Pole head ring for a rotor for an electric machine, rotor for an electric machine, electric machine, electric axle drive for a motor vehicle, motor vehicle and method for producing a rotor

Abstract

A pole head ring (100) for a rotor for an electric machine, said rotor being designed as a salient-pole rotor and having a body with rotor teeth, comprises a plurality of pole heads (110) arranged at a distance to one another along the circumference of the pole head ring (100). Each of the pole heads (100) comprises a coupling portion (112) for coupling to one of the rotor teeth and two winding window portions (114) which are formed so as to radially outwardly delimit a winding window for a rotor coil unit provided on the rotor tooth. The coupling portion (112) is positioned between the winding window portions (114), and a radially inwardly protruding support projection (124) for supporting the coil unit against centrifugal forces is formed in each of the winding window portions (114). At least one of the winding window portions (114) of each pole head (110) is equipped with a flux barrier feature (130), by means of which the magnetic resistance in the winding window portion (114) is increased in comparison to the magnetic resistance outside the winding window porttion (114).

Description

[0001] Pole head ring for a rotor for an electric machine, rotor for an electric machine, electric machine, electric axle drive for a motor vehicle, motor vehicle and method for producing a rotor

[0002] The present invention relates to a pole head ring for a rotor for an electrical machine, a rotor for an electrical machine, an electrical machine, an electric axle drive for a motor vehicle, a motor vehicle and a method for producing a rotor.

[0003] Conventional rotors for electrical machines can have a support surface or a support feature for coils or windings for transmitting centrifugal forces or for supporting against centrifugal forces in a pole head ring, whereby an accumulation of material in the form of large wall thicknesses can occur in the pole head ring, which can lead, for example, to magnetic stray fluxes.

[0004] Against this background, the present invention provides an improved pole head ring for a rotor for an electric machine, an improved rotor for an electric machine, an improved electric machine, an improved electric axle drive for a motor vehicle, an improved motor vehicle, and an improved method for producing a rotor according to the main claims. Advantageous embodiments emerge from the subclaims and the following description.

[0005] According to embodiments, in particular in a pole head ring of a rotor for an electric machine, flux barriers can be formed in the pole head ring in the region of the winding window of each pole of the rotor. This can increase the magnetic resistance, so that the leakage flux can be minimized, suppressed, or attenuated. Thus, despite the material accumulation in the pole head ring, which can arise due to the contact surface of the coils or the winding in the pole head ring for transmitting the centrifugal forces and can manifest itself in the form of large wall thicknesses, the magnetic resistance can be increased and, consequently, such magnetic leakage fluxes can be minimized. Therefore, the torque density of the electric machine can be improved. A pole head ring for a rotor for an electric machine, wherein the rotor is designed as a salient pole rotor and has a body with rotor teeth,comprises a plurality of pole heads arranged spaced apart from one another along a circumference of the pole head ring, each of the pole heads having a coupling section for coupling to one of the rotor teeth and two winding window sections formed to radially outwardly delimit a winding window for a coil unit of the rotor arranged on the rotor tooth, the coupling section being arranged between the winding window sections, wherein a radially inwardly projecting support projection is formed in each of the winding window sections for supporting the coil unit against centrifugal forces, characterized in that a flux barrier feature is formed in at least one of the winding window sections of each pole head, by means of which a magnetic resistance in the winding window section is increased compared to outside the winding window section.

[0006] The electric machine can be provided for an electric drive train of a vehicle. The electric machine can be designed as a synchronous machine, a separately excited synchronous machine, or an electrically excited synchronous machine. The pole heads can be arranged spaced from one another along the circumference of the pole head ring by intermediate sections. The pole head ring can be designed as a closed ring. The flux barrier feature can reduce the wall thickness and, additionally or alternatively, the amount of material of the pole head ring in the winding window section compared to outside the winding window section. It can therefore already be advantageous if a flux barrier feature is arranged on only one side of a pole. The pole head ring can be constructed from identical, one-piece, axially stacked sheets, in particular electrical sheets.The body can be constructed from identical, one-piece, axially stacked sheets, in particular electrical sheets.

[0007] In other words, flux barriers can be incorporated radially outside the winding window of the respective pole, for example in the form of windows in the pole head ring. The flux barrier or the at least one flux barrier feature can thus, in particular, form a tapered portion or a reduction in the amount of material within the pole head ring radially outside the respective coil arrangement. Based on electromagnetic and structural-mechanical simulations, for example, in a closed pole head ring, the area radially outside the winding window of a pole or the area radially outside the contact surface of the winding has proven advantageous for such a flux barrier.The central area between two poles in a closed pole head ring has proven to be less advantageous from a structural mechanics point of view because it would limit the maximum possible circumferential speed, since a taper in this area would reduce the forces that can be transmitted in the tangential direction (due to strength).

[0008] By means of embodiments of a pole head ring mentioned herein, a significant increase in torque density can be achieved for a rotor and thus also for an electrical machine, and the advantages achieved by increasing the copper fill factor can also be enhanced. By using, for example, a laminated core star as the body of the rotor, it is possible, for example, for the centrifugal forces acting on the body to be transmitted in a tangential direction in a radially inner annular region of the body. The centrifugal forces acting on coil units, for example air coils, of the rotor and the pole head ring can be supported via a positive connection, for example a tongue and groove connection, between the body and the pole head ring as well as the annular shape of the pole head ring. By means of embodiments of a pole head ring mentioned herein, magnetic stray fluxes, i.e.a magnetic flux that closes within the ring but does not contribute to torque generation, and additionally or alternatively, magnetic short circuits between two adjacent poles are prevented or at least reduced, whereby torque density and efficiency can be increased.

[0009] A flux barrier feature can also be formed in both winding window sections of each pole head. In this case, both flux barrier features of each pole head can be shaped identically with respect to one another. Such an embodiment offers the advantage of simple and cost-effective production of the pole head. Alternatively, a flux barrier feature can be formed in both winding window sections of each pole head. In this case, both flux barrier features of each pole head can be shaped differently with respect to one another. Such an embodiment offers the advantage that magnetic stray fluxes can be minimized particularly reliably.

[0010] Both flux barrier features of each pole head can have different contours with respect to one another. Additionally or alternatively, both flux barrier features of each pole head can have different dimensions with respect to one another. Additionally or alternatively, both flux barrier features of each pole head can have different radial and / or tangential positions in the winding window sections. Such an embodiment offers the advantage that flux barrier features designed asymmetrically with respect to both sides of the pole head can further attenuate magnetic stray fluxes. This can be achieved by flux barrier features of different sizes and additionally or alternatively by different radial and / or tangential positions of the flux barrier features. Furthermore, it can be advantageous to use a different contour for the left and right flux barriers of each pole.

[0011] Furthermore, at least one of the flux barrier features can have at least one undercut or at least one bead on an inner circumference or an outer circumference of the pole head ring adjacent to the support projection. Such an embodiment offers electromagnetic and structural advantages, whereby material accumulation can be reduced by one or more arbitrarily shaped geometries.

[0012] In addition, at least one of the flux barrier features can have at least one axial through-opening or at least one axial through-bore in the support projection. Additionally or alternatively, at least one of the flux barrier features can have a round, oval, trapezoidal, trapezoid-like, rectangular, or rectangle-like contour. Such an embodiment offers electromagnetic and structural mechanical advantages, whereby material accumulation can be reduced by one or more arbitrarily shaped geometries.

[0013] For example, a trapezoidal contour can be particularly advantageous, as it allows homogeneous wall thicknesses and thus parallel surfaces to be generated in the pole head ring in the area around the flux barrier feature.

[0014] According to one embodiment, the pole head ring can have a first outer radius in the region of the coupling sections and a second outer radius in the region of intermediate sections by which the pole heads are spaced from one another. In this case, the first outer radius can be larger than the second outer radius. To optimize the air gap fields, it can be advantageous not to design the outer contour of the pole head ring cylindrically, but rather with different radii. It can be particularly advantageous to design the outer contour above the teeth larger in the radial direction than the outer contour between the poles. This type of outer contour can reduce resulting losses and improve NVH behavior (NVH = Noise Vibration Harshness; noise, vibration, roughness; audible and / or noticeable vibrations).

[0015] The pole head ring can also have at least one coupling feature in each coupling section that can be positively coupled to a rotor tooth of the body. In particular, the pole head ring can have two coupling features in each coupling section. In this case, one of the coupling features and a support projection can be combined in a common projection section that is arranged in a boundary region comprising part of the coupling section and part of one of the winding window sections. Such an embodiment offers the advantage that a mechanical coupling or connection between the pole head ring and the body can be robust and stable, whereby force flows in the body and pole head ring can be favorable when the rotor is rotating.A rotor for an electrical machine, wherein the rotor is designed as a salient pole rotor, comprises a body with rotor teeth and an embodiment of a pole head ring mentioned herein.

[0016] When the rotor is assembled, each of the rotor teeth can be mechanically coupled to one of the coupling sections of the pole head ring. The mechanical coupling can be implemented as a positive connection, for example, a tongue and groove connection, between the body and the pole head ring.

[0017] The rotor can also have a plurality of coil units. In this case, at least one coil unit can be or is arranged on each of the rotor teeth. Additionally or alternatively, each coil unit can be designed as an air-core coil. The coil unit can also be referred to as a coil arrangement or winding arrangement. In particular, investment costs and manufacturing costs of the rotor winding can be reduced by using air-core coils instead of a needle winding. By using plug-in air-core coils, the minimum distance between adjacent coils can be significantly reduced compared to a needle winding. This can enable an increase in the copper fill factor and maximum utilization of the winding window. The air-core coils can be or are pushed onto a body, for example designed as a laminated core star, from the radial outside.

[0018] According to one embodiment, in the assembled state of the rotor, the center axes of the pole heads can have an angular offset with respect to the center axes of the rotor teeth. In the assembled state of the rotor, the rotor teeth are coupled to the coupling sections. By setting such an angular offset between the tooth of the body or laminated core star and the pole head of the pole head ring or laminated core ring, a skew can be implemented, which can further improve the NVH behavior of the electric machine. The offset can assume a value that deviates by a few degrees from 360° / p / 4, where p is equal to the number of pole pairs. The set offset can also be a length offset instead of an angular offset. According to one embodiment, a flux barrier and contour optimization for such a rotor with a closed pole head ring can thus be enabled.

[0019] An electric machine comprises a stator and a rotor rotatably mounted relative to the stator, wherein the rotor is designed as an embodiment of a rotor mentioned herein.

[0020] An embodiment of a rotor mentioned herein can be advantageously employed or used in an electrical machine, in particular a synchronous machine or electrically excited synchronous machine, in order to enable a reduction of magnetic stray fluxes and an increase in the torque density.

[0021] The invention also relates to an electric axle drive for a motor vehicle having at least one electric motor, a transmission device, and a power converter. The electric axle drive is characterized in that the electric motor is designed as described.

[0022] The transmission device may comprise a gearbox for reducing the speed of the electric machine and a differential.

[0023] The invention also relates to a motor vehicle with an electric axle drive and / or an electric motor. The motor vehicle is characterized in that the electric axle drive and / or the electric motor are designed as described.

[0024] A method for manufacturing an embodiment of a rotor mentioned herein comprises the following steps:

[0025] Providing the pole head ring and the body; and

[0026] Coupling the pole head ring and the body to each other. Additionally, the method may include a step of arranging a plurality of coil units on the rotor teeth of the body. Coil units may be provided as air-core coils and plugged onto the rotor teeth.

[0027] The invention is explained in more detail by way of example with reference to the accompanying drawings. They show:

[0028] Fig. 1 is a schematic representation of an embodiment of a pole head ring for a rotor for an electrical machine;

[0029] Fig. 2 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0030] Fig. 3 is a schematic representation of a body of an embodiment of a rotor for an electrical machine;

[0031] Fig. 4 is a schematic exploded view of a body and coil units of an embodiment of a rotor for an electrical machine;

[0032] Fig. 5 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0033] Fig. 6 is a schematic representation of a coil unit of an embodiment of a rotor for an electrical machine;

[0034] Fig. 7 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0035] Fig. 8 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0036] Fig. 9 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0037] Fig. 10 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0038] Fig. 11 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0039] Fig. 12 is a schematic representation of an embodiment of a rotor for an electrical machine; Fig. 13 is a schematic representation of an embodiment of a pole head ring for a rotor for an electrical machine;

[0040] Fig. 14 is a schematic representation of an embodiment of a rotor for an electrical machine;

[0041] Fig. 15 is a schematic representation of an electrical machine according to an embodiment;

[0042] Fig. 16 is a flowchart of an embodiment of a method for producing a rotor for an electrical machine; and

[0043] Fig. 17 is a schematic representation of a motor vehicle with an electric axle drive according to an embodiment.

[0044] In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0045] Fig. 1 shows a schematic representation of an embodiment of a pole head ring 100 for a rotor for an electrical machine, for example in an axial plan view. According to one embodiment, the pole head ring 100 is constructed from identical, one-piece, axially stacked laminations, in particular electrical laminations. Thus, the pole head ring 100 can also be referred to as a laminated core pole head ring. According to one embodiment, the rotor for which the pole head ring 100 is provided is designed as a salient pole rotor. The rotor also comprises a body with rotor teeth. The rotor will be discussed in more detail with reference to subsequent figures.

[0046] The pole head ring 100 comprises a plurality of pole heads 110, which are arranged spaced apart from one another along a circumference of the pole head ring 100. Each of these plurality of pole heads 110, in turn, comprises a coupling section 112 and two winding window sections 114. The coupling section 112 is arranged between the winding window sections 114. The coupling section 112 of each pole head 110 is shaped to be coupled or coupled to one of the rotor teeth of the body. The two winding window sections 114 of each pole head 110 are shaped to radially outwardly delimit a winding window for a coil unit of the rotor arranged on the rotor tooth. In particular, adjacent pole heads 110 are spaced or separated from one another by an intermediate section 115.

[0047] The pole head ring 100 also includes a plurality of radially inwardly projecting support projections 124. Such a support projection 124 is formed or arranged in each of the winding window sections 114. Each support projection 124 is shaped to support a respective coil unit against centrifugal forces. In other words, such a support projection 124 represents a support surface as a support for a coil unit in the radially outward direction.

[0048] The pole head ring 100 further comprises a plurality of flux barrier features 130. A flux barrier feature 130 is formed in at least one of the winding window sections 114 of each pole head 110. Each of the flux barrier features 130 increases the magnetic resistance in the winding window section 114 compared to outside the winding window section 114.

[0049] In other words, each of the flux barrier features 130 is shaped and positioned to increase the magnetic resistance in the winding window section 114 compared to outside the winding window section 114, or to cause a higher magnetic resistance in the winding window section 114 than outside the winding window section 114. Thus, at least one flux barrier feature 130 is shaped or arranged in the region of each pole head 110.

[0050] According to one embodiment, and as also illustrated purely by way of example in Fig. 1, two flux barrier features 130 are provided per pole head 110. Thus, one flux barrier feature 130 is formed in each of the two winding window sections 114 of each pole head 110. According to one embodiment, and as also shown purely by way of example in Fig. 1, both flux barrier features 130 of each pole head 110 are formed identically to one another. Here, the flux barrier features 130 of each pole head 110 are, for example, trapezoidal or trapezoid-like, each designed as at least one axial through-opening or at least one axial through-bore in the support projection 124.

[0051] According to another embodiment, both flux barrier features 130 of each pole head 110 are shaped differently from one another. Thus, depending on the specific configuration, both flux barrier features 130 of each pole head 110 have different contours and / or different dimensions and / or different radial and / or tangential positions in the winding window sections 124.

[0052] According to one embodiment, the pole head ring 100 comprises at least one coupling feature 122 in each coupling section 120. The coupling feature 122 can be positively coupled to a rotor tooth of the body. In the illustration of Fig. 1, one of the coupling features 122 and a support projection 124 are combined in a common projection section 120. The coupling feature 120 extends tangentially as a nose away from the radially inwardly projecting support projection 124. Thus, the pole head ring 100 comprises a plurality of projection sections 120 that are spaced apart from one another along a circumference of the pole head ring 100. The projection portion 120 is arranged in a boundary region, comprising a portion of the coupling portion 112 and a portion of one of the winding window portions 140. Thus, each pole head 110 comprises two projection portions 120.Depending on the embodiment, a flux barrier feature 130 is formed in at least one or in each of the projection sections 120 of each pole head 110.

[0053] Fig. 2 shows a schematic representation of an embodiment of a rotor 200 for an electrical machine, for example in an axial plan view. The rotor 200 is designed as a salient-pole rotor. Of the rotor 200, only a pole head ring 100 and a body 240 are shown in the illustration in Fig. 2, by way of example. The pole head ring 100 corresponds to or is similar to the pole head ring from Fig. 1. The pole head ring 100 surrounds the body 240. Thus, the pole head ring 100 is arranged radially outwardly with respect to the body 240. The body 240 comprises a plurality of rotor teeth 242. The rotor teeth 242 extend radially outward toward the pole head ring 100. In particular, the rotor teeth 242 extend radially outward from an annular rotor yoke 244 of the body 240 toward the pole head ring 100. Each rotor tooth 242 is positively connected or coupled to the pole head ring 100 in the region of a coupling portion of the same.The body 240 has a star-shaped layout. According to one exemplary embodiment, the body 240 is constructed from identical, one-piece, axially stacked laminations, in particular electrical laminations. Thus, the body 240 can also be referred to as a laminated core star.

[0054] Adjacent to each of the rotor teeth 242 is a winding window 250, which defines a receiving space for a coil unit of the rotor 200. A coil unit can be arranged or is arranged in each winding window 250, and thus on each of the rotor teeth 242. The winding windows 250 are delimited by the radially inner rotor yoke 244 of the body 240, the radially outer winding window sections and support projections of the pole head ring 100, and the rotor teeth 242, wherein winding windows 250 of adjacent rotor teeth 242 are separated from one another along a radially extending centerline 245 between the adjacent rotor teeth 242 by a minimum coil spacing.

[0055] Fig. 3 shows a schematic representation of a body 240 of an exemplary embodiment of a rotor for an electrical machine, for example in an axial top view. The body 240 corresponds to or is similar to the body of Fig. 2. According to the exemplary embodiment shown here, connecting features designed as grooves 343 are formed on a radially outer end portion of each rotor tooth 242. The grooves 343 are formed to interact with the coupling features of the pole head ring 100 according to the tongue and groove principle or another positive connection.

[0056] Fig. 4 shows a schematic exploded view of a body 240 and a plurality of coil units 450 of an embodiment of a rotor for an electric machine, for example in an axial plan view. The coil units 450 are designed as air-core coils. In the illustration in Fig. 4, the coil units 450 are shown radially outside the rotor teeth of the body 240. For mounting the coil units 450 on the rotor teeth, one coil unit 450 can be plugged onto a respective rotor tooth of the body 240 in a radially inward direction, for example. In the illustration in Fig. 4, only six coil units 450 and six rotor teeth are provided by way of example. In an at least partially assembled state of the rotor, at least one coil unit 450 is thus arranged on each of the rotor teeth.

[0057] Fig. 5 shows a schematic representation of an embodiment of a rotor 200 for an electrical machine, for example in an oblique view. The rotor 200 is provided for an electrically excited synchronous machine or separately excited synchronous machine. The rotor 200 is shown in an assembled or mounted state. The rotor 200 corresponds to or is similar to the rotor from Fig. 2 and comprises at least the pole head ring 100 from Fig. 1 and / or Fig. 2, the body from one of Figures 2 to 4, wherein only rotor teeth 242 and rotor yoke 244 of the body are explicitly designated here, and the coil units 450 from Fig. 4. In the representation in Fig. 5, the rotor 200 has, by way of example only, six coil units 450 and six rotor teeth 242. In the assembled state of the rotor 200, according to the embodiment shown here, a coil unit 450 is arranged on each of the rotor teeth 242.

[0058] Fig. 6 shows a schematic representation of a coil unit 450 of an exemplary embodiment of a rotor for an electrical machine, shown in an oblique view. The coil unit 450 corresponds to or is similar to one of the coil units shown in Fig. 4 and / or Fig. 5. The coil unit 450 is designed as an air-core coil and is designed to be plugged onto one of the rotor teeth of the rotor body.

[0059] The coil unit 450 has an annular, oval and / or double-U-shaped outline. In the illustration of Fig. 6, two insulating bodies 652 of the coil unit 450 are shown, which are arranged on the narrow sides of the coil unit 450, two further insulating bodies 654 are shown, which are arranged on the long sides of the coil unit 450, wherein the further insulating bodies 654 are designed, for example, as insulating paper, and a winding 655 or winding arrangement. Fig. 7 shows a schematic illustration of an embodiment of a rotor 200 for an electrical machine, by way of example in a cross-sectional illustration. In particular, Fig. 7 shows a cross-sectional illustration of a rotor which corresponds to or is similar to the rotor from Fig. 5.

[0060] Here, the pole head ring 100, the body 240, and the coil units 450 of the rotor 200 are shown. The body 240 also shows rotor teeth 242 and the rotor yoke 244. According to the exemplary embodiment shown here, the body 240 comprises six rotor teeth 242. A coil unit 450 designed as an air-core coil is attached to each of the rotor teeth 242.

[0061] The pole head ring 100 corresponds to or is similar to the pole head ring of Fig. 1, Fig. 2 and / or Fig. 5. Only the flux barrier features 130 of the pole head ring 100 are explicitly designated in Fig. 7. According to the exemplary embodiment shown here, two flux barrier features 130 are arranged per pole head. Thus, the pole head ring 100 comprises, for example, twelve flux barrier features 130. Each of the flux barrier features 130 is formed as an axial through-opening or at least one axial through-bore in the support projection of the pole head ring 100. Each of the flux barrier features 130 has a trapezoidal or trapezoid-like contour. This enables homogeneous wall thicknesses of the pole head ring 100 around each of the flux barrier features 130.

[0062] Fig. 8 shows a schematic representation of an embodiment of a rotor 200 for an electric machine, exemplary in a cross-sectional view. The rotor 200 corresponds to the rotor of Fig. 7, except that each of the flux barrier features 130 is formed as a relief cut on an inner circumference of the pole head ring 100 adjacent to the support projection.

[0063] Fig. 9 shows a schematic representation of an embodiment of a rotor 200 for an electric machine, exemplarily in a cross-sectional view. The rotor 200 corresponds to the rotor of Fig. 7 and / or Fig. 8, with the exception that each of the flux barrier features 130 has at least one axial through-opening or at least one axial through-bore, here merely by way of example three axial through-openings or three axial through-bores, in the support projection, wherein each such through-bore or through-opening has a round contour.

[0064] Fig. 10 shows a schematic representation of an embodiment of a rotor 200 for an electric machine, exemplarily in a cross-sectional view. The rotor 200 corresponds to the rotor of Fig. 7, Fig. 8, and / or Fig. 9, except that each of the flux barrier features 130 is formed as a bead on an outer circumference of the pole head ring 100 adjacent to the support projection.

[0065] Fig. 11 shows a schematic representation of an embodiment of a rotor 200 for an electric machine, exemplarily in a cross-sectional view. The rotor 200 corresponds to the rotor of Fig. 7, Fig. 8, Fig. 9, and / or Fig. 10, except that each of the flux barrier features 130 is formed as an axial through-opening or an axial through-bore in the support projection, which has a rectangular or rectangle-like contour, for example, a square contour.

[0066] Fig. 12 shows a schematic representation of an embodiment of a rotor 200 for an electrical machine, for example in a cross-sectional representation of a sector. Fig. 12 shows a sector of a rotor that corresponds to or is similar to the rotor from Fig. 5 and / or Fig. 7. The representation in Fig. 12 is a partial representation of Fig. 7. More precisely, the rotor 200 in Fig. 12 corresponds to the rotor from Fig. 5 and / or Fig. 7 with the exception that the pole head ring 100 has different outer radii and thus deviates from a precisely cylindrical contour.

[0067] The pole head ring 100 corresponds to the pole head ring from Fig. 1 with the exception that the pole head ring 100 in Fig. 12 has a first outer radius R1 in the region of the coupling sections and a second outer radius R2 in the region of intermediate sections by which the pole heads are spaced from one another. The first outer radius R1 is greater than the second outer radius R2. In other words, the pole head ring 100 in Fig. 12 has the first outer radius R1 in the region of the rotor teeth 242 and has the second outer radius R2 in the region centrally between the rotor teeth 242 and thus between the poles. The second outer radius R2 is thus in the region of the radially extending center line shown in Fig. 2 between the adjacent rotor teeth 242.

[0068] Fig. 13 shows a schematic representation of an embodiment of a pole head ring 100 for a rotor for an electrical machine, for example in an axial plan view of a part of the pole head ring 100. The principle of different outer radii of the pole head ring from Fig. 12 is illustrated again using a partial section of the pole head ring from Fig. 9.

[0069] Of the pole head ring 100, four projection sections 120 are shown, each with coupling feature 122 and support projection 124, the flux barrier features 130 formed merely as examples as three axial through-openings or three axial through-bores with a round contour, the first outer radius R1, the second outer radius R2 and a circumferential line U1, which is drawn according to or corresponding to the first outer radius R1. It can be seen even more clearly that the second outer radius R2 is smaller than the first outer radius R1.

[0070] Fig. 14 shows a schematic representation of an embodiment of a rotor 200 for an electrical machine, for example in an axial plan view. Of the rotor 200, a pole head ring 100 with a plurality of pole heads 110 and a body 240 with a plurality of rotor teeth 242 and a rotor yoke 244 are shown. The components of the rotor 200 shown here are similar to the components of the rotor from Fig. 2, wherein in Fig. 14, in which the rotor 200 is shown in a partially assembled state, center axes M110 of the pole heads 110 or poles have an angular offset Aa with respect to center axes M242 of the rotor teeth 242. The angular offset Aa makes it possible to achieve an oblique

[0071] Fig. 15 shows a schematic representation of an electrical machine 1500 according to one exemplary embodiment. The electrical machine 1500 is embodied, in particular, as a synchronous machine, separately excited synchronous machine, or electrically excited synchronous machine. The electrical machine 1500 comprises a rotor 200 and a stator 1506. The rotor 200 is rotatably mounted relative to the stator 1506. The rotor 200 corresponds to or is similar to the rotor from one of the previously described figures.

[0072] It should be noted that in Fig. 15 the rotor 200 is shown as being inside and the stator 1506 as being outside merely as an example.

[0073] Fig. 16 shows a flowchart of an embodiment of a method 1600 for manufacturing a rotor for an electric machine. The manufacturing method 1600 can be executed to manufacture the rotor from one of the figures described above or a similar rotor. The manufacturing method 1600 includes a providing step 1602 and a coupling step 1604.

[0074] In the provision step 1602, the pole head ring and the body are provided. In particular, in the provision step 1602, the pole head ring and / or the body are constructed from identical, one-piece, axially stacked sheets, in particular electrical sheets. Subsequently, in the coupling step 1604, the pole head ring and the body are coupled together.

[0075] The manufacturing method 1600 optionally additionally includes a step of arranging a plurality of coil units on the rotor teeth of the body. The coil units are provided as air-core coils and plugged onto the rotor teeth.

[0076] Fig. 17 shows a schematic representation of a motor vehicle 1700 with an electric axle drive 1705 according to an exemplary embodiment. The illustration in Fig. 17 shows wheels 1701 of the motor vehicle 1700, four wheels 1701 merely by way of example, an electrical energy storage device 1703, for example a battery, and the electric axle drive 1705. The electric axle drive 1705 comprises a power converter 1707, an electric machine 1500, and a transmission device 1709. The electric machine 1500 is the electric machine from Fig. 15 or a similar electric machine.

[0077] Electrical energy for operating the electrical machine 1500 is provided by a power supply device, here the electrical energy storage device 1703. The electrical energy storage device 1703 is designed to provide direct current, which is converted into an alternating current, for example a three-phase alternating current, using a power converter 1707 of the electric axle drive 1705 and provided to the electrical machine 1500.

[0078] A shaft driven by the electric machine 1500 is coupled directly or using the transmission device 1709 to at least one wheel 1701 of the motor vehicle 1700. Thus, the motor vehicle 1700 can be propelled using the electric machine 1500. According to one embodiment, the electric axle drive 1705 comprises a housing in which at least the power converter 1707, the electric machine 1500, and the transmission device 1709 are arranged.

[0079] The exemplary embodiments described and shown in the figures are chosen only as examples. Different exemplary embodiments can be combined with one another, either completely or with regard to individual features. An exemplary embodiment can also be supplemented by features of another exemplary embodiment.

[0080] Furthermore, method steps according to the invention can be repeated and carried out in a different order than that described.

[0081] If an embodiment includes an "and / or" link between a first feature and a second feature, this can be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature, and according to another embodiment, either only the first feature or only the second feature. Reference numerals

[0082] 100 pole head rings

[0083] 110 Pole head

[0084] 112 Coupling section

[0085] 114 Changing window section

[0086] 115 Intermediate section

[0087] 120 projection section

[0088] 122 Coupling feature

[0089] 124 Support projection

[0090] 130 River barrier feature

[0091] 200 rotor

[0092] 240 Corpus

[0093] 242 rotor tooth

[0094] 244 Rotor yoke

[0095] 245 Center line

[0096] 250 changing windows

[0097] 343 groove

[0098] 450 coil unit

[0099] 652 insulating bodies

[0100] 654 additional insulating bodies

[0101] 655 winding

[0102] R1 first outer radius

[0103] R2 second outer radius

[0104] U1 circumference according to the first outer radius

[0105] M110 center axis pole head M242 center axis rotor tooth

[0106] Aa angular offset

[0107] 1500 electric machine

[0108] 1506 Stator

[0109] 1600 manufacturing processes

[0110] 1602 Deployment step

[0111] 1604 Coupling step

[0112] 1700 motor vehicles

[0113] 1701 wheels

[0114] 1703 electrical energy storage

[0115] 1705 electric axle drive

[0116] 1707 power converter

[0117] 1709 Gearbox

Claims

Patent claims 1. Pole head ring (100) for a rotor (200) for an electrical machine (1500), wherein the rotor (200) is designed as a salient pole rotor and has a body (240) with rotor teeth (242), wherein the pole head ring (100) has a plurality of pole heads (110) arranged spaced apart from one another along a circumference of the pole head ring (100), wherein each of the pole heads (100) has a coupling section (112) for coupling to one of the rotor teeth (242) and two winding window sections (114) which are shaped to radially outwardly delimit a winding window (250) for a coil unit (450) of the rotor (200) arranged on the rotor tooth (242), wherein the coupling section (112) is arranged between the winding window sections (114) is arranged, wherein in each of the winding window sections (114) a radially inwardly projecting support projection (124) is formed for supporting the coil unit (450) against centrifugal forces, characterized in thatthat in at least one of the winding window sections (114) of each pole head (110) a flux barrier feature (130) is formed, by which a magnetic resistance in the winding window section (114) is increased compared to outside the winding window section (114).

2. Pole head ring (100) according to claim 1, characterized in that a flux barrier feature (130) is formed in both winding window sections (114) of each pole head (110), wherein both flux barrier features (130) of each pole head (110) are formed identically with respect to one another.

3. Pole head ring (100) according to claim 1, characterized in that a flux barrier feature (130) is formed in both winding window sections (114) of each pole head (110), wherein both flux barrier features (130) of each pole head (110) are shaped differently with respect to one another.

4. Pole head ring (100) according to claim 3, characterized in that both flux barrier features (130) of each pole head (110) have different contours and / or different dimensions and / or different radial and / or tangential positions in the winding window sections (114) with respect to each other.

5. Pole head ring (100) according to one of the preceding claims, characterized in that at least one of the flux barrier features (130) has at least one undercut or at least one bead on an inner circumference or an outer circumference of the pole head ring (100) adjacent to the support projection (124).

6. Pole head ring (100) according to one of the preceding claims, characterized in that at least one of the flux barrier features (130) has at least one axial through-opening or at least one axial through-bore in the support projection (124) and / or has a round, oval, trapezoidal, trapezoid-like, rectangular or rectangle-like contour.

7. Pole head ring (100) according to one of the preceding claims, characterized in that the pole head ring (100) has a first outer radius (R1) in the region of the coupling sections (112) and a second outer radius (R2) in the region of intermediate sections (115) by which the pole heads (110) are spaced from one another, wherein the first outer radius (R1) is larger than the second outer radius (R2).

8. Pole head ring (100) according to one of the preceding claims, characterized in that the pole head ring (100) has at least one coupling feature (122) in each coupling section (112) which can be positively coupled to a rotor tooth (242) of the body (240).

9. Rotor (200) for an electrical machine (1500), wherein the rotor (200) is designed as a salient pole rotor, wherein the rotor (200) has a body (240) with rotor teeth (242) and a pole head ring (100) according to one of the preceding claims.

10. Rotor (200) according to claim 9, characterized in that the rotor (200) has a plurality of coil units (450), wherein at least one coil unit (450) can be arranged or is arranged on each of the rotor teeth (242), and / or wherein each coil unit (450) is designed as an air coil.

11. Rotor (200) according to one of claims 9 to 10, characterized in that in an assembled state of the rotor (200), central axes (M110) of the pole heads (110) have an angular offset (Aa) with respect to central axes (M242) of the rotor teeth (242).

12. Electrical machine (1500) with a stator (1506) and a rotor (200) rotatably mounted relative to the stator (1506), characterized in that the rotor (200) is designed according to one of claims 9 to 11.

13. Electric axle drive (1705) for a motor vehicle (1700) with at least one electric machine (1500), a transmission device (1709) and a power converter (1707), characterized in that the electric machine (1500) is designed according to claim 12.

14. Motor vehicle (1700) comprising an electric axle drive (1705) according to claim 13 and / or an electric machine (1500) according to claim 12 and / or a rotor (200) according to one of claims 9 to 11.

15. A method (1600) for manufacturing a rotor (200) according to any one of claims 9 to 11, wherein the method (1600) comprises the following steps: providing (1602) the pole head ring (100) and the body (240); and Coupling (1604) the pole head ring (100) and the body (240) together.

Images