Laminated core for an electric machine, electric machine having a laminated core and method for manufacturing a stator base

Abstract

Laminated core (10) for forming a pole of an electrical machine (12), electrical machine (12), and method for producing a stator base body (16), with individual metal sheets (20) stacked on one another in the axial direction, the metal sheets forming T-shaped segments (22) with a radially outer yoke region (24) with an outer circumference (25) and a radially inwardly extending tooth web (26), wherein, at the yoke region (24), the metal sheets (20) have a connecting protrusion (30) in tangential direction (9) at a first side (18) and, in tangential opposition, a corresponding recess (31) for the connecting protrusion (30) at a second side (19), wherein, at least at a radially inner side (33) of the connecting protrusion (30), an inner circular-arc segment (35) is configured, an outer center (37) of which is spaced apart from the outer circumference (25) by a radial spacing (47) in the radial direction within the yoke region (26).

Description

TECHNICAL FIELD

[0001] The invention relates to a laminated core for an electrical machine and to an electrical machine having a laminated core and to a method for producing a stator base. BACKGROUND

[0002] From DE 10 2017 201 178 A1 a stator of an electrical machine is known, in which a laminated core is formed from individual stamped metal sheets in an axial stack. Here, in the radially outer yoke region a stamped packaging structure is configured, which connects the individual metal sheets to one another in the axial direction. In order to join the individual laminated core segments together, at these laminated core segments tangentially tab-like protrusions are formed, which are inserted into corresponding tangential recesses. The disadvantage in this embodiment is that this geometry of the tab-like protrusions is not suitable for the production of the stator by means of the pre-cut technique, in which the individual laminated core segments are separated at the intended breaking point and then joined to one another again at exactly the same point. These disadvantages should be eliminated by the solution according to the invention, in which the magnetic flux losses in the yoke region of the laminated core should be minimized. SUMMARY

[0003] Accordingly, the device according to the invention and the method according to the invention have the advantage that the T-shaped metal sheet segments can be joined particularly advantageously into one total base over the entire circumference by virtue of the special geometry of the connecting protrusions of the T-shaped metal sheet segments. Here, the geometry of the connecting protrusions and the corresponding recesses for the connecting protrusions are optimized for the so-called "pre-cut production method", in which the individual metal sheet layers are stamped in full cutting with predefined intended breaking points between the individual T-shaped segments to some extent. Here, the individual T-shaped segments are separated from the metal sheet base, so that their tooth stems can be better wound. A higher slot fill factor can be achieved thereby, which increases the efficiency of the electrical machine. If an inner circular arc segment is stamped at the radially inner side of the connecting protrusion (towards the tooth stem), the center of which is located radially within the yoke region of the T-shaped segment, then two adjacent T-shaped segments can be separated with minimal force expenditure without the connecting protrusions of the T-shaped segments being deformed upon separation. By preserving the contour of the connecting protrusions upon separation of the T-shaped segments, the T-shaped segments can be joined together again after they have been wound with great accuracy, so that there are virtually no joining gaps between the individual T-shaped segments in the tangential direction. Positioning torques and thus noise generation of the electrical machine can be reduced very effectively thereby. Furthermore, electromagnetic drag forces are minimized and asymmetries are reduced, which leads to better efficiency.

[0004] The advantageous expansion and improvement concepts are achieved by the measures mentioned in the present disclosure. The connecting protrusion here extends tangentially from the tangential side of the T segment, which tangential side extends approximately radially. The radially inner circular arc profile of the connecting protrusion is here configured in such a way that the center of the circular arc profile has a tangential distance from the tangential side of the radially extending boundary of the T segment. It is thereby possible to prevent the connecting protrusion from engaging the associated recess when the T segment is tilted and the T segment is separated. It is thereby ensured that even in a non-optimal tangential separation direction, no deformation of the connecting protrusion and / or the recess occurs when separating. It is thereby possible to minimize the disturbance of the magnetic flux between two adjacent T segments that are joined together.

[0005] It has proven particularly advantageous if the center of the inner tooth flank profile has a distance of 0.05 to 1.0 mm, in particular preferably 0.1 to 0.3 mm. If the T segment of the internal rotor motor has a tooth stem that extends radially inwards, for example, then the adjacent T segment can also be separated without deformation when the tooth stem is tilted at the boundary here that extends approximately radially. If the radially inner tooth root of the tooth stem moves apart from one another more strongly with respect to the tangential direction than the associated yoke region, it is ensured that the radially inner profile of the connecting protrusion does not rub against the corresponding recess when separating. If the center of the radially inner profile of the connecting protrusion is arranged radially inside the connecting protrusion, it is ensured by the stronger curvature of the inner side that even when the T segment is tilted around the outer profile of the yoke region, the inner side profile forms a gap to the corresponding recess. It is thereby reliably possible to prevent the T segment from deforming at the joint gap when the T segment is separated if the T segment is tilted undesirably.

[0006] It can also be the case in the pre-cut technique that the T segments are tilted at the inner circumference of the yoke region when separating the T segments, so that the radially outer yoke region moves apart from one another more strongly than the radially inner yoke region or tooth root. In order to ensure that the T segments are separated without deformation also for this case, it is optionally also possible and advantageous to design the radially outer profile of the connecting protrusion as a circular arc section whose midpoint is arranged radially outside the inner diameter of the yoke region. It is preferred that this inner center for the outer protrusion profile can also preferably be arranged radially inside the extension of the connecting protrusion.

[0007] If the centers of the inner circular arc sections of the outer connection protrusion are also arranged at a tangential distance from the radial delimitation of the yoke region, the connection protrusion can likewise be reliably prevented from deforming when the T-shaped segments are separated. In a preferred embodiment, the outer circular arc sections are configured mirror-symmetrically in the radial direction relative to the inner circular arc sections of the connection protrusion. Here, the radially inner centers are preferably arranged at a radial distance from one another, flush in the radial direction with the radially outer centers. In a preferred embodiment, the connection protrusion has a flat face at its tangentially outermost end, which extends approximately in the radial direction.

[0008] The inner and / or outer circular arc sections are preferably not tangentially extended up to the delimitation of the yoke region. Rather, for manufacturing-technical reasons and in order to avoid notch cracks, a transition region of a radius or another shape is configured, for example, between the circular arc sections and the delimitation. The tangential extension length thereof preferably corresponds to the tangential distance of the inner and / or outer centers to the radial delimitation. This means that the circular arc sections do not extend over the entire tangential extension length (height) of the connection protrusion, but rather are configured as exact circular arcs only over a tangential section.

[0009] The connection protrusion is preferably not arranged exactly centrally in the radial direction in the yoke region, but rather is offset radially outward toward the outer circumference. Here, the radial distance between the outer circumference of the yoke region and the radially outer side of the connection protrusion is in the order of magnitude of the tangential height and / or radial width of the connection protrusion. Thereby, a longer straight region of the delimitation in the radial direction is preserved in the radially inner region than in the radially outer region, which has a positive effect on the undisturbed magnetic flux between adjacent T-shaped segments. Depending on the overall diameter of the stator or the laser welding process, however, the radial distance between the outer circumference of the yoke region and the radially outer side of the connection protrusion can also have a size other than the height and / or radial width of the connection protrusion.

[0010] In the case of punched sheet metal, the individual T-shaped segments are particularly advantageously connected to one another in one process step by means of a punched packaging structure in the axial direction. Thereby, an additional connection process between the axially stacked sheet metals is eliminated. The punched packaging structure reliably holds the laminations of the individual T-shaped segments in the axial direction from one another after separation of the T-shaped segments, so that their tooth stems can be wound in a simple manner by means of coil wire, for example, enameled copper wire. Here, a plurality of T-shaped segments can also be wrapped, for example, by means of uninterrupted coil wire. The punched packaging structure is preferably configured as an elongated crimp, the longitudinal direction of which is particularly advantageously oriented along the magnetic field lines in the T-shaped segments.

[0011] The laminated core is particularly advantageously suitable for forming a stator composed of T-shaped individual segments, the tooth stems of which extend radially inward. After winding of the tooth stems, each T-shaped stator segment provides a separate stator pole, which acts together with the rotor as an internal rotor.

[0012] The winding of the T-shaped segments is preferably configured as a single tooth winding, which is energized in the control electronics of the electric machine. The single tooth coils can be connected in different ways to an electronically commutated electric motor.

[0013] By manufacturing the stator base body by means of the so-called "pre-cut" method, the advantages of the free access to the tooth stems being wound can be combined with the advantages of the stator yoke, leaving only minimal joining gaps between the individual T-shaped segments. Here, all the T-shaped metal sheets are separated from the only metal sheet layer almost simultaneously in a first step when stamping and are pressed back into the original position again in an axial direction in a second step. In the yoke region, a predefined breaking point is thus created at the separation site, wherein the individual T-shaped segments remain connected to one another as a stator base body over the entire circumference. When stamping, the individual metal sheet layers are preferably connected to one another in an axial direction by means of a stamping package. The individual T-shaped segments are separated from the stator base body shortly before the tooth stems are wound. After the tooth stems have been wound, the separated T-shaped segments are joined again into a circular ring in the original position, wherein the predefined breaking points are again abutted on one another exactly in the tangential direction.

[0014] By shaping the side of the connecting protrusion with an inner and / or outer circular arc segment, it is possible to prevent a bite between the connecting protrusion and the adjacent recess, if the T-shaped segments are tilted or rotated relative to one another when separating.

[0015] For separating the T-shaped segments, a separation wedge is introduced into the slots of the stator base body in an axial direction in a particularly simple manner. A tangential separation force is thereby promoted between the adjacent tooth segments, which promotes the separation of the tooth segments at the predefined breaking point. If the separation force promoted by the separation wedge deviates from the exact tangential direction, the T-shaped tooth segments are slightly tilted relative to one another, so that the yoke regions move away from one another more strongly at their outer circumference than at their inner diameter. This can occur, for example, if the separation wedge spreads the tooth stems more quickly or more intensively in the region of the tooth stem of the tooth stem than in the radially outer region of the tooth stem. However, due to the geometry of the connecting protrusion according to the application, this non-optimal separation force also does not lead to a deformation of the connecting protrusion or the corresponding receptacle.

[0016] It has proven to be particularly advantageous to arrange and configure the laminated core of the stator segment in the form of a T. This stator segment forms a single tooth segment in which, at the yoke region of the ring segment shape, exactly one tooth web extends radially. An electrical coil is wound onto this tooth web, which then forms a radially acting magnetic pole at the tooth shoe. The electrical coil is preferably configured as a single tooth coil, which is wound onto an insulating cover that is fitted onto the stator segment. A plurality of such T-shaped stator segments can be assembled to form a ring-closed stator, wherein the yoke regions respectively lie against one another in tangential direction. In the stator or in the rotor, as an alternative to the electrical windings, permanent magnets can also be arranged, wherein the laminated core then forms a magnetic ground for this purpose. The stator and / or the rotor formed from the laminated core can be configured as part of an electrical machine, in particular an electrical motor, with very great cost advantage. A plurality of T-shaped single tooth segments can be assembled, for example, as a stator, the electrical windings of which are commutated brushlessly. For this purpose, control electronics are preferably arranged above the stator segments in axial direction, by means of which the individual electrical coils are connected to one another. In this embodiment, a rotor can be arranged within the tooth neck, in which, for example, permanent magnets are arranged.

[0017] Embodiments of the present application are shown in the drawings and explained in greater detail in the following description. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic cross-sectional view of an electrical machine with a laminated core in the form of a T; and

[0019] Figure 2 is an enlarged view of a partial region of a laminated core according to the present application; and Figure 1

[0020] Figure 3 schematically shows the separation of two laminated cores. DETAILED DESCRIPTION

[0021] Figure 1 ​An electrically commutated motor 13 is shown as an electric machine 12 according to the application. The electric machine has a stator 14 with a stator base body 16 radially outward. The stator base body 16 is assembled from individual T-shaped segments 22, which have a yoke region 24 radially outward, from which tooth stems 26 extend radially inward. At the radially inward end of the tooth stems 26, tooth roots 28 are configured, which then form the magnetic poles of a rotor 15 that is to be supported radially in the stator 14. An insulating cover 56 is arranged on each T-shaped segment 22, which is then wound with an electrical winding 58. In this embodiment, each T-shaped segment 22 has a single tooth coil 59, which is connected to the control electronics of the electric machine 12 by means of a wiring device, not shown. Here, too, one or more T-shaped segments 22 can be wrapped, for example, with uninterrupted winding wire. The stator base body 16 is assembled from individual metal sheets 20, which are stacked one above the other in the axial direction. The individual T-shaped segments 22 thus each form a laminated core 10. A plurality of laminated cores 10, for example 12, form the stator base body 16 over the entire circumference, which is inserted, for example, into a motor housing, not shown. The individual metal sheets 20 are separated from one another by lateral boundary lines 40, which extend approximately radially 7 from the outer circumference 25 of the yoke region 24 to its inner diameter 23. At the first boundary line 40 of the T-shaped segment 22, a connecting projection 30 extends tangentially 9, which in the assembled state engages into a corresponding recess 31 of an adjacent T-shaped segment 22. Figure 2 An enlarged portion of the yoke region 24 with the connecting projection 30 is shown in Figure 1 The rotor 15 has a plurality of permanent magnets 60 in

[0022] In Figure 2The yoke region 24 of the lamination stack 10 has an outer circumference 25 and an inner diameter 23. Either the outer circumference 25 or the inner diameter 23 can have regions which differ from a circular arc. For example, axial grooves 68 or sinusoidal contours or flat faces 70 can be integrated. However, decisive for the arrangement and for the shape of the connecting projection 30 are the inner diameter 23 and the outer circumference 25 in the region of the yoke region 24 toward the lateral delimitation 40 of the adjacent lamination stack 10. The lateral delimitation 40 extends exactly along the radial direction 7 over a large portion of its extension. The connecting projection 30 extends from the lateral delimitation 40 in the tangential direction 9, where it engages into the corresponding recess 31 of the adjacent lamination stack 10, as is shown in Figure 1 The connecting projection 30 has a radially inner side 33 which is configured as an inner circular arc segment 35. The outer center 37 of this inner circular arc segment 35 is arranged with a radial spacing 47 within the outer circumference 25, in this special configuration in particular within the radial extension, that is to say, within the width 72 of the connecting projection 30. Furthermore, the outer center 37 is arranged at a tangential spacing 44 from the lateral delimitation 40. Here, the inner circular arc segment extends in the tangential direction 9 to the outer center 37 and then turns via a tangential transition region 74 into the lateral delimitation 40. The transition region 74 from the radially inner tooth side 33 to the lateral delimitation 40 can for example be configured as a radius in order to prevent a notch from being formed in the transition region 74.

[0023] In this embodiment, the radially outer side 34 of the connecting projection 30 is also configured as an outer circular segment 36. The inner center 38 of this circular segment is arranged at a radial spacing 48 outside the inner diameter 23 of the yoke region 24. In this particular embodiment, the inner center 38 is likewise arranged within the radial width 72 of the connecting projection 30. The radial center 38 likewise has a spacing 44 to the lateral boundary line 40, which corresponds to the spacing 44 between the outer center 37 and the lateral boundary line 40. In the embodiment shown, the outer circular segment 36 is configured symmetrically to the inner circular segment 35. The plane of symmetry is formed here by a center line 75 through the connecting projection 30 in the tangential direction 9. The outer circular segment 36 is also connected to the lateral boundary line 40 by a tangential transition region 74. The connecting projection 30 has a flat face 42 at its tangential end, which extends approximately in the radial direction 7 and thus parallel to the lateral boundary line 40. The connecting projection 30 is arranged at a radial center of the yoke region 24 between the outer circumference 25 and the radial outer side 34 at a radial spacing 50. The spacing 50 has, for example, the same size as the radial width 72 or the tangential height 71 of the connecting projection 30. The radial spacing 51 between the inner diameter 23 and the radial inner side 33 is correspondingly configured, in particular, to be greater than the outer spacing 50. The radial spacing 52 between the inner center 38 and the outer center 37 can be, in particular, 30% to 90% of the radial width 72 of the connecting projection 30, but can also be greater than the radial width 72. The corresponding recess 31 of an adjacent lamination 10 or at the opposing lateral boundary line 40 of the same lamination 10 in the tangential direction 9 has a corresponding geometry to this connecting projection 30. The lateral boundary line 40 of the connecting projection 30 and the opposing recess 31 is manufactured here with a uniform stamping edge. Here, each individual sheet metal 20 at the yoke region 24 is separated in the axial direction in a first step by means of this stamping edge according to the pre-cut method and is pressed back into the original position in a second step in order to form the intended breaking point. Thereby, a closed stator base body 16 is produced over the entire circumference, which is separated only after the winding of the individual T-shaped segments 22.

[0024] In Figure 3This separation process is shown in Fig. 1 with the aid of two laminations 10. The lateral delimitation 40 of the connecting projection 30 and the counter- recess 31 is also configured as a connection structure of the two yoke regions 24 as a rated breaking point. In order to separate the two laminations 10, a separating wedge 92 is pressed into the stator slot 90 between the two tooth stems 26 in the axial direction. This separating wedge 92 generates a separating force between the two yoke regions 24, by which the rated breaking point is separated. The ideal separating force 94 is oriented here exactly in the tangential direction 9 and thus perpendicular to the radial delimitation 40. The connecting projection 30 can be released from the recess 31 without deformation by this ideal separating force 94. But if an inclined moment 96 is generated around the point of inclination 97 at the outer circumference 25 by the separating wedge 92, then in principle an inclination of the connecting projection 30 and / or the recess 31 results in the inclination. In the shown schematic position of the separating wedge 92 in the stator slot 90 it can be seen that the separating wedge 92 presses the tooth stems 26 away from one another more strongly in the region of the tooth roots 28 than at the yoke regions 24. In this case an extended, largely unavoidable inclined moment 96 is thus generated, which does not result in a destructive deformation of the connecting projection 30 due to the geometry according to the invention. It is likewise theoretically possible that a compressive inclined moment 98 is generated around the inner point of inclination 99 at the inner diameter 23 during the separation process. But by the geometry according to the invention of the circular-arc segments 35, 36 at the lateral sides 33, 34 of the connecting projection 30, a deformation of the connecting projection 30 and / or the recess 31 can also be prevented in the case of such undesired occurrence of the inclined moments 96, 98. After the separation of the laminations 20, these are wound with electrical windings 58 and are then again pressed together in their uniform position in the tangential direction 9. The rated breaking point is thus joined together again, so that the joint gap between the individual laminations 10 is minimized. In Figure 3 A stamping packaging structure 88 is shown in Fig. 2, by which the individual laminations 20 are connected to one another in the axial direction. The stamping packaging structure 88 is arranged in the radial direction 7 for example with its longitudinal extension in the tooth stem 26. Two further stamping packaging structures 88 are arranged in the yoke regions 24, respectively, wherein their longitudinal direction forms an angle with the tangential direction 9 and is ideally oriented along the occurring magnetic field lines.

[0025] It is to be noted that, as far as the embodiments shown in the drawings and the description are concerned, a multiplicity of combination possibilities of the individual features with respect to one another is possible. Thus, for example, the specific contour of the individual laminated cores 20, the arrangement and number of the tooth flanks 26 and the configuration of the yoke regions 24 can be changed accordingly. Likewise, the inner circular arc section 35 can also be configured without the formation of an outer circular arc section 36, or the contour of the inner side 33 can differ from the contour of the outer side 34. The radial position and size of the connecting protrusion 30 can also be adapted to the requirements of the electric machine 12 and the production possibilities thereof. The application is particularly suitable for the rotational drive of components or for the adjustment of parts in motor vehicles, but is not limited to this application.

Claims

1. Lamination core (10) for forming a magnetic pole of an electrical machine (12), with individual metal sheets (20) which are stacked on top of one another in an axial direction, the metal sheets forming T-shaped segments (22) with a radially outer yoke region (24) with an outer circumference (25) and a tooth stem (26) which projects radially inwards, wherein At the yoke region (24), the sheet metal (20) has a connecting protrusion (30) along the tangential direction (9) at the first side (18) and a corresponding recess (31) for the connecting protrusion (30) oppositely along the tangential direction at the second side (19), wherein at least at a radially inner side (33) of the connecting protrusion (30) an inner circular arc segment (35) is configured, an outer center (37) of which is located radially within the yoke region (24) at a radial spacing (47) from the outer circumference (25), wherein at the first side (18) where the connecting protrusion (30) is arranged a lateral delimitation (40) is configured, which extends along the radial direction (7) over a large part of its radial extension and whose outer center (37) of the inner circular arc segment (35) is arranged along the tangential direction (9) at a spacing (44) from the delimitation (40) in the direction of the connecting protrusion (30), and wherein the inner circular arc segment (35) extends along the tangential direction (9) to the outer center (37) and then turns away from the outer center (37) to the lateral delimitation (40) via a tangential transition region (74).

2. The lamination core (10) according to claim 1, characterized in that The laminated core (10) is configured for forming a stator (14) of an electric machine (12).

3. The lamination core (10) according to claim 1, characterized in that The spacing (44) between the lateral radial delimitation (40) and the outer center (37) along the tangential direction (9) is 0.05 mm to 1.0 mm.

4. The lamination core (10) according to claim 3, characterized in that The spacing (44) between the lateral radial delimitation (40) and the outer center (37) along the tangential direction (9) is 0.05 mm to 0.3 mm.

5. The lamination core (10) according to any one of claims 1 to 4, characterized in that The outer center (37) is arranged in a region within the connecting protrusion (30) with respect to the radial direction (7).

6. The lamination stack (10) according to claim 3 or 4, characterized in that At a radially outer side (34) of the connecting protrusion (30) an outer circular arc segment (36) is configured, an inner center (38) of which is located radially outside the inner diameter (23) of the yoke region (24).

7. The lamination stack (10) according to claim 6, characterized in that The inner center (38) is arranged along the tangential direction (9) at a spacing from the delimitation (40) in the direction of the connecting protrusion (30), wherein the inner center (38) is arranged radially in a region within the connecting protrusion (30) and the outer circular arc segment (36) is configured mirror-symmetrically with respect to the radial direction (7) to the inner circular arc segment (35).

8. The lamination core (10) according to any one of claims 1 to 4, characterized in that A tangential tip of the connecting protrusion (30) is configured flattened and has a flat face (42) along the radial direction (7).

9. The lamination core (10) according to claim 6, characterized in that Between the inner and / or outer circular arc segment (35, 36) and the lateral radial delimitation (40) a transition region (74) is configured, wherein an extension length of the transition region (74) corresponds to the tangential spacing (44) of the inner and / or outer center (38, 37) from the lateral radial delimitation (40) along the tangential direction (9).

10. The lamination stack (10) according to claim 6, characterized in that The connecting projection (30) is arranged outside the radial center of the lateral delimitation (40) and the spacing (50) between the radially outer side (34) and the outer circumference (25) of the yoke region (24) corresponds to the tangential height (71) or the radial width (72) of the connecting projection (30).

11. The lamination core (10) according to any one of claims 1 to 4, characterized in that The individual sheet metal pieces (20) are connected to one another in the axial direction by means of the stamped encapsulation (88), wherein the first stamped encapsulation (88) in the tooth stem (26) and one or two further stamped encapsulations (88) are symmetrically configured in the yoke region (26).

12. Stator (14) or rotor (15), characterized in that The stator or rotor is assembled from a plurality of the sheet metal core (10) according to any one of the preceding claims and the tooth stems (26) are wound with electrical windings (58) to form magnetic poles.

13. Electric machine (12) with a stator (14) or a rotor (15) according to claim 12, wherein The electric machine (12) is assembled from sheet metal cores (10) each configured as a T segment (22) and the electrical windings (58) of each T segment (22) are configured to be electronically commutated by means of control electronics.

14. Method for manufacturing a stator base (16), characterized in that The following method steps: - stamping all of the sheet metal pieces (20) of a single sheet layer (21) by means of a pre-cut technique such that the T segments (22) of each sheet layer (21) remain connected to one another by means of a rated breaking point, - wherein all of the T segments (22) of each sheet layer (21) are first stamped in a full-cut technique similar to the stator device and then almost completely separated from one another in a further stamping step and are pressed back into the original position again in a further step, so that the individual T segments are only still connected to one another by a small plastic deformation, - stacking and connecting a plurality of sheet layers (21) into a stator base body (16) in the axial direction by means of stamped encapsulations (88), - separating the stator base body (16) into individual sheet metal cores (10) according to any one of claims 1 to 11 and winding the tooth stems (26) of the sheet metal cores, - and then joining the sheet metal cores (10) into a stator base body (16) exactly as before by means of the rated breaking point.

15. The method of claim 14, wherein, - and in the separation into T segments (22), the connecting projection (30) is released from the recess (31) without the inner and / or outer circular arc segments (35, 36) being deformed. The T segments (22) are separated from the stator base body (16) by means of a separation wedge (92) which is pressed in between the tooth stems (26) in the axial direction at two opposite axial end sides.

16. The method according to claim 14 or 15, characterized in that The connecting projection (30) is arranged outside the radial center of the lateral delimitation (40) and the spacing (50) between the radially outer side (34) and the outer circumference (25) of the yoke region (24) corresponds to the tangential height (71) or the radial width (72) of the connecting projection (30). The individual sheet metal pieces (20) are connected to one another in the axial direction by means of the stamped encapsulation (88), wherein the first stamped encapsulation (88) in the tooth stem (26) and one or two further stamped encapsulations (88) are symmetrically configured in the yoke region (26). The stator or rotor is assembled from a plurality of the sheet metal core (10) according to any one of the preceding claims and the tooth stems (26) are wound with electrical windings (58) to form magnetic poles. The electric machine (12) is assembled from sheet metal cores (10) each configured as a T segment (22) and the electrical windings (58) of each T segment (22) are configured to be electronically commutated by means of control electronics. The following method steps: - stamping all of the sheet metal pieces (20) of a single sheet layer (21) by means of a pre-cut technique such that the T segments (22) of each sheet layer (21) remain connected to one another by means of a rated breaking point, - wherein all of the T segments (22) of each sheet layer (21) are first stamped in a full-cut technique similar to the stator device and then almost completely separated from one another in a further stamping step and are pressed back into the original position again in a further step, so that the individual T segments are only still connected to one another by a small plastic deformation, - stacking and connecting a plurality of sheet layers (21) into a stator base body (16) in the axial direction by means of stamped encapsulations (88), - separating the stator base body (16) into individual sheet metal cores (10) according to any one of claims 1 to 11 and winding the tooth stems (26) of the sheet metal cores, - and then joining the sheet metal cores (10) into a stator base body (16) exactly as before by means of the rated breaking point.

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