Rotor with overlapping areas and method for assembling the rotor

Abstract

A rotor 2 for an electrical machine is provided, comprising a plurality of rotor poles 3 distributed in the circumferential direction, each of which has at least one magnet unit 4a, 4b; with at least two partial laminated cores 5a, 5b, 5c, 5d, wherein each partial laminated core 5a, 5b, 5c, 5d comprises a star-shaped laminated core 6 and a plurality of insert segments 7, wherein the laminated core 6 has a central shaft receptacle 8 for the rotationally fixed reception of a rotor shaft 9 and a plurality of radially aligned tooth sections 10, between which a radially outwardly open segment receptacle 11 is formed for each rotor pole 3 for receiving the at least one magnet unit 4a, 4b and the at least one insert segment 7, wherein the shaft receptacles 8 of the partial laminated cores 5a, 5b, 5c, 5d are congruent and the segment receptacles 11 of the at least two partial laminated cores 5a, 5b, 5c, 5d are offset from one another in the circumferential direction by a helix angle 101 with respect to the rotor rotation axis 100;and with a bandage 25 enclosing the partial laminated cores 5a, 5b, 5c, 5d, by means of which the magnet units 4a, 4b and the insert segments 7 are held in the respective segment receptacle 11, wherein in each case a tooth section 10 and in each case a insert segment 7 are arranged in an overlap region 14 of an adjacent tooth section 10 of the partial laminated core 5a, 5b, 5c, 5d offset by the helix angle 101;

Description

[0001] The invention relates to a rotor for an electrical machine having the features of the preamble of claim 1. Furthermore, the invention relates to a method for assembling the rotor.

[0002] Rotors for electrical machines are known, which typically have a rotor core formed from several individual laminations stacked one above the other. The rotor core has several circumferentially distributed magnetic pockets for accommodating permanent magnets. For rotors of permanently excited synchronous machines (PSMs), so-called buried permanent magnets are generally used. These are embedded within the rotor core and secured by banding the rotor core. This banding of the rotor core achieves particularly high mechanical strength and speed stability.

[0003] Furthermore, rotors for electrical machines are known that are constructed from several partial laminated cores. The partial laminated cores are formed from several individual laminations stacked one above the other, each of which has several magnetic pockets distributed circumferentially for accommodating the permanent magnets. To reduce rotational irregularities, it is known to rotate the partial laminated cores relative to each other in the circumferential direction by a so-called helix angle, resulting in a helix of the magnetic pockets.

[0004] The document DE 10 2019 117 686 A1 discloses a rotor device for an electric machine, comprising a rotor, a rotor core, a bandage radially surrounding the rotor core, and a plurality of rotor poles. The rotor poles each comprise at least two magnet units buried in the rotor core, namely internal magnet units, and at least one magnet unit arranged between the rotor core and the bandage, namely surface magnet units.

[0005] The object of the invention is to create a rotor of the type mentioned above, which is characterized by a damage-free assembly of the rotor, in particular of the bandage.

[0006] This object is achieved by a rotor having the features of claim 1 and a method having the features of claim 13. Further features, advantages, and effects of the invention are described in the subclaims and the description with the accompanying figures.

[0007] The subject matter of the invention is a rotor which is designed and / or suitable for an electric machine. In particular, the electric machine is designed and / or suitable for an electric axle drive and / or for driving a motor vehicle. The electric machine is preferably designed as an internal rotor, wherein the rotor is arranged radially inside a stator. For example, the electric machine can also be designed as a starter-generator (SG) and for this purpose interact with an internal combustion engine in a vehicle. The electric machine is particularly preferably designed as a permanent magnet synchronous machine, PSM for short. An optional subject matter of the invention relates to an electric machine with the rotor.

[0008] The rotor has a plurality of rotor poles distributed in the circumferential direction, each comprising at least or exactly one magnet unit. In particular, the magnet units are to be understood as radially inner, in particular buried, magnet units. Optionally, the rotor can have at least one radially outer magnet unit per rotor pole. In particular, the rotor has 1n, 2n, 3n, 4n or 5n magnet units, where n corresponds to the number of rotor poles. In particular, the rotor has 1n, 2n or 3n inner magnet units and optionally 1n, 2n or 3n outer magnet units, where n corresponds to the number of rotor poles. Preferably, the magnet units each comprise one or more pole-generating magnets, in particular permanent magnets. Preferably, the rotor has more than four, preferably more than six, in particular more than eight rotor poles, which are evenly distributed in the circumferential direction.

[0009] The rotor has at least or exactly two partial laminated cores, each partial laminated core comprising a star-shaped laminated core and a plurality of insert segments, also referred to as pole caps. In particular, the at least two partial laminated cores are arranged together on the rotor shaft in the axial direction with respect to the rotor axis of rotation sequentially and / or in a rotationally fixed manner. Preferably, the at least two partial laminated cores are connected to one another, in particular in multiple parts, to form a rotor laminated core. For example, the rotor or the rotor laminated core can comprise more than two, preferably more than four, in particular more than six of the partial laminated cores. Preferably, the laminated core is circumferentially closed, in particular essentially annular. Alternatively, however, the laminated core can also be circumferentially segmented. For example, the segmentation can occur in the circumferential direction in the region of the pole edges or at the pole edges.Preferably, the insert segments are formed separately from the laminated core or as separate components. Preferably, each rotor pole is assigned exactly one insert segment.

[0010] The laminated core has a central shaft receptacle for the rotationally fixed reception of a rotor shaft, wherein the shaft receptacles of the partial laminated cores are arranged congruently with one another. In particular, the central shaft receptacle extends continuously and / or linearly through the laminated core in the axial direction. Preferably, the central shaft receptacle is formed as a central through-opening or a central opening through which the rotor shaft is guided coaxially with respect to the rotor rotation axis. In particular, the shaft receptacles of all partial laminated cores are congruent in the circumferential direction or aligned with one another in the axial direction. Particularly preferably, the shaft receptacle has a polygonal shape, in particular a polygonal shape corresponding to the number of rotor poles. Preferably, the shaft receptacle and the rotor shaft have n-fold rotational symmetry, where n corresponds to the number of rotor poles.In particular, the rotor rotation axis is defined by a rotation axis of the rotor shaft.

[0011] The laminated core has a plurality of radially aligned tooth sections, between which a radially outwardly opening segment receptacle is formed for each rotor pole to receive the at least one magnet unit and the at least one insert segment. In other words, at least one magnet unit and at least one insert segment are arranged in each segment receptacle. Preferably, the magnet unit is inserted and / or clamped in the circumferential direction between the tooth sections and in the radial direction between the laminated core and insert segment. Preferably, the tooth sections or the segment receptacles of a partial laminated core extend parallel and / or in the same direction in the axial direction with respect to the rotor axis of rotation. In particular, the tooth sections are directed substantially radially outwards with respect to the rotor axis of rotation. Preferably, the tooth sections are formed integrally on the laminated core.In particular, the segment receptacles have a contour that is complementary and / or geometrically similar to the insert segments. The insert segments are preferably supported on the magnet units in a form-fitting manner in the circumferential direction and / or in the radial direction relative to the rotor rotation axis. Particularly preferably, the insert segments are supported on the magnet units with a precise fit and / or without play. The insert segments can be accommodated in the segment receptacles such that their radial outer side defines an outer circumference of the rotor and / or is arranged on a common pitch circle around the rotor rotation axis.

[0012] The segment receptacles of the at least two partial laminated cores are offset from one another in the circumferential direction by a helix angle with respect to the rotor rotation axis. In particular, the resulting helix of the magnet receptacles can reduce and / or optimize the noise behavior, in particular the noise-vibration-harshness (NVH) behavior and / or the rotational irregularities of the rotor. Preferably, the helix angle within the rotor laminated core between the first and the second partial laminated core creates an offset that is designed and / or suitable for axially supporting the magnets. In particular, the helix angle is smaller than a pole pitch of the rotor. Here, the distance between two adjacent magnet receptacles or magnet receptacle openings of two adjacent rotor poles is to be understood as the pole pitch. In other words, the helix angle is smaller than an angle defined by a center-to-center distance between two adjacent rotor poles.The angle can thus be represented as 360 / n, where “n” corresponds to the number of rotor poles.

[0013] The rotor has a bandage enclosing the partial laminated cores, via which the magnet units and the insert segments are held in the respective segment receptacle. Preferably, a lateral surface of the rotor laminated core or of the partial laminated cores is completely covered with the bandage and / or completely enclosed by the bandage. The bandage can be designed as a thread bandage, which is formed by a thread wound in a strand around the rotor. Preferably, the thread is band-shaped and / or has an elliptical or rectangular cross-section. The thread can preferably be formed from carbon fiber or other fiber materials, such as metal fibers or a fiber composite material, for example fiber-reinforced plastic. In particular, the thread can be embedded in a matrix.

[0014] Within the scope of the invention, it is proposed that one tooth section and one insert segment are each arranged in an overlap region of an axially adjacent tooth section of the partial laminated core offset by the helix angle. In other words, for each tooth section, one axially adjacent tooth section and one axially adjacent insert segment are each arranged in the overlap region of the tooth section. In particular, the overlap region is to be understood as an imaginary axial extension of the tooth section on the outer circumference of the tooth tip. Preferably, the overlap region is defined in the circumferential direction by a circumferential width of the tooth tip. Preferably, the tooth sections and the insert segments are arranged overlapping in the overlap region in such a way that exposed transition edges in the axial direction are avoided or reduced to a harmless level.A rotor is thus proposed which is characterized by a particularly simple and damage-free bandaging, whereby the bandage can be subjected to a high pre-tensioning force right from the start.

[0015] The invention is based on the finding that the slanting of the magnet receptacles creates exposed edges on the outer diameter of the rotor core, particularly in the transition area between two offset partial cores. When bandaging the rotor core, particularly with high preloads or tensile forces, the thread can be damaged or torn at these exposed edges. By overlapping the tooth sections and insert segments, exposed edges in the transition area can be avoided or reduced to a harmless level. This prevents damage to the bandage during bandaging and increases process reliability.

[0016] In a specific implementation, it is provided that the tooth sections largely overlap with respect to a circumferential width of a tooth tip. Alternatively or optionally additionally, the tooth sections overlap by more than 50% of a circumferential width of the tooth tip. In particular, the circumferential width is to be understood as a width of the tooth tip measured in the circumferential direction at its outer circumference. The circumferential width can be defined, for example, as an angular or linear dimension relative to the total circumference of the partial laminated core. Preferably, all tooth tips of the partial laminated cores have the same circumferential width. The circumferential width of the tooth tip can correspond to 0.5 times, in particular 0.4 times, especially 0.25 times the circumferential width of an insert segment. For example, the circumferential width has an angular dimension of 8 degrees, wherein the tooth sections overlap with each other by an angular dimension of at least or more than 4 degrees.This ensures a wide overlap of the tooth sections and at the same time reduces the risk of sharp-edged transitions.

[0017] In another specific embodiment, the overlap of the tooth sections essentially corresponds to an angular range of the helix angle. In particular, "essentially" means that the overlap corresponds exactly to the angular dimension of the helix angle or to an angular dimension with a maximum percentage deviation of + / - 10% of the helix angle. For example, the helix angle is greater than 2 degrees, preferably greater than 4 degrees, and especially greater than 6 degrees. This ensures a generous overlap of the tooth sections when the partial lamination stacks are beveled.

[0018] In a more specific embodiment, the total overlap of the tooth section and the insert segment in the overlap region corresponds to more than 90%, preferably more than 95%, of a circumferential width of the overlap region or of the tooth section. In principle, the tooth section and the circumferentially adjacent insert segment can be arranged in the overlap region in equal proportions, e.g., 45% of the overlap width each. Alternatively, however, the tooth section can also be arranged over more than 50%, e.g., 55%, of the overlap width, and the insert segment can be arranged over less than 50%, e.g., 35%, of the overlap width in the overlap region.For example, the overlap between the tooth section and the insert segments in the overlap area amounts to an angular dimension of more than 7.2 degrees with a circumferential width of 8 degrees, with the remaining 0.8 degrees defined by an axial gap formed in the circumferential direction between the insert segment and the tooth tip on the outer circumference. This enables a virtually edge-free transition between the partial lamination stacks in the axial direction relative to the rotor rotation axis.

[0019] In a further development, the tooth sections have a widened tooth tip in the radial direction relative to the rotor rotation axis. In particular, the tooth sections have a widened, preferably V-shaped, widening that diverges in the radial direction. In particular, the widened tooth tips reduce the axial gap between the insert segments and the tooth tips, without contacting the insert segments. By widening the tooth tips, the axial gap between the tooth sections and the insert segments can be reduced, and the overlap on the outer circumference can be increased, without having to reduce the size of the segment receptacles.

[0020] In a specific implementation, it is provided that the rotor poles each have at least or exactly two magnet units arranged in a V-shape relative to one another, wherein one surface of the magnet units is completely covered by the insert segment and one side surface of the magnet units is completely covered by a side flank of the respective adjacent tooth section. In particular, the magnet units are cuboid-shaped, wherein, viewed in cross-section, the surface faces the laminated core or the insert segment and the side surface faces the respective tooth section. Preferably, “fully covered” is to be understood to mean that the surface of the magnet units facing the insert segment is completely covered in the radial direction by the insert segment and the side surface of the magnet units facing the respective tooth section is completely covered in the circumferential direction by the tooth section.In particular, the V-shaped arrangement opens outwards in the radial direction with respect to the rotor rotation axis. In other words, the two magnet units of each rotor pole are arranged at an angle to the radius of the rotor and / or along a secant. In particular, the two magnet units are arranged mirror-imaged with respect to an associated center line and / or d-axis of the respective rotor pole, which lies in the center of each rotor pole. Particularly preferably, the widening of the tooth tip is complementary to the V-shaped arrangement of the magnet units, so that the tooth flanks of the tooth sections extend on both sides parallel and / or in the same direction to the side surfaces of the adjacent magnet units on the facing side surface. Thus, a virtually gap-free overlap of the magnet units in the respective segment receptacle is proposed, whereby the exposed edges and / or their spacing can be significantly reduced.

[0021] In a further specific implementation, it is provided that the tooth sections and the insert segments jointly define an at least approximately closed outer surface. Here, “at least approximately closed” means that the outer surface of the individual partial laminated cores or of the rotor laminated core is closed down to the reduced axial gap between tooth sections and insert segments. The axial gap preferably has a gap width of less than 1 mm, more preferably less than 0.5 mm. The insert segments and the tooth tips preferably have the same outer radius and / or radius of curvature. In other words, the outer circumference of the tooth sections and the insert segments each touches a common pitch circle around the rotor axis of rotation. A rotor laminated core is thus proposed which is characterized by an almost edge-free outer surface and is therefore particularly suitable for bandaging with a sensitive bandage, such as, for example,a thread bandage, is suitable.

[0022] In a further development, the tooth sections are arranged asymmetrically on the respective partial laminated core with respect to an axis of symmetry of the shaft holder running in the radial direction to the rotor rotation axis. Put simply, the tooth sections of each rotor pole are formed with an asymmetry or offset from the shaft holder in the circumferential direction on the laminated core. In particular, the axis of symmetry can be defined by a radial centerline or vertical axis, about which the shaft holder is mirrored. To form the helix angle, the laminated core of one partial laminated core is rotated by 180 degrees around the axis of symmetry relative to the laminated core of the other partial laminated core.In particular, “rotated” means that the laminated core of a first partial laminated core is rotated about the axis of symmetry relative to the laminated core of a second partial laminated core such that an end face of the laminated core previously facing away from the second partial laminated core faces the second partial laminated core. Due to the asymmetry, a single or multiple skew can be easily created in the rotor laminated core by rotating the partial laminated cores about the respective axis of symmetry. A further advantage is that to create the skew, the at least two partial laminated cores can be of identical construction or design, since the skew is created solely by rotating them about the vertical axis. This makes the manufacturing process particularly simple and cost-effective.

[0023] In a further embodiment, it is provided that the laminated cores each have a plurality of through-openings distributed and / or spaced apart in the circumferential direction, which are designed and / or suitable for forming a cooling channel and / or for weight reduction. The through-openings of the laminated cores of all partial laminated cores are congruent or aligned with one another in the axial direction. In other words, the through-openings penetrate the rotor laminated core continuously and / or in a straight line in the axial direction. In particular, the through-openings designed as cooling channels define a flow path along which the coolant flows through the rotor in the axial direction with respect to the rotor axis of rotation and transports heat away. The through-openings are preferably arranged symmetrically in the respective laminated core with respect to the axis of symmetry.designed so that the through-openings of one partial laminated core are aligned or can be aligned with the through-openings of the other partial laminated core when the corresponding laminated core is rotated around the symmetry axis or vertical axis. Specifically, the rotor laminated core has one cooling channel per rotor pole. The advantage is that by rotating the laminated cores, a skew in the rotor laminated core is easily implemented, while at the same time the through-openings, in particular the cooling channels, run straight through the rotor laminated core.

[0024] In a further embodiment, the insert segments are captively secured in the respective segment receptacle in a pre-assembled state, at least in the radial direction with respect to the rotor rotation axis. In particular, the pre-assembled state is understood to mean a state of the rotor before assembly of the bandage or without a bandage. In other words, the insert segments are fixed in the respective segment receptacle in such a way that the insert segments are secured against falling out in the pre-assembled state, i.e. without a bandage. Thus, the magnet units are held captively in the respective segment receptacle by the insert segments before assembly of the bandage. In particular, “directly” is understood to mean that the insert segments are connected directly to the tooth sections and / or adjacent insert segments without additional securing means or assembly tools.Optionally, at least the insert segments are directly secured in the respective segment holder in the axial and / or circumferential direction during pre-assembly. By directly securing the insert segments in the respective segment holder, assembly can be significantly simplified, as separate assembly tools are no longer required.

[0025] In one specific embodiment, it is provided that the insert segments are each fixed directly to the tooth sections and / or the immediately adjacent insert segments in the pre-assembled state via a positive connection and / or a frictional connection and / or a material connection. The insert segments can be detachably connected to the tooth sections and / or the immediately adjacent insert segments via the positive connection and / or frictional connection and non-detachably connected to the tooth sections and / or the immediately adjacent insert segments via the material connection. Preferably, the positive connection is created by an axial interlocking of the insert segments with the axially adjacent insert segments and / or tooth sections of the adjacent partial laminated core and / or a circumferential interlocking of the insert segments with the circumferentially adjacent tooth sections of the associated partial laminated core.Preferably, the frictional connection is created by axially clamping or pressing the insert segments between the axially adjacent insert segments and / or tooth sections of the adjacent partial laminated cores and / or end plates. Preferably, the material connection is created by bonding the insert segments to the tooth sections and / or insert segments of the adjacent partial laminated core and / or the tooth sections of the associated partial laminated core. Thus, a rotor is proposed which is characterized by a particularly simple and cost-effective fixation of the insert segments.

[0026] In a specific implementation, it is provided that the laminated core is formed by a plurality of individual laminates stacked in the axial direction with respect to the rotor rotation axis, and the insert segments are formed by a plurality of individual laminated segments stacked in the axial direction with respect to the rotor rotation axis, wherein the individual laminates and / or the individual laminated segments of the at least two partial laminated cores are designed as identical parts. The individual laminates and the individual laminated segments are preferably each joined to form the respective partial laminated core, which in turn are connected together, in particular in multiple parts, to form the rotor laminated core. The individual laminates and the individual laminated segments are preferably each formed from a magnetized and / or magnetizable material, preferably a steel alloy. In particular, the individual laminates and the individual laminated segments are designed as so-called electrical sheets.However, with multiple skews, the individual laminations of additional partial lamination stacks can also be designed differently. Thus, a rotor skew can be created using at least two identical partial lamination stacks. This proposes a rotor lamination stack that can be manufactured particularly cost-effectively.

[0027] Another object of the invention relates to a method for assembling the rotor, as already described above, in which the rotor shaft is provided; one of the partial laminated cores is positively connected to the rotor shaft; the other partial laminated core is positively connected to the rotor shaft, offset by a helix angle relative to the partial laminated core, so that at least the magnet receptacles within the rotor laminated core between the at least two partial laminated cores are rotated relative to one another by the helix angle and the tooth sections of the two partial laminated cores are arranged overlapping one another in the axial direction with respect to the rotor rotation axis; the magnet units and the insert segments are inserted into the segment receptacles, and the laminated core is then wrapped with the bandage. The description of the method steps is not intended to specify a sequence for their execution.Rather, individual steps can be swapped, repeated, or omitted. In concrete terms, this means that the magnet units and / or the insert segments can be inserted or pre-assembled into the respective segment holders even before the partial laminated cores are mounted on the rotor shaft.

[0028] In particular, it is provided that the partial laminated cores are manufactured separately from one another in a manufacturing process, e.g., by means of stamping and stacking, and are then stacked in the axial direction relative to the rotor rotation axis according to the described method. The respective partial laminated cores thus represent segments of the rotor, so-called rotor segments, which are arranged successively on a common rotor carrier, preferably the rotor shaft, in the axial direction relative to the rotor axis. The partial laminated cores are preferably identical in construction, in particular as already described above. In principle, the rotor laminated core can be constructed from the two partial laminated cores.Preferably, however, the rotor lamination stack is constructed from more than two, preferably at least four, of the partial lamination stacks, wherein one or more of the partial lamination stacks are rotated by the helix angle during the process in order to create a single or multiple helix of the rotor lamination stack. In particular, the rotor lamination stack is wrapped in multiple layers with a pre-tensioned thread during taping. The thread is preferably applied at a defined angle to the rotor rotation axis. The width of the thread can correspond to the pitch per revolution. In principle, the first layer of the taping can be wound with no or very little pre-tension in order to prevent damage to the thread due to exposed edges.However, due to the overlap of the tooth sections and the resulting reduction in exposed edges, the thread can be pre-tensioned right at the beginning after a tying process without being damaged or broken.

[0029] In one specific embodiment, the laminated core of one partial laminated core stack is rotated about a vertical axis relative to the laminated core of the other partial laminated core stack to form the helix angle. In principle, the rotor laminated core stack can be constructed from both partial laminated cores. However, the rotor laminated core stack is preferably constructed from more than two, preferably at least four of the partial laminated cores, with one or more of the partial laminated cores being rotated about the vertical axis, in particular by 180 degrees, during the process to create the helix of the rotor laminated core stack. In particular, the laminated cores are rotated about the vertical axis before assembly on the rotor shaft to create the helix angle. For this purpose, the laminated cores, in particular tooth sections or the segment receptacles, are designed asymmetrically with respect to the vertical axis.When the lamination cores are rotated 180 degrees around the axis of symmetry, the shaft mounts and, if applicable, the through holes align, while the segment mounts of the rotor poles are offset circumferentially by the helix angle, or the tooth sections are arranged so that they overlap. Thus, a rotor helix can be created using at least two identical or identical partial lamination stacks.

[0030] In a further specification, it is provided that the insert segments are captively secured directly to the tooth sections of the respective segment receptacles and / or the insert segments of the at least one adjacent partial laminated core prior to banding. The insert segments can be secured to the adjacent tooth sections and / or the adjacent insert segments in a form-fitting manner, at least in the radial direction, e.g., via a snap connection. Alternatively, or optionally, in addition, the insert segments can be secured to the adjacent insert segments in a force-fitting manner, at least in the radial direction, e.g., via axial pressing. Alternatively, or optionally, in addition, the insert segments can be secured to the adjacent tooth sections and / or the adjacent insert segments in a material-to-material manner, e.g., via adhesive bonding.It is therefore possible to propose a securing device for the insert segments to prevent them from being lost during bandaging.

[0031] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These show: Fig. 1 a perspective view of a slanted rotor core of a rotor as an embodiment of the invention; Fig. 2 a detailed view of the rotor core from Fig. 1; Fig. 3 a perspective view of a rotor in a final assembly state.

[0032] Fig. 1 shows a rotor core 1 of a rotor 2 for an electrical machine, as in Fig. 3, in a perspective view. In the illustrated embodiment, the rotor 2 comprises twelve rotor poles 3 evenly distributed in the circumferential direction around a rotor rotation axis 100, with each rotor pole 3 having two V-shaped magnet units 4a, 4b. The magnet units 4a, 4b are each formed by at least one pole-generating magnet, which is designed, for example, as a rod-shaped permanent magnet.

[0033] The rotor laminated core 1 comprises four partial laminated cores 5a, 5b, 5c, 5d arranged one behind the other in the axial direction with respect to a rotor rotation axis 100, each of which is formed from a star-shaped laminated core 6 and, for each rotor pole 3, from an insert segment 7. The laminated cores 6 are each formed by a plurality of individual laminated cores stacked one above the other in the axial direction with respect to the rotor rotation axis 100, and the insert segments 7 are formed by a plurality of individual laminated core segments stacked one above the other in the axial direction with respect to the rotor rotation axis 100, which are each manufactured by stamping and connected to one another within the respective partial laminated core 5a, 5b, 5c, 5d.

[0034] The lamination cores 6 each have a plurality of radially outwardly oriented tooth sections 10. Between the tooth sections 10, a radially outwardly open segment receptacle 11 is formed for each rotor pole 3 and extends in the axial direction with respect to the rotor rotation axis 100, in which the two magnet units 4a, 4b and the insert segments 7 are received. The insert segments 7 can be fixed directly in a form-fitting and / or force-fitting and / or material-fitting manner to the tooth sections 10 of the segment receptacle 11 and / or to the axially adjacent insert segments 7 of an adjacent partial lamination package 5a, 5b, 5c, 5d in order to hold the insert segments 7 and thus also the magnet units 4a, 4b in a pre-assembled state, as in Fig. 1, to secure them against loss. Additionally, the magnet units 4a, 4b can be held captively in the respective segment receptacle 11, e.g., positively and / or non-positively, whereby the sheet metal core 6 and / or the tooth sections 19 can each have a corresponding recess, holding structure, or the like for this purpose.

[0035] The sheet cores 6 furthermore have a central shaft holder 8 for the rotationally fixed mounting of a rotor shaft 9, as in Fig. 3. The partial laminated cores 5a, 5b, 5b, 5c or the laminated cores 6 are connected to the rotor shaft 9 via the shaft holder 8 in a form-fitting and / or force-fitting manner in the circumferential direction around the rotor rotation axis 100. For this purpose, the shaft holder 8 has a support surface 13 for each rotor pole 3, each of which is supported on a counter surface (not shown) formed on the rotor shaft 9.

[0036] The laminated cores 6 of each partial laminated core stack 5a, 5b, 5c, 5d each have a through-opening 12 for each rotor pole 3, which serves to form a cooling channel and / or to reduce weight. The through-openings 12 are each formed in the circumferential direction between the magnet receptacles 4a, 4b or between the support surfaces 13 of two adjacent poles 3 on an inner circumference of the laminated core 6 or the shaft receptacle 8. The shaft receptacles 8 and the through-openings 12 each extend parallel to the rotor rotation axis 100, wherein the shaft receptacles 8 and the through-openings 12 of all partial laminated core stacks 5a, 5b, 5c, 5d are arranged congruently or in alignment with one another. This ensures assembly (e.g., positive connection to the shaft) or the cooling function (axially continuous channels).

[0037] To reduce torque fluctuations, also known as "torque ripple," the rotor lamination stack 1 has a skew. For this purpose, the magnet receptacles 11 of the two middle partial lamination stacks 5b, 5c are rotated in the circumferential direction around the rotor axis 100 relative to the two outer partial lamination stacks 5a, 5d by a skew angle 101, so that an offset is formed within the rotor lamination stack 1 between the magnet receptacles 11 of the first partial lamination stack 5a and the magnet receptacles 11 of the second partial lamination stack 5b, as well as between the magnet receptacles 11 of the third partial lamination stack 5b and the magnet receptacles 11 of the fourth partial lamination stack 5c. The rotor lamination stack 1 thus has a V-shaped skew. For example, the resulting skew angle between the magnet receptacles 101 is less than 5 degrees.

[0038] To form the bevel, magnet receptacles 11 are arranged offset in the circumferential direction relative to the shaft receptacle 8. For this purpose, the tooth sections 10 are arranged asymmetrically on the respective partial laminated core 6 with respect to an axis of symmetry 102 of the shaft receptacle 8 running in the radial direction to the rotor rotation axis 100. To create the bevel angle 101, during assembly, the second and third partial laminated core 5b, 5c are each rotated 180 degrees around the axis of symmetry 102 relative to the first and fourth partial laminated core 5a, 5d, whereby the shaft receptacles 8 and the through openings 12 of all partial laminated cores 5a, 5b, 5c, 5d are simultaneously brought into alignment.

[0039] The bevel can result in exposed edges on the outer diameter of the rotor core 1, which pose a problem when bandaging the rotor 1, especially with high preloads or tensile forces. The tooth sections 10 should therefore be designed to avoid exposed edges or reduce them to a harmless level.

[0040] For this purpose, the tooth sections 10 each have a widening of the tooth head 15 that increases in the radial direction relative to the rotor rotation axis 100, which widens the tooth head 15 in each case, defining an overlap region 14 for an axially adjacent tooth section 10 and an axially adjacent insert segment 7 of the adjacent partial laminated core 5b, 5c offset by the helix angle 101. As shown in Fig. 1, the overlap region 14 is defined by a circumferential width 16 of the tooth tip 15. The overlap region 14 is to be understood as the region of the tooth tip 15 in which the adjacent tooth tip 15 and the adjacent insert segment 7 overlap with the axially adjacent tooth tip 15 in the axial direction with respect to the rotor rotation axis 100. It is provided that the joint or summed overlap of the tooth tip 15 and the insert segment 7 of the second or third partial laminated core 5b, 5c in the respective overlap region 14 of the first or fourth partial laminated core 5a, 5d corresponds to more than 90% of the circumferential width 16. In addition, it can be provided that the tooth sections 10 or the tooth heads 15 of the second or third partial laminated core 5b, 5c are arranged with a more than 50% overlap with the tooth sections 10 or the tooth heads 15 of the first or fourth partial laminated core 5a, 5d with respect to the circumferential width 16.For example, the overlap of the tooth sections 10 can essentially correspond to an angular range of the helix angle 101.

[0041] In an axial view relative to the rotor rotation axis 100, the tooth sections 10 have a radially diverging V-shaped widening of the tooth tip 15, which minimizes the axial gap 17 formed between the insert segments 7 and the tooth tip 15 without contact between them. For example, the axial gap 17 has a gap width of less than 0.5 mm. Due to the narrow gap width of the axial gap 17, the tooth tips 15 and the insert segments 7 jointly define an at least approximately closed lateral surface 18, which is interrupted only by the reduced axial gap 17.

[0042] As in Fig. 2, the magnet units 4a, 4b are each formed by a cuboid-shaped permanent magnet, wherein a surface 19 facing the insert segments 7 is completely covered by the insert segment 7 in an installed situation. In other words, the two magnet units 4a, 4b for each segment receptacle 11 are completely covered in the radial direction by the associated insert segment 7. Furthermore, a side surface 20 of the magnet units 4a, 4b facing the tooth sections 10 is completely covered by a side flank 21 of the respective adjacent tooth section 10. In other words, the two magnet units 4a, 4b for each segment receptacle 11 are completely covered in the circumferential direction by the two associated tooth sections 10. In particular, the side flanks 21 extend parallel to the side surfaces 21 of the magnet units 4a, 4b.For this purpose, the V-shaped widenings of the tooth sections 10 can be designed to be complementary to the V-shape of the segment receptacles 11.

[0043] Fig. Figure 3 shows a perspective view of the rotor 2, which is designed or suitable for an electric machine (not shown) of an electric vehicle. The electric machine is a permanent magnet synchronous machine.

[0044] The rotor shaft 9 has a shaft section 22 designed as a hollow shaft, which is connected to a support section 23 via a flange connection. The shaft section 22 and the support section 23 are designed as separate components. The shaft section 22 essentially serves to rotatably support the rotor shaft 9 in a housing of the electrical machine. For this purpose, rotor bearings, e.g., roller bearings, can be mounted on the shaft section 9. For example, the rotor rotation axis 100 is defined by a rotation axis of the shaft 9. The support section 23 can be coaxial with respect to the rotor rotation axis 100 by the shaft holder 8, as in Fig. 1, wherein the sheet metal core 6 and the support section 23 are connected to one another in a form-fitting and / or force-fitting manner via the shaft holder 8 in the circumferential direction around the rotor rotation axis 100.

[0045] The rotor 2 has two end plates 24, which are arranged on the support section 23 at each end of an axial end face of the rotor laminated core 1, coaxial with the rotor rotation axis 100. The two end plates 24 are designed as balancing discs formed separately from the laminated core 1 or the support section 23.

[0046] The rotor 2 also has a bandage 25, which encloses the rotor laminated core 1 or the partial laminated cores 5a, 5b, 5b, 5c on their outer circumference or the outer surface 18. The bandage 25 serves to hold the individual components of the rotor laminated core 1 together and to shield the rotor 1 against heat. The magnet units 4a, 4b and the insert segments 7 are each captively held or clamped between the laminated core 6 and the bandage 25 in the segment holders 11. For example, the bandage 25 can be formed by a carbon fiber wrapping. By reducing the exposed edges between the individual partial laminated cores 5a, 5b, 5b, 5c, damage to the bandage 25 during banding with high prestresses or tensile forces can be prevented, thereby increasing process reliability. Reference symbol 1 rotor lamination package 2 rotors 3 rotor poles 4a, b Magnet units 5a-c Partial laminated cores 6 sheet core 7 insert segments 8 shaft recording 9 Rotor shaft 10 tooth sections 11 segment recordings 12 through openings 13 support surfaces 14 Overlap area 15 Tooth head 16 circumference width 17 Axial gap 18 Shell surface 19 Surface 20 side surface 21 side flank 22 wave section 23 supporting section 24 end sections 100 Rotor rotation axis 101 Helix angle 102 axis of symmetry QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 10 2019 117 686 A1

[0004]

Claims

[1] Rotor (2) for an electrical machine, - with a plurality of rotor poles (3) distributed in the circumferential direction, each having at least one magnet unit (4a, 4b); - with at least two partial laminated cores (5a, 5b, 5c, 5d), each partial laminated core (5a, 5b, 5c, 5d) comprising a star-shaped laminated core (6) and a plurality of insert segments (7), the laminated core (6) having a central shaft receptacle (8) for rotationally fixedly receiving a rotor shaft (9) and a plurality of radially aligned tooth sections (10), between which a radially outwardly open segment receptacle (11) is formed for each rotor pole (3) for receiving the at least one magnet unit (4a, 4b) and the at least one insert segment (7), the shaft receptacles (8) of the partial laminated cores (5a, 5b, 5c, 5d) being congruent and the segment receptacles (11) of the at least two partial laminated cores (5a, 5b, 5c, 5d) being circumferentially offset by a helix angle (101) relative to one another with respect to the rotor rotation axis (100). are offset; - with a bandage (25) enclosing the partial sheet packages (5a, 5b, 5c, 5d), by means of which the magnet units (4a, 4b) and the insert segments (7) are held in the respective segment holder (11); characterized by in that in each case one tooth section (10) and one insert segment (7) are arranged in an overlapping region (14) of an adjacent tooth section (10) of the partial laminated core (5a, 5b, 5c, 5d) offset by the helix angle (101). [2] Rotor (2) according to claim 1, characterized by that at least the tooth sections (10) are arranged largely and / or at least 50% in the overlap region (14) with respect to a circumferential width (16) of a tooth head (15). [3] Rotor (2) according to claim 1 or 2, characterized by that at least one overlap of the tooth sections (10) substantially corresponds to an angular range of the helix angle (101). [4] Rotor (2) according to one of the preceding claims, characterized bythat the total overlap of the tooth section (10) and the insert segment (7) in the overlap region (14) corresponds to more than 90% of a circumferential width (16) of the overlap region (14). [5] Rotor (2) according to one of the preceding claims, characterized by that the tooth sections (10) have a tooth head (15) widened in the radial direction with respect to the rotor rotation axis (100). [6] Rotor (2) according to one of the preceding claims, characterized by that the rotor poles (3) each have at least two magnet units (4a, 4b) arranged in a V-shape relative to one another, wherein a surface (19) of the magnet units (4a, 4b) is completely covered by the respective insert segment (7) and a side surface (20) of the magnet units (4a, 4b) is completely covered by a side flank (21) of the respectively adjacent tooth section (10). [7] Rotor (2) according to one of the preceding claims, characterized bythat the tooth sections (10) and the insert segments (7) jointly define an at least approximately closed lateral surface (18). [8] Rotor (2) according to one of the preceding claims, characterized by that the tooth sections (10) are arranged asymmetrically on the respective laminated core (6) with respect to an axis of symmetry (102) of the shaft holder (8) running in the radial direction to the rotor rotation axis (100), wherein the laminated core (6) of one partial laminated core (5a) is rotated by 180 degrees about the axis of symmetry (102) relative to the laminated core (6) of the other partial laminated core (5b) to form the helix angle (101). [9] Rotor (2) according to one of the preceding claims, characterized bythat the laminated cores (6) each have a plurality of through openings (12) distributed in the circumferential direction for forming a cooling channel and / or for weight reduction, wherein the through openings (12) of the laminated cores (6) of all partial laminated cores (5a, 5b, 5c, 5d) are aligned congruently with one another. [10] Rotor (2) according to one of the preceding claims, characterized by that the insert segments (6) are captively fixed in the respective segment holder in a pre-assembled state at least in the radial direction with respect to the rotor rotation axis (100). [11] Rotor (2) according to one of the preceding claims, characterized by that the insert segments (7) in the pre-assembled state are each fixed directly to the tooth sections (10) and / or the immediately adjacent insert segments (7) via a form-fitting connection and / or a frictional connection and / or a material connection. [12] Rotor (2) according to one of the preceding claims, characterized by in that the laminated core (6) is formed by a plurality of individual laminates stacked in the axial direction with respect to the rotor rotation axis (100) and the insert segments (7) are formed by a plurality of individual laminated segments stacked in the axial direction with respect to the rotor rotation axis (100), wherein the individual laminates and / or the individual laminated segments of the partial laminated cores (5a, 5b, 5c, 5d) are designed as identical parts. [13] Method for assembling the rotor (2) according to one of the preceding claims, in which: - the rotor shaft (9) is provided; - one of the partial laminated cores (5a) is positively connected to the rotor shaft (9); - the other partial laminated core (5b) is positively connected to the rotor shaft (9) offset by the helix angle (101) relative to the partial laminated core (5a), so that at least the segment receptacles (11) between the at least two partial laminated cores (5a, 5b) are rotated relative to one another by the helix angle (101) and the tooth sections (10) of the two partial laminated cores (5a, 5b) are arranged overlapping one another in the axial direction with respect to the rotor rotation axis (100); - the magnet units (4a, 4b) and the insert segments (7) are inserted into the segment receptacles (7); - the partial sheet packages (5a, 5b) are then wrapped with the bandage (25). [14] Method according to claim 13, characterized bythat the laminated core (6) of one partial laminated core package (5a) is rotated relative to the laminated core (6) of the other partial laminated core package (5b) about an axis of symmetry (102) of the shaft holder (8) in order to rotate the laminated cores (6) within the at least two partial laminated core packages (5a, 5b) by the helix angle (102) relative to one another. [15] Method according to claim 13 or 14, characterized by that the insert segments (7) are secured in a captive manner directly to the tooth sections (10) of the respective segment holder (11) and / or to the insert segments (7) of the at least one adjacent partial laminated core (5b) before bandaging.

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