DE102021202679A1 - Stator base body for an electrical machine, and an electrical machine having a stator base body, and method for producing a stator base body - Google Patents

Abstract

Stator base body (16) for forming magnetic poles of an electrical machine (12), and a method for producing a stator base body (16) with individual laminations (20) stacked axially on top of one another, which form T-shaped segments (22) that have a radially outer Jochbereich (24) and a radially inwardly projecting toothed shaft (26), wherein on the yoke area (24) the T-shaped segments (22) on a first side (18) in the tangential direction (9) a connecting lug (30) and on a second side (19) have a corresponding recess (31) for a connecting lug (30) tangentially opposite, wherein between the T-shaped segments (22) of each lamella layer (21) radial separating lines (40) are formed by means of precut technology, which are between the connecting lugs (30) and the corresponding recesses (31), the yoke areas (24) forming an outer circumference (25) of the stator base body (16), which in first tangential areas (81) of the tooth shaft (26) has flattened sections (3) and in second tangential areas (82) between the flattened sections (83) circular sections (84).

Description

The invention relates to a stator base body for an electrical machine, and an electrical machine having a stator base body, and a method for producing a stator base body according to the species of the independent claims.

State of the art

With the DE 10 2019 206 512 A1 a stator of an electrical machine has become known which has, for example, six stator segments with a central region of the stator yoke running in a straight line. This is intended to save material during production. The radial stator teeth are here arranged as separately formed components in the circumferential direction between the rectilinear yoke areas. Due to the separate design of the stator teeth, the magnetic yoke and thus the cogging torque of such an electric motor is very limited.

From the EP 3 343 734 A1 an EC motor is known in which the stator base body is manufactured using precut technology. In this case, the stator has an outer circumference which is round over the circumference and which can be inserted into a cylindrical motor housing. The disadvantage of this design is that such a geometry requires a relatively large installation space for the electric motor, which is not available in certain applications, such as for adjustment drives in motor vehicles. This disadvantage is to be remedied by the solution according to the invention, with the magnetic flux losses in the yoke area of the disk packs being intended to be minimized.

Disclosure of Invention

Advantages of the Invention

The device according to the invention and the method according to the invention with the features of the independent claims has the advantage that the formation of the flattened sections on the outer circumference of the stator base body means that the electric machine can also be installed in smaller installation spaces, such as a side door or in the sunroof of the motor vehicle. The flattened sections are preferably designed as flat surfaces on the outer circumference of the stator. In order to be able to disassemble the basic stator body into individual T-shaped stator segments using the so-called precut technique, circular sections are also formed on the outer circumference of the basic stator body in addition to the flattened sections, by means of which the T-segments can be reassembled to form the stator after winding. These outer diameter circular portions are formed in each T-segment on either side of the central flattened portion so that the tangential ends of the yoke portions of two adjacent T-segments are rejoined via the circular portions just at the parting line. A connecting lug with a corresponding recess can be formed on the dividing line, for example, or the yoke areas can alternatively have a relatively flat radial dividing line.

Advantageous further developments and improvements of the embodiments specified in the independent claims are possible as a result of the measures listed in the dependent claims. In order to keep the width across flats of the stator as small as possible, the radial width of the yoke area at its central area with respect to the circumferential direction at the flattened sections is made smaller than the radial width in the area of the tangential ends of the yoke area, where it is circular on its outer diameter . As a result, on the one hand sufficient material is made available at the tangential ends of the yoke areas in the radial direction for forming the separating line using the precut technique, and on the other hand the yoke area is formed on the flattened section with a smaller overall diameter of the stator. The smallest radial dimension of the yoke area is in particular directly on the peripheral area of the stator tooth, or directly adjacent to the tooth shaft.

The radial width of the yoke area in the flattened area can be reduced compared to the circular sections to such an extent that the radial width of the yoke area is approximately half the size of the tangential dimension of the tooth shank. This still ensures a sufficiently large magnetic flux from the toothed shaft into the two yoke areas, and on the other hand a reliable precut connection with the connecting lug and the recess between the individual yoke segments can be formed.

On the one hand, to ensure that the individual T-shaped laminations hold together before the stator is wound and, on the other hand, to be able to be separated for winding with little force, a connecting lug on one tangential end of the yoke area engages in a corresponding recess on the opposite tangential end of the adjacent one T segment. The dimensions of the connecting nose of the precut geometry are approximately the same in the radial direction and in the tangential direction. The same naturally applies to the corresponding recess at the tangential end of the yoke range, which also has approximately the same dimension in the radial direction and tangential direction. In order to make the precut connection mechanically stable enough, the connecting lug and the corresponding recess are preferably formed approximately in the middle on the dividing line with respect to the radial direction.

To form the precut parting line, the radial diameter of the stator is slightly reduced in the area where the parting line meets the outer circumference radially compared to the circular sections. As a result, the lamellar plate can be stamped and then compressed again without the outer circumference increasing at this point as a result of the forming process. The peripheral area of the reduced stator diameter extends in particular over the tangential area from the intersection of the dividing line with the outer circumference and the so-called buckling line with the outer circumference. The buckling line extends in the radial direction at a tangential distance from the dividing line. On the outer circumference, this tangential distance is preferably at least the dimension of the sheet metal thickness—and is formed in particular on the tangential side of the yoke area with the connecting lug. The circular outer circumference of the stator then extends, starting from the parting line in the tangential direction to the nearest flattened section, and also starting from the buckling line in the opposite circumferential direction to the tangentially opposite flattened section of the outer circumference. This ensures that in the area of the dividing line and the buckling line there is no radial bulging on the outer circumference due to the material deformation of the T-segments when the dividing line is formed, which would protrude beyond the diameter of the circular sections of the stator.

In order to position two adjacent T-segments precisely relative to one another, flanks are formed radially on the outside and inside of the connecting lug, which run approximately in the tangential direction. These tangential flanks rest radially on corresponding mating contact surfaces of the opposite recess of the adjacent T-segment. These tangential flank areas are advantageously formed over a tangential extension of 0.1 to 0.4 mm, so that a sufficiently stable guidance of the connecting lug of the first T-segment is ensured in the recess of the second T-segment.

A start angle of about 30° to 50° is formed radially on the outside and inside along the separating line on the connecting lug, starting from its tangential tip . With this design, the connecting lug can be detached from the recess of the corresponding T-segment with little effort in order to separate the T-segments.

In order to connect the individual lamina layers to one another axially, they are connected to one another axially in a particularly simple manner by means of so-called stamped packets. These stamped packages are, for example, circular, or also oval or elongated, and are arranged in the area of the radial center line of the toothed shaft. In particular, a first stamped package is arranged radially in the yoke area and a second stamped package is arranged radially in the tooth base area. It is particularly favorable if an end lamella has perforations in which the material is completely removed within the perforated pack and material of the axially adjacent lamellar layer is pressed plastically into this perforation in the axial direction. In order to ensure sufficient plastic deformation of the stamped package, the sheet metal laminations are approximately 0.4 to 0.7 mm thick.

The stator base body, stamped using pre-cut technology, can advantageously be transported as a single part as a whole. For winding, the individual T-shaped laminations are separated from one another in the tangential direction so that the tooth shaft is freely accessible for winding a single-tooth coil. After winding the individual T-shaped laminations, they are joined together again in exactly the same arrangement, so that the yoke areas interlock at the dividing lines. The ready-wound T-shaped plate packs can also be joined so closely together in the area of the tooth base that the slot opening between two adjacent tooth bases is only a factor of 0.5 to 1.0 of the sheet metal thickness. As a result, a very high copper fill factor can be achieved, as a result of which the power density of such an electronically commutated machine can be increased.

Due to the formation of the flattened areas of the outer circumference of the stator body, a stator base body with exactly six stator teeth with a very small width across flats can be produced very advantageously. In this case, two flattened--in particular flat--areas are diametrically opposite one another, so that they run approximately parallel to one another. In this embodiment with exactly six--or alternatively exactly twelve--stator teeth, the diameter of the stator base body can be reduced on both radially opposite sides by the flattened sections compared to a circular circumference. The flattened portions can also be formed on a three or nine tooth stator to reduce the stator diameter. Here, however, the flattened areas are not exactly diametrically opposed.

The wound stator base body is advantageously designed as part of an electrical machine in which a rotor is rotatably mounted radially inside the stator base body. When the stator base body is stamped, laminated layers for the rotor base body can be stamped out particularly favorably at the same time radially within the individual stator segments, so that the sheet metal waste is significantly reduced. Permanent magnets are arranged in the basic rotor body and are preferably fastened to the surface of the basic rotor body.

To manufacture the stator, the individual layers of laminations are first punched out, with the T-shaped segments remaining connected to one another in the tangential direction using the pre-cut technique or the Kiri-Make method. With the precut technique, the individual T-segments are only punched through up to a certain fraction (1/2 to 7/8) and then pressed back into the starting position in the axial direction. The material tears between two T-segments along the dividing line and claws plastically into their coarse "fracture structure" when pushed back. As a result, the T-shaped segments remain connected to one another in the circumferential direction, despite being completely separated, via a plastic material deformation at the predetermined breaking point. The individual layers of lamellae are connected to one another in the axial direction, preferably by means of stamped stacking. To make the stator teeth more accessible for winding, the stator base body, which is closed in the circumferential direction, is separated between the individual T-shaped stator segments at the predetermined breaking point. After that, insulating masks can be placed axially onto the stator segments and wound with a single-tooth coil in a particularly favorable manner. After winding, the individual T-shaped stator segments are reassembled at their predetermined breaking points in the way they were arranged before they were separated. For this purpose, the individual T-segments are marked, for example, in particular numbered consecutively.

In order to save installation space when installing the electrical machine, the stator segments are stamped out on their outer circumference in such a way that they have a radial flattening in the circumferential area of the stator tooth. In the area of the two opposite tangential ends of the yoke area, the outer circumference is circular, so that the radial dimension in the area of the dividing line between the two adjacent T-segments is also larger than in the flattened sections of the yoke area.

To separate the T-shaped stator segments from the stator body, wedges can be pressed between the stator teeth in the axial direction. In order to reassemble the individual T-shaped stator segments to form the stator after they have been wound, the T-shaped segments are inserted axially into a round, funnel-shaped assembly tool so that the yoke areas are pressed radially at their circular sections by the assembly tool towards the center of the stator, whereby the individual T-segments are also joined together again in the circumferential direction at the predetermined breaking points. The circular sections allow the T-segments to be joined together in the round assembly tool by means of the archway effect, so that the wound T-segments are again precisely positioned with respect to one another.

By manufacturing a stator body using the so-called "precut" process, the advantages of a freely accessible toothed shaft to be wound can be combined with the advantages of a stator yoke, between whose individual T-segments only a minimal joint gap remains. In the precut manufacturing process, the individual layers of laminations are punched out in a quasi full cut with predefined predetermined breaking points between the individual T-segments. The individual T-segments are separated from the stator body so that their tooth shafts can be better wound. As a result, a higher slot fill factor can be achieved, which increases the efficiency of the electrical machine. When punching the sheet metal laminations, the individual T-segments are connected to the axially adjacent sheet metal laminations in a particularly advantageous manner in one operation by means of punched packs. This eliminates an additional connection process between the axially layered laminations. The stamped packs reliably hold the sheet metal lamellae of the individual T-segments together axially after they have been separated, so that their toothed shanks can easily be wound with a coil wire, for example enamelled copper wire.

character list

Embodiments of the invention are shown in the drawings and explained in more detail in the following description.

• 1 schematisch einen Querschnitt durch eine elektrische Maschine, mit T-förmigen Lamellenpaketen,
• 2 eine weitere Ausführung eines unbewickelten Statorgundkörpers,
• 3 ein vereinzeltes T-förmiges Statorsegment gemäß 2, und
• 4 eine vergrößerte Darstellung einer weiteren Ausführung eines Jochbereichs.

Show it:

• 1 a schematic cross-section through an electrical machine with T-shaped laminations,
• 2 another version of an unwound stator body,
• 3 according to an isolated T-shaped stator segment 2 , and
• 4 an enlarged view of another embodiment of a yoke area.

1 12 shows an electrically commutated motor 13 as the electrical machine 12 according to the invention. The electrical machine 12 has a stator 14 with a stator base body 16 radially on the outside. The stator base body 16 is composed of individual T-shaped laminated cores 10 which have a yoke area 24 radially on the outside, from which a tooth 17 with a toothed shaft 26 extends radially inward. At the radially inner end of the tooth shafts 26 tooth roots 28 are formed, which then form the magnetic poles for the rotor 15 mounted radially inside the stator 14 . Insulating masks 56 are arranged on each of the T-shaped laminated cores 10 and an electrical winding 58 is then wrapped around them. In this exemplary embodiment, each laminated core 10 has a single-tooth coil 59, which is connected to control electronics of the electrical machine 12 via a wiring arrangement that is not shown. In this case, for example, two—or more—lamella packs 10 can be wound through with an uninterrupted winding wire. The stator base body 16 is composed of individual laminations 20 which are stacked axially one on top of the other. The individual disk packs 10 are composed of a plurality of T-shaped segments 22 of the individual disk layers 21 stacked axially one on top of the other. Several disk packs 10 (for example 12 pieces) form the stator base body 16 over the entire circumference, which is used, for example, in a motor housing (not shown). The rotor 15 in 1 has a plurality of permanent magnets 60 which are accommodated in a basic rotor body 62 . The permanent magnets 60 are arranged here, for example, on the radial surface of the rotor base body 62 . In the tangential direction 9 between the permanent magnets 60 , holding webs 64 are formed here on the basic rotor body 62 , which separate the permanent magnets 60 , which are preferably magnetized in the radial direction 7 , from one another in the circumferential direction 9 . In the exemplary embodiment, the permanent magnets 60 are designed in the shape of a loaf of bread, so that the outer circumference 66 of the rotor 15 is designed to be approximately circular. In particular, eight permanent magnets 60 are arranged on the rotor 15, which interact with the twelve stator poles formed by the T-shaped laminated cores 10. In alternative designs, 6/4 or 3/2 or 9/6 or 12/10 motor topologies are used. The individual laminations 20 of each lamina layer 21 are separated from one another by lateral separating lines 40 which extend approximately in the radial direction 7 from the outer circumference 25 of the yoke area 24 to its inner diameter 23 . In this embodiment, a connecting lug 30 extends on the dividing line 40 of the T-segment 22 in the tangential direction 9 on a first side 18 and engages in a corresponding recess 31 on a second side 19 of an adjacent T-segment 22 in the assembled state. An enlarged part of the yoke area 24 with the connecting lug 30 and its specific geometry is shown in 4 shown. The dividing line 40 between the individual T-shaped segments 22 of a layer of lamellae 21 is produced by means of what is known as the pre-cut technique (or kiri-make). The individual T-segments 22 are not completely separated from one another axially from a sheet metal lamella 20 that is closed over the entire circumference in a first step using a punching tool, and a second step to form a predetermined breaking point between the T-segments 22 is axially returned to the original position pushed back. This results in a stator base body 16 which is closed over the entire circumference and which is only separated for the winding of the individual T-shaped laminated cores 10 . The recess 31 has a geometry corresponding to the opposite connecting lug 30 , between which the dividing line 40 of the two opposite T-segments 22 in the tangential direction 9 runs in the radial direction 7 . The connecting lug 30 and the opposite recess 31 are produced in the same process step using the identical punching edge of the punching tool. During the stamping process, the outer circumference 25 of the stator base body 16 is completely severed, with the individual T-segments 22 remaining connected in the circumferential direction 9 via the predetermined breaking point of the separating line 40 . At least one flattened section 83 is punched out in a first tangential area 81 on the outer circumference 25 of the yoke areas 24 and covers the toothed shaft 26 in the circumferential direction 9 . Circular sections 84 of the outer circumference 25 are punched out on both sides of the T-segment 22 in each case adjacent to the flattened section 83 . In order to reassemble the individual disk packs 10 to form the stator 14 after winding, they are inserted axially into an assembly tool 100 which is cylindrical and conical. The circular sections 84 of the yoke areas 24 bear radially against the assembly tool 100 and are pressed radially towards one another, so that the disk packs 10 are positioned exactly towards one another via the archway effect. The outer diameter for such a stator base body 16 is, for example, 25-60 mm.

In 2 an unwound stator base body 16 with exactly six T-shaped segments 22 in a laminated layer 21 is shown schematically. Each T-segment has a flattened area in the center in the circumferential direction 9 82 on the outer circumference 25. Circular sections 84 are then formed on each T-segment 22 towards the two tangential ends 18, 19 of the yoke area 24. FIG. As a result, flattened sections 83 alternate with circular sections 84 over the circumference of the stator base body 16 . The latter are formed here in the area of the transition from two adjacent T-segments 22 . That is, the circular sections 84 are each arranged between two adjoining flattened sections 83a, 83b of two different T-segments 22. In the transition area 38 between two adjacent T-shaped segments 22, a so-called crease line 41 is formed by the precut method next to the dividing line 40, which is produced by the plastic reshaping (push-back) after the incomplete punching. The buckling line 41 is formed on the outer circumference 25 at a tangential distance 39 from the dividing line 40 which corresponds to at least a sheet metal thickness 87 of the laminated layer 21 . The buckling line 41 is preferably formed in the first side 18 of the yoke area, on which the connecting lug 30 is formed. Between the dividing line 40 and the buckling line 41, the outer circumference 25—in contrast to the circular section 84—preferably has a reduced radius 44 so that the diameter of the outer circumference 25 is not increased when the dividing line 40 is formed. That is, the circular portion 84 extending from one T-segment 22 to the adjacent T-segment 22 may be interrupted at the parting line 40 by a very small peripheral region 38 having the reduced radius 44. Due to the flattened sections 83, a radial dimension 85 of the flattened yoke areas 24 is smaller than a radial dimension 86 of the circular yoke areas 24 at their tangential ends 18, 19. The inner diameter 23 of the yoke areas 24, on the other hand, is preferably approximately constant with the exception of the tooth shanks 26. As a result, more radial space is available at the tangential ends 18, 19 of the T-segments for the formation of the separating line 40 with the connecting lug 30 and the corresponding recess 31. In particular, the radial dimension 86 of the circular sections 84 is larger than would be necessary for the magnetic circuit design, since the smaller radial dimension 85 of the flattened sections 83 immediately adjacent to the toothed shaft 26 form the bottlenecks for the magnetic flux. Since the individual disk packs 10 can be wound freely in the precut technique, the tangential distance 29 between two adjacent tooth bases 28 can be made very small, so that it is in the range of 0.3 to 1.0 mm, for example. In 2 only the uppermost layer of laminations 20a is shown schematically in the lamellar packets 10 with the marking 80 “3” and “4”, in which only punched holes 89 are formed as punched packets 56, 88. All other disk layers 20b are also shown for the disk packs 10 "2, 1, 6, 5", with the top disk layer 20a being missing in the disk pack 10 "2". As a result, in the transition from disk pack 10 “2” to “3”, the dividing line 40 is shown schematically completely separated—as is the case after the disk packs 10 have been separated before they are wound.

Such an isolated plate pack 10 with the marking "1". 2 is in 3 pictured. The T-shaped segments 22 of the individual lamellar layers 21 are held together axially by means of the stamped packages 54, 88. The punched packs 54, 88 are particularly circular here, with circular punched holes 89 being punched out in the uppermost sheet metal lamina 20a, into which the material of the sheet metal lamina 20b of the lamina layer 21 lying underneath is plastically pressed. A first stamped packet 54 is formed, for example, in the center of the tooth base 28 , with a second stamped packet 88 being formed tangentially in the center of the yoke area 24 . In order to separate two adjacent disk packs 10 of the stator base body 16 , at least one separating wedge is preferably pressed axially into a stator slot 90 between the two toothed shafts 26 . This separating wedge generates a separating force between the two yoke areas 24, which separates the predetermined breaking point. An ideal separating force is aligned exactly in the tangential direction 9 and thus perpendicular to the radial separating line 40 . This ideal separating force enables the connecting lug 30 to be released from the recess 31 without being deformed. After the laminations 10 have been separated, the insulating masks 56 are placed on them and then wound as a single-tooth coil 59 . The markings 80 on the end face—or also the DMC fields 79 attached to the outer circumference 25 for data transmission—serve to ensure that the disk packs 10 are reassembled after the winding in exactly the same arrangement as before the separation. As a result, the individual “break-off structure” of each predetermined breaking point comes together again, as a result of which the cogging torque of the electrical machine 12 is optimized. At the first tangential end 18 of the yoke area 24 the connecting lug 30 is formed, which again engages in the recess 30 of the disk pack 10 “6” after assembly. At the opposite, second tangential end 19, the recess 31 is formed in the yoke area 24, into which the connecting lug 30 of the adjacent disk pack 10 "2" then engages again. It can be seen again that the two tangential ends 18, 19 of the yoke area 24 have a greater radial extension 86 of the yoke area 24 at the circular sections 84 than the radial extension 85 at the flattened sections 83 of the yoke area 24.

A geometry of a parting line 40 is enlarged based on a further embodiment in FIG 4 is shown. The yoke area 24 of a T-shaped segment 22 (and thus also of the disk pack 10) has an outer circumference 25 and an inner diameter 23. FIG. The outer circumference 25 is designed as a circular section 84 towards the parting line 40 . Both the outer circumference 25 and the inner diameter 23 can have small areas that deviate from an arc of a circle. For example, a region 39 between the dividing line 40 and the fold line 41 is again drawn in, at which the radius 44 is slightly reduced compared to the circular section 84 . The inner diameter 23 and the outer circumference 25 in the tangential peripheral area of the separating line 40 are decisive for the formation and the "punchability" of the connecting lug 30. The separating line 40 runs over most of it in a radial extension 76 in the radial direction 7. The separating line 40 extends in the area the connecting lug 30 in the tangential direction 9, where it also forms the corresponding recess 31 of the adjacent disk pack 10 - as in 1 is shown. The connecting lug 30 has an inner flank 33 and an outer flank 34 which each extend approximately in the tangential direction 9 over a certain area (eg 0.1-0.4 mm). The inner and outer flanks 33, 34 merge via a tangential transition region 74 into the radial extension 76 of the dividing line 40, where this meets the outer circumference 25 approximately perpendicularly. The transition region 74 from the inner and outer flanks 33, 34 to the radial extension 76 of the dividing line 40 can be designed as a radius, for example, in order to prevent notch formation in the transition region 74. At its tangential end 42 , the connecting lug 30 has in particular a flat surface which extends over a short plateau region 46 approximately in the radial direction 7 - and thus parallel to the radial extension 76 of the dividing line 40 . The tangential end 42 of the connecting nose 30 transitions into the inner and outer flanks 33, 34 of the connecting nose 30 at a starting angle 43 of a nose radius 49 of 20°-50°, in particular 30°-40°. The inner and outer flanks 33, 34 are in direct radial contact with opposing counter flanks 35, 36 after the wound disk packs 10 have been assembled, as a result of which the adjacent T-segments 22 are adjusted to one another. The connecting lug 30 is arranged approximately radially centrally between the outer circumference 25 and the inner diameter 23 of the yoke area 24 . For example, the distance 50 of the inner and outer flanks 33, 34 to the inner diameter 23 and the outer circumference 25 is approximately the same dimension as a radial width 72 or a tangential height 71 of the connecting lug 30. The radial width 72 and the tangential height 71 of the connecting lug 30 are preferably about the same size and are in particular about one third of the radial dimension 86 of the circular sections 84 of the yoke area 24. The radial dimension 86 of the yoke area 24 on the circular section 84 adjacent to the dividing line 40 is again larger than the radial dimension 85 of the yoke portion 24 at the flattened portion 83 toward the tooth shank 26.

It should be noted that with regard to the exemplary embodiments shown in the figures and in the description, a wide variety of possible combinations of the individual features are possible. For example, the specific contour of the individual T-shaped segments 22, the arrangement and number of the tooth shafts 26, and the design of the yoke areas 24 can be varied accordingly. Likewise, the specific arrangement and design of the flattened and circular sections 83, 84 on the outer circumference 25 can be adapted to the available installation space and to the assembly tool 100. The shape and dimensions of the connecting lug 30 can also be adapted to the requirements of the electrical machine 12 and its production possibilities. The invention is particularly suitable for the rotary drive of components or for the adjustment of parts in a motor vehicle, but is not limited to this application. Because of the flattened sections 83, small motors with a high power density can also be made available.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102019206512 A1 [0002]
• EP 3343734 A1 [0003]

Claims (15)

Stator base body (16) for forming magnetic poles of an electrical machine (12), with individual laminations (20) stacked axially on top of one another, which form T-shaped segments (22), which have a radially outer yoke area (24) and a radially inwardly projecting toothed shank (26), and between the T-shaped segments (22) of each lamellar layer (21) radial dividing lines (40) are formed by means of precut technology, which run between two adjacent yoke areas (24), the yoke areas (24) having an outer periphery (25) of the stator base body (16), which has flattened sections (83) in first tangential areas (81) of the toothed shaft (26) and circular sections (84) in second tangential areas (82) between the flattened sections (83). Stator body (16) after claim 1 , characterized in that the radial dimension (85) of the yoke areas (24) at the flattened sections (83) on the tooth shaft (26) is smaller than the radial dimension (86) of the yoke areas (24) at the circular sections (84) , which are formed towards the radial parting lines (40) - and in particular the yoke region (24) immediately adjacent to the toothed shaft (26) has a minimum radial dimension (85). Stator body (16) after claim 1 or 2 , characterized in that the minimum radial dimension (85) of the yoke area (24) directly next to the toothed shaft (26) corresponds to approximately half the width (27) of the toothed shaft (26) in the tangential direction (9). Stator base body (16) according to one of the preceding claims, characterized in that on the yoke area (24) on a first side (18) in the tangential direction (9) there is a connecting lug (30) and on a second side (19) tangentially opposite a corresponding recess ( 31) for the connecting lug (30), the separating lines (40) running in the radial direction (7) between the connecting lugs (30) and the corresponding recesses (31), with the connecting lug (30) in particular having a tangential extension (71) which corresponds approximately to the radial extent (72) of the connecting lug (30), and preferably the connecting lug (30) and the corresponding recess (31) are arranged approximately radially centrally in the yoke area (24). Stator base body (16) according to one of the preceding claims, characterized in that the dividing line (40) meets the outer circumference (25) radially on the outside approximately perpendicularly, and by the precut method tangentially at least around the tangential extension (71) of a sheet thickness (87 ) a radially extending fold line (41) is formed at a distance from the dividing line (40), and the circular sections (84) extend from the dividing line (42) to a first flattened section (83a), and from the fold line (41) to a second flattened section (83b) - and in particular the outer circumference (25) in the circumferential area (39) between the dividing line (40) and the buckling line (41) has a reduced radius (44) compared to the circular sections (84). Stator base body (16) according to one of the preceding claims, characterized in that the connecting lug (30) has flanks (33, 34) which run approximately in the tangential direction (9) and rest on radially opposite opposing flanks (35, 36) of the recess (31). - in particular over a tangential extension of about 0.1 to 0.3 mm. Stator base body (16) according to one of the preceding claims, characterized in that the connecting lug (30) has lug radii (49) on both sides in the region of its free end (42), the starting angle (43) of which with respect to the radial direction (7) is approximately 30° to 45° ° amount. Stator base body (16) according to one of the preceding claims, characterized in that the T-shaped segments (22) of the stacked laminations (20) are axially connected to one another by means of round stamped packages (54, 88), with a first stamped package (54) in particular in a tooth base (28) of the tooth shank (26) and a further punched packeting (88) on a radial line to the first punched packeting (88) in the yoke area (24), and preferably the punched packetings (54, 88) are at least one radial distance from the Have outer circumference (25) and / or the inner diameter (24), which corresponds to the sheet thickness (87). Stator base body (16) according to one of the preceding claims, characterized in that an uppermost sheet metal lamina (20a) has punchings (89) as a stamped package (88), into which the material of the sheet metal lamina (20b) following below is pressed - and the sheet metal laminations (20 ) approximately have an axial thickness (87) of about 0.5 mm. Stator base body (16) according to one of the preceding claims, characterized in that the stator base body (16) is composed of several individually wound T-shaped laminations (10), and the electrical Windings (58) are designed as single-tooth coils (59) so that they can be commutated electronically by means of control electronics - in particular the tangential distance (29) between the tooth bases (28) of the T-shaped lamella packs (10) being 0.5 - 0.9 times the Sheet thickness (87) is. Stator base body (16) according to one of the preceding claims, characterized in that the stator base body (16) has exactly three teeth (17) with exactly three flattened areas (83) of the outer circumference (25), or exactly six teeth (17) with exactly six flattened areas Areas (83) of the outer circumference (25), or exactly nine teeth (17) with exactly nine flattened areas (83) or exactly twelve teeth (17) with exactly twelve flattened areas (83) of the outer circumference (25). Electrical machine (12) with a stator base body (14) according to one of the preceding claims, wherein a rotor (15) is arranged radially inside the stator base body (16), the rotor base body (62) of which is composed of individual sheet metal layers (21), which consist of the Sheet metal laminations (20) have been punched out radially inside the tooth bases (28), and the rotor base body (62) accommodates permanent magnets (60) which interact with the magnetic poles of the tooth shafts (26) - and are designed in particular as surface magnets. Method for producing a stator (14), in particular with a stator base body (16) according to one of the preceding claims, characterized by the following method steps: - Punching out the laminations (20) by means of precut technology, such that the T-shaped segments (22) of each lamellar layer (21) remain connected to one another by means of a predetermined breaking point (40) - whereby the T-shaped segments (22) of each lamellar layer (21) are first only partially punched through, and in a further step are pressed back into the original axial position, so that the individual T-segments (22) are physically completely separated and remain connected to one another only by clawing into one another, - axial stacking and connection of several lamellar layers (21) to form the stator base body (16) - in particular by means of stamped packets (56, 88) - separating the stator base body (16) to individual T-shaped disk packs (10) and winding their tooth shafts (26) - Then together The laminations (10) are joined to the stator (14) in exactly the same way as the laminations (10) were previously connected to one another via the predetermined breaking points (40) - whereby the individual successive lamina layers (21) preferably have at least one toothed segment (22) are twisted against each other in the circumferential direction (9). procedure after Claim 13 , characterized in that the yoke areas (24) are stamped with an outer periphery (25) which in a first tangential area (81) of the tooth shank (26) has a flattened portion (83) and in second tangential areas (82) adjacent to the flattened portion (83) has circular portions (84). procedure after Claim 13 or 14 , characterized in that the T-shaped laminations (10) are separated from the stator base body (16) by means of separating wedges which are pressed axially between the toothed shafts (26), and the laminations (10) after winding with their outer circumference ( 25) can be inserted into a conical, round assembly tool (100) or directly into a stator housing in order to be assembled into the stator (14), the outer circumference (25) only having the circular sections (84) radially on the round assembly tool or on Stator housing rests - and in particular the tool (100) has a wear-resistant coating.

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