Method for reshaping and introducing windings into rotor body or stator body

Abstract

The invention relates to a method for reshaping a winding (20) and introducing the winding (20) into a rotor or stator body (100). In order to achieve a compact structure of a stator or rotor of an electric machine with advantageous electromagnetic properties, the following method steps are proposed: preforming a stranded wire (25) to form a winding, the slots (102) are arranged on the rotor body or stator body (100) such that the straight sections (22, 22 ', 22' ', 22 ''') of the stranded wire (25) are connected via the bent winding head sections (24) of the stranded wire (25) in order to form a wave-shaped winding or a ring-shaped winding, introducing the winding into the rotor body or stator body (100) such that the straight sections lie in the slots (102) and the winding head sections (24) of the winding project on the axial end face of the rotor body or stator body (100), and compacting the winding head section (24) in order to reduce the axial projection of the winding head section.

Description

Technical Field

[0001] The invention relates to a method for reshaping a winding and introducing the winding into a rotor body or a stator body. Background Art

[0002] When assembling the rotor or stator, continuous copper coil windings are used. A distinction is made between centralized winding and distributed winding. Distributed winding is characterized by an almost sinusoidal path of the magnetic field in the air gap, which has a positive effect on the machine's torque curve. However, compared to centralized winding, disadvantages include larger winding heads and higher string resistance.

[0003] So-called flat wire windings, which consist of solid conductors with a rectangular cross-section, are particularly frequently used in high-power electric machines and generally enable optimal utilization of the available slot cross-sections in the rotor or stator. However, at high frequencies of conductor currents, current displacement effects (skin effect, proximity effect) mean that the conductor cross-section is no longer fully utilized, resulting in additional ohmic losses.

[0004] In this context, EP 3 934 067 A1 discloses a winding for an electric machine comprising a profiled litz wire with a rectangular cross section. Due to the large number of electrically insulated and relatively thin individual conductors of the profiled litz wire, current displacement effects and associated losses are reduced.

[0005] Distributed windings for electric motors are usually manufactured as flat winding mats in the form of wave windings or toroidal windings and are then introduced into the slots of the stator or rotor. The wave winding comprises a plurality of interwoven wires that are bent multiple times in opposite directions so that straight sections or wire protrusions of the wires that are parallel to each other and intended to fill the slots of the stator body or rotor body are connected by roof-shaped winding heads that protrude beyond the front side of the rotor or stator being produced. A flat and rotatable winding template and a wire processing device can be used to produce the wave winding as an initial flat winding mat. DE102015120963A1 describes an exemplary method for producing a wave winding.

[0006] After the flat winding mat is produced on the winding template, it is removed from the winding template and transferred to a box-shaped member. For example, the box-shaped member can be designed as an elongated linear box-shaped member. The box-shaped member preferably has several receiving portions for the wires in the longitudinal direction. Alternatively, the box-shaped member can also be designed as a rotary box-shaped member. The receiving portions are each formed between two webs, thereby creating a groove-shaped receiving space. In the case of a linear box-shaped member, these groove-shaped receiving spaces typically extend perpendicularly to the longitudinal direction along the width direction of the linear box-shaped member. Typically, the length of the linear box-shaped member in the longitudinal direction is greater than the width of the linear box-shaped member in the width direction. The winding mat can be compacted in the box-shaped member and safely transferred from the manufacturing process step to another process step in which the winding mat is inserted into the rotor body or stator body. The box-shaped member is intended to ensure that the individual wires of the winding mat, and in particular the straight wire sections of the winding mat intended to be inserted into the slots, do not shift relative to each other during processing and compaction. If a wave winding as described above is inserted into a box, and in particular into a linear box, the result is that in the starting and ending areas of the wave winding only individual conductors are located in the slots of the linear box, and in subareas of the linear box a plurality of conductors can also be located one above the other in the slots of the linear box. Summary of the Invention

[0007] The present invention relates to optimizing the wave windings used as coil windings in rotors or stators. Due to their generally cylindrical shape, the rotors or stators have slots that can have parallel slot flanks. Alternatively, these can be designed so that the tooth flanks of the teeth arranged between the slots are parallel. In the latter case, when viewed in cross-section or axially relative to the axis of rotation of the rotor or stator, the resulting slot cross-section is conical or trapezoidal. This latter embodiment has the advantage that the reluctance of each tooth, when viewed in the radial direction, is the same.

[0008] When filling the slots, it is desirable to achieve the highest possible filling factor, i.e., to fill the slots as completely as possible with wire so that the available installation space can be used as completely as possible for electromagnetic-related components (wires). In this context, a method is known from US 2016 / 0 056 696 A1, in which the straight sections of a wave winding are inserted into a receptacle in a box-like part and formed onto the receptacle by shaping the wire.

[0009] The invention is based on the object of achieving a compact design of a stator or a rotor of an electric machine with advantageous electromagnetic properties.

[0010] This object is achieved by a method having the features according to claim 1, a stator having the features according to claim 11, and a rotor having the features according to claim 12. Embodiments of the invention can be found in the dependent claims.

[0011] The method according to the invention serves to reshape and introduce a winding into a slotted rotor body or stator body of an electric machine.

[0012] In a first method step, a stranded wire is first provided. The stranded wire is preferably provided in the form of a twisted stranded wire, wherein the individual strands electrically insulated from one another have a twist. The advantage of this twist is that, when the conductor bundle formed as a stranded wire expands axially, the individual strands continuously change their position relative to the cross-sectional area of ​​the conductor bundle. The strands arranged centrally at one axial point are positioned at another axial point in the outer region of the conductor bundle and can therefore transfer the heat generated in the strands to the slot sides of the rotor or stator. In this way, the twist contributes to improved thermal conductivity compared to conductor bundles with parallel arranged wires. The strand structure can have a single twist or twisting step of the twisted strands, or a multi-stage structure with several twisting and twisting steps, the strand structure then differing in the twisting direction of the individual strands or the twisted strands as well as the strands as a whole.

[0013] The specially twisted stranded wires are then preformed into windings, wherein straight sections of the stranded wires are connected via bent winding head sections of the stranded wires to form a wave winding or a toroidal winding.

[0014] The preformed winding is then inserted into the rotor body or the stator body, with the straight sections located in the slots and the winding head sections of the winding protruding from the axial end face of the rotor body or the stator body.

[0015] The invention is based on the recognition that, with a distributed winding and a stranded wire structure according to the invention, there is considerable potential for reducing the axial length of the stator or rotor. In principle, a distributed winding can withstand more in the axial direction, i.e. in the region of the end winding heads, than a centralized winding. Typically, relatively rigid flat linear windings or strip windings are often used, in particular for high-power motors, such as those for traction drives in electric vehicles, e.g. with a continuous output of >50 kW. With such a winding, the winding heads are already preformed during the production of the flat winding mat. Once the winding mat has been inserted into the stator or rotor, the winding heads can only be formed to a very limited extent, since the high rigidity of the conductor would require very high bending forces, which could damage the winding insulation in particular.

[0016] On the other hand, the design of the winding based on stranded wire according to the present invention enables compaction of the winding head section after the winding has been inserted into the rotor or stator body. This is due to the significantly greater flexibility of stranded wire. This final compaction step significantly reduces the axial protrusion of the winding head, making it possible to provide a motor with distributed winding and a significantly shorter axial length compared to the prior art.

[0017] If the strands are configured as profiled strands, for example with a rectangular cross section, a very high slot filling factor can be achieved. The strands can already be pre-configured as profiled strands or alternatively formed into the desired profile in a box with a corresponding slot-shaped receptacle.

[0018] Before the winding is introduced into the rotor body or the stator body, the following method steps can be performed:

[0019] The winding is introduced into the box-shaped part, wherein the straight sections of the stranded wire are inserted into the slot-shaped receptacles of the box-shaped part,

[0020] • Pressing the twisted wire into the receiving portion of the box-like member, thereby molding the twisted wire to the receiving portion.

[0021] In particular, the straight wire section of the stranded wire is pressed into the receiving portion of the box-shaped member, thereby shaping the straight wire section and molding the stranded wire with the straight wire section to the receiving portion. In particular, the box-shaped member can be designed as a linear box-shaped member. Alternatively, the box-shaped member can be designed as a rotary box-shaped member.

[0022] The above method has the advantage that the box-shaped part and its receiving part serve as a kind of former for forming the stranded wire winding. Preferably, the receiving part of the box-shaped part has the same cross section as the slots of the rotor or stator into which the winding is inserted after being formed and removed from the box-shaped part.

[0023] According to another embodiment of the method, the stranded wire in the receiving portion is shaped to have a substantially conical cross-section. This is particularly advantageous if the tooth flanks of the rotor or stator, into which the winding is to be inserted, are designed to be parallel. The advantage of parallel tooth flanks is that the magnetic permeability of the tooth flanks remains essentially constant along their radial extent. On the other hand, due to the parallel tooth flanks, the slot flanks of the substantially cylindrical rotor or stator body are not parallel, and the slot cross-section is therefore substantially trapezoidal.

[0024] If the stranded wire is initially preformed into a winding mat, the winding can then be rolled into a helical shape before being introduced into the rotor or stator body, axially introduced into the rotor or stator body, and radially expanded into the slots of the rotor or stator body. This method is particularly suitable for stators of internal rotor machines or rotors of external rotor machines.

[0025] Alternatively, embodiments of the invention in which the winding is inserted into a segmented stator or rotor body are also advantageous. Here, the individual segments can be joined with winding mats that have essentially been wound to their final outer diameter and then connected together.

[0026] After the winding mat is introduced into the stator or rotor, the winding head is compacted, which is particularly effective due to the stranded wire used. Preferably, a compactor is used to press the winding head section axially against the rotor or stator body. Before compaction, support fingers can be attached to each stator tooth. These support fingers protect the slot protrusions of the slot insulation during the compaction process. This prevents damage to the slot insulation during the compaction process. Furthermore, the support fingers protect the wire insulation from damage during compaction.

[0027] If a molding tool is arranged around the winding head segment, the radial expansion of the winding head segment can be limited during the pressing process, so that the radial installation space of the machine can be kept as compact as possible.

[0028] In a preferred embodiment of the invention, in addition to the axially oriented compaction, compaction of the winding head segment in the radial direction is also achieved by using a compactor for axial pressing, which has an inclined surface, through which the winding head segment is pressed radially outward while the compactor is moved axially in the direction of the rotor package or the stator package.

[0029] The axial protrusion of the winding head can be reduced even further since, in an advantageous embodiment of the invention, the compactor is rotated by a predetermined rotation angle relative to the stator body or rotor body during the axial pressing process.

[0030] To reduce springback of the stranded conductors during compaction, the windings are optionally bonded after compacting the winding head sections to reduce axial protrusion. For example, a material bond is created by gluing the wires together with a bonding varnish. This bonding varnish is typically heat-activated and liquefied. Diffusion into the stranded conductor cavity and subsequent curing solidifies the previously formed conductor structure in the winding head, creating a mechanically stable structure. The bonding varnish is typically a special varnish applied as part of the individual strand production process or during the individual wire production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further features, details and advantages of the invention emerge from the wording of the claims and from the following description of exemplary embodiments with reference to the accompanying drawings. In the drawings:

[0032] Figure 1 A and Figure 1B: Schematic representation showing two different variants of the method sequence for shaping the stranded wire in a linear box-like element;

[0033] Figure 2 : shows a partial schematic representation of a top view of a linear box-like member with an inserted wave winding;

[0034] Figure 3 : A schematic partial axial cross-sectional view showing a portion of a wave winding inserted into a rotor body or a stator body;

[0035] Figure 4 : shows a schematic cross-sectional view of a stator body with an inserted wave winding;

[0036] Figure 5 : shows a schematic cross-sectional view of a stator body with an inserted wave winding during compaction of a winding head using a compactor according to a first embodiment;

[0037] Figure 6 : shows a schematic cross-sectional view of a stator body with inserted wave windings after compacting the winding heads 24 using the compactor 40 of the first embodiment;

[0038] Figure 7 : shows another schematic cross-sectional view of a stator body with an inserted wave winding;

[0039] Figure 8 : shows a schematic cross-sectional view of a stator body with an inserted wave winding during compaction of the winding head 24 using a compactor 40 of a second embodiment;

[0040] Figure 9 : shows a schematic cross-sectional view of a stator body with inserted wave windings after compacting the winding heads 24 using a compactor 40 of a second embodiment;

[0041] Figure 10A and Figure 10B : shows a side view of the winding head before and after compaction; and

[0042] Figure 11A 、 Figure 11B and Figure 11C : Shows a side view of the winding head as the compactor rotates during the pressing process. DETAILED DESCRIPTION

[0043] Unless otherwise specified, the reference numerals are used consistently below. Unless otherwise specified, the reference numerals in the text always refer to all figures. Similarly, unless otherwise specified, all reference numerals in the figures always refer to the entire description of the following exemplary embodiments.

[0044] under, Figure 1 The receiving portion 12 is shown, wherein the straight material sections 22, 22', 22", 22'" of the wave winding 20 are located in the receiving portion. Figure 2 As can be seen in FIG, the linear box 10 has a plurality of such receptacles 12 in its longitudinal direction L.

[0045] Figure 1 A and Figure 1 B each shows a schematic illustration of a sequence of two different method variants for forming a stranded wire 25 in a linear box-like element 10. In this method, the straight wire segments 22, 22', 22", 22'" of the stranded wire 25 of the wave winding 20 are first inserted into the linear box-like element 10. For this purpose, the linear box-like element 10 has a receiving portion 12, wherein the receiving portion 12 is delimited by webs 14, 14' in the longitudinal direction L of the linear box-like element. The receiving portion 12 has an opening 16 through which the straight wire segments 22, 22', 22", 22'" can be inserted into the receiving portion 12 so that the straight wire segments 22, 22', 22", 22'" are located in the receiving portion 12 perpendicular to the longitudinal direction L of the linear box-like element, that is, in the width direction B. In this exemplary embodiment, the receiving portion 12 comprises a receiving space having a tapered cross section, wherein the width of the receiving portion 12 in the region of the opening 16 of the receiving portion 12 is greater than the width in the lower region of the receiving portion 12 .

[0046] According to Figure 1 In the method sequence of A, the stranded wire 25 is inserted into the receiving portion 12 with its straight sections 22, 22', 22", 22'", the wire width 26 substantially corresponds to the width of the receiving portion 12 in the upper region, and the width of the receiving portion 12 decreases as the depth of the receiving portion increases and is less than the wire width 26.

[0047] exist Figure 1 In FIG. 1B , the stranded wire 25 is inserted with its straight sections 22 , 22 ′, 22 ″, 22 ′″ into the receiving portion 12 , wherein the width of the receiving portion 12 decreases with increasing depth of the receiving portion 12 , and the wire width 26 substantially corresponds to the width of the receiving portion 12 in the lower region. In the region of the receiving portion 12 close to the opening 16 , the width of the receiving portion 12 is greater than the wire width 26.

[0048] In the following step 2), the wave winding is pressed together with its straight material sections 22, 22', 22", 22'" in the receiving part 12 of the linear box-shaped part 10 by means of a pressing tool 30, thereby forming the stranded wire 25 and molding the stranded wire 25 together with its straight material sections 22, 22', 22", 22'" to the receiving part 12, and in particular to the webs 14, 14'.

[0049] For according to Figure 1 In the variant A, a wire width 26 is selected that corresponds approximately to the average width of the receiving portion 12. Thus, after pressing, the lowest possible shaping is achieved evenly across all changes in the shape of the conductor 25, thereby subjecting the insulation of the stranded wire 25 to less stress. The lower straight wire section 22' is compressed in the width direction of the receiving portion, or in the longitudinal direction L of the linear box-like element 10, and the upper wire section 22 is stretched in the width direction of the receiving portion, or in the longitudinal direction L of the linear box-like element 10.

[0050] For according to Figure 1 In variant B, the width of the receiving portion 12 or its extent in the longitudinal direction L of the linear box-shaped element is selected so that the wire width 26 is less than or equal to the minimum width of the conically tapering receiving portion 12. This results in all the straight wire sections 22, 22' being stretched in the longitudinal direction L of the linear box-shaped element 10. The straight wire sections 22, 22' do not have any displacement perpendicular thereto, which advantageously prevents any damage to the insulation.

[0051] In step 3), the final state of the shaped stranded wire 25 in the linear box 10 is shown. In a subsequent step (not shown), the wire 25 or wave winding 20 is removed from the linear box 10 and transferred to an insertion tool or a rotor body or stator body 100.

[0052] It can be seen that through forming, Figure 1 The lower straight material section 22' in A is stretched in the longitudinal direction L of the linear box-shaped member, and Figure 1 The upper straight material section 22 in A is compressed in the longitudinal direction L of the linear box 10. Figure 1 In B, the two straight material sections 22, 22' are compressed in the longitudinal direction L by forming, resulting in the same Figure 1 Compared with the design of the linear box-shaped member 10 of A, the total height of the wire group is lower.

[0053] A person skilled in the art will recognize that more than two layers of straight material segments 22, 22', 22", 22'" may be positioned in the receiving portion 12 of the linear box-like element 10. In step 2), pressing is performed using a suitable pressing tool 30 which engages in the receiving portion 12 and shapes the straight material segments 22, 22', 22", 22'" or wires 25 by molding them to the webs 14, 14' of the receiving portion 12. The forming may be performed simultaneously for all receiving portions 12 (in step 2), for example, by means of a pressing punch. Figure 1Only one receiving portion 12 of the linear box-shaped member 10 is shown representatively in FIG, but it is also conceivable that the straight material segments 22, 22', 22", 22"' are rolled into the receiving portion 12 of the linear box-shaped member 10 by rollers equipped with pressing webs. Of course, regarding the Figure 1 A and Figure 1 Variations of the width configuration of the receiving portion 12 relative to the wire width 26 of B can be present together within the linear box 10, wherein the width of the receiving portion 12 can also vary along the course of the linear box 10, ie in its longitudinal direction L.

[0054] For clarity, Figure 2 A schematic partial top view of a linear box 10 with an inserted winding 20, designed as a wave winding, is shown. As can be seen, the wave winding, with its straight wire sections 22 of conductor, is located in a receptacle 12 of the linear box 10. The receptacles 12 are each bounded by webs 14, 14'. Along the course of the stranded wire 25, the straight wire sections 22 adjoin a winding head 24 of the wave winding, which in this exemplary embodiment is located outside the receptacle 12 and outside the linear box 10. The winding head 24 is positioned outside the receptacle 12 in the width direction B of the linear box 10. After subsequent use in a rotor or stator body, the winding head 24 protrudes axially beyond the rotor or stator body, thereby initially increasing the axial installation space required for the electric machine, a significant limitation when used, for example, as an electric traction drive in electric or hybrid vehicles. The heat dissipation of winding heads protruding in this way is often also a particular challenge, since no thermal connection of the conductor to the stator or rotor lamination stack is provided.

[0055] Figure 3A schematic, partial axial cross-sectional view of a portion of a winding 20 inserted into a rotor or stator body 100 is shown. The winding 20 is inserted into a slot 102, where the slot 102 is bounded on both sides by teeth 106, 106' with parallel tooth flanks 108, 108', resulting in radially varying slot widths that, in the exemplary embodiment shown, increase with increasing radius. The slot 102 is radially outwardly bounded by a slot base 104 and radially inwardly bounded by yoke sections 107, 107' of the teeth 106, 106'. The wave winding nearly completely fills the slot 102 with straight wire sections 22, 22', 22", 22'" formed according to the method described above. Here, not just two layers of stranded wire 25 are inserted into the slot 102 of the rotor or stator body 100, but four layers of stranded wire 25 or straight wire sections 22, 22', 22", 22'" are inserted. In one variant, each of these four layers can be formed in the receiving portion 12 of the linear box 10, or the wave winding can be formed in two layers, wherein the winding 20 is then inserted in two turns into the substantially cylindrical rotor or stator body 100. It should be understood that the shaping in the linear box 10 must then be performed according to the subsequent position in the rotor or stator body, and the geometry of the receiving portion along the longitudinal direction L of the linear box 10 is correspondingly changed in order to adapt to the radially varying slot cross-section of the rotor or stator body 100. For this purpose, the linear box 10 can have a fixed geometry or have webs 14, 14' or the boundaries of the receiving portion 12 that are somewhat movable or replaceable.

[0056] Figure 4 A schematic cross-section of a stator body 100 with an inserted wave winding is shown. Rectilinear sections 22 , 22 ′, 22 ″, 22 ′″ of litz wire 25 are located in slots 102 of the stator body, and winding heads 24 protrude axially above the stator body 100 by a height h1 .

[0057] Figure 5 A schematic cross-sectional view of a stator body 100 with an inserted wave winding is shown during compaction of a winding head 24 using a compactor 40 according to a first embodiment. In addition to the compactor 40, a molding tool 42, designed as an open-diameter ring, is arranged radially around the winding head 24 and a support finger 41. A support finger 41 is mounted on each stator tooth. The support finger's task is to protect the slot insulation (not shown) from damage during the compaction process. The support finger 41 secures the bent region of the winding head 24 at a defined distance from the stator body 100, preventing the slot insulation from buckling on the stator body 100.

[0058] In order to compact the winding heads 24, the compactor 40 is moved axially toward the stator body so that the winding heads 24 are compressed from the first height h1 to the second height h2. Figure 6 The final state is shown in .

[0059] Figure 7 A further schematic cross-sectional view of a stator body 100 with an inserted wave winding and an axially protruding winding head is shown. In addition to the initial height hi of the winding head 24, a radial initial width w1 is also shown.

[0060] Figure 8 A schematic cross-sectional view of a stator body 100 with an inserted wave winding is shown during compaction of the winding heads 24 using a second embodiment of a compactor 40. This second version of the compactor 40 has a ramp 43 which, when the compactor 40 is pressed axially against the stator body 100, also results in radial compression of the winding heads 24 in addition to the axial compression. Figure 9 It is shown that at the end of the compaction process the winding head has been reduced both in its axial extension (from h1 to h2 ) and in its radial extension (from w1 to w2 ).

[0061] Figure 10A and Figure 10B A side view of the winding head before and after compaction is shown. It can also be seen here that the axial conductor height in the winding head decreases from h1 to h2.

[0062] on the other hand, Figure 11A 、 Figure 11B and Figure 11C A side view of the winding head 24 is shown while the compactor 40 is rotating during the compaction process. The conductor profile in the winding head 24 can be modified by a predetermined rotation angle, which accompanies the axial pressing process of the compactor 40 in a manner similar to the screw-in process, so that the axial expansion of the winding head is even further reduced.

[0063] All features and advantages arising from the claims, the description and the drawings, including construction details, spatial arrangements and method steps, may be essential to the invention, either individually or in any combination.

[0064] Reference Signs List

[0065] 10 Box-shaped pieces, linear box-shaped pieces

[0066] 12 Reception Department

[0067] 14, 14' web

[0068] 16 Opening

[0069] 20 windings

[0070] 22, 22', 22", 22"' straight sections

[0071] 24 Winding head

[0072] 25 stranded wire

[0073] 26 Wire Width

[0074] 27 single wire

[0075] 28 Formed stranded wire

[0076] 29 Loosely stranded wire

[0077] 30 Pressing tools

[0078] 40 Compactor

[0079] 41 Support finger

[0080] 42 Molding Tools

[0081] 43 bevel

[0082] 100 rotor body or stator body

[0083] 102 slots

[0084] 104 slot base

[0085] 106, 106' teeth

[0086] 107, 107' Yoke Section

[0087] 108, 108' tooth side

[0088] L Longitudinal direction

[0089] B width direction

Claims

1. A method for reshaping and introducing a winding (20) into a rotor body or stator body (100) of an electric machine provided with slots (102), the method comprising the following method steps: preforming the stranded wire (25) to form the winding so that the straight sections (22, 22', 22", 22'") of the stranded wire (25) are connected via the bent winding head section (24) of the stranded wire (25) to form a wave winding or a toroidal winding, The winding is introduced into the rotor body or the stator body (100) so that the straight section is located in the slot (102) and the winding head section (24) of the winding protrudes on the axial end face of the rotor body or the stator body (100), and • Compacting the winding head section (24) to reduce the axial protrusion of the winding head section.

2. The method according to claim 1, wherein As the stranded wire (25), a stranded wire with a profile is used.

3. The method according to claim 1 or 2, wherein: Before the winding is introduced into the rotor body or the stator body (102), the following method steps are performed: The winding is introduced into a box-like element (10), wherein the straight sections (22, 22', 22", 22'") of the stranded wire (25) are inserted into the groove-shaped receiving portion (12) of the box-like element (10), Pressing the twisted wire (25) into the receiving portion (12) of the box-like member so that the twisted wire (25) is molded to the receiving portion (12).

4. The method according to claim 3, wherein: The twisted wires (25) in the receiving portion (12) are shaped to form a tapered cross section.

5. The method according to any one of the preceding claims, wherein For compaction using a compactor (40), the winding head section (24) is pressed axially against the rotor body or the stator body (100).

6. The method according to claim 5, wherein: Before pressing, a supporting finger (41) is mounted on each stator tooth, said supporting finger protecting the slot protrusions of the slot insulation during the pressing process.

7. The method according to claim 5 or 6, wherein: A molding tool (42) is arranged to enclose the winding head section (24) so ​​as to limit radial expansion of the winding head section (24) during the pressing process.

8. The method according to any one of claims 5 to 7, wherein: The compactor (40) is rotated by a predetermined rotation angle relative to the stator body or the rotor body (100) during an axial pressing process.

9. The method according to any one of the preceding claims, wherein A compactor (40) is used for axial pressing, the compactor having an inclined surface (43), by which the winding head section (24) is pressed radially outwards while the compactor (40) is moved axially in the direction of the rotor package or the stator package (100).

10. The method according to any one of the preceding claims, wherein After compacting the winding head section (24) to reduce the axial protrusion, the winding is bonded to secure the winding.

11. A stator for an electric machine, comprising a stator body with slots (102) and a winding made of stranded wire (25), wherein: The straight sections (22, 22', 22", 22'") of the stranded wires are connected via the bent winding head section (24) of the stranded wires (25) to form a wave winding or a toroidal winding, the straight sections (22, 22', 22", 22'") being located in the slots (102) and the winding head section (24) of the winding protruding from the axial end face of the stator body, wherein the winding head section (24) is compacted.

12. A rotor for an electric machine, comprising a rotor body with slots (102) and a winding made of stranded wire (25), wherein: The straight sections (22, 22', 22", 22'") of the stranded wires are connected via the bent winding head section (24) of the stranded wires (25) to form a wave winding or a toroidal winding, the straight sections (22, 22', 22", 22'") being located in the slots (102) and the winding head section (24) of the winding protruding from the axial end face of the rotor body, wherein the winding head section (24) is compacted.

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