Stator for an electric machine, vehicle and method for manufacturing the stator

Abstract

The invention relates to a stator (10) for an electric machine (52), comprising at least one stator tooth ring (12) extending in a ring shape around an axial direction (11), wherein the stator tooth ring (12) is segmented in the axial direction (11) into at least one axial tooth ring of the first type (30) and at least one axial tooth ring of the second type (32), wherein the at least one axial tooth ring of the first type (30) is segmented in a circumferential direction (15) of the stator tooth ring (12) into at least one T-shaped tooth segment (24) with teeth (14) pointing outwards in a radial direction (13) of the stator tooth ring (12), and the at least one axial tooth ring of the second type (32) is segmented in the circumferential direction (15) of the stator tooth ring (12) into at least one U-shaped tooth segment (26) with teeth (14) pointing outwards in the radial direction (13) of the stator tooth ring (12). It is segmented. The stator has improved magnetic properties and simultaneously allows for wave winding.

Description

[0001] The invention relates to a stator for an electric machine, a vehicle and a method for manufacturing the stator.

[0002] Electrical machines can have a stator and a rotor. For example, JP 2014-155374 A discloses a stator in which a stator tooth ring is formed from a plurality of tooth rings. Each tooth ring is formed from tooth segments. The tooth segments of a tooth ring are positively connected to one another. A stator tooth ring can be formed from a stack of tooth rings.

[0003] A key performance indicator for electrical machines is power density, defined as the power generated per unit mass. The higher the power density, the lower the mass of the electrical machine can be. Particularly in mobile applications, such as electric vehicles and aircraft, this can reduce the required acceleration energy and thus increase the range. A reduction in the stator mass can be achieved, for example, by using a wave winding, which allows for a shorter axial length of the winding head. This reduces both the mass and the heat losses from the electrical circuit.

[0004] However, the use of wave windings requires radial insertion of the windings between the teeth of the stator tooth ring. Tooth tips, which can be flange-like and radially inside a free end of the teeth on the stator tooth ring, must therefore be omitted. This can lead to high conductance fluctuations, which can cause harmonics and, in turn, high losses at high rotational speeds in the rotor. Furthermore, torque ripple and noise, vibration, and harshness (NVH) behavior can be negatively affected.

[0005] Furthermore, WO 2022 / 218520 A1 discloses a stator toothed ring consisting of comb-like ring segments, the teeth of which point outwards so that windings can be inserted radially from the outside. The ring segments can be made from grain-oriented electrical steel.

[0006] The object of the invention is to provide an improved stator and an improved method for manufacturing a stator that can provide improved magnetic properties and at the same time enable a wave winding.

[0007] The problem is solved by the features of the independent claims. Advantageous further developments are the subject of the dependent claims and the following description.

[0008] According to a first aspect, a stator for an electrical machine is described, comprising at least one stator tooth ring extending in a ring-like manner around an axial direction, wherein, according to the invention, the stator tooth ring is segmented in the axial direction into at least one axial tooth ring of the first type and at least one axial tooth ring of the second type, wherein the at least one axial tooth ring of the first type is segmented in a circumferential direction of the stator tooth ring into at least one T-shaped tooth segment with teeth pointing outwards in a radial direction of the stator tooth ring, and the at least one axial tooth ring of the second type is segmented in the circumferential direction of the stator tooth ring into at least one U-shaped tooth segment with teeth pointing outwards in the radial direction of the stator tooth ring.

[0009] The stator thus has a segmented design consisting of at least two tooth rings. The T-shaped and U-shaped tooth segments in the first and second types of tooth rings each allow a wave winding to be inserted radially outwards into the stator tooth ring. The legs of the U-shaped tooth segments and the base of the T-shaped tooth segments are oriented radially outwards from the stator tooth ring and can form the teeth of the stator tooth ring. The legs of the U-shape can each form half a tooth, with two legs of two U-shaped tooth segments forming one tooth. The head of the T-shape and the base of the U-shaped tooth segments can thus provide a closed surface radially inwards on the stator tooth ring.The closed outer surface overcomes the aforementioned disadvantages of the prior art, where tooth tips cannot be incorporated when using wave winding. Furthermore, the magnetic properties of the prior art can be improved by using T-shaped and U-shaped tooth segments, particularly when using materials with different conductivities in different directions.

[0010] According to some embodiments, it is conceivable that the stator tooth ring can alternately have a tooth ring of the first type and a tooth ring of the second type in the axial direction.

[0011] The first and second type of tooth rings can be coupled axially such that their teeth are aligned. Furthermore, the arrangement of the first and second type of tooth rings can be configured such that a U-shaped tooth segment overlaps the connection between two T-shaped tooth segments. Likewise, a T-shaped tooth segment can overlap the connection between two U-shaped tooth segments. This increases the stability of the stator tooth ring.

[0012] According to some embodiments, it is conceivable that the at least one T-shaped tooth segment can be oriented with a foot of the T-shape facing outwards in the radial direction of the stator tooth ring.

[0013] The base of the T-shaped tooth segment can thus form a tooth of the first type of tooth ring. In this way, every tooth can be formed from a T-shaped tooth segment. Therefore, in the event of defective tooth segments, only the corresponding tooth segment needs to be removed from the production line. This reduces rejects in the production of tooth segments.

[0014] According to some embodiments, it is conceivable that the at least one U-shaped tooth segment can be oriented outwards with an opening of the U-shape in the radial direction of the stator tooth ring.

[0015] The base of the U-shaped tooth segment can thus form a tooth of the first type of tooth ring. The base is understood as the connection between the two legs of the U-shape. In this way, every tooth can be formed from a U-shaped tooth segment. Therefore, in the event of defective tooth segments, only the corresponding tooth segment needs to be removed from the production line. This reduces rejects in the production of tooth segments.

[0016] According to some embodiments, it is conceivable that the at least one T-shaped tooth segment and / or the at least one U-shaped tooth segment may have at least one electrical steel sheet oriented in the radial direction of the stator tooth ring.

[0017] By using tooth segments, a grain orientation pointing radially can be provided for each tooth. Unlike segments with multiple teeth, deviations in grain orientation from the radial direction at the segment edges are negligible for T-shaped and U-shaped tooth segments. This minimizes losses during magnetization reversal, further improving the stator's magnetic properties.

[0018] According to some embodiments, it is conceivable that the at least one axial tooth ring of the first type can only have T-shaped tooth segments and / or that the at least one axial tooth ring of the second type can only have U-shaped tooth segments.

[0019] This allows the number of different parts required for manufacturing the gear rings to be limited to two. Furthermore, this simplifies the manufacturing process and thus reduces costs.

[0020] According to some embodiments, it is conceivable that the at least one T-shaped tooth segment can be materially bonded to the at least one axial tooth ring of the first type and / or that the at least one U-shaped tooth segment can be materially bonded to the at least one axial tooth ring of the second type.

[0021] This allows the surfaces of the tooth segments to be kept simple, making production more cost-effective and reducing scrap in the production of tooth segments.

[0022] According to some embodiments, it is conceivable that a first angular length of the at least one T-shaped tooth segment can correspond to a pole pitch of the stator and / or that a second angular length of the at least one U-shaped tooth segment can correspond to the pole pitch of the stator.

[0023] The number of tooth segments thus corresponds to the number of teeth in a toothed ring. This can simplify the manufacturing of the toothed ring and avoid manufacturing errors.

[0024] According to some embodiments, it is conceivable that the at least one tooth ring of the first type and the at least one tooth ring of the second type can be connected to each other by a material bond.

[0025] The manufacture of the stator tooth ring can be simplified by using the material-bonded connection between the tooth rings of the first and second type.

[0026] According to some embodiments, it is conceivable that the stator may further have a stator yoke ring which extends around the stator tooth ring and may be materially and / or form-fitted to the stator tooth ring, wherein the stator yoke ring may preferably have non-grain-oriented electrical steel.

[0027] The stator yoke ring can thus couple to the free end sections of the teeth of the stator tooth ring and be connected to them via a material bond and / or a form-fit connection. For example, after the windings have been inserted into the stator tooth ring, the stator tooth ring can be inserted into the stator yoke ring to close the openings between the teeth of the stator tooth ring. The use of non-conoriented electrical steel further improves the magnetic properties. This allows magnetic field lines generated circumferentially around the windings to cause only minimal losses in the stator yoke ring during magnetization reversal.

[0028] According to some embodiments, it is conceivable that the stator yoke ring can be formed from a plurality of sub-segments, wherein preferably an angular length of the sub-segments in the circumferential direction can correspond to a pole pitch of the stator.

[0029] According to a second aspect, a vehicle is described comprising at least one electric machine, wherein the electric machine has at least one stator according to the preceding description.

[0030] The advantages, effects, and further developments of the vehicle result from the advantages, effects, and further developments of the stator described above. To avoid repetition, reference is therefore made to the preceding description in this regard.

[0031] According to a third aspect, a method for manufacturing a stator according to the preceding description is described, comprising at least the following steps: manufacturing at least one tooth ring of the first kind and at least one tooth ring of the second kind; manufacturing at least two pairs of tooth rings, each pair of tooth rings comprising one tooth ring of the first kind and one tooth ring of the second kind; joining the at least two pairs of tooth rings together to produce at least one stator tooth ring.

[0032] According to some embodiments, it is conceivable that the method may further include at least the following step: Inserting a wave winding of an electrical conductor in a radial direction from the outside to the inside into the stator toothed ring.

[0033] According to some embodiments, it is conceivable that the method may further include at least the following step: attaching a stator yoke ring to the stator tooth ring, wherein the stator yoke ring extends around the stator tooth ring.

[0034] The advantages, effects, and further developments of the method result from the advantages, effects, and further developments of the stator and vehicle described above. To avoid repetition, reference is therefore made to the preceding description in this regard.

[0035] The invention is described below with reference to an exemplary embodiment and the accompanying drawing. The drawing shows: Fig. 1 a schematic representation of a stator; Fig. 2a, b a schematic representation of tooth segments; Fig. 3 a schematic representation of the manufacture of a stator gear ring; Fig. 4a, b a schematic representation of the manufacture of a stator; Fig. 5 a schematic representation of part of an electrical machine; Fig. 6. A schematic representation of a vehicle; and Fig. 7. A flowchart of the process.

[0036] In Fig. Figure 1 shows a stator, which in its entirety is designated by the reference numeral 10. The stator 10 has a stator tooth ring 12 and a stator yoke ring 20.

[0037] The stator tooth ring 12 has a plurality of teeth 14 between which electrical conductors 14 of windings can be arranged. In this embodiment, the stator 10 is designed in the form of a hollow cylinder extending along an axial direction 11, which can also be referred to as the axial direction. Extending from the axial direction 11 are the radial direction 13, which can also be referred to as the radial direction, and the circumferential direction 15, which preferably extends circularly around the axial direction 11.

[0038] In the radial direction 13 inside, the stator 10 can have tooth heads 28 on the stator tooth ring 12 in order to bridge the gaps between the free end sections of the teeth 14.

[0039] The stator yoke ring 20 can be formed around the stator tooth ring 12 and enclose the stator tooth ring 12 in circumferential direction 15.

[0040] The stator tooth ring 12 is segmented into tooth rings in the axial direction 11. This means that the stator tooth ring 12 can be composed of a plurality of tooth rings which can be stacked in the axial direction 11 to form a hollow cylinder that can constitute the stator tooth ring 12.

[0041] The toothed rings can be connected to each other, for example, by material bonding and / or by form-fitting.

[0042] Each tooth ring can itself be segmented into tooth segments 24, 26, which are exemplified in Fig. 2a and Fig. 2b are shown.

[0043] Fig. Figure 2a shows a T-shaped tooth segment 24, which is arranged with its base 25 on the stator yoke ring 20 and can be connected to the stator yoke ring 20, and whose head of the T-shape is oriented radially inwards. The head of the T-shape can form a tooth head 28.

[0044] In this embodiment, the foot 25 of the T-shaped tooth segment 24 forms a tooth 14 of the stator tooth ring 12.

[0045] In Fig. Figure 2b shows a U-shaped tooth segment 26. The U-shape has a base 27 from which two legs 22 extend. The base 27 is oriented radially inwards towards the stator tooth ring 12. Free end sections of the legs 22 are arranged on the stator yoke ring 20 and can be connected to it.

[0046] The legs 22 of a U-shaped tooth segment 26 can each provide one half of a tooth 14 of a stator tooth ring 12. The other half of the tooth 14 can be provided by a leg 22 of an adjacent U-shaped tooth segment 26.

[0047] In the Fig. 2a and Fig. Figure 2b shows the tooth segments 24, 26 in the assembled state.

[0048] As in Fig. As shown in Figure 3, the T-shaped tooth segments 24 can be used to manufacture a tooth ring of the first type 30. The U-shaped tooth segments 26 can be used to manufacture a tooth ring of the second type 32.

[0049] To manufacture a tooth ring of the first type 30, a plurality of T-shaped tooth segments 24 can be connected to one another such that the free end sections of the heads of two adjacent T-shaped tooth segments 24 are attached to one another. The T-shaped tooth segments 24 are connected in such a way that they form a ring, with the respective base of the T-shaped tooth segments 24 being oriented radially outwards.

[0050] For the production of a second type of tooth ring 32, a plurality of U-shaped tooth segments 26 can be used. The outer surfaces of the legs 22 of the U-shape of each pair of U-shaped tooth segments 26 can be joined together, with the plurality of U-shaped tooth segments 26 forming a ring. The respective base 27 of the U-shaped tooth segments 26 can be oriented radially inwards, so that the legs 22 are oriented outwards and can provide the teeth 14.

[0051] Both the tooth ring of the first type 30 and the tooth ring of the second type 32 thus have outwardly open tooth gaps between the teeth 14, into which an electrical conductor 16 with a wave winding can be inserted in a later process step.

[0052] Each type 30 tooth ring and type 32 tooth ring can then be connected to each other in the axial direction 11. The connection of the type 30 tooth rings and the type 32 tooth rings is such that the teeth 14 are aligned with each other in the axial direction 11. They then form a pair of tooth rings 34. The connection points between the heads of the T-shaped tooth segments 24 can then be covered by the base 27 of the U-shaped tooth segments 26. Furthermore, the connection points between the legs 22 of the U-shaped tooth segments 26 can be covered by the foot 25 of the T-shaped tooth segments 24.

[0053] By covering the connection points, the stability of the pair of toothed rings 34 can be increased.

[0054] In the radial direction 13 inwards, the tooth rings 30, 32 have a closed outer surface 38. This is provided on the one hand by the bases 28 of the U-shaped tooth segments 26 and the interconnected heads 27 of the T-shaped tooth segments 24.

[0055] The number of T-shaped tooth segments 24 used can be selected such that it corresponds to the number of teeth 14 to be used on the stator tooth ring 12. The same applies to the U-shaped tooth segments 26.

[0056] Furthermore, the T-shaped tooth segments 24 and the U-shaped tooth segments 26 can be made from a grain-oriented electrical steel sheet. The grain orientation can be aligned in the radial direction 13.

[0057] Because a separate tooth segment 24 or two separate tooth segments 26 can be used for each tooth 14, the grain orientation for each tooth can be aligned with high accuracy in the radial direction 13.

[0058] A multitude of paired tooth rings 34 can be stacked to form a stator tooth ring 12 and joined together by a material-locking and / or form-locking connection. A second-type tooth ring 32 rests against a first-type tooth ring 30 of an adjacent paired tooth ring 34. The number of paired tooth rings 34 used is selected such that the desired length of the stator tooth ring 12 is achieved.

[0059] After the stator tooth ring 12 has been manufactured, an electrical conductor 16 can be inserted in a wave winding extending radially 13 outwards between the teeth 14. This is exemplified in Fig. 4a shown. The joining direction 40 is directed inwards in the radial direction 13 towards the axial direction 11.

[0060] After joining the electrical conductor 16, a stator yoke ring 20 can be provided. In some embodiments, the stator yoke ring 20 can be made from segments 46, 48 and / or from non-grain-oriented electrical steel.

[0061] The number of segments 46, 48 can correspond to the number of teeth 14.

[0062] The stator yoke ring 20 under the stator tooth ring 12 can be connected to each other by material bonding and / or form bonding.

[0063] Fig. Figure 5 shows a section of the stator 10 in an electric machine 52. The stator 10 extends around a rotor 42 of the electric machine 52. An air gap 45 can extend between the stator 10 and the rotor 42.

[0064] When current flows through the electrical conductors 16, magnetic field lines 44 can form and extend around the conductors 16. Due to the grain orientation of the tooth segments 24, 26 in the radial direction 13, the tooth 14 exhibits high permeability in the radial direction 13. Transverse to the radial direction 13, i.e., in the circumferential direction 15, the tooth 14 can exhibit low permeability. Because of the low permeability in the circumferential direction 15, the magnetic field lines 44 extend through the air gap 45 into the iron material of the rotor 42 and can therefore provide a greater torque than would be the case with high permeability of the tooth 14 in the circumferential direction 15.

[0065] If the stator yoke ring 20 is made of non-grain-oriented electrical steel, it exhibits high permeability in all directions. This allows the magnetic field lines 44 to extend closely along the electrical conductors 16 after passing into the stator yoke ring 20.

[0066] The electric machine 52 can, for example, be part of a vehicle 50, as in Fig. Figure 6 shows that the electric machine 52 can, for example, be configured as an electric motor for an electric vehicle. The electric motor can drive at least one wheel of the vehicle 50.

[0067] Fig. Figure 7 shows a method 100 for manufacturing a stator 10 according to the description above.

[0068] According to a first step 102, at least one tooth ring of the first type 30 and at least one tooth ring of the second type 32 can initially be manufactured. The tooth ring of the first type 30 can have at least one T-shaped tooth segment 24. The tooth ring of the second type 32 can have at least one U-shaped tooth segment 26. Furthermore, the tooth ring of the first type 30 can consist solely of T-shaped tooth segments 24. The tooth ring of the second type 32 can consist solely of U-shaped tooth segments 26.

[0069] According to a further step 102, at least two pairs of toothed rings 34 can be produced from a toothed ring of the first type 30 and a toothed ring of the second type 32. For this purpose, a toothed ring of the first type 30 can be joined to a toothed ring of the second type 32 by a material-locking and / or form-locking connection.

[0070] In a further step 106, the at least two pairs of toothed rings 34 are attached to each other. The pairs of toothed rings 34 can be attached to each other in the axial direction 11, such that their teeth 14 are aligned with each other.

[0071] This allows a stator gear ring 32 to be produced.

[0072] According to a further, optional step 108, a wave winding of an electrical line 16 can then be inserted in radial direction 13 from the outside to the inside into the stator toothed ring 12.

[0073] According to a further optional step 110, a stator yoke ring 20 can be attached to a stator tooth ring 12. The stator yoke ring 20 can extend around the stator tooth ring 16 in its axial direction 11.

[0074] The example described above does not in any way limit the invention. Rather, the invention can be modified in numerous ways. All features of the invention described above can be essential to the invention, either alone or in combination. Reference symbol list 10 Stator 11 Axial direction 12 Stator gear ring 13 Radial direction 14 teeth 15 Circumferential direction 16 electrical conductors 20 Statorjochring 22 thighs 24 T-shaped tooth segments 25 feet 26 U-shaped tooth segment 27 base 28 Tooth head 30 toothed rings of the first type 32 Second type toothed ring 34 pairs of tooth rings 38 Inside 40 Leading direction 42 Rotor 44 magnetic field line 45 air gap 46 Stator yoke segment 48 Stator yoke segment 50 vehicles 52 electric machine QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] JP 2014-155374 A

[0002] WO 2022 / 218520 A1

[0005]

Claims

[1] Stator (10) for an electric machine (52), comprising at least one stator tooth ring (12) extending in a ring shape around an axial direction (11), characterized by , that the stator tooth ring (12) is segmented in the axial direction (11) into at least one axial tooth ring of the first type (30) and at least one axial tooth ring of the second type (32), wherein the at least one axial tooth ring of the first type (30) is segmented in a circumferential direction (15) of the stator tooth ring (12) into at least one T-shaped tooth segment (24) with teeth (14) pointing outwards in a radial direction (13) of the stator tooth ring (12) and the at least one axial tooth ring of the second type (32) is segmented in the circumferential direction (15) of the stator tooth ring (12) into at least one U-shaped tooth segment (26) with teeth (14) pointing outwards in the radial direction (13) of the stator tooth ring (12). [2] Stator (10) according to claim 1, characterized by, that the stator tooth ring (12) has an alternating tooth ring of the first kind (30) and a tooth ring of the second kind (32) in the axial direction (11). [3] Stator (10) according to claim 1 or 2, characterized by , that the at least one T-shaped tooth segment (24) with a foot (25) of the T-shape is oriented outwards in the radial direction (13) of the stator tooth ring (12), and / or that the at least one U-shaped tooth segment (26) with an opening of the U-shape is oriented outwards in the radial direction (13) of the stator tooth ring (12). [4] Stator (10) according to any of the preceding claims, characterized by , that the at least one T-shaped tooth segment (24) and / or the at least one U-shaped tooth segment (26) have at least one electrical steel sheet oriented in the radial direction (13) of the stator tooth ring (12). [5] Stator (10) according to any of the preceding claims, characterized by, that the at least one axial tooth ring of the first type (30) has only T-shaped tooth segments (24) and / or that the at least one axial tooth ring of the second type (32) has only U-shaped tooth segments (26). [6] Stator (10) according to any of the preceding claims, characterized by , that the at least one T-shaped tooth segment (24) is materially connected to the at least one axial tooth ring of the first type (30) and / or that the at least one U-shaped tooth segment (26) is materially connected to the at least one axial tooth ring of the second type (32). [7] Stator (10) according to any of the preceding claims, characterized by , that a first angular length of the at least one T-shaped tooth segment (24) corresponds to a pole pitch of the stator (10) and / or that a second angular length of the at least one U-shaped tooth segment (26) corresponds to the pole pitch of the stator (10). [8] Stator (10) according to any of the preceding claims, characterized by , that the at least one tooth ring of the first kind (30) and the at least one tooth ring of the second kind (32) are joined together by a material bond. [9] Stator (10) according to any of the preceding claims, characterized by , that the stator (10) further comprises a stator yoke ring (20) which extends around the stator tooth ring (12) and is materially and / or form-fitted to the stator tooth ring (12), wherein the stator yoke ring (20) preferably comprises non-grain-oriented electrical steel. [10] Stator (10) according to claim 9, characterized by , that the stator yoke ring (20) is formed from a plurality of sub-segments (46, 48), wherein preferably an angular length of the sub-segments (46, 48) in circumferential direction (15) corresponds to a pole pitch of the stator (10). [11] Vehicle (50) comprising at least one electric machine (52), wherein the electric machine (52) has at least one stator (10) according to any of the preceding claims. [12] Method (100) for manufacturing a stator (10) according to any one of claims 1 to 10, comprising at least the following steps: a. Manufacturing (102) at least one tooth ring of the first kind (30) and at least one tooth ring of the second kind (32); b. Manufacturing (104) at least two pairs of toothed rings (34), each pair of toothed rings (34) comprising a toothed ring of the first kind (30) and a toothed ring of the second kind (32); c. Attaching (106) the at least two pairs of tooth rings (34) together to produce at least one stator tooth ring (12). [13] Method (100) according to claim 12, characterized by , that the procedure (100) further includes at least the following step: a. Inserting (108) a wave winding of an electrical conductor (16) in radial direction (13) from the outside to the inside into the stator toothed ring (12). [14] Method according to claim 12 or 13, characterized by , that the procedure (100) further includes at least the following step: a. Attaching (110) a stator yoke ring (20) to the stator tooth ring (12), wherein the stator yoke ring (20) extends around the stator tooth ring (12).

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