Rotor having offset lamination sub-stacks with overlap regions and method for assembling the rotor

Abstract

The invention relates to a rotor (2) for an electric machine, having a plurality of rotor poles (3) which are distributed in the circumferential direction and each have at least one magnet unit (4a), (4b); having at least two lamination sub-stacks (5a), (5b), (5c), (5d), wherein each lamination sub-stack (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 receiving a rotor shaft (9) for conjoint rotation and a plurality of radially oriented tooth sections (10), between which, for each rotor pole (3), a radially outwardly open segment receptacle (11) for receiving the at least one magnet unit (4a), (4b) and the at least one insert segment (7) is formed, wherein the shaft receptacles (8) of the lamination sub-stacks (5a), (5b), (5c), (5d) are congruent and the segment receptacles (11) of the at least two lamination sub-stacks (5a), (5b), (5c), (5d) are offset in respect to one another in relation to the axis of rotation of the rotor (100) in the circumferential direction by an angle of inclination (101); and having a bandage (25) which surrounds the lamination sub-stacks (5a), (5b), (5c), (5d) and via which the magnet units (4a), (4b) and the insert segments (7) are held in the respective segment receptacle (11), wherein in each case one tooth section (10) and in each case one insert segment (7) are arranged in an overlap region (14) of an adjacent tooth section (10) of the lamination sub-stack (5a), (5b), (5c), (5d) offset by the angle of inclination (101).

Description

[0001] Rotor with offset laminated cores with overlapping areas and method for assembling the rotor

[0002] 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.

[0003] 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 magnetic pockets distributed circumferentially 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 bandaging the rotor core. The bandaging of the rotor core achieves particularly high mechanical strength and speed stability.

[0004] Furthermore, rotors for electrical machines are known that are constructed from several partial laminated cores. The partial laminated cores are formed from several individual sheets stacked one above the other, each of which has several magnetic pockets distributed in the circumferential direction 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.

[0005] The publication DE 10 2019 117 686 A1 discloses a rotor device for an electrical 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. The object of the invention is to create a rotor of the type mentioned above, which is characterized by damage-free assembly of the rotor, in particular 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 electrical machine. In particular, the electrical machine is designed and / or suitable for an electric axle drive and / or for driving a motor vehicle. The electrical machine is preferably designed as an internal rotor, wherein the rotor is arranged radially inside a stator. For example, the electrical machine can also be designed as a starter-generator (SG) and for this purpose interact with an internal combustion engine in a vehicle. The electrical machine is particularly preferably designed as a permanent magnet synchronous machine, PSM for short. An optional subject matter of the invention relates to an electrical 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 for each rotor pole. In particular, the rotor has 1 n, 2 n, 3 n, 4 n or 5 n magnet units, where n corresponds to the number of rotor poles. In particular, the rotor has 1 n, 2 n or 3 n inner magnet units and optionally 1 n, 2 n or 3 n 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.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 rotation axis, sequentially and / or rotationally fixed. Preferably, the at least two partial laminated cores are connected together, 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, especially 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 take place 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, exactly one insert segment is assigned to each rotor pole.

[0009] 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 penetrates the laminated core continuously and / or rectilinearly 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.

[0010] The laminated core has a plurality of radially aligned tooth sections, between which a radially outwardly open 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.

[0011] 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 be used to 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. In this case, the pole pitch is understood to be the distance between two adjacent magnet receptacles or magnet receptacle openings of two adjacent rotor poles.In other words, the helix angle is smaller than an angle defined by the 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. The rotor has a bandage enclosing the partial laminated cores, via which bandage the magnet units and the insert segments are held in the respective segment holder. 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 made of 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.

[0012] 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. The overlap region is preferably defined in the circumferential direction by a circumferential width of the tooth tip. The tooth sections and the insert segments are preferably 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.

[0013] 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 prestresses 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.

[0014] 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.

[0015] 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 sheet stacks are beveled.

[0016] 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% each of the overlap width. 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 being 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.

[0017] 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 the segment receptacles having to be reduced in size.

[0018] 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 mirrored 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 distance can be significantly reduced.

[0019] 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 except for the reduced axial gap between the 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 a virtually edge-free outer surface and is thus particularly suitable for bandaging with a delicate bandage, such as a thread bandage. In a further development, it is provided that 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. In simple terms, the tooth sections of each rotor pole are designed with an asymmetry or off-center offset on the laminated core in the circumferential direction relative to the shaft holder. In particular, the axis of symmetry can be defined by a radial center line or vertical axis, across which the shaft holder is mirrored.To create the helix angle, the lamination core of one partial laminated core is rotated 180 degrees around the axis of symmetry relative to the lamination core of the other partial laminated core. In particular, “rotated” means that the lamination core of a first partial laminated core is rotated around the axis of symmetry relative to the lamination core of a second partial laminated core in such a way that an end face of the lamination core previously facing away from the second partial laminated core faces the second partial laminated core. The asymmetry thus makes it easy to create single or multiple helixes in the rotor laminated core by rotating the partial laminated cores around the respective axis of symmetry. A further advantage is that to create the helix, the at least two partial laminated cores can be of the same construction or identical design, since the helix is ​​created simply by rotating them around the vertical axis.This makes the manufacturing process particularly simple and cost-effective.

[0020] 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. Preferably, the through-openings are 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 axis of symmetry 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.

[0021] In a further embodiment, the insert segments are captively secured in the respective segment holder in a pre-assembly state, at least in the radial direction with respect to the rotor rotation axis. In particular, the pre-assembly 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 holder in such a way that the insert segments are secured against falling out in the pre-assembly state, i.e. without a bandage. Thus, the magnet units are held captively in the respective segment holder 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 direction 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.

[0022] In one specific embodiment, it is provided that the insert segments are each fixed in the pre-assembled state directly to the tooth sections and / or the immediately adjacent insert segments 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 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 engagement of the insert segments with the axially adjacent insert segments and / or tooth sections of the adjacent partial laminated core and / or a circumferential engagement 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 gluing 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 particularly simple and cost-effective fixation of the insert segments.

[0023] 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.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 at a helix angle relative to the partial laminated core, such 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.

[0024] 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 one after the other on a common rotor carrier, preferably the rotor shaft, in the axial direction relative to the rotor axis. The partial laminated cores are preferably structurally identical, in particular as already described. In principle, the rotor laminated core can be constructed from the two partial laminated cores.Preferably, however, the rotor laminated core is constructed from more than two, preferably at least four, of the partial laminated cores, wherein one or more of the partial laminated cores are rotated by the helix angle during the process in order to create a single or multiple helix of the rotor laminated core. In particular, the rotor laminated core is wrapped in multiple layers with a pre-tensioned thread during banding. 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 banding 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 also be subjected to pre-tension right at the beginning after a tying process without it being damaged or broken.

[0025] In one specific embodiment, the lamination core of one partial lamination stack is rotated about a vertical axis relative to the lamination core of the other partial lamination stack to form the helix angle. In principle, the rotor lamination stack can be constructed from the two partial lamination stacks. However, the rotor lamination stack is preferably constructed from more than two, preferably at least four of the partial lamination stacks, with one or more of the partial lamination stacks being rotated about the vertical axis, in particular by 180 degrees, during the process to create the helix of the rotor lamination stack. In particular, the lamination cores are rotated about the vertical axis before assembly on the rotor shaft to create the helix angle. For this purpose, the lamination 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 receptacles and, if applicable, the through holes are aligned, while the segment receptacles 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.

[0026] In a further specification, it is provided that the insert segments are secured in a captive manner 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 additionally, 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 additionally, the insert segments can be secured to the adjacent tooth sections and / or the adjacent insert segments in a material-fitting 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.

[0027] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. In the following:

[0028] Fig. 1 is a perspective view of a slanted rotor core of a rotor as an embodiment of the invention;

[0029] Fig. 2 shows a detailed view of the rotor core from Fig. 1;

[0030] Fig. 3 is a perspective view of a rotor in a final assembly state.

[0031] Figure 1 shows a rotor core 1 of a rotor 2 for an electrical machine, as shown in Figure 3, in a perspective view. In the exemplary embodiment shown, the rotor 2 comprises twelve rotor poles 3 evenly distributed in the circumferential direction around a rotor rotation axis 100, wherein each rotor pole 3 has two magnet units 4a, 4b arranged in a V-shape. 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.

[0032] 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 laminates 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.

[0033] The lamination cores 6 each have a plurality of radially outwardly oriented tooth sections 10. Between the tooth sections 10, a segment receptacle 11 is formed for each rotor pole 3, which is open radially outward 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 secure the insert segments 7 and thus also the magnet units 4a, 4b against loss in a pre-assembled state, as shown in Figure 1. In addition, the magnet units 4a, 4b can be captively mounted in the respective segment holder 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.

[0034] The laminated cores 6 further comprise a central shaft receptacle 8 for the rotationally fixed reception of a rotor shaft 9, as shown in Figure 3. The partial laminated cores 5a, 5b, 5b, 5c or the laminated cores 6 are connected to the rotor shaft 9 via the shaft receptacle 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 receptacle 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.

[0035] The laminated cores 6 of each partial laminated core 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, with the shaft receptacles 8 and the through-openings 12 of all partial laminated cores 5a, 5b, 5c, 5d being 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).

[0036] To reduce torque fluctuations, also known as "torque ripple," the rotor laminated core 1 has a skew. For this purpose, the magnet receptacles 11 of the two middle partial laminated cores 5b, 5c are rotated in the circumferential direction around the rotor axis 100 relative to the two outer partial laminated cores 5a, 5d by a skew angle 101, so that an offset is formed within the rotor laminated core 1 between the magnet receptacles 11 of the first partial laminated core 5a and the magnet receptacles 11 of the second partial laminated core 5b, as well as between the magnet receptacles 11 of the third partial laminated core 5b and the magnet receptacles 11 of the fourth partial laminated core 5c. The rotor laminated core 1 thus has a V-shaped skew. For example, the resulting skew angle between the magnet receptacles 101 is less than 5 degrees.

[0037] 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.

[0038] 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 in such a way that exposed edges are avoided or reduced to a harmless level.

[0039] For this purpose, the tooth sections 10 each have a widening of the tooth tip 15 that increases in the radial direction with respect to the rotor rotation axis 100, which widens the tooth tip 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 indicated in Figure 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 common or summed overlap of the tooth head 15 and the insert segment 7 of the second or third partial laminated core 5b, 5c in the respective overlap area 14 of the first orfourth partial laminated core 5a, 5d corresponds to more than 90% of the circumferential width 16. Furthermore, it can be provided that the tooth sections 10 or the tooth tips 15 of the second or third partial laminated core 5b, 5c are arranged to overlap the tooth sections 10 or the tooth tips 15 of the first or fourth partial laminated core 5a, 5d by more than 50% 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.

[0040] 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 reduces an axial gap 17 formed between the insert segments 7 and the tooth tip 15 to a minimum without them contacting each other. For example, the axial gap 17 has a gap width of less than 0.5 mm. Due to the small 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. As shown in Figure 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 per 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 adjacent tooth section 10. In other words, the two magnet units 4a, 4b per 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 complement the V-shape of the segment receptacles 11.

[0041] Figure 3 shows the rotor 2 in a perspective view, which is designed or suitable for an electrical machine, not shown, of an electric vehicle. The electrical machine is a permanent magnet synchronous machine.

[0042] 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 electric machine. For this purpose, rotor bearings, e.g. rolling bearings, can be mounted on the shaft section 9. For example, the rotor axis of rotation 100 is defined by a rotation axis of the shaft 9. The support section 23 can be guided coaxially with respect to the rotor axis of rotation 100 through the shaft holder 8, as described in Figure 1, wherein the laminated core 6 and the support section 23 are connected to one another in a positively and / or non-positively manner in the circumferential direction around the rotor axis of rotation 100 via the shaft holder 8.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.

[0043] 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 held or clamped captively 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.

[0044] Reference symbol

[0045] 1 rotor lamination package

[0046] 2 rotors

[0047] 3 rotor poles

[0048] 4a, b Magnet units

[0049] 5a-c Partial laminated cores

[0050] 6 sheet core

[0051] 7 insert segments

[0052] 8 shaft recording

[0053] 9 Rotor shaft

[0054] 10 tooth sections

[0055] 11 segment recordings

[0056] 12 through openings

[0057] 13 support surfaces

[0058] 14 Overlap area

[0059] 15 Tooth head

[0060] 16 circumference width

[0061] 17 Axial gap

[0062] 18 Shell surface

[0063] 19 Surface

[0064] 20 side surface

[0065] 21 side flank

[0066] 22 wave section

[0067] 23 supporting section

[0068] 24 end sections

[0069] 100 Rotor rotation axis

[0070] 101 Helix angle

[0071] 102 axis of symmetry

Claims

Patent 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 toothed 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 congruent with respect to the rotor rotation axis (100) are offset from one another in the circumferential direction by a helix angle (101); - 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); characterized in that in each case one tooth section (10) and one 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).

2. Rotor (2) according to claim 1, characterized in 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 in 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 in that the total overlap of the tooth portion (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 in 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 in 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 respective adjacent tooth section (10).

7. Rotor (2) according to one of the preceding claims, characterized in that 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 in 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 in that 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 in that the insert segments (6) 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 (100).

11. Rotor (2) according to one of the preceding claims, characterized in 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 force-fitting connection and / or a material connection.

12. Rotor (2) according to one of the preceding claims, characterized 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 formed as identical parts.

13. A 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 holders (7); - the partial sheet packages (5a, 5b) are then wrapped with the bandage (25).

14. The method according to claim 13, characterized in that 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 in that the insert segments (7) are secured in a captive manner before bandaging directly to the tooth sections (10) of the respective segment holder (11) and / or to the insert segments (7) of at least one adjacent partial laminated core (5b).

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