Rotor sheet for a rotor of an electric drive machine, as well as a rotor for an electric drive machine

Abstract

The invention relates to a rotor lamination for a rotor of an electric drive machine with a rotor axis and an outer rim for a motor vehicle, comprising At the outer edge, a number of magnet layouts corresponding to a desired number of poles, each with three layers of magnet mounting rows, wherein each magnetic receptacle array has a plurality of magnetic receptacles for receiving one shoulderless magnet each, wherein a radially extending central web is provided between the magnet mounts of the magnet layout, wherein the central web has an increasing radial-inward extension in the circumferential direction, and wherein the magnet receptacles adjacent to the central web have radially inward radii of curvature, the radius of curvature of the magnet receptacles of the outer row of magnet receptacles being smaller than the radius of curvature of the magnet receptacles of the inner row of magnet receptacles. The invention further relates to a rotor. With the rotor lamination or rotor proposed here, a high torque and at the same time a high rotational speed can be achieved with a cost-effective magnet layout.

Description

[0001] The invention relates to a rotor lamination for a rotor of an electric drive machine, a rotor disk with such a rotor lamination, a rotor for an electric drive machine, a drive machine with such a rotor for a motor vehicle, and a motor vehicle with such a drive machine.

[0002] Especially for electrified vehicles, particularly battery electric vehicles (BEVs), there is an increasing demand for electric drive motors that exhibit extremely high power density under continuous dynamic loads. In the high-performance sector, for example, for road-legal sports cars, high torque and a fast response time are also required. High torques can primarily be generated with a large rotor diameter. Alternatively or additionally, high torques can be achieved at the consumer by providing a high rotational speed (i.e., higher than the required speed), which is then reduced, thus multiplying the torque. With increasing rotor diameter, the loads increase considerably, especially at high speeds, primarily due to the relatively high density of (for example, permanent) magnetic material.At the same time, geometric deviations (so-called radial pumping) of the rotor should be minimized as much as possible.

[0003] Based on this, the present invention aims to overcome, at least partially, the disadvantages known from the prior art. The features of the invention are defined in the independent claims, for which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically meaningful way, whereby the explanations in the following description and features from the figures, which comprise supplementary embodiments of the invention, can also be used.

[0004] The invention relates to a rotor lamination for a rotor of an electric drive machine with a rotor axis and an outer rim for a motor vehicle, comprising At the outer edge, a number of magnet layouts corresponding to a desired number of poles, each with three layers of magnet mounting rows, wherein each magnetic receptacle array has a plurality of magnetic receptacles for receiving one shoulderless magnet each, wherein a radially extending central web is provided between the magnet mounts of the magnet layout, wherein the central web has an increasing radial-inward extension in the circumferential direction, and wherein the magnet receptacles adjacent to the central web have radially inward radii of curvature, wherein the radius of curvature of the magnet receptacles of the outer magnet receptacle row is smaller than the radius of curvature of the magnet receptacles of the inner magnet receptacle row.

[0005] The following text refers to the aforementioned rotor axis whenever the axial direction, radial direction, or direction of rotation and corresponding terms are used, unless explicitly stated otherwise. Ordinal numbers used in the preceding and subsequent descriptions serve solely for unambiguous identification and do not indicate any order or ranking of the components referred to. An ordinal number greater than one does not necessarily imply the presence of another such component.

[0006] The rotor lamination (also called rotor blade) proposed here is suitable for high rotational speeds and high torques. Alternatively or additionally, a more cost-effective and / or better magnetically conductive material can be used. Such a rotor lamination is provided in axial stacks, each with an insulating layer, in a size appropriate to the requirements, as a so-called laminated core. In some embodiments, a rotor comprises several such laminated cores. The insulating material is formed, for example, by means of a so-called baked-on varnish. When used in an electric drive machine (preferably a so-called PSM [permanent synchronous machine]), a rotor shaft is centrally located, onto which at least one laminated core is mounted in a torque-resistant manner.

[0007] In one embodiment, the rotor outer diameter is at least 100 mm [one hundred millimeters], preferably between 120 mm and 150 mm. In one embodiment, the maximum design speed is at least 20 thousand rpm [twenty thousand revolutions per minute], preferably a maximum of 24 thousand rpm.

[0008] Each rotor lamination has a radially inner edge for (direct or indirect) attachment to a rotor shaft and a radially outer edge. The outer edge borders the so-called air gap towards the stator.

[0009] The rotor lamination incorporates multiple magnet receptacles arranged in a repeating pattern along the direction of rotation, known as the magnet layout. The alignment of the magnets within these receptacles is intended to generate a magnetic field that maximizes the magnetically induced force (on the stator side) perpendicular to the rotor radius while minimizing the force parallel to the rotor radius. Known configurations include (single-layer or multi-layer) V-arrangements, delta-arrangements, U-arrangements, tangential arrangements, and, in multi-layer embodiments, combinations of these configurations. The number of these magnet layouts corresponds to the desired number of poles or (in a paired-symmetric arrangement) the number of pole pairs.For the rotor lamination proposed here, used in applications with high torques and correspondingly large rotor diameters, 3 to 5 pole pairs, or (including odd numbers) 6 to 10 poles, are advantageous. Each pole is assigned half of two adjacent magnet layouts in the direction of rotation.

[0010] Magnetic materials with high flux density typically have a high mass density (for example, neodymium-iron-boron [NdFeB] with a mass density of, for example, 7.5 g / cm³). 3and a magnetic remanent flux density of 1.0 T to 1.4 T), but at the same time, low tensile strength. If the magnetic material cracks or breaks under load, this significantly deteriorates the alignment of the magnetic field and thus the efficiency of the electric drive motor. Furthermore, it can lead to a change in the mass distribution, thereby increasing the imbalance or even causing a fragment to break off from its intended position. This can, in some cases, result in total failure of the rotor or the electric drive motor. Even if mechanical properties can potentially be improved with a composite magnetic material (for example, with epoxy resin, polyamide, or polyester as matrix materials), these properties must be maintained within a narrow temperature range.

[0011] For large rotor diameters and simultaneously high rotational speeds, it is therefore advantageous if the magnets in the magnet holders are subjected primarily or exclusively to compressive stress. It is therefore proposed here to design the magnets without shoulders. In other words, the magnets do not have any projections that would be engaged in the respective magnet holder to transmit tensile force (due to centrifugal force during operation). Preferably, the magnets used are rectangular in their (at least rough) basic cross-section (optionally with chamfers at the corners). Alternatively, the magnets used are curved (e.g., circular arc-shaped) and / or convex (e.g., lens-shaped or concave) in their (at least rough) basic cross-section (optionally with chamfers at the corners). Preferably, the basic cross-section is free of projections, depressions, indentations, and / or bulges.

[0012] In a preferred embodiment, a magnet in the plane of the rotor lamination has a short extension (also referred to as magnet height) and a long extension (also referred to as magnet width), wherein a section of the short extension is connected to a corresponding stop in the insert and subjected to pressure under centrifugal force. Preferably, the complementary magnet receptacle is designed with a shoulder as a stop. The magnet width is preferably inclined at an angle of at least 10° (ten degrees) up to a maximum of 60° to the tangent to the radial central axis of the central web (angle values ​​are always expressed as 2π or one complete rotation from 0° to 360°). The magnet height is preferably inclined at an angle of at least 10° up to a maximum of 60° to the radial central axis of the central web.

[0013] By increasing the radial-inward extension (i.e., width in the rotational direction) of the central web (in operation towards the rotor shaft), the overlap of internal stresses is reduced. This results in higher strength of the rotor lamination. For example, the extension is selected such that, under a design maximum load, the mechanical peak stress is 600 MPa (six hundred megapascals) and the overall maximum stress is below 450 MPa. A peak stress is preferably located in a region with an overall extension of at most 25%, preferably at most 10%, of the central web's overall extension. An overall maximum stress below 450 MPa is present in the remaining area of ​​the central web's overall extension, with this overall maximum stress in this region being particularly preferably above 200 MPa.

[0014] To avoid a notch effect, it is proposed here that the radial inner radius of curvature be larger than the radial outer radius of curvature towards the central web. In one embodiment, the magnet receptacles have radially increasing radii of curvature from the outer row of magnet receptacles to the inner row of magnet receptacles adjacent to the central web. In another embodiment, the magnet receptacles have radially increasing radii of curvature from row of magnet receptacles to row of magnet receptacles adjacent to the central web.

[0015] In one embodiment, the radius of curvature of the outer and middle rows of magnet holders is equal to or less than half the height of the magnet holder that is complementary to the magnet height. In another embodiment, the radius of curvature of the inner rows of magnet holders is greater than half the height of the magnet holder that is complementary to the magnet height, preferably equal to or greater than this height.

[0016] In one embodiment, the free section of the magnet receptacle required by the size of such an inner radius of curvature is arranged exclusively radially inward, offset from the center of the magnet receptacle or from the entire magnet receptacle. For example, a J-shape is formed.

[0017] Regardless of the specific embodiment, the distance between two rows of magnet holders is preferably equal to or less than the height of the magnet. In one embodiment, the magnet holders of two adjacent rows of magnet holders (of a magnet layout) are aligned parallel to each other. In another embodiment, the magnet holders of two adjacent rows of magnet holders (of a magnet layout) are inclined away from each other at an angle of at least 10°, preferably at least 30°, and particularly preferably at most 45°, preferably with the angled opening facing the central web.

[0018] In a further advantageous embodiment of the rotor lamination, it is proposed that at least two of the three magnet mounting rows are U-shaped. wherein immediately adjacent magnet mounts of a magnet mount series are arranged at an angle of at least 10° to each other.

[0019] It is proposed here that two of the three magnet receptacle rows are U-shaped, with the base of the U-shape located at the central web and the tangents of the base of the U-shape and the outer edge being oriented perpendicular to the radial extent of the central web. In one embodiment, the radially inner magnet receptacle rows are U-shaped. In another embodiment, the radially outer magnet receptacle row is V-shaped, with the magnet receptacles in this V-shape preferably being oriented parallel to the magnet receptacles of at least the nearest rows of the other magnet receptacles immediately adjacent to the central web.

[0020] In one embodiment, several magnet receptacles are provided on one side (i.e., the front and / or rear circumferential side) of the central web in a series of magnet receptacles, each preferably accommodating a single magnet. Alternatively or additionally, several magnets can be accommodated in a single magnet receptacle, wherein the magnets inserted in a common magnet receptacle preferably touch each other or are spaced apart from each other only by a tolerated clearance. Between two inserted magnets, a shoulder is preferably provided on the angled side (i.e., the outer side of the U-shape) of the respective magnet receptacle for the (pressure-transmitting) contact of an inserted magnet.

[0021] In one embodiment, the edge magnet has a large radius of curvature which is larger than the radius of curvature on the central web side (i.e., the central) of the outer row of magnet holders and / or the middle row of magnet holders. In one embodiment, the radius of curvature on the edge is equal to or greater than half the height of the magnet holder that is complementary to the magnet height, preferably equal to or greater than this height.

[0022] In one embodiment, the free section of the magnet receptacle required by the size of such an edge-side radius of curvature is arranged exclusively offset outwards in the direction of rotation from the center of the magnet receptacle. For example, a J-shape is formed, preferably with the J-shape being formed exclusively by a projecting shoulder for the pressure-transmitting contact of an inserted magnet in the magnet receptacle, whereby the free section in the direction of the magnet height does not extend beyond the magnet receptacle. Rather, the free section in the direction of the magnet height ends at or before the complementary receiving edge of the magnet receptacle.

[0023] In an advantageous embodiment of the rotor lamination, it is further proposed that the rotor lamination be made of a high-strength material with a tensile strength of at least 600 MPa.

[0024] In one embodiment, a high-strength sheet metal material with a tensile strength of 700 MPa [seven hundred megapascals] to 950 MPa is used. Such a high-strength sheet metal material is particularly suitable for a rotor with a large outer diameter and / or high rotational speeds (for example, as mentioned above). The magnet layout proposed here effectively compensates for the increase in (magnetic) losses associated with the high strength.

[0025] According to another aspect, a rotor disk is proposed, comprising a rotor lamination according to an embodiment as described above and shoulderless magnets mounted in the magnet receptacles. wherein the bridge-side magnets each have a chamfer facing radially outwards on the bridge side with an extent over at least 25% of the short extent of the respective magnet.

[0026] Reference is made here to the embodiments mentioned in the preceding description. The rotor disk comprises a rotor lamination in one of the aforementioned embodiments, wherein shoulderless magnets are mounted in the magnet receptacles. Such a rotor disk can be used in a rotor stack or lamination stack, preferably a plurality of such identically, and especially preferably identically, designed rotor disks in such a lamination stack. In a lamination stack (as already mentioned above), a plurality of rotor disks (rotor laminations equipped with magnets in the embodiment shown here) are spaced apart from one another by means of a magnetically insulating material, preferably connected to one another.

[0027] It is further proposed (purely optionally) that the magnets on the web side each have a large chamfer facing radially outwards. These magnets thus have a bevel, which is inclined away from a radial centerline of the central web in a radially outward direction. In one embodiment, the respective chamfer has an extent (along the respective intersecting outer edges of the respective magnet) of at least 25% [twenty-five percent], preferably at least 50%, particularly preferably more than 50% up to 90% or more, of the short extent of the respective magnet. With a (preferred) chamfer angle of 45°, the two extents of the chamfer are identical, but with a different chamfer angle, they differ in length.

[0028] In an advantageous embodiment of the rotor disk, it is further proposed that the web-side radial-inner chamfer is larger than the web-side radial-outer chamfer.

[0029] For the magnets located radially further inwards on the web side (or centrally located), preferably only on the innermost row of magnet holders, a trapezoidal or ramp shape is formed on the web side by the chamfer. This has the advantage that a high fill factor for the respective magnet holder can be achieved, while at the same time a large radius of curvature is possible. Fill factor is the ratio of the area of ​​a magnet holder to the area of ​​a magnet it holds. Preferably, a chamfer on the web-side magnet is adapted to the respective web-side radius of curvature and its relative position on the magnet holder; for example, the extent (at least on the long side, i.e., the magnet width, of the respective magnet) of the respective chamfer is (at least approximately) equal to the respective radius of curvature.

[0030] In one embodiment, the size of the web-side chamfers increases radially inwards.

[0031] In an advantageous embodiment of the rotor disk, it is further proposed that the edge magnets have a chamfer on their edge.

[0032] In a preferred embodiment, the remaining material of the rotor lamination between the magnet holders of the magnet holder rows and the outer edge is as small as possible, for example equal to or smaller than the gap size of the so-called air gap between the rotor and the stator. Here, too, it is advantageous to provide a large radius of curvature (compare previous description, for example in J-shape).

[0033] For a high degree of filling, a chamfer is also advantageous here, for which (as an optional embodiment) reference is made to the embodiments according to the description of the web-side (or central) chamfers analogously.

[0034] In one embodiment, the chamfers are progressively steeper in the circumferential direction, starting from the central web and extending outwards relative to the respective magnet. Preferably, a chamfer surface (inclined to the adjacent lateral extensions of the magnet) is created which, under load (magnetic field applied by energizing the stator), is oriented perpendicular or at least approximately perpendicular to the stator field lines opposite the respective magnet, for example, at a current angle of ± 90° [ninety degrees]. In another embodiment, the chamfers in question are perpendicular or at least approximately perpendicular to the respective radius or to the radial centerline of the central web.

[0035] According to another aspect, a rotor for an electric drive machine is proposed with a rotor axis and an outer edge, having at the outer edge a number of magnet layouts corresponding to a desired number of poles, each with three layers of magnet mounting rows, wherein each magnetic imaging series comprises a plurality of magnetic images, each with one shoulderless magnet captured, wherein a radially extending central web is provided between the magnet mounts of the magnet layout, wherein the central web has an increasing radial-inward extension in the circumferential direction, and wherein the magnet receptacles adjacent to the central web have radially inward radii of curvature, wherein the radius of curvature of the magnet receptacles of the outer magnet receptacle row is smaller than the radius of curvature of the magnet receptacles of the inner magnet receptacle row.

[0036] The rotor is suitable for high speeds and high torques. Alternatively or additionally, a more cost-effective and / or better magnetically conductive material can be used. When used in an electric drive machine (preferably a so-called PSM [permanent synchronous machine]), a rotor shaft is centrally located, onto which the rotor is mounted in a torque-resistant manner. The design features described in this approach make it possible to create a rotor that offers high power density and efficient magnetic field utilization for electric drive machines. These properties are particularly important for applications requiring high reliability and efficiency, such as in electrified vehicles.

[0037] In an optional embodiment, the rotor comprises a plurality of axially spaced and magnetically insulated rotor disks (for example, in an embodiment as described above), each equipped with the aforementioned magnet layouts. This arrangement enables a modular design, allowing the overall length and performance of the rotor to be adapted to the specific requirements of an electric drive machine.

[0038] The rotor is radially bounded on the outside by an outer rim, which, in use in an electric drive motor, borders the so-called air gap to the stator. Within the ring between the rotor shaft and the outer rim, a number of magnet layouts corresponding to the desired number of poles are positioned. These magnet layouts each consist of three layers of magnet holder rows. Within these magnet layouts are magnet holders in which magnets are mounted.

[0039] A radially extending central web is provided between the individual magnet mounts, exhibiting an increasing radial-inward extension in the direction of rotation. The function of the central web is to support the structural integrity of the rotor and ensure effective transmission of the magnetic forces. The central web proposed here is preferably designed such that internal stresses during operation can be limited to a maximum threshold by achieving good load distribution. The magnet mounts adjacent to the central web have radially inward rounding radii, which help to reduce stress concentrations and thereby increase the mechanical (tensile) strength of the magnet mounts and the surrounding material.In an optional version, the radii of curvature of the outer magnet mounting rows are smaller than those of the inner rows, allowing for efficient adaptation to geometric and physical requirements.

[0040] Regarding the design of the magnet mounts, as well as the shoulderless magnets in these magnet mounts, reference is made, at least analogously, to the preceding description of the properties of the rotor lamination or the rotor discs.

[0041] In a further advantageous embodiment of the rotor, it is proposed that the rotor has a plurality of axially electrically insulated and spaced-apart rotor disks. wherein the rotor disks each have the magnet layouts and the magnets incorporated therein.

[0042] It should be noted that in one embodiment, the rotor disks and / or the magnets inserted into the respective rotor laminations are designed differently from the preceding description, and may differ from one another within a single rotor. Preferably, the rotor laminations, and particularly preferably the rotor disks (including the inserted magnets), are identical within a single rotor, and / or at least some of the rotor laminations or rotor disks are designed as described above.

[0043] According to another aspect, an electric drive motor for a motor vehicle is proposed, featuring a stator, a rotor shaft and a rotor according to an embodiment as described above, wherein a dynamic magnetic field can be output by means of the stator, which in turn allows a torque to be generated on the rotor shaft by means of the rotor.

[0044] The electric drive machine (preferably a so-called PSM [permanent synchronous machine]) comprises a stator (for example, with a copper winding, preferably a so-called hairpin winding), a rotor shaft, and a rotor connected to the rotor shaft in a torque-resistant manner. In one embodiment, the rotor comprises a plurality of rotor laminations or rotor disks (preferably combined as at least one laminated core), of which at least one, preferably all, are configured as described above. The stator is configured such that it can generate a dynamic magnetic field, which, in interaction with the magnets of the rotor, can generate a torque (to be transmitted via the rotor shaft), for example, to propel a motor vehicle.

[0045] The rotor of the proposed electric drive machine is designed according to an embodiment as described above and is preferably configured to enable efficient transmission of magnetic forces, thereby achieving high torque output (or, in recuperation mode, high torque absorption). Alternatively or additionally, a more cost-effective material and / or one with lower magnetic losses (usually at the expense of lower tensile strength) can be used for the rotor. Furthermore, alternatively or additionally, a magnetic material with a lower flux density and / or a lower maximum permissible temperature (for example, composite magnet material) can be used.

[0046] According to another aspect, a motor vehicle is proposed comprising a transport cabin, at least one electric drive motor according to an embodiment as described above, and at least one drive wheel, wherein the drive wheel can be driven by the electric drive motor to propel the motor vehicle.

[0047] The motor vehicle is designed to transport at least one passenger and / or goods and therefore has at least one transport compartment (e.g., passenger compartment and / or cargo compartment). The motor vehicle is driven via at least one drive wheel by means of the torque from at least one electric drive motor (also referred to as a traction motor in this function). This electric drive motor comprises a rotor, as described above, mounted on a rotor shaft, and a stator, which is equipped with a correspondingly controlled electrical voltage supply to deliver torque to the rotor shaft. For example, the electric drive motor is configured as a PSM (Power Shift Motor).For example, the electric drive motor is used on a second (additional) drive axle of the motor vehicle, while another (electric and / or fuel-burning) traction motor is used as the main drive for the motor vehicle. Alternatively or additionally, the electric drive motor described herein is configured as the main drive in a given embodiment, wherein the electric drive motor is designed for continuous operation under heavy load.

[0048] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is illustrated in Fig. 1 an electric drive motor in cross-section; Fig. 2 a magnetic layout in a 6-pole magnetic field; Fig. 3 a magnetic layout of a rotor disk; Fig. 4 the magnet layout according to Fig. 3 with internal mechanical stresses; Fig. 5 the magnet layout according to Fig. 3 with a magnetic field without current being supplied to the stator; Fig. 6 the magnet layout according to Fig. 3 with a magnetic field of a current-energized stator with a current angle of -45°; and Fig. 7. A motor vehicle in a schematic top view.

[0049] In Fig. Figure 1 shows a cross-section of an electric drive machine 3 designed as a permanent synchronous machine (PSM). A rotor shaft 33 is shown centrally at the rotor axis 4, to which a rotor 2 (for example, formed as a stack of rotor laminations 1 with inserted magnets, i.e., rotor disks 25) is connected in a torque-resistant manner. Bounded by the outer edge 5 is the so-called air gap 42, and radially behind it (i.e., further out) is the stator 32 with its stator winding 43 (here, for example, designed as a hairpin winding). A clockwise direction of rotation 20 in the plane of the blades is shown here (and will be used for clarity in the following sections), which defines the position of the magnet mounts in the (here purely optional, six) magnet layouts 7. It should be noted that an electric drive machine 3 is often configured to deliver (and, if necessary, receive) torque in both directions.

[0050] In Fig. Figure 2 schematically represents a (pars-pro-toto) single magnet layout 7 arranged in a 6-pole magnetic field 34, as it exists in a quasi-static state when a stator-induced torque is applied across a rotor disk 25 or a rotor 2. The rotor lamination 1 or rotor disk 25 or rotor 2 has an outer radius 48 at its outer edge 5 and an inner radius 47 at its rotor shaft receptacle, relative to the rotor axis 4. For example, such a rotor disk 25 or rotor 2 is configured for thermal shrink-fitting onto a rotor shaft 33.

[0051] It can be seen here that, in the magnet layout 7 shown, the relatively forward-rotating magnet receptacle 11 (relative to the exemplary direction of rotation 20) is assigned to a different (relatively forward-rotating) magnet pole 49 than the relatively rear-rotating magnet receptacle 12 (namely, the relatively rear-rotating) magnet pole 49. A possible embodiment of this magnet layout 7 is explained in detail below.

[0052] In Fig. Figure 3 shows a single magnet layout 7 in a (repeating in the direction of rotation 20) section of a rotor disk 25 (or a rotor 2) in an advantageous embodiment, as for example in Fig. 1 and Fig. 2 used.

[0053] With reference to the exemplary direction of rotation 20, a group of (here three) forward-rotating magnet mounts 11 are arranged in front of a radially continuous central web 18, and a group of (here three) rear-rotating magnet mounts 12 are arranged in front of and behind the central web 18. The central web 18 is formed here from remaining material of the rotor lamination 1 (or the rotor 2) between the magnet mounts 11, 12 of the magnet layout 7, whereby a radial center line 41 can be determined in the center of the central web 18 in the direction of rotation 20. Perpendicular to this radial center line 41, a dimension arrow is drawn for the extent 19 of the central web 18 at each of the respective magnet mount rows 8, 9, 10. It can be seen that the extent 19 of the central web 18 in the inner magnet mounting row 10 is larger than in the outer magnet mounting row 8.Here, the central web 18 (purely optional) extends from the outer magnet mounting row 8, via the middle magnet mounting row 9 to the inner magnet mounting row 10 with increasing extension 19.

[0054] Here in Fig. The magnets 11 and 12 are arranged in a U-shape: an inner magnet receptacle 10 (radially adjacent to the central web 18, relative to the radial center line 41) and (approximately parallel to this) a middle magnet receptacle 9 (radially adjacent to the central web 18). Conceptually enclosed outside the middle magnet receptacle 9 in this magnet layout 7 is (purely optionally) an outer magnet receptacle 8, formed in a V-shape. In the magnet receptacles 11 and 12, roughly rectangular magnets 13, 14, 15, 16, and 17 are mounted, with relatively large chamfers resulting in an actual shape that deviates from this basic rectangular form. In the inner magnet holder row 10 and in the middle magnet holder row 9, two magnets 14,16,15,17 are held in the respective rotating front magnet holder 11 and in the respective rotating rear magnet holder 12, which are each positively engaged by the associated magnet holder 11,12.In the outer magnet holder row 8, an (outer) magnet 13 is held in the front rotating magnet holder 11 and in the rear rotating magnet holder 12.

[0055] The magnets 13, 14, 15, 16, 17 are designed here (purely optionally all) without shoulders, whereby a suitable system for absorbing the centrifugal force is formed by the respective magnet receptacle 11, 12, namely in a pressure force-transmitting manner.

[0056] On the central web 18, the respective magnet receptacles 11, 12 in each row of magnet receptacles 8, 9, 10 form (web-side) radii of curvature 21, 22, 23, whereby in the inner row of magnet receptacles 10 the (inner) radius of curvature 23 is (significantly) larger than the (outer) radius of curvature 21 in the outer row of magnet receptacles 8. Here, the radii of curvature 21, 22, 23 (purely optionally) are implemented in increasing size from the outer row of magnet receptacles 8, through the middle row of magnet receptacles 9, to the inner row of magnet receptacles 10. For all the (web-side) radii of curvature 21, 22, 23 shown, the transitions from the respective magnet receptacles 11, 12 are formed tangentially on the radial-outer side (at least approximately, preferably while maintaining a technically and / or economically reasonable tolerance).Furthermore, the radial-inside transitions from the respective magnet receptacles 11, 12 (at least approximately, preferably within a technically and / or economically reasonable tolerance) are not formed tangentially (purely optionally for all) the (web-side) rounding radii 21, 22, 23 shown, or (purely optionally for the middle row of magnet receptacles 9 and the outer row of magnet receptacles 8) are formed by transitioning into a smaller rounding radius (not specified here) into the long extension of the respective magnet receptacle 11, 12. Here, (purely optionally) for the inner row of magnet receptacles 10, an (inner) rounding radius 23 is chosen to be so large that it is significantly exceeded by the cutout of the respective magnet receptacle 11, 12 necessary for the magnet shape, thus resulting in a J-shape.

[0057] At the outer edge 5, a (edge-side) radius of curvature 40 is formed (with a remaining material web that is as thin as possible between the respective magnet holder 11,12 and the outer edge 5), wherein, in all the (edge-side) radii of curvature 40 shown, the transitions from the respective magnet holder 11,12 are formed radially-outside (at least approximately, preferably while maintaining a technically and / or economically reasonable tolerance).Furthermore, (purely optional for all) the (web-side) radii of curvature 21, 22, 23 shown, the radial-inside transitions from the respective magnet holder 11, 12 are not formed tangentially (at least approximately, preferably while maintaining a technically and / or economically reasonable tolerance), or (here purely optional for all magnet holders 11, 12) a (edge-side) radius of curvature 40 is chosen to be so large that it is significantly exceeded by the cutout of the respective magnet holder 11, 12 necessary for the magnet shape, thus resulting in a J-shape.

[0058] The magnets 14, 16, 15, 17 in the magnet receptacles 11, 12, each holding two magnets, are inclined to each other at an angle 24 of approximately 40°. Thus, a U-shape can be approximated sufficiently and cost-effectively using rectangular magnets 14, 15, 16, 17. In the illustrated embodiment, the magnets 14, 15, 16, 17 of the middle row of magnet receptacles 9 and the inner row of magnet receptacles 10 are optionally (at least approximately) aligned parallel to each other in the U-shape.

[0059] In Fig. 4 is the magnet layout 7 according to Fig. Figure 3 shows internal mechanical stresses (as they occur under centrifugal force at a design maximum rotational speed), where some areas are designated pars-pro-toto as area 50 of highest stress and area 51 of lowest stress, respectively. It is clearly evident that the internal stresses reach their highest values ​​in the area of ​​the central web 18, and there in the area of ​​the radii of curvature 21, 22, and 23. At the same time, it is clearly evident that a notch effect is effectively suppressed by the magnet layout 7 proposed here.

[0060] For the sake of clarity, the chamfers and the basic shape of the magnets are only described here, whereby for the radii of curvature and extent 19 of the central web 18, reference is made to the description at Fig. 3 is referred to.

[0061] The magnets 13, 14, 15, 16, 17 (here designated pars-pro-toto exclusively at the inner, front-edged magnet 17 with dimension lines) have a magnet width 38, which corresponds to the long extent of the rectangle, and a magnet height 39, which corresponds to the short extent of the rectangle. This shape is complementary to the respective magnet receptacles 11, 12 for the transmission of pressure force under applied centrifugal force. The magnet width 38 is therefore oriented tangentially to the U-shape and the magnet height 39 perpendicular to it. The magnets 13, 14, 15, 16, 17 also have an (axial) magnetic depth (into the plane of the blade), wherein this is, for example, 0.1 mm [one tenth of a millimeter] to 0.5 mm, preferably, for example, 0.2 mm or 0.35 mm, wherein, in the case of a rotor disk 25, the magnetic depth preferably corresponds to the (axial) thickness of the rotor sheet 1.

[0062] Each of the magnets 13, 14, 15 located on the bridge side, i.e., centrally or adjacent to the central bridge 18, has a radially outer chamfer 26, 27, 28. Optionally, the central chamfers 26, 27, 28 are all formed at an angle of approximately 45°. The outermost magnet 13 has a central outer chamfer 26, and the central middle magnet 14 has a central middle chamfer 27, each with an extent of slightly less than 50% of the magnet height 39. The central inner magnet 15 has a central inner chamfer 28 with an extent of almost 100% of the magnet height 39, resulting in a trapezoidal or ramp shape.

[0063] At the outer edges, i.e., the magnets 13, 16, 17 closest to the outer edge 5, a radially outer chamfer 29, 30, 31 is provided, meaning that the only outer magnet 13 has both a central chamfer 26 and an outer chamfer 29. Optionally, the inner outer chamfers 30, 31 are formed at an angle of approximately 45°, while the outer outer chamfer 29 is formed as an imaginary extension of the edge line of the long extension of the outer magnet 13 and is shallower. The inner outer magnet 17 has an inner chamfer 31, and the middle outer magnet 16 has a middle chamfer 30, each with an extension of approximately 25% of the magnet height 39.The outer magnet 13 has an outer chamfer 29 on its edge with an extent of about 15% on the side of the magnet height 39 and about 50% of the magnet height 39 on the side of the magnet width 38, so that the chamfer surface is tangentially oriented to a circle concentric with the outer edge 5.

[0064] In Fig. 5 is the magnet layout 7 according to Fig. Figure 3 shows a magnetic field 34 without current being supplied to the stator 32. The magnetic pole 49, extending from the second winding slot on the left in the direction of rotation 20 of the section shown, is recognizable by the field lines of the magnetic field 34.

[0065] In Fig. 6 is the magnet layout 7 according to Fig. Figure 3 shows a magnetic field 34 with maximum design current and a 45° current angle of the stator 32. The magnetic pole 49, extending along the radial tangent to the inner magnet 17 at the edge of the rear rotating magnet holder 12, is visible in the field lines of the magnetic field 34 at the magnetic pole 49 in the stator 32 at the sixth winding slot on the left, which continues in the direction of rotation 20 of the section shown.

[0066] In Fig.Figure 7 shows a motor vehicle 6 with a traction battery (preferably designed as a high-voltage battery 46) in a schematic top view. A transport cabin 35 (for example, designed as a passenger cabin) is provided centrally in the motor vehicle 6. The motor vehicle 6 includes (here purely optionally two) electric drive motors 3, one on a front axle and one on a rear axle of the motor vehicle 6. The rear electric drive motor 3 is connected to two drive wheels 36, 37 via a transmission gearbox 44 and a differential 45, transmitting torque to the left and right sides.

[0067] Optionally, a second electric drive motor 3 is arranged in the front area of ​​the vehicle 6, which is connected to further drive wheels 36, 37 on the left and right, transmitting torque. Thus, (optionally) all four wheels of the vehicle 6 are configured as drive wheels 36, 37. Alternatively, a pure rear-wheel drive or a pure front-wheel drive is provided with one or more drive motors 3.

[0068] The electric drive motors 3 can be supplied with electrical power by means of the high-voltage battery 46. Thus, a drive torque can be converted into a propulsion of the motor vehicle 6 by means of the electric drive motors 3 via the drive wheels 36, 37.

[0069] The invention relates to a rotor lamination for a rotor of an electric drive machine with a rotor axis and an outer rim for a motor vehicle, comprising At the outer edge, a number of magnet layouts corresponding to a desired number of poles, each with three layers of magnet mounting rows, wherein each magnetic receptacle array has a plurality of magnetic receptacles for receiving one shoulderless magnet each, wherein a radially extending central web is provided between the magnet mounts of the magnet layout, wherein the central web has an increasing radial-inward extension in the circumferential direction, and wherein the magnet receptacles adjacent to the central web have radially inward radii of curvature, the radius of curvature of the magnet receptacles of the outer row of magnet receptacles being smaller than the radius of curvature of the magnet receptacles of the inner row of magnet receptacles. The invention further relates to a rotor.

[0070] With the rotor lamination or rotor proposed here, a high torque and at the same time a high rotational speed can be achieved with a cost-effective magnet layout. Reference symbol list 1 rotor lamination 2 Rotor 3 electric drive motors 4 Rotor axis 5 outer edge 6 Motor vehicle 7 Magnet Layout 8 outer magnet mounting row 9 medium magnetic recording row 10 inner magnetic recording row 11 rotating front magnet holder 12 rear rotating magnet holders 13 outer magnet 14 central middle magnet 15 central inner magnet 16 edge-side middle magnet 17 edge-side inner magnet 18 Central Bridge 19 Extension of the central footbridge 20 Direction of rotation 21 outer radius of curvature 22 mean rounding radius 23 inner radius of curvature 24 angles 25 Rotor disc 26 central outer chamfer 27 central middle phase 28 central inner chamfer 29 edge-side outer chamfer 30 edge-side middle chamfer 31 edge-side inner chamfer 32 Stator 33 Rotor shaft 34 Magnetic field 35 Transport cabin 36 left drive wheel 37 right drive wheel 38 magnet width 39 Magnet height 40 edge radius 41 radial center line of the central web 42 air gap 43 Stator winding 44 transmission gears 45 Differential 46 high-voltage battery 47 inner radius 48 outer radius 49 Magnetic pole 50 highest voltage range 51 Lowest voltage range

Claims

[1] Rotor sheet (1) for a rotor (2) of an electric drive machine (3) having a rotor axis (4) and an outer rim (5) for a motor vehicle (6), comprising at the outer edge (5) a number of magnet layouts (7) corresponding to a desired number of poles, each with three layers of Magnetic recording series (8, 9, 10), wherein each magnetic receptacle row (8,9,10) has a plurality of magnetic receptacles (11,12) for receiving one shoulderless magnet (13,14,15,16,17) each, wherein a radially extending central web (18) is provided between the magnet receptacles (11, 12) of the magnet layout (7), wherein the central web (18) has a radially inward increasing extension (19) in the direction of rotation (20), and wherein the magnet receptacles (11,12) adjacent to the central web (18) have radially inward radii of curvature (21,22,23), wherein the radius of curvature (21) of the magnet receptacles (11,12) of the outer row of magnet receptacles (8) is smaller than the radius of curvature (23) of the magnet receptacles (11,12) of the inner row of magnet receptacles (10). [2] Rotor sheet (1) according to claim 1, wherein at least two of the three magnet mounting rows (9,10) are U-shaped, wherein immediately adjacent magnet mountings (11,12) of a magnet mounting row (8,9,10) are arranged at an angle (24) of at least 10° to each other. [3] Rotor sheet (1) according to claim 1 or claim 2, wherein the rotor sheet (1) is made of a high-strength material with a tensile strength of at least 600 MPa. [4] Rotor disk (25), comprising a rotor plate (1) according to one of the preceding claims and shoulderless magnets (13, 14, 15, 16, 17) received in the magnet receptacles (11, 12), wherein the web-side magnets (13,14,15) each have a chamfer (26,27,28) directed radially outwards on the web side with an extension over at least 25% of the short extension of the respective magnet (13,14,15). [5] Rotor disk (25) according to claim 4, wherein the web-side radial inner chamfer (26, 27, 28) is larger than the web-side radial outer chamfer (26). [6] Rotor disk (25) according to claim 4 or claim 5, wherein the edge magnets (13,16,17) have a chamfer (29,30,31) on their edge. [7] Rotor (2) for an electric drive machine (3) having a rotor axis (4) and an outer rim (5), comprising at the outer edge (5) a number of magnet layouts (7) corresponding to a desired number of poles, each with three layers of magnet mounting rows (8, 9, 10), wherein each series of magnetic images (8,9,10) has a plurality of magnetic images (11,12) each with one shoulderless magnet (13,14,15,16,17) captured, wherein a radially extending central web (18) is provided between the magnet receptacles (11, 12) of the magnet layout (7), wherein the central web (18) has a radially inward increasing extension (19) in the direction of rotation (20), and wherein the magnet receptacles (11,12) adjacent to the central web (18) have radially inward radii of curvature (21,22,23), wherein the radius of curvature (21) of the magnet receptacles (11,12) of the outer row of magnet receptacles (8) is smaller than the radius of curvature (23) of the magnet receptacles (11,12) of the inner row of magnet receptacles (10). [8] Rotor (2) according to claim 7, wherein the rotor (2) has a plurality of axially electrically insulated and spaced-apart rotor disks (25), wherein the rotor disks (25) each have the magnet layouts (7) and magnets (13,14,15,16,17) incorporated therein. [9] electric drive motor (3) for a motor vehicle (6), comprising a stator (32), a rotor shaft (33) and a rotor (2) according to claim 7 or claim 8, wherein a dynamic magnetic field (34) can be output by means of the stator (32), which can be used to generate a torque on the rotor shaft (33) by means of the rotor (2). [10] Motor vehicle (6) comprising a transport cabin (35), at least one electric drive motor (3) according to claim 9 and at least one drive wheel (36,37), wherein the drive wheel (36,37) can be driven by means of the electric drive motor (3) to propel the motor vehicle (6).

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