages relating to the various configurations of the rotor device according to the invention can be applied analogously to corresponding configurations of the additional rotor device according to the invention.

[0059] According to a further aspect of the invention, a rotor for an electric asynchronous machine is also provided. The rotor comprises a rotor device or further rotor device according to the invention, as well as the plurality of rotor bars arranged in the plurality of bar recesses. In particular, the number of rotor bars corresponds to the number of bar recesses, and exactly one rotor bar is arranged in each bar recess.

[0060] Further embodiments of the rotor according to the invention follow directly from the various configurations of the rotor device according to the invention and vice versa.

[0061] In particular, individual features and corresponding explanations as well as advantages relating to the various embodiments of the rotor device according to the invention can be transferred analogously to corresponding embodiments of the rotor according to the invention.

[0062] According to another aspect of the invention, an electric asynchronous machine is specified which has a rotor according to the invention.

[0063] Further embodiments of the asynchronous machine according to the invention follow directly from the various configurations of the rotor device according to the invention, and vice versa. In particular, individual features and corresponding explanations as well as advantages relating to the various embodiments of the rotor device according to the invention can be transferred analogously to corresponding embodiments of the asynchronous machine according to the invention.

[0064] The invention also includes the combination of the features of the described embodiments.

[0065] The following describes exemplary embodiments of the invention. This is illustrated by: Fig. 1 a schematic cross-sectional representation through a part of an electric asynchronous machine according to the invention and an exemplary embodiment of a rotor device according to the invention; Fig. 2 a cross-sectional view through a part of another exemplary embodiment of a rotor device according to the invention; Fig. 3 a cross-sectional view through a part of another exemplary embodiment of a rotor device according to the invention; Fig. 4 a cross-sectional view through a part of another exemplary embodiment of a rotor device according to the invention; Fig. 5 a cross-sectional view through a part of another exemplary embodiment of a rotor device according to the invention; Fig. 6 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 7 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 8 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 9 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 10 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 11 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 12 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 13 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 14 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention; Fig. 15 a cross-sectional view through a part of a further exemplary embodiment of a rotor device according to the invention; and Fig. 16 a cross-sectional view through part of another exemplary embodiment of a rotor device according to the invention.

[0066] The embodiments described below are preferred embodiments of the invention. In these embodiments, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described.

[0067] In the figures, functionally identical elements can each be provided with the same reference symbols.

[0068] In Fig. Figure 1 above shows a cross-sectional view, i.e., a section view with a section plane perpendicular to the rotor axis, of a part of an asynchronous machine 1 according to the invention, comprising a rotor device 2 according to the invention, rotor bars 5 arranged therein, and a stator with stator windings 4. Below in Fig. Figure 1 shows a detailed section 6 of the rotor device 2.

[0069] The rotor device 2 comprises a laminated core 17 with congruently stacked laminations. The laminated core 17 has a plurality of bar recesses 5a, 5b for the rotor bars 5, distributed around the axis of rotation of the laminated core, which corresponds to the axis of rotation of the rotor or the rotor device. For some or all of the bar recesses 5a, 5b, or for all of the bar recesses 5a, 5b, the laminated core 17 has a recess for field guidance 7a, 7b, which is arranged between an outer end 9 of the respective bar recess 5a, 5b and an outer edge 10 of the laminated core 17.

[0070] The bar recess 5a shown on the left and the bar recess 5b shown on the right are, in particular, identical in design. Likewise, the recess for the field guide 7a shown on the left and the recess for the field guide 7b shown on the right are, in particular, identically designed. For example, all bar recesses 5a, 5b and / or all recesses for the field guide 7a, 7b of the rotor device 2 or the lamination stack 17 can be identically designed. Consequently, some dimensions shown here and in the following are not necessarily shown for every bar recess 5a, 5b or for every recess for the field guide 7a, 7b. In the example of the Fig. 1. The bar recesses 5a, 5b are elongated and extend radially with respect to the rotor's axis of rotation. In particular, the radial extent of the bar recesses 5a, 5b is greater than their tangential or rotational width. For example, the bar recesses 5a, 5b can be wedge-shaped, i.e., widen outwards, so that an inner width b2 of the bar recess is smaller than an outer width b1 of the bar recess. A distance between adjacent bar recesses, or between the respective radial centers of the bar recesses, is characterized by wlr. wlr is given, for example, by wlr=π⋅2⋅dR⋅NR360, where N R the total number of rotor bars is designated 5 and d R the diameter of the rotor.

[0071] The recess for the field guide 7a, 7b is wider in the tangential direction than the outer width b1 of the bar recesses 5a, 5b, so that it completely shields the outer end 9 of the bar recesses 5a, 5b from the outside. The recess for the field guide 7a, 7b forms an outer sheet metal web 12 with a height hss1 and an inner sheet metal web 11 with a height hss2. Preferably, the outer contours of the recesses for the field guide 7a, 7b, which face the respective bar recess 5a, 5b, are curved, so that a constant height hss2 of the inner sheet metal web 11 results.

[0072] For example, the rod recesses 5a, 5b can have an outer width b1 in the range of 2 to 7 mm and an inner width b2 of 0.35 x b1 to 0.65 x b1. The radial height of the rod recesses 5a, 5b can be, for example, 4.5 x b1 to 7 x b1. In the resulting asynchronous machine 1, an air gap can, for example, have a height of 2 x d. B up to 5 xd B amount to, where d B The thickness of a single sheet of the sheet stack 17 can be, for example, 0.15 mm to 0.35 mm. The height hss1 of the outer sheet web 12 can be, for example, in the center of the recess 7a, 7b or the bar recess 5a, 5b, as can the height hss2 of the inner sheet web 11, of 0.5 xd. B up to 2 xd B The sum of hss1 and hss2 is preferably equal.

[0073] In Fig. Figure 2 schematically shows a sheet metal stack 17 of a further exemplary embodiment of a rotor device 2 according to the invention, wherein the embodiment of Fig. 2 on the one of the Fig. 1 is based below.

[0074] In the embodiment of the Fig. 2 The sheet metal assembly 17 has a first further recess for field guidance 8 between two adjacent bar recesses 5a, 5b, which extends radially outwards from the outer end 9 of the adjacent bar recesses 5a, 5b and, for example, as in Fig. 2 indicates that it forms an outer edge 10 of the sheet metal package 17, or in other words, is designed as a notch in the outer edge 10.

[0075] The first additional recess for field guidance 8 creates a further guide contour between the rod recesses 5a, 5b, which further reduces variations and ultimately further improves the efficiency, torque and power of the asynchronous machine.

[0076] The first further recess for field guidance 8 can, for example, be arranged centrally between the two rod recesses 5a, 5b. The width bff in the tangential direction of the first further recess for field guidance 8 is, for example, smaller than the outer width b1 of the rod recesses 5a, 5b. This also applies, for example, to the height hff of the first further recess for field guidance 8 in the radial direction.

[0077] The first further recess for field guidance 8 can be designed geometrically differently. In the example of the Fig. 2 is the contour of the first further recess for field guidance 8, for example a semi-ellipse, whereas in the example of the Fig. 3 essentially corresponds to a rectangle with rounded corners, in particular rounded corners by quarter circles, and in the example of the Fig. 4 an isosceles triangle.

[0078] In the examples of Fig. 2, Fig. 3 and Fig. 4 The first further recess for the field guide 8 extends to the very outer end of the sheet metal stack 17. However, this is not necessarily the case, as in the exemplary embodiments of the Fig. 5 and the Fig. 6 shown. In these embodiments, which are based on the embodiments of the Fig. 4 or the Fig. Based on the first further recess for the field guide 8, a further outer sheet metal web 13 is formed between the first further recess for the field guide 8 and the outer edge 10 of the sheet metal stack 17. A height hff in the radial direction of the further outer sheet metal web 13 can, for example, also be in the range of 0.5 xd. B up to 2 xd B lay.

[0079] In the characters Fig. 7 and Fig. Figure 8 shows two further exemplary embodiments of the lamination stack 17 of the rotor device 2 according to the invention, which are based on the exemplary embodiments of the Fig. 4 respectively Fig. 2. Here, the sheet metal stack 17 has a second further recess for field guidance 14 between the two adjacent bar recesses 5a, 5b, which is arranged radially inwards with respect to the first further recess for field guidance 8, so that a further inner sheet metal web 15 is formed between the second further recess for field guidance 14 and the first further recess for field guidance 8.

[0080] For example, the height of the further inner sheet web 15 hssff can be less than the height hss1 and the height hss2 of the outer and inner sheet webs 11 and 12, respectively. In these examples, the first further recess 8 for field guidance is designed as a notch at the edge 10 of the sheet stack 17. In this case, the height hff of the first further recess for field guidance 8 can, for example, be less than the sum of the heights hss1 and hss2 of the outer sheet web 12 and the inner sheet web 11, respectively.

[0081] The second, further recess for field guidance 14, which is offset inwards, shows in the example of the Fig. Figure 7 shows the outline of an isosceles triangle with an axis of symmetry in the radial direction and an inward-pointing vertex. In the example of the Fig. 8 is the second further recess for field guidance 14, which is elliptically shaped.

[0082] The recess for field guidance 7a, 7b can be filled with air or another non-magnetic material. This applies analogously in corresponding embodiments to the first further recess for field guidance 8 and / or the second further recess for field guidance 14. This is shown schematically in Fig. 9, Fig. 10 and Fig. 11 based on the embodiment from Fig. 6 shown. In the example of the Fig. 9. The recesses for field guidance 7a, 7b are filled with air, and the first further recess for field guidance 8 is filled with another non-magnetic material, for example, a ceramic or plaster or a non-magnetic anisotropic steel. In the example of the Fig. In contrast, the first further recess for field guidance 8 (number 10) is filled with air, and the recesses for field guidance 7a and 7b are filled with the other non-magnetic material. In the example of the Fig. 11. Both the recesses for field guidance 7a, 7b and the first further recess for field guidance 8 are filled with the other non-magnetic material.

[0083] In Fig. Figure 12 shows a further exemplary embodiment of a laminated core 17 of a rotor device 2 according to the invention. In this example, an outer contour of the laminated core 17, in particular a radius of the laminated core 17 defining this outer contour, is periodically modulated, wherein one period of the modulation corresponds to a distance between the bar recesses 5a, 5b, in particular a distance between the radial rays extending from the axis of rotation of the rotor through the center of the respective bar recess 5a, 5b. An amplitude of the modulation is defined in Fig. 12 indicated by amplr. In particular, the modulation can be such that, in the case of a hypothetical linear unfolding of the lamination stack 17, as in Fig. Figure 13 shows that it is sinusoidal or approximately sinusoidal. Fig. Figure 14 shows a linear development of an exemplary variant in which the sheet metal stack 17 does not have the recess for field guidance 7a, 7b. For example, the following applies: amplr≥2⋅hss1+2⋅hss2+hk, where hk denotes the radial height of the recess for field guidance 8.

[0084] In Fig. 15 shows a variant based on the example of Fig. 13 is based on the lamination stack 17, which is radially enclosed by a sleeve 16, for example a sleeve made of carbon fiber reinforced plastic or glass fiber reinforced plastic, so that the wave troughs of the periodic modulation are covered. This reduces rotor losses and increases the power or torque of the asynchronous machine. Furthermore, air friction can be reduced because the surface is more homogeneous.

[0085] In Fig. Figure 16 shows another exemplary embodiment of the sheet metal stack 17, which is based on the embodiment of the Fig. 13 is based on this. Here, for example, both the recesses for field guidance 7a, 7b and the area outside the lamination stack 17 are filled with the non-magnetic material 18. Thus, the combination of the lamination stack 17 and the non-magnetic material 18 surrounding the lamination stack 17 has a circular outer contour, which reduces air friction. Reference symbol list 1 Asynchronous machine 2 Rotor device 3 Stator 4 stator windings 5 rotor bars 5a, 5b Bar recesses 6 Excerpt 7a, 7b Exceptions for field management 8. Exclusion for field guidance 9 outer end of the rod recess 10 outer edge of the sheet metal package 11 inner sheet metal web 12 outer sheet metal web 13 outer sheet metal web 14 Exclusion for field management 15 inner sheet metal web 16 Sleeve 17 sheet metal package 18 non-magnetic material QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2011 114 161 A1

[0003] WO 2023 168915 A1

[0004]

Claims

[1] Rotor device (2) for an electric asynchronous machine (1) comprising a laminated core (17) having a plurality of bar recesses (5a, 5b) distributed around an axis of rotation of the laminated core (17) for a plurality of rotor bars (5) and having for at least some of the bar recesses (5a, 5b) a recess for field guidance (7a, 7b) which is arranged between an outer end (9) of the respective bar recess (5a, 5b) and an outer edge (10) of the laminated core (17), wherein - the sheet metal stack (17) between two adjacent bar recesses (5a, 5b) has a first further recess for field guidance (8) which extends radially outwards from the outer end (9) of the adjacent bar recesses (5a, 5b); and - through the first further recess for field guidance (8) a further outer sheet metal web (13) is formed between the first further recess for field guidance (8) and the outer edge (10) of the sheet metal package (17). [2] Rotor device (2) according to claim 1, wherein the recess for field guidance (7a, 7b) extends in a tangential direction over at least 50% of the width of the respective rod recess (5a, 5b). [3] Rotor device (2) according to one of the preceding claims, wherein the width of the recess for field guidance (7a, 7b) is at least 50% of the width of the respective rod recess (5a, 5b) and at most 120% of the width of the respective rod recess (5a, 5b). [4] Rotor device (2) according to one of the preceding claims, wherein the recess for field guidance (7a, 7b) forms an inner sheet metal web (11) between the outer end (9) of the respective rod recess (5a, 5b) and the recess for field guidance (7a, 7b) and an outer sheet metal web (12) between the recess for field guidance (7a, 7b) and the outer edge (10) of the sheet metal stack (17). [5] Rotor device (2) according to claim 4, wherein the laminated core (17) comprises a plurality of laminations and - the height of the inner sheet web (11) and / or the height of the outer sheet web (12) is at least 50% of the sheet thickness of the sheets and / or at most 200% of the sheet thickness of the sheets; and / or - the height of the recess for field guidance (7a, 7b) is at least 200% of the sheet thickness of the sheets and / or at most 500% of the sheet thickness of the sheets. [6] Rotor device (2) according to one of the preceding claims, wherein the first further recess for field guidance (8) is designed as a notch in the outer edge (10) of the lamination stack (17). [7] Rotor device (2) according to one of the preceding claims, wherein the lamination stack (17) has a second further recess for field guidance (14) between the two adjacent bar recesses (5a, 5b), which is arranged offset inwards with respect to the first further recess for field guidance (8), so that a further inner lamination web (15) is formed between the second further recess for field guidance (14) and the first further recess for field guidance (8). [8] Rotor device (2) according to one of the preceding claims, wherein the recess for field guidance (7a, 7b) is filled with a non-magnetic material. [9] Rotor device (2) according to one of the preceding claims, wherein a radius of the laminated stack (17) defining an outer contour of the laminated stack (17) is periodically modulated, wherein one period of the modulation corresponds to a distance between the bar recesses (5a, 5b). [10] Rotor device (2) according to claim 9, wherein the modulation is sinusoidal. [11] Rotor device (2) according to one of claims 9 or 10, wherein the laminated core (17) is surrounded on the outer contour by a non-magnetic material (18). [12] Rotor for an electric asynchronous machine (1) comprising a rotor device (2) according to one of the preceding claims and the plurality of rotor bars (5) arranged in the plurality of bar recesses (5a, 5b). [13] Electric asynchronous machine (1) with a rotor according to claim 12.

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