DE102024203700A1 - Rotor for an electric machine, electric machine, electric axle drive for a motor vehicle, motor vehicle and method for producing a rotor - Google Patents

Abstract

A rotor (100) for an electrical machine, wherein the electrical machine is designed as an electrically excited synchronous machine, wherein the rotor (100) is designed as a salient-pole rotor, comprises a body (110) with rotor teeth (112) and a pole head ring (120). The pole head ring (120) comprises a plurality of pole heads (122) arranged spaced apart from one another along a circumference of the pole head ring (120). Each of the pole heads (122) is shaped for coupling to one of the rotor teeth (112). The pole head ring (120) comprises a plurality of permanent magnets (130).

Description

The present invention relates to a rotor for an electric machine, to an electric machine, to an electric axle drive for a motor vehicle, to a motor vehicle and to a method for producing a rotor.

Conventional rotors of electrically excited synchronous machines, for example, can be equipped with permanent magnets. Such permanent magnets are often found in the form of spoke magnets. This can be used to improve power density and efficiency, although stability aspects and the author's mechanical strength must also be considered.

Against this background, the present invention provides 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.

According to embodiments, permanent magnets can be provided in the rotor ring or pole head ring of electrical machines, in particular electrically excited synchronous machines. In other words, permanent magnets can be added to the pole head ring of a rotor for an electrical machine, in particular an electrically excited synchronous machine, in order to compensate for stray fluxes or to reduce them by saturating the pole head ring. In this way, improved efficiencies can be achieved in the driving cycle, or a ring thickness can be increased while maintaining the same efficiency in order to increase the mechanical strength of the rotor. The permanent magnets can be arranged on or within the sheet metal of the pole head ring in such a way that mechanical operational stability can be ensured and a magnetic short circuit can be avoided as far as possible.

A rotor for an electrical machine, wherein the electrical machine is designed as an electrically excited synchronous machine, wherein the rotor is designed as a salient pole rotor, comprises a body with rotor teeth and a pole head ring, wherein the pole head ring has a plurality of pole heads arranged spaced apart from one another along a circumference of the pole head ring, wherein each of the pole heads is shaped for coupling to one of the rotor teeth, wherein the pole head ring has a plurality of permanent magnets.

The electric machine can be provided for an electric drive train of a vehicle. The pole head ring can also be referred to as a rotor ring. The pole heads can be arranged along the circumference of the pole head ring, spaced from one another by intermediate sections. The pole head ring can be designed as a closed ring. The pole head ring can be constructed from identical, one-piece, axially stacked laminations, in particular electrical laminations. The body can be constructed from identical, one-piece, axially stacked laminations, in particular electrical laminations. The body can have a rotor yoke, wherein the rotor teeth extend radially outward from the rotor yoke.

One possible way to construct rotors for electrical machines, particularly electrically excited synchronous motors, is a two-part concept with a rotor lamination ring enclosing the rotor. The rationale for such a ring is to ensure mechanical strength when a rotor with plug-in coils is to operate at higher speeds. This presents an optimization problem, as the lamination ring should be as thick as possible from a mechanical perspective, but as thin as possible from an electromagnetic perspective, as the ring represents a magnetic short circuit. The main problem with such a ring is the magnetic flux that flows through the ring from one pole to the next without passing through the air gap, and the ring thus weakens the air gap field. These problems can be solved or at least significantly mitigated according to embodiments. By using permanent magnets, the magnetic short circuit can be compensated for, and higher efficiency and performance can be achieved with the same rotor ring thickness. By using permanent magnets, the rotor ring can be reinforced, i.e. made thicker, while maintaining the same efficiency and performance, and a higher mechanical strength can be achieved, which also promotes a higher achievable speed.

According to one embodiment, the permanent magnets can be formed from a material comprising neodymium-iron-boron (NdFeB), samarium-cobalt (SmCo), samarium-iron-nitride (SmFeN), iron-nitride (FeN), aluminum-nickel-cobalt (AlNiCo), or iron-chromium-cobalt (FeCrCo). Such an embodiment offers the advantage that, depending on the specific application and rotor geometry, suitable permanent magnets with favorable material properties can be used.

Each of the pole heads can also have a coupling section for coupling to one of the rotor teeth and two winding window sections that are shaped to radially outwardly delimit a winding window for a coil unit of the rotor arranged on the rotor tooth. In this case, the coupling section can be arranged between the winding window sections. The coupling section can also be understood as a pole head. In this case, the winding window sections can at most be understood as part of the pole heads. According to one embodiment, each of the winding window sections can have one of the permanent magnets. Such an embodiment offers the advantage that the main magnetic flux or rotor flux can be supported and stray magnetic fluxes can be attenuated.

In particular, when the rotor is in the assembled state, 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. 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. Thus, a mechanical coupling or connection between the pole head ring and the body can be designed to be robust and stable, whereby force flows in the body and pole head ring can be favorable when the rotor is rotating.

Furthermore, a flux barrier feature can be formed in each of the winding window sections of each pole head, by means of which a magnetic resistance in the winding window section can be increased compared to outside the winding window section. In this case, each of the flux barrier features can have an axial through-opening or through-bore. 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. Additionally or alternatively, at least one of the flux barrier features can have a round, oval, trapezoidal, trapezoid-like, rectangular, or rectangular-like contour. This offers electromagnetic and structural mechanical advantages, whereby material accumulation can be reduced by one or more arbitrarily shaped geometries. In other words, the rotor ring or pole head ring can have flux barriers in the form of recesses. Flux barriers can be formed in the pole head ring, particularly in the region of the winding window of each pole of the rotor. This allows the magnetic resistance to be increased, so that the leakage flux can be minimized, suppressed, or attenuated. Despite the material accumulation in the pole ring, which can occur due to the contact surface of the coils or the winding in the pole ring for transmitting the centrifugal forces and can manifest itself in the form of thick walls, 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.

In addition, the permanent magnets can be arranged within the flux barrier features. Additionally or alternatively, one of the permanent magnets can be incorporated into each of the flux barrier features. While such flux barriers can already improve the performance of the electric machine, the pole head ring equipped with permanent magnets can significantly reduce the impact of magnetic short circuits on the machine's properties.

According to one embodiment, the permanent magnets can be accommodated in the pole head ring. Alternatively, the permanent magnets can be mounted radially inside the pole head ring. Depending on the specific rotor design, this allows for a magnetically and mechanically advantageous configuration of the permanent magnets in the pole head ring.

The permanent magnets can also be magnetized radially. Additionally or alternatively, the permanent magnets arranged adjacent to a pole head can be magnetized parallel to each other along a radial main extension axis of the rotor tooth coupled to the pole head. Such an embodiment offers the advantage that a main magnetic field of the respective pole can be reliably supported.

Furthermore, the permanent magnets can each be magnetized radially outward or inward, depending on the main magnetic field of the nearest pole head. This also allows the main magnetic field of the pole to be reliably supported.

According to one embodiment, the permanent magnets can be magnetized tangentially. Additionally or alternatively, the permanent magnets arranged adjacent to a pole head can be magnetized toward or away from the pole head. Such an embodiment offers the advantage that a magnetic short-circuit flux can be reliably counteracted.

With tangential magnetization, the permanent magnets can act together with the field winding as a Halbach array, which can amplify the air gap field and also make it possible to reduce the rotor teeth and rotor yoke, i.e., achieve a thinner inner rotor yoke and rotor teeth, and create more space for the field winding. The permanent magnets can be magnetized tangentially or similarly sideways in the direction of the short-circuit flux to achieve higher saturation in the lamination ring and thus indirectly amplify the air gap field.

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.

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.

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 improve power density and efficiency.

The invention also relates to an electric axle drive for a motor vehicle comprising 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.

The transmission device may include a gearbox for reducing the speed of the electric machine and a differential.

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.

• Versehen des Polkopfrings mit der Mehrzahl von Permanentmagneten;
• Bereitstellen des mit den Permanentmagneten versehenen Polkopfrings und des Korpus; und
• Koppeln des Polkopfrings und des Korpus miteinander.

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

• Providing the pole head ring with the plurality of permanent magnets;
• Providing the pole head ring provided with the permanent magnets and the body; and
• Coupling the pole head ring and the body together.

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. The arranging step may be performed before the coupling step.

• 1 eine schematische Darstellung eines Ausführungsbeispiels eines Rotors für eine elektrische Maschine;
• 2 eine schematische Darstellung eines Ausführungsbeispiels eines Rotors für eine elektrische Maschine;
• 3 eine schematische Darstellung eines Ausführungsbeispiels eines Rotors für eine elektrische Maschine;
• 4 eine schematische Darstellung eines Ausführungsbeispiels eines Rotors für eine elektrische Maschine;
• 5 eine schematische Darstellung eines Ausführungsbeispiels eines Rotors für eine elektrische Maschine;
• 6 eine schematische Darstellung eines Ausführungsbeispiels eines Rotors für eine elektrische Maschine;
• 7 eine schematische Darstellung einer elektrischen Maschine gemäß einem Ausführungsbeispiel;
• 8 ein Ablaufdiagramm eines Ausführungsbeispiels eines Verfahrens zum Herstellen eines Rotors für eine elektrische Maschine; und
• 9 eine schematische Darstellung eines Kraftfahrzeugs mit einem elektrischen Achsantrieb gemäß einem Ausführungsbeispiel.

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

• 1 a schematic representation of an embodiment of a rotor for an electrical machine;
• 2 a schematic representation of an embodiment of a rotor for an electrical machine;
• 3 a schematic representation of an embodiment of a rotor for an electrical machine;
• 4 a schematic representation of an embodiment of a rotor for an electrical machine;
• 5 a schematic representation of an embodiment of a rotor for an electrical machine;
• 6 a schematic representation of an embodiment of a rotor for an electrical machine;
• 7 a schematic representation of an electrical machine according to an embodiment;
• 8 a flowchart of an embodiment of a method for producing a rotor for an electric machine; and
• 9 a schematic representation of a motor vehicle with an electric axle drive according to an embodiment.

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.

1 shows a schematic representation of an embodiment of a rotor 100 for an electric machine. The electric machine is intended, for example, as a drive unit for a vehicle. The electric machine is designed as an electrically excited synchronous machine. The rotor 100 is designed as a salient-pole rotor.

The rotor 100 comprises a body 110 and a pole head ring 120. According to one embodiment, the body 110 and the pole head ring 120 are constructed from identical, one-piece, axially stacked laminations, in particular electrical laminations. The body 110 has a plurality of rotor teeth 112. The pole head ring 120, which can also be referred to as a rotor lamination ring, has a plurality of pole heads 122. The plurality of pole heads 122 are arranged spaced apart from one another along a circumference of the pole head ring 120. Each of the pole heads 122 is shaped for coupling to one of the rotor teeth 112. The pole head ring 120 also includes a plurality of permanent magnets 130.

It should be noted that 1 an axial plan view of, by way of example, only one sector of the rotor 100, wherein the sector shown comprises the area around a rotor tooth 112 and thus a rotor pole. The body 110 comprises a plurality of rotor teeth 112. The rotor teeth 112 extend radially outward toward the pole head ring 120. In particular, the rotor teeth 112 extend radially outward from an annular rotor yoke 114 of the body 110 in the direction of the pole head ring 100. Each rotor tooth 112 is positively connected or coupled to the pole head ring 120 in the region of a coupling section thereof. The body 110 has a star-shaped plan view. The rotor 100 also comprises a plurality of coil units 140. Thus, at least one coil unit 140 or rotor winding can be or is arranged on each of the rotor teeth 112. Optionally, the coil units are also designed as air coils.

According to the exemplary embodiment shown here, the permanent magnets 130 are accommodated in the pole head ring 120. The permanent magnets 130 are formed, for example, from a material comprising neodymium-iron-boron, samarium-cobalt, samarium-iron-nitride, iron-nitride, aluminum-nickel-cobalt, or iron-chromium-cobalt. According to the exemplary embodiment shown here, the permanent magnets 130 are radially magnetized, as symbolically illustrated by magnetization directions 135. The permanent magnets 120 are also magnetized radially outwardly according to a main magnetic field 115 or rotor flux of the nearest pole head 122 or rotor tooth 112. Thus, the magnetization of the permanent magnets 130 is such that a main field of the pole is supported.

Furthermore, according to the exemplary embodiment illustrated here, each of the pole heads 122 comprises a coupling section 124 for coupling to one of the rotor teeth 112 and two winding window sections 126. The winding window sections 126 are shaped to radially outwardly delimit a winding window for the coil unit 140 of the rotor 100 arranged on the rotor tooth. In each pole head 122, the coupling section 124 is arranged between the winding window sections 126. According to the exemplary embodiment illustrated here, a permanent magnet 130 is arranged in each of the winding window sections 126. In other words, each winding window section 126 has a permanent magnet 130.

According to the exemplary embodiment illustrated here, the pole head ring 120 further comprises a plurality of flux barrier features 128. In particular, a flux barrier feature 128 is formed in each of the winding window sections 126 of each pole head 122. Each individual flux barrier feature 128 increases a magnetic resistance in the respective winding window section 126 compared to outside the winding window section 126. In other words, each individual flux barrier feature 128 is shaped and positioned to increase the magnetic resistance in the winding window section 126 compared to outside the winding window section 126 or to cause a higher magnetic resistance in the winding window section 126 than outside the winding window section 126. For example, each of the flux barrier features 128 is formed as an axial through-opening or through-bore.

According to the exemplary embodiment illustrated here, the permanent magnets 130 of the pole head ring 120 are arranged within the flux barrier features 128. In particular, one of the permanent magnets 130 is accommodated in each of the flux barrier features 128. In other words, the permanent magnets 130 are arranged within flux barriers and have a radial magnetization.

2 shows a schematic representation of an embodiment of a rotor 100 for an electric machine. The rotor 100 in 2 corresponds to the rotor from 1 with the exception that the permanent magnets 130 have a different magnetization direction 135. According to the exemplary embodiment illustrated here, the permanent magnets 130 arranged adjacent to a pole head 122 or rotor tooth 112 are magnetized parallel to one another along a radial main extension axis of the rotor tooth 112 coupled to the pole head 122. The permanent magnets 130 are each magnetized radially outwardly in accordance with the main magnetic field 115 or rotor flux of the nearest pole head 122. Thus, the permanent magnets 130 are also accommodated in the flux barrier features 128 here and have a mutually parallel magnetization or magnetization direction 135 for each pole head 122.

3 shows a schematic representation of an embodiment of a rotor 100 for an electric machine. The rotor 100 in 3 corresponds to the rotor from 1 and/or 2 except that the permanent magnets 130 have a different magnetization direction 135. According to the exemplary embodiment illustrated here, the permanent magnets 130 are magnetized tangentially. The permanent magnets 130 arranged adjacent to a pole head 122 or rotor tooth 112 are magnetized toward the pole head 122 or rotor tooth 112. In other words, the magnetization directions 135 of the permanent magnets 130 of each pole head 122 point toward the rotor tooth 112.

Thus, the permanent magnets 130 are also incorporated into the flux barrier features 128 here and exhibit tangential magnetization. This allows for the implementation of a flux collector concept. As an alternative to the angle of the tangential magnetization or magnetization direction 135 shown, other angles are also conceivable, provided the flux collector principle is maintained.

4 shows a schematic representation of an embodiment of a rotor 100 for an electric machine. The rotor 100 in 4 corresponds to the rotor from 3 except that the permanent magnets 130 have a different magnetization direction 135. According to the exemplary embodiment illustrated here, the permanent magnets 130 arranged adjacent to a pole head 122 or rotor tooth 112 are magnetized away from the pole head 122 or rotor tooth 112. In other words, the magnetization directions 135 of the permanent magnets 130 of each pole head 122 point away from the rotor tooth 112.

Thus, the permanent magnets 130 are also incorporated into the flux barrier features 128 here and exhibit tangential magnetization. In this way, saturation of the rotor ring or pole head ring 120 can be achieved. As an alternative to the angle of the tangential magnetization or magnetization direction 135 shown, other angles are also conceivable, provided the principle of saturation of the rotor ring or pole head ring 120 is maintained.

5 shows a schematic representation of an embodiment of a rotor 100 for an electric machine. The rotor 100 in 5 corresponds to the rotor from 1 except that, according to the embodiment shown here, the permanent magnets 130 are mounted radially inward on the pole head ring 120. Thus, the permanent magnets 130 are arranged outside the flux barrier features 128, which, according to the embodiment shown here, are also formed in the pole head ring 120 merely by way of example.

The permanent magnets 130 are thus radially magnetized or have a radial magnetization direction 135. The permanent magnets 130 are magnetized radially outward according to the main magnetic field 115 of the nearest pole head 122 or rotor tooth 112. Thus, a combination of directly amplified air gap field and saturation of the rotor ring or pole head ring 120 is feasible.

6 shows a schematic representation of an embodiment of a rotor 100 for an electric machine. The rotor 100 in 6 corresponds to the rotor from 5 with the exception that the permanent magnets 130 have a different magnetization direction 135. Thus, according to the exemplary embodiment presented here, the permanent magnets 130 are mounted radially inward on the pole head ring 120, but are magnetized tangentially, with the permanent magnets 130 arranged adjacent to a pole head 122 or rotor tooth 112 being magnetized toward the pole head or rotor tooth 112. Thus, a combination of directly amplified air gap field and saturation of the rotor ring or pole head ring 120 is feasible.

With reference to the figures described above, exemplary embodiments are summarized again below and, in other words, briefly explained.

Permanent magnets 130, which may preferably be NdFeB, SmCo, SmFeN, FeN, but also AlNiCo or FeCrCo, are or will be arranged in the sheet metal ring or pole head ring 120 of the Rotor 100, particularly at the transition from the pole piece or rotor tooth 112 to the pole head ring 120, within the flux barrier features 128, radially within the pole head ring 120, or in other positions where the permanent magnets 130 help counteract or compensate for the magnetic short circuit. In other words, permanent magnets 130 are or will be inserted into the flux barrier features 128 or at the transition from the pole piece or rotor tooth 112 to the pole head ring 120 to compensate for the stray flux or to reduce it by saturating the pole head ring 120.

The permanent magnets 130 can be magnetized either radially, parallel, or similarly directed outwards or inwards to support the main field 115 of the pole, or tangentially or similarly in a sideways direction, in a flux collector arrangement, to counteract the short-circuit flux. With tangential magnetization, the permanent magnets 130 can act together with the field winding or coil unit 140 as a Halbach array, which strengthens the air gap field and simultaneously allows the rotor teeth 112 and the rotor yoke 114 to be reduced in size and create more space for the field winding or coil unit 140. The permanent magnets 130 can also be magnetized tangentially or similarly directed sideways in the direction of the short-circuit flux to achieve greater saturation in the lamination ring or pole head ring 120 and thus indirectly strengthen the air gap field.

7 shows a schematic representation of an electric machine 700 according to an exemplary embodiment. The electric machine 700 is designed as a synchronous machine, in particular an electrically excited synchronous machine. The electric machine 700 comprises a rotor 100 and a stator 750. The rotor 100 is rotatably mounted relative to the stator 750. The rotor 100 corresponds to or is similar to the rotor from one of the previously described figures.

It should be noted that in 7 The rotor 100 is shown as internal and the stator 750 as external merely as an example.

8 shows a flowchart of an embodiment of a method 800 for manufacturing a rotor for an electric machine. The manufacturing method 800 can be executed to manufacture the rotor from one of the figures described above or a similar rotor. The manufacturing method 800 includes a providing step 802, a providing step 804, and a coupling step 806.

In the provision step 802, the pole head ring is provided with the plurality of permanent magnets. In the provision step 804, the pole head ring provided with the permanent magnets and the body are provided. In particular, in the provision step 804, the pole head ring and/or the body are constructed from identical, one-piece, axially stacked laminations, in particular electrical laminations. Subsequently, in the coupling step 806, the pole head ring and the body are coupled to one another.

The manufacturing method 800 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.

9 shows a schematic representation of a motor vehicle 900 with an electric axle drive 905 according to an embodiment. Of the motor vehicle 900, 9 Here, wheels 901, only four wheels 901 as an example, an electrical energy storage device 903, for example a battery, and the electric axle drive 905 are shown. The electric axle drive 905 comprises a power converter 907, an electric machine 700 and a transmission device 909. The electric machine 700 is the electric machine from 7 or a similar electrical machine.

Electrical energy for operating the electrical machine 700 is provided by a power supply device, here the electrical energy storage device 903. The electrical energy storage device 903 is designed to provide direct current, which is converted into an alternating current, for example a three-phase alternating current, using a power converter 907 of the electric axle drive 905 and provided to the electrical machine 700.

A shaft driven by the electric machine 700 is coupled directly or using the transmission device 909 to at least one wheel 901 of the motor vehicle 900. Thus, the motor vehicle 900 can be propelled using the electric machine 700. According to one embodiment, the electric axle drive 905 comprises a housing in which at least the power converter 907, the electric machine 700, and the transmission device 909 are arranged.

The embodiments described and shown in the figures are only examples. Different embodiments may be completely different or may be different in relation to individual features. One embodiment can also be supplemented by features of another embodiment.

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

If an embodiment comprises an “and/or” link between a first feature and a second feature, this can be read such that the embodiment according to one embodiment has both the first feature and the second feature and according to another embodiment has either only the first feature or only the second feature.

Reference symbol

100

rotor

110

Corpus

112

rotor tooth

114

Rotor yoke

115

Main field

120

Pole head ring

122

Pole head

124

Coupling section

126

Changing window section

128

River barrier feature

130

permanent magnet

135

Magnetization direction

140

Coil unit

700

electric machine

750

stator

800

Manufacturing process

802

Step of oversight

804

Deployment step

806

Pairing step

900

motor vehicle

901

Wheels

903

electrical energy storage

905

electric axle drive

907

power converter

909

Gearbox

Claims (15)

Rotor (100) for an electrical machine (700), wherein the electrical machine (700) is designed as an electrically excited synchronous machine, wherein the rotor (100) is designed as a salient pole rotor, wherein the rotor (100) has a body (110) with rotor teeth (112) and a pole head ring (120), wherein the pole head ring (120) has a plurality of pole heads (122) arranged at a distance from one another along a circumference of the pole head ring (120), wherein each of the pole heads (122) is shaped for coupling to one of the rotor teeth (112), characterized in that the pole head ring (120) has a plurality of permanent magnets (130). Rotor (100) according to Claim 1 , characterized in that the permanent magnets (130) are formed from a material comprising neodymium-iron-boron, samarium-cobalt, samarium-iron-nitrite, iron-nitrite, aluminum-nickel-cobalt or iron-chromium-cobalt. Rotor (100) according to one of the preceding claims, wherein each of the pole heads (122) has a coupling section (124) for coupling to one of the rotor teeth (112) and two winding window sections (126) which are shaped to radially outwardly delimit a winding window for a coil unit (140) of the rotor (100) arranged on the rotor tooth (112), wherein the coupling section (124) is arranged between the winding window sections (126), characterized in that each of the winding window sections (126) has one of the permanent magnets (130). Rotor (100) according to Claim 3 , characterized in that in each of the winding window sections (126) of each pole head (122) a flux barrier feature (128) is formed, by which a magnetic resistance in the winding window section (126) is increased compared to outside the winding window section (126), wherein each of the flux barrier features (128) has an axial through-opening or through-bore. Rotor (100) according to Claim 4 , characterized in that the permanent magnets (130) are arranged to be received in the flux barrier features (128) and/or wherein one of the permanent magnets (130) is received in each of the flux barrier features (128). Rotor (100) according to one of the preceding claims, characterized in that the permanent magnets (130) are accommodated in the pole head ring (120). Rotor (100) according to one of the Claims 1 until 5 , characterized in that the permanent magnets (130) are mounted radially inward on the pole head ring (120). Rotor (100) according to one of the preceding claims, characterized in that the permanent magnets (130) are radially magnetized and/or the permanent magnets (130) arranged adjacent to a pole head (122) are magnetized parallel to one another along a radial main extension axis of the rotor tooth (112) coupled to the pole head. Rotor (100) according to one of the preceding claims, characterized in that the permanent magnets (130) are each magnetized radially outwardly or inwardly in accordance with a main magnetic field (115) of the nearest pole head (122). Rotor (100) according to one of the Claims 1 until 7 , characterized in that the permanent magnets (130) are magnetized tangentially and/or the permanent magnets (130) arranged adjacent to a pole head (122) are magnetized towards the pole head (122) or away from the pole head (122). Rotor (100) according to one of the preceding claims, characterized in that the rotor (100) has a plurality of coil units (140), wherein at least one coil unit (140) can be arranged or is arranged on each of the rotor teeth (112), and/or wherein each coil unit (140) is designed as an air coil. Electrical machine (700) with a stator (750) and a rotor (100) rotatably mounted relative to the stator (750), characterized in that the rotor (100) is designed according to one of the Claims 1 until 11 is executed. Electric axle drive (905) for a motor vehicle (900) with at least one electric machine (700), a transmission device (909) and a power converter (907), characterized in that the electric machine (700) according to Claim 12 is trained. Motor vehicle (900), comprising an electric axle drive (905) according to Claim 13 and/or an electrical machine (700) according to Claim 12 and/or a rotor (100) according to one of the Claims 1 until 11 . Method (800) for manufacturing a rotor (100) according to one of the Claims 1 until 11 , wherein the method (800) comprises the following steps: providing (802) the pole head ring (120) with the plurality of permanent magnets (130); providing (804) the pole head ring (120) provided with the permanent magnets (130) and the body (110); and coupling (806) the pole head ring (120) and the body (110) to one another.