Stator for an electric machine with an improved radial mounting option for a stator winding, as well as an electric machine, vehicle and related manufacturing processes.

Abstract

A stator (6) for an electric machine (1) is disclosed, comprising a stator lamination stack (7, 7a...7c) which includes several stator laminations (8) stacked one above the other in an axial direction along a stator axis (RA), stator slots (9) with stator teeth (15) arranged in the stator lamination stack (7, 7a...7c), and stator windings (10) arranged in the stator slots (9). Furthermore, the stator (6) includes a stator tooth extension (17a...17d) which is mounted on a radially inwardly facing end face (B) of at least one of the stator teeth (15) and which projects tangentially laterally over at least one of the side faces (C, C') of the at least one stator tooth (15) with respect to the stator axis (RA) in a tangential projection direction (D). Furthermore, an electric machine (1) with such a stator (6) and a vehicle (19) with such an electric machine (1) are disclosed.Finally, methods for manufacturing a stator tooth supplement (17a...17d) and a stator (6) are presented.

Description

TECHNICAL AREA

[0001] The invention relates to a stator for an electric machine, comprising a stator lamination stack with several stator laminations stacked one above the other in an axial direction along a stator axis, stator slots with intervening stator teeth arranged in the stator lamination stack, and stator windings arranged in the stator slots. The invention further relates to an electric machine with such a stator and to a vehicle with such an electric machine, wherein the electric machine is intended for propelling the vehicle. The invention also relates to methods for manufacturing a stator tooth assembly and a stator. STATE OF THE ART

[0002] A stator, an electric machine, a vehicle, and a process of the above type are each generally known. In the manufacture of a stator for an electric machine, one process step consists of inserting the conductors of the stator winding into the stator slots. Typically, the stator slots have relatively narrow, inward-facing openings, which is advantageous for holding the stator winding in the slots and can also aid the magnetic flux. The relatively thin wires of a wire winding can be easily inserted into the stator slots through these narrow, inward-facing openings. In contrast, U-pins, I-pins, or X-pins are usually about the same width as the stator slots, so they cannot be inserted radially into the stator slots through narrow openings but must be inserted into the slots through the end faces of the stator lamination stack.Another embodiment of a stator winding consists of a continuous wave winding, which cannot be moved into the stator slots through either narrow, inward-facing openings or the end faces of the stator lamination stack. Accordingly, in this case, the inward-facing opening of a stator slot is comparatively wide (in particular, as wide as the stator slot itself), which is disadvantageous with regard to holding the stator winding in the stator slots and supporting the magnetic flux. REVELATION OF THE INVENTION

[0003] Accordingly, one object of the invention is to provide an improved stator, an improved electric machine, an improved vehicle, and methods for manufacturing a stator tooth supplement and a stator. In particular, a solution is to be provided for the radial mounting of comparatively wide conductors of a stator winding through the inwardly facing openings of the stator slots.

[0004] The object of the invention is achieved by a stator as disclosed in the introductory paragraph, wherein a stator tooth extension is mounted on a radially inwardly facing end face of at least one of the stator teeth, or, in other words, wherein a stator tooth extension is mounted on the radially inwardly facing tip or end of at least one of the stator teeth. The stator tooth extension projects laterally beyond at least one of the side faces of the at least one stator tooth with respect to the stator axis in a tangential projection direction.

[0005] Furthermore, the object of the invention is solved by an electric machine with a stator of the type shown and a rotor which is rotatably arranged in the stator.

[0006] Furthermore, the object of the invention is solved by a vehicle, wherein the vehicle comprises an electric machine of the above type and wherein the electric machine is provided for propelling the vehicle.

[0007] Advantageously, a stator tooth extension can be made from several tooth extension laminations stacked on top of each other in the axial direction along the stator axis. Generally, the stator tooth extension can be made of electrical steel, conductive plastic, or a ferromagnetic material. Similarly, the tooth extension laminations can also be made of electrical steel, conductive plastic, or a ferromagnetic material. The tooth extension laminations can be bonded together using an adhesive or a thermosetting resin, just as the stator laminations can be bonded together. The thermosetting resin can, for example, be a baked-on lacquer. Bonding the tooth extension laminations together forms a solid body.

[0008] In this context, the object of the invention is further achieved by a method for manufacturing a stator tooth supplement of a stator as described above, which comprises the following steps: a) Providing a base material for sheet metal, b) Separating a stator lamination sheet and at least one tooth supplement sheet from the metal sheet base material in a common process step, c) Repeat step b) for several stator laminations and d) Stacking several tooth supplement plates on top of each other to form the stator tooth supplement.

[0009] In step b), the separation of the stator lamination sheet and the at least one tooth supplement sheet from the metal sheet base material can be carried out, for example, by cutting (in particular by laser beam cutting) or punching. In particular, the tooth supplement sheets can be joined together using an adhesive or a thermosetting resin in or after step d). Since the tooth supplement sheets can be joined together in the same way as the stator lamination sheets, proven methods are generally available for manufacturing the stator tooth supplements.

[0010] In step d), the same number of tooth extension laminations can be stacked on top of each other as the number of stator laminations stacked on top of each other to form the stator lamination stack. In other words, the number of tooth extension laminations stacked on top of each other for a stator tooth extension corresponds to the number of stator laminations stacked on top of each other for the stator lamination stack. In one variation, each tooth extension lamination originates from a different process step b), so that (exclusively) tooth extension laminations originating from different process steps b) are stacked on top of each other. In another variation, the tooth extension laminations originating from different process steps b) can be mixed together, so that a stator tooth extension can comprise several tooth extension laminations originating from the same process step b).

[0011] However, the above embodiments are not the only possibilities for forming a stator tooth supplement. In another embodiment, the stator tooth supplement can also be extruded. In this way, a solid body is formed without connecting the individual tooth supplement sheets to one another. For example, the stator tooth supplements can be made of extruded electrical steel, extruded conductive plastic, or an extruded ferromagnetic material.

[0012] In this context, the object of the invention is additionally solved by a method for manufacturing a stator tooth supplement of a stator as described above, wherein the stator tooth supplement is extruded.

[0013] In general, the stator tooth extension can project tangentially from only one of the side faces of the corresponding stator tooth relative to the stator axis in the tangential projection direction, or it can project tangentially from both side faces of the corresponding stator tooth relative to the stator axis in opposite tangential projection directions. Furthermore, the stator tooth extension can project straight, so that there is a single tangential direction per projection, or it can project along an arc, so that there are many (infinite) tangential directions per projection. In the latter case, the multitude of tangential projection directions around the circumference relative to the stator axis can be considered a single circumferential projection direction.Accordingly, the stator tooth supplement can project laterally around the circumference in a circumferential projection direction with respect to the stator axis, extending over at least one of the side surfaces of the at least one stator tooth.

[0014] By using the proposed measures, conductors of the stator winding can be inserted into the stator slots through their inward-facing openings when the stator tooth extensions are removed, even if the stator winding conductors are approximately the same width as the stator slots, which is usually the case for U-pins, I-pins, or X-pins, and especially for continuous wave windings. At the same time, the inward-facing openings are at least partially closed when the stator tooth extensions are installed, which is advantageous for holding the stator winding in the stator slots and can also enhance the magnetic flux.The above measures are particularly advantageous when the stator winding is designed as a continuous wave winding, since a continuous wave winding is neither made of comparatively thin wires as in wire windings nor of pins that can be inserted through the end faces of the stator core. Nevertheless, the proposed measures apply to all types of stator windings, especially wire windings and windings made of U-pins, I-pins, or X-pins. Finally, the proposed measures make it possible to retain the stator winding in the stator slots and also to support the magnetic flux, even with comparatively wide, inwardly facing end face openings in the stator slots.

[0015] As previously explained, in some embodiments the conductors of the stator winding can only be inserted into the stator slots if the stator tooth extensions have been removed. In other embodiments, the removal of the stator tooth extensions allows for easy assembly of the stator windings. Thus, a method for manufacturing a stator to solve the inventive problem may comprise the following process steps: - Providing a stator lamination stack, - Inserting the stator winding into the stator slots through their inward-facing openings with the stator tooth supplement(s) removed and - Mounting the stator tooth extension(s) onto the stator teeth.

[0016] Further advantageous embodiments are disclosed in the claims and in the description as well as in the figures.

[0017] In one embodiment, a stator tooth supplement can be provided. i) per each of the stator teeth or ii) for several stator teeth.

[0018] If a stator tooth supplement is provided for each of the stator teeth, the fabrication and handling of the stator tooth supplement is effortless. If a stator tooth supplement is provided for multiple stator teeth, the stator tooth supplement can be mounted onto the stator teeth more easily, i.e., with fewer process steps. In a special embodiment of case ii), a single annular stator tooth supplement is provided for all stator teeth. Accordingly, the stator tooth supplement can then be mounted onto the stator teeth in a single process step.

[0019] In another embodiment, the stator can comprise several stator tooth extensions, wherein I) Air gaps are provided between adjacent stator tooth extensions or II) Adjacent stator tooth extensions touch each other (in a contact area).

[0020] In case I), a magnetic short circuit in the area of ​​the stator tooth extensions can be prevented, whereas case II) offers a possibility for a complete closing of the stator slots, which is advantageous from an aerodynamic point of view and with regard to avoiding contamination of the stator slots.

[0021] In an advantageous embodiment, the magnetic permeability of the stator tooth extension can vary in the tangential (or circumferential) projection direction(s). In particular, the magnetic permeability of the stator tooth extension can be lowest in the center of a radially inward-facing opening from one of the stator slots. In this way, a magnetic short circuit in the area of ​​the stator tooth extensions can be prevented, or at least its effect can be reduced. Accordingly, the proposed measures are advantageous when adjacent stator tooth extensions touch each other in a contact area (see Case II above).

[0022] In general, varying magnetic permeability can be provided both in the case of stator tooth supplementation with stacked tooth supplementation sheets and in the case of extruded stator tooth supplementation.

[0023] For example, dental supplement plates can be printed from a plastic base material with varying densities of distributed conductive particles. These particles could be made from electrical steel or a ferromagnetic material. Printing processes such as jet printing or screen printing can be used in this context. Alternatively, a metal sheet base material from which the dental supplement plates are cut can have varying magnetic conductivity. The considerations outlined above regarding the printing of dental supplement plates also apply to printing from a metal sheet base material.

[0024] In extruded stator tooth extensions, the extensions can be made of extruded conductive plastic with varying magnetic conductivity in the tangential (or circumferential) projection direction(s) of the extension. In other words, the extruded conductive plastic is inhomogeneous in the tangential or circumferential projection directions, which can be achieved by extruding different materials from different dies. Here, too, for example, a base plastic material can have a varying density of distributed conductive particles. These particles can also be made of electrical steel or a ferromagnetic material.

[0025] Advantageously, the stator tooth extension can be mounted to at least one stator tooth using an undercut joint, soldering, and / or gluing. An example of an undercut joint is a dovetail joint, but other undercut joints are also applicable. The undercut joint can be attached by soldering and / or gluing. This means the stator tooth extension can be fixed to the corresponding stator tooth(s) by the undercut joint and soldering, or by the undercut joint and gluing.

[0026] However, the stator tooth extension can also be attached to the stator tooth(s) simply by soldering and / or gluing, without undercut connections. In such an embodiment, the inward-facing end face(s) of the stator tooth(s) can, for example, be designed as simple blunt ends. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The invention will now be described in more detail with reference to certain embodiments; however, the invention is not limited to these. Fig. Figure 1 shows a half-section view of an exemplary electrical machine; Fig. 2 shows an oblique view of an exemplary stator lamination stack; Fig. Figure 3 shows a section of the stator lamination stack. Fig. 2 in detail, some with stator tooth extensions mounted; Fig. Figure 4 shows a detailed oblique view of a stator tooth supplement with several stacked tooth supplement lamellae; Fig. 5 is a section of the stator lamination stack of the Fig. 2 to 4 in cross-section, which additionally shows the stator winding; Fig. 6 corresponds Fig. 5, wherein adjacent stator tooth additions each touch in a contact area; Fig. 7 corresponds Fig. 5, wherein a stator tooth supplement is provided for several stator teeth; Fig. Figure 8 shows an oblique view of an annular stator tooth extension and Fig. Figure 9 shows a schematic representation of an electric vehicle. DETAILED DESCRIPTION

[0028] Generally, identical or similar parts are identified by the same / similar designations and reference numerals. The features disclosed in the description apply to parts with the same / similar designations or reference numerals. Information regarding orientation and relative position refers to the corresponding figure.

[0029] Fig. Figure 1 shows a half-section view of an exemplary electric machine 1. The electric machine 1 comprises a machine housing 2 with a stator housing 3, a first end shield 4, a second end shield 5, and a stator shaft or rotor shaft RA. Furthermore, the electric machine 1 comprises a stator 6, which is arranged in the stator housing 3 and which includes a stator lamination stack 7 in which several stator laminations 8 are stacked one above the other in an axial direction along the stator shaft RA. Additionally, the stator 6 includes stator slots 9, which are arranged in the stator lamination stack 7, and stator windings 10, which are arranged in the stator slots 9. The electric machine 1 also comprises a rotor 11 with a rotor shaft 12 and a rotor lamination stack 13 mounted on the rotor shaft 12. The rotor 11 is in Fig. Figure 1 is not shown in detail, but it can comprise rotor laminations stacked one above the other in an axial direction, and rotor windings or rotor magnets arranged in the rotor lamination stack. Furthermore, the electric machine 1 comprises a first (roller) bearing 14a in the first bearing shield 4 and a second (roller) bearing 14b in the second bearing shield 5 for rotatably supporting the rotor 11 about the stator axis or rotor axis RA.

[0030] Fig. Figure 2 shows an oblique view of an embodiment of the stator lamination stack 7a and shows in particular that the stator lamination stack 7a has several stator slots 9 between which stator teeth 15 are located.

[0031] Fig. Figure 3 shows a section of the stator lamination stack 7a in Fig. 2 in detail and shows in particular recesses 16 in the inwardly facing end faces B of the stator teeth 15. In addition, it shows Fig. 3 several stator tooth extensions 17a...17a'', which are inserted into the recesses 16. In Fig. 3. The stator tooth extension 17a is not fully inserted into the corresponding recess 16 in order to provide a better view of the shape of the stator tooth extension 17a. It should also be noted that in reality all stator teeth 15 or recesses 16 are each equipped with a corresponding stator tooth extension 17a...17a''.

[0032] In detail, the stator tooth extensions 17a...17a'' are each mounted on radially inwardly facing end faces B of the stator teeth 15 or on the radially inwardly facing tips or ends of the stator teeth 15 and project laterally beyond at least one of the side faces C, C' of the at least one stator tooth 15 in a tangential projection direction D with respect to the stator axis RA.

[0033] At the in Fig. In the embodiment shown in Figure 3, the stator tooth extensions 17a...17a'' each project tangentially beyond both side faces C, C' of the corresponding stator tooth 15 in opposite tangential projection directions D relative to the stator axis RA. However, the stator tooth extensions 17a...17a'' could also each project tangentially beyond only one of the side faces C, C' of the corresponding stator tooth 15 in a single tangential projection direction D. This means that the stator tooth extensions 17a...17a'' could also each project either to the left or to the right, or in other words, clockwise or counterclockwise.

[0034] The stator tooth extensions 17a...17a'' can project straight, so that there is a single tangential direction D per projection, or they can project along an arc, so that there are many (infinite) tangential directions D per projection. In the latter case, the multitude of tangential projection directions D around the circumference with respect to the stator axis RA can be considered as a (single) circumferential projection direction D. Accordingly, the stator tooth extensions 17a...17a'' can project laterally around the circumference with respect to the stator axis RA in a circumferential projection direction D over at least one of the side faces C, C' of the at least one stator tooth 15.

[0035] In the illustrated embodiment, the stator tooth extensions 17a...17a'' are mounted to the stator teeth 15 by means of an undercut connection E. An example of an undercut connection E is a dovetail joint, but other undercut connections E can also be used. The stator tooth extensions 17a...17a'' can be attached in the recesses 16 by soldering and / or gluing. In another embodiment, the stator tooth extensions 17a...17a'' can be mounted to the stator teeth 15 simply by soldering and / or gluing without undercut connections E. In such an embodiment, the inwardly facing end faces B of the stator teeth 15 can, for example, be shaped as simple blunt ends. As in Fig. As can be seen in Figure 3, the stator tooth extensions 17a...17a'' can partially close the inwardly facing openings F of the stator slots 9.

[0036] Fig. Figure 4 shows a detailed oblique view of a stator tooth extension 17a, which is made of several tooth extension plates 18 stacked one above the other in the axial direction along the stator axis RA. The tooth extension plates 18 can be made of electrical steel, conductive plastic, or a ferromagnetic material. The tooth extension plates 18 can also be bonded together using an adhesive or a thermosetting resin, just as the stator lamination plates 8 can be bonded together. The thermosetting resin can, for example, be a baked-on lacquer. By bonding the tooth extension plates 18 together, a solid body is formed.

[0037] However, the foregoing embodiment is not the only way to form a stator tooth extension 17a. In another embodiment, the stator tooth extension 17a can also be extruded. In this way, a solid body is formed without connecting the individual tooth extension plates 18 to one another. Here, too, the stator tooth extensions 17a can be made of extruded electrical steel, extruded conductive plastic, or an extruded ferromagnetic material.

[0038] In the case of stacked tooth supplement plates 18, a method for manufacturing a stator tooth supplement 17a may comprise the following steps: a) Providing a base material for sheet metal, b) Separating a stator lamella plate 8 and at least one tooth supplement plate 18 from the metal sheet base material in a common process step, c) Repeat step b) for several stator laminations 8 and d) Stacking several tooth supplement plates 18 on top of each other to form the stator tooth supplement 17a.

[0039] In step b), the separation of the stator lamella plate 8 and the at least one tooth supplement plate 18 from the metal sheet base material can be carried out, for example, by cutting (in particular by laser beam cutting) or punching.

[0040] In step d), in particular, the same number of tooth extension plates 18 can be stacked on top of each other as stator lamination plates 8 can be stacked on top of each other to form the stator lamination stack 7a. In other words, the number of tooth extension plates 18 stacked on top of each other for a stator tooth extension 17a corresponds to the number of stator lamination plates 8 stacked on top of each other for the stator lamination stack 7a.

[0041] As already explained, the tooth supplement plates 18 can be joined together using an adhesive or a thermosetting resin, which can be done in or after step d). Since the tooth supplement plates 18 can be joined together in the same way as the stator lamination plates 8, proven methods are available for manufacturing the stator tooth supplements 17a.

[0042] In one modification, each tooth supplement plate 18 originates from a different process step b), so that (exclusively) tooth supplement plates 18 originating from different process steps b) are stacked on top of each other. In another modification, the tooth supplement plates 18 originating from different process steps b) can be mixed together, so that a stator tooth supplement 17a can comprise several tooth supplement plates 18 originating from the same process step b).

[0043] Fig. Figure 5 now shows a section of the stator lamination stack 7a of the Fig. 2 to 4 in cross-section, with the stator winding 10 also shown. As in Fig. As can be seen in Figure 5, the conductors of the stator winding 10 are approximately the same width as the stator slots 9. Accordingly, these conductors can only be moved into the stator slots 9 through the inward-facing openings F if the stator tooth extensions 17a...17a'' are removed. Thus, a method for manufacturing a stator 7a can comprise the following process steps: - Providing a stator lamination stack 7a, - Inserting the stator winding 10 into the stator slots 9 through their inward-facing openings F with the stator tooth supplement(s) 17a...17a'' removed and - Mounting the stator tooth extension(s) 17a...17a'' on the stator teeth 15.

[0044] In general, the above applies to all types of stator windings 10, for example, wire windings and windings made of U-pins, I-pins, or X-pins. In particular, the above also applies to continuous wave windings, since a continuous wave winding is neither made of comparatively thin wires as in wire windings nor of pins that can be inserted through the end faces of the stator lamination stack 7a. Wire windings and windings made of U-pins, I-pins, or X-pins generally allow for comparatively small openings F in the stator lamination stack 7a, which is advantageous for holding the stator winding 10 in the stator slots 9 and can also support the magnetic flux. The proposed stator tooth additions 17a...17a'' now provide the same function for the situation in which the inward-facing openings F are (approximately) as wide as the stator slots 9 and in particular when the stator winding 10 is designed as a continuous wave winding.

[0045] During the Fig. In the embodiment disclosed in Figures 2 to 5, air gaps G are provided between adjacent stator tooth extensions 17a...17a''. However, this is not the only possibility, and in Fig. Figure 6 shows a cross-sectional section of another stator lamination stack 7b, in which adjacent stator tooth extensions 17b...17b'' ​​touch each other in a contact area H. In other words, the stator tooth extensions 17b...17b'' ​​completely close the inwardly facing openings of the stator slots 9, which is advantageous from an aerodynamic point of view and also to prevent contamination of the stator slots 9.

[0046] To prevent a magnetic short circuit in the area of ​​the stator tooth extensions 17b...17b'', the magnetic permeability µ of the stator tooth extension 17b...17b'' ​​can vary in the tangential or circumferential projection directions D in a specific embodiment. In particular, the magnetic permeability µ of the stator tooth extension 17b...17b'' ​​can be lowest in the center of the radially inwardly facing openings F of the stator slots 9, as shown in Fig. 6 is the case. In this way, a magnetic short circuit in the area of ​​the stator tooth extensions 17b...17b'' ​​can be prevented, or its effect can at least be reduced.

[0047] In general, a varying magnetic permeability µ can be provided for both stacked tooth supplement sheets 18 and extruded stator tooth supplements 17b...17b''.

[0048] For example, the dental supplement plates 18 can be printed from a plastic base material with varying densities of distributed conductive particles. These particles could, for example, be made of electrical steel or a ferromagnetic material. Printing processes such as jet printing or screen printing can be used in this context. Alternatively, a metal sheet base material from which the dental supplement plates 18 are cut can have varying magnetic conductivity. The considerations outlined above regarding the printing of dental supplement plates 18 also apply to the printing of a metal sheet base material.

[0049] In extruded stator tooth extensions 17b...17b'', the stator tooth extensions 17b...17b'' ​​can be made of extruded conductive plastic with varying magnetic conductivity in the lateral projection directions D of the stator tooth extension 17b...17b''. In other words, the extruded conductive plastic is inhomogeneous in the tangential or circumferential projection directions D, which can be achieved by extruding different materials from different dies. Here, too, for example, a plastic base material can have a varying density of distributed conductive particles. These particles can also be made of electrical steel or a ferromagnetic material, for example.

[0050] In the embodiments of the Fig. For each stator tooth 15, 2 to 6, a stator tooth extension 17a...17b'' ​​is provided. However, this is not the only possibility, and Fig. Figure 7 shows a cross-sectional section of a modified stator lamination stack 7c, in which a stator tooth extension 17c...17c'' is provided for several stator teeth 15. In the example in Fig. Figure 7 provides for a stator tooth extension 17c...17c'' for three stator teeth 15. However, any other number greater than one is also applicable, for example, two, four, etc. By using the proposed measures, the stator tooth extension 17c...17c'' can be mounted more easily, i.e., with fewer process steps, on the stator teeth 15.

[0051] The considerations outlined above in the context of varying permeability µ also apply to the embodiment in Fig. 7. Furthermore, adjacent stator tooth additions 17c...17c'' can be arranged as in Fig. 6 also touch in a contact area H instead of having an air gap G between adjacent stator tooth extensions 17c...17c''.

[0052] Fig. Figure 8 shows a special embodiment of a stator tooth extension 17d, which is provided for several stator teeth 15. Specifically, a single annular stator tooth extension 17d is provided for all stator teeth 15. Accordingly, the stator tooth extension 17d can be mounted on the stator teeth 15 in a single process step. Here, too, the considerations that were set out above in the context of the varying permeability µ also apply to the embodiment in Figure 8. Fig. 8.

[0053] The in the context of Fig. The different aspects disclosed in Sections 2 to 8 are interchangeable within all disclosed embodiments, and modifications or aspects disclosed in the context of one embodiment may be applied partially or completely to other embodiments. This applies in particular to... - how the stator tooth additions 17a...17d protrude laterally (straight or arc-shaped, bilaterally or unilaterally), - how the stator tooth extensions 17a...17d are mounted on the stator teeth 15 (by means of an undercut connection E, soldering and / or gluing), - the structure of the stator tooth additions 17a...17d (stacked or extruded) and the manufacturing process thereof, - the material of the stator tooth supplements 17a...17d (electrical steel, conductive plastic or ferromagnetic material), - the varying magnetic permeability µ of the stator tooth additions 17a...17d and - the method for inserting the stator winding into the stator slots.

[0054] For example, the stator tooth extensions 17a...17a'' can have a varying magnetic permeability µ, the stator tooth extensions 17b...17d can be stacked or extruded, etc.

[0055] Ultimately, it shows Fig.9 an electric vehicle 19 with an electric machine 1 as defined above, which is intended for propelling the electric vehicle 19. In detail, the electric machine 1 is coupled to an optional transmission 20, drive shafts 21 and finally to the wheels 22. The electric machine 1 can be intended for powering the electric vehicle 19 continuously in a pure electric car or intermittently, e.g. in combination with an internal combustion engine in a hybrid vehicle.

[0056] It should be noted that the invention is not limited to the embodiments disclosed herein, but that combinations of the various variants are possible. In practice, the electric machine 1, its stator 6, and the electric vehicle 19 may have more or fewer parts than shown in the figures. It should also be noted that the electric machine 1, its stator 6, and the electric vehicle 19, or parts thereof, are not necessarily drawn to scale in the figures. Furthermore, the description may include subject matter of other independent inventions.

[0057] It is also noted that the term "comprises" does not exclude other elements, and the use of the articles "a" does not preclude the plural form. Furthermore, elements described in connection with different embodiments may be combined. It is also noted that reference numerals in the claims are not to be interpreted as limiting the scope of protection of the claims. List of reference symbols 1 electric machine 2 machine housings 3 Stator housings 4 first storage sign 5 second storage sign 6 Stator 7, 7a...7c Stator lamination stack 8 stator lamellae 9 stator slots 10 Stator winding 11 Rotor 12 Rotor shaft 13 Rotor lamination package 14a, 14b storage 15 Stator tooth 16 recess 17a...17d stator tooth supplement 18 tooth supplement plate 19 vehicles 20 gearboxes 21 Side shaft 22 wheel RA Stator axis / Rotor axis B inwardly facing end face of the stator tooth C, C' Side surface of the stator tooth D tangential or circumferential projection direction E undercut joint F inward-facing opening of a stator slot G air gap H Contact area µ magnetic permeability

Claims

[1] Stator (6) for an electric machine (1) comprising the following: - a stator lamination stack (7, 7a...7c) with several stator lamination sheets (8) stacked on top of each other in an axial direction along a stator axis (RA), - Stator slots (9) with stator teeth (15) which are arranged interspersed within the stator lamination stack (7, 7a...7c) and - Stator windings (10) which are arranged in the stator slots (9), characterized by , that - a stator tooth extension (17a...17d) which is mounted on a radially inwardly facing end face (B) of at least one of the stator teeth (15) and which projects tangentially laterally over at least one of the side faces (C, C') of the at least one stator tooth (15) with respect to the stator axis (RA) in a tangential projection direction (D). [2] Stator (6) according to claim 1, characterized by, that the stator tooth extension (17a...17d) projects tangentially over both side surfaces (C, C') of the at least one stator tooth (15) with respect to the stator axis in opposite tangential projection directions (D). [3] Stator (6) according to claim 1 or 2, characterized by , that a stator tooth supplement (17a...17d) is provided i) for each of the stator teeth (15) or ii) for several stator teeth (15). [4] Stator (6) according to claim 3, characterized by , that in case ii) a single ring-shaped stator tooth supplement (17d) is provided for all stator teeth (15). [5] Stator (6) according to any one of claims 1 to 3, characterized by , that the stator (6) comprises several stator tooth extensions (17a...17d), wherein I) Air gaps (G) are provided between adjacent stator tooth extensions (17a...17d) or II) Adjacent stator tooth additions (17a...17d) touch each other. [6] Stator (6) according to any one of claims 1 to 5, characterized by , that a stator tooth supplement (17a...17d) is made from several tooth supplement plates (18) which are stacked on top of each other in the axial direction along the stator axis (RA). [7] Stator (6) according to any one of claims 1 to 6, characterized by , that the stator tooth supplement (17a...17d) is made of electrical steel, conductive plastic or a ferromagnetic material. [8] Stator (6) according to any one of claims 1 to 7, characterized by , that a magnetic permeability (µ) of the stator tooth supplement (17a...17d) varies in the tangential projection direction (D). [9] Stator (6) according to claim 8, characterized by , that the magnetic permeability (µ) of the stator tooth supplement (17a...17d) is lowest in the middle of a radially inwardly facing opening (F) of one of the stator slots (9). [10] Stator (6) according to any one of claims 1 to 9, characterized by, that the stator tooth extension (17a...17d) is mounted on the at least one stator tooth (15) by means of an undercut connection (E), by soldering and / or by gluing. [11] Electric machine (1) comprising a stator (6) according to any one of claims 1 to 10 and a rotor (11) rotatably arranged in the stator (6). [12] Vehicle (19) with an electric machine (1) according to claim 11, wherein the electric machine (1) is provided for propelling the vehicle (19). [13] Method for manufacturing a stator tooth supplement (17a...17d) of a stator (6) according to any one of claims 1 to 10, comprising the following steps: a) Providing a base material for sheet metal, b) Separating a stator lamella sheet (8) and at least one tooth supplement sheet (18) from the metal sheet base material in a common process step, c) Repeat step b) for several stator laminations (8) and d) Stacking several tooth supplement plates (18) on top of each other to form the stator tooth supplement (17a...17d). [14] Method for producing a stator tooth supplement (17a...17d) of a stator (6) according to any one of claims 1 to 10, wherein the stator tooth supplement (17a...17d) is extruded. [15] Method for manufacturing a stator (6) according to any one of claims 1 to 10, comprising the following steps: - Provision of the stator lamination stack (7, 7a...7c), - Inserting the stator winding (10) into the stator slots (9) through their inward-facing openings (F) with the stator tooth supplement (17a...17d) removed and - Mounting the stator tooth extension (17a...17d) onto the stator teeth (15).

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