Method for manufacturing a laminated core for an electric machine, in particular for an axial flux machine

Abstract

The invention relates to a method for manufacturing a laminated core (10) for an electric machine, in which a strip (12) is wound around a winding axis (14) to form a coil (16) such that respective length ranges (L) of the strip (12) form layers (18) arranged on top of each other in the radial direction (20) of the laminated core (10), wherein at least one edge region (R1) of the strip (12), which ends along the winding axis (14) at the at least one edge region (R1), is trimmed by high-speed shearing with a cutting speed of more than 2.2 meters per second.

Description

[0001] The invention relates to a method for manufacturing a laminated core for an electric machine, in particular for an axial flux machine, according to the preamble of claim 1.

[0002] DE 10 2021 003 706 A1 discloses a method for manufacturing a rotor for an electric machine. Furthermore, DE 10 2007 019 911 A1 discloses a method for manufacturing sheet metal parts, in particular electrical steel parts. EP 2 355 313 ​​A1 discloses an axial flux machine, also known as an axial flux motor. WO 2016 / 113567 A1 and EP 3 245 719 A0 also disclose an axial flux machine. US 2010 / 0090555 A1 also discloses an axial flux machine. DE 10 2016 207 944 A1 discloses a package system for an electric machine. JP 2019-1655519 A1 also discloses an axial flux machine.

[0003] The object of the present invention is to provide a method for manufacturing a laminated core for an electric machine, in particular for an axial flux machine, such that high component quality and advantageous mechanical properties of the laminated core can be achieved.

[0004] This problem is solved by a method with the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] The invention relates to a method for manufacturing a laminated core for an electric machine, in particular for an axial flux motor. Preferably, the electric machine is used in or for a motor vehicle, in particular as a traction machine, by means of which the motor vehicle can be driven, in particular purely electrically. Preferably, the electric machine is a high-voltage component whose electrical voltage, in particular its operating or nominal voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and most preferably several hundred volts. This allows for particularly high electrical power outputs for the, in particular purely, electric propulsion of the motor vehicle.In its fully manufactured state, the electric machine, preferably designed as an axial flux machine, has at least one stator and at least one rotor. Particularly when the electric machine is designed as an axial flux machine, at least a portion of the stator and at least a portion of the rotor are arranged successively in the axial direction of the electric machine, i.e., side by side, one after the other, or one behind the other, in particular such that an air gap is arranged in the axial direction of the electric machine between the portion of the stator and the portion of the rotor. The rotor can be driven by means of the stator and is thereby rotatable about an axis of rotation extending in the axial direction of the electric machine relative to the stator, so that, for example, the electric machine can provide torques via its rotor for, in particular, purely electric, propulsion of the motor vehicle.

[0006] In this method, a strip is wound around a winding axis (which is not explicitly defined) into a coil such that respective lengths of the strip form layers arranged one on top of the other in the radial direction of the laminated core, the axial direction of which is perpendicular to the radial direction of the laminated core. The radial direction of the laminated core is perpendicular to the winding axis. The axial direction of the laminated core is parallel to the winding axis or coincides with the winding axis. In the fully manufactured state of the electrical machine, that is, with respect to the fully manufactured state of the electrical machine containing the laminated core, the axial direction of the laminated core is aligned with the axial direction of the electrical machine, and its radial direction is perpendicular to the axial direction of the electrical machine.Thus, in the fully manufactured state of the electric machine, the radial direction of the laminated core runs in the radial direction of the electric machine. The axial direction of the electric machine coincides with the axis of rotation. In particular, the lengths are wound around the imaginary winding axis in such a way that, viewed in a cross-sectional plane perpendicular to the axial direction of the laminated core, the lengths are wound in a spiral shape, i.e., they run in a spiral. Preferably, the laminated core is or is formed in a disk or ring shape, so that preferably the laminated core is or is formed as a ring-shaped laminated core.

[0007] Preferably, the strip is made of a metallic material, in particular sheet metal, and especially electrical steel, so that the laminated core wound to form the coil can advantageously conduct a magnetic flux or a magnetic field provided by a magnet. In particular, it is conceivable that, in the fully assembled state of the electric machine, at least the aforementioned magnet, which is designed, for example, as a permanent magnet, is supported by the laminated core. The laminated core can be used for the stator and thus as a stator lamination stack of the stator. Furthermore, it is conceivable that the laminated core can be used for the rotor and thus as a rotor lamination stack of the rotor.

[0008] In order to achieve particularly high component quality and especially advantageous mechanical properties of the laminated core, the invention provides that at least one edge region of the strip, which terminates along the winding axis at the at least one edge region, is trimmed by high-speed shearing (HGSS) at a cutting speed of more than 2.2 meters per second. The at least one edge region is also referred to as the first edge region or simply as the edge region. When the edge region or the at least one edge region is mentioned before and below, unless otherwise specified, this refers to the first edge region.Since, with regard to the method for manufacturing the laminated core, the strip, viewed along the winding axis, ends at at least one edge region, the strip, in the axial direction of the laminated core or the axial direction of the electrical machine, ends at at least one edge region in the fully manufactured state of the laminated core or the electrical machine, respectively. For example, by trimming the at least one edge region, an edge of the strip is formed, which, after trimming the at least one edge region along the winding axis, ends at the edge.Since at least one edge area is trimmed by high-speed shearing, excessive deformation and, in particular, excessive edge pull-in (also known as edge curl) can be avoided, allowing the edge and thus the strip to be produced with a particularly high quality. Furthermore, compared to conventional solutions, the invention enables a reduction in remagnetization losses, thereby facilitating particularly efficient operation of the electric machine (also known as an electric motor). Because the laminated core is manufactured by winding the strip onto the coil, the laminated core is a wound core, preferably designed as a wound ring core.

[0009] The invention is based in particular on the following findings and considerations: Axial flux machines (AFMs), also known as axial flux motors, typically have a disc-shaped design, as, for example, the aforementioned parts of the stator and rotor are disc-shaped. This disc-shaped design enables novel drive concepts, particularly axle drive concepts, for motor vehicles compared to conventional radial flux machines. Due to space constraints, the outer diameter of the axial flux machine is relatively limited, especially for coaxial applications in passenger cars. Therefore, and for efficiency reasons, an increase in the efficiency of the respective axial flux machine is sought for future mass production applications compared to conventional solutions.Electrical machines, especially axial flux machines, with high power density and high speeds or speed capacities, typically require high-strength and precise laminated cores, for example, formed as ring-shaped cores, made from, in particular, wound strip, especially electrical steel. Since the strip is preferably made of electrical steel, it is then also referred to as electrical steel. The strip, or in particular the raw material from which the strip is formed, is usually cut to a predetermined width in a rolling mill, thus initially producing the strip as slit strip. The strip is then typically processed further to produce the laminated core.However, a technical problem is identified in this regard, namely that technical restrictions in the rolling mill and in slit strip production, particularly with regard to surface topography, strip width, width tolerances, cut edge characteristics including burrs, corrosion protection, packaging marks (imprints), etc., remain directly in the strip from which the sheet metal stack is produced and have a limiting effect on, for example, a functional surface directly bordering the aforementioned slit, as well as on an adhesive surface between the layers (also referred to as ring layers) or those formed as ring layers, and on a joining surface on the back side of the sheet metal stack, which can negatively affect efficiency. In particular, it is intended that the layers are bonded together using an adhesive, specifically in such a way that the respective layers are bonded together via their respective adhesive surfaces using the adhesive.The aforementioned problems and disadvantages can now be avoided by the invention. In particular, compared to roll cutting, high-speed shear cutting enables the achievement of high edge quality, while avoiding undesirable hardening of the edge area or the edge itself.

[0010] In order to ensure a particularly high component quality of the lamination stack, in one embodiment of the invention it is provided that the at least one edge region is trimmed in a state in which the at least one edge region is not yet wound onto the coil, so that preferably the at least one edge region is wound onto the coil only after the trimming of the at least one edge region.

[0011] In order to produce the sheet metal stack with high quality in a timely and cost-effective manner, a further embodiment of the invention provides that the at least one edge region extends over the entire longitudinal extent of the strip, perpendicular to the winding axis. In this embodiment, a complete cut of the strip, for example, which is designed as a sheet metal strip, is thus provided, also referred to as a closed cut, since the sheet metal strip is trimmed in its at least one edge region over its entire longitudinal extent, and in particular simultaneously.

[0012] Preferably, the at least one edge region, in particular the strip, is trimmed to size by cutting the at least one edge region to a dimension, that is, to a dimension that is particularly predetermined or predeterminable, wherein the dimension extends, for example, along the winding axis or parallel to the winding axis. Thus, for example, the aforementioned dimension is a width of the strip running along the winding axis or parallel to the winding axis.

[0013] Preferably, the at least one edge region is a first lateral edge region of the tape, such that, viewed along the winding axis, the at least one edge region is located on a first side of the tape or at a first end of the tape. The tape has a second end, which is opposite the first end along the winding axis. The tape has a further edge region at the second end, such that, viewed around a winding axis, the at least one edge region and the further edge region are opposite each other. If, for example, only one-sided trimming is provided, the tape is trimmed only at or within the at least one edge region with respect to both the at least one edge region and the further edge region.If double-sided trimming, that is, trimming of the tape on both sides, is intended, then both the at least one edge region and the additional edge region opposite the at least one edge region along the winding axis are trimmed. The preceding and following explanations regarding the at least one edge region can readily be applied to the additional edge region, and vice versa. Since the at least one edge region is located at the first end and the additional edge region at the second end, the at least one edge region and the additional edge region lie opposite each other along the winding axis. Viewed along the winding axis, the tape also ends at the second end and thus also at the additional edge region.When the term "edge area" or "at least one edge area" is used before and below, unless otherwise specified, it refers to the first edge area, i.e., the edge area of ​​the band located at the first end.

[0014] High-speed shearing enables the creation of adiabatic shear bands, thus preventing excessive edge pull-in, excessive burr formation, and excessive work hardening of at least one edge region. Consequently, a particularly high component quality of the sheet metal stack can be achieved.

[0015] Since the further edge area is viewed along the winding axis and thus, in relation to the fully manufactured state of the lamination stack, is opposite at least one edge area in the axial direction of the lamination stack, the further edge area or the second end is arranged on a second side of the strip, the second side of which is opposite the first side viewed along the winding axis.

[0016] Another embodiment is characterized in that the at least one edge region extends over a first part of the entire longitudinal extent of the strip running perpendicular to the winding axis, wherein the at least one edge region is trimmed, while a second edge region of the strip, extending over a second part of the entire longitudinal extent of the strip running perpendicular to the winding axis and adjoining the at least one edge region along the longitudinal extent of the strip, is not trimmed and ends at the second edge region along the winding axis.The at least one edge region (first edge region) and the second edge region are arranged at the same, in particular first, end of the tape and thus on the same, in particular first, side of the tape, such that the tape terminates at the at least one edge region and at the second edge region in a direction that coincides with or runs parallel to the winding axis. Thus, the tape terminates at the further edge region in a second direction that runs parallel to or coincides with the winding axis and is opposite to this direction, such that the further edge region, viewed along the winding axis, is arranged opposite both the at least one edge region and the second edge region.If the strip is trimmed in at least one edge region while the second edge region is not trimmed, then in this embodiment the strip is not trimmed simultaneously along its entire length, but rather an incremental trim, also known as an open cut, is provided, in particular a side trim. This allows for a particularly high component quality.

[0017] It has proven particularly advantageous if, after trimming at least one edge area, the second edge area is also trimmed by high-speed shearing at a cutting speed of more than 2.2 meters per second. This allows for a particularly high component quality of the sheet metal stack.

[0018] In a further embodiment of the invention, the at least one edge region is part of a first longitudinal region of the strip. Thus, the first longitudinal region is arranged on the first side and, in particular, at the first end of the strip, especially when viewed along the winding axis.

[0019] To avoid excessive deformation resulting from trimming the strip and thus achieve particularly high component quality, a further embodiment of the invention provides that the at least one edge region is trimmed by means of a tool, wherein the first length section is moved translationally in a direction of movement relative to the tool and is thereby moved into the tool. The at least one edge region is trimmed while the first length section is arranged in the tool and while no movement of the first length section occurs in the direction of movement and relative to the tool. In particular, it is provided that the at least one edge region is trimmed while relative movements between the first length section and the tool are prevented. This allows for particularly high trimming quality.This allows for a particularly high cutting quality and therefore a particularly high component quality.

[0020] To enable the production of the sheet metal stack with particularly high component quality and in a particularly time- and cost-effective manner, a further embodiment of the invention provides that at least one edge region is trimmed while the first length region is arranged in the tool, while the first length region does not move in the direction of movement and relative to the tool, and while a second length region of the strip, extending in front of the first length region in the direction of movement, is wound around the winding axis to form the spool. The winding of the second length region and the trimming of the first length region or the at least one edge region thus occur simultaneously, but are decoupled from each other, by or in such a way that the at least one edge region is trimmed while the second length region is wound onto the spool.This decoupling is achieved, for example, by arranging a third length section between the first and second length sections along the longitudinal axis of the strip. This third section initially forms a fold or a wave, particularly by moving the first length section translationally in the direction of movement relative to the tool. When the second length section is wound onto the spool while the first length section is in the tool and at least one edge section is trimmed, the fold or wave is at least partially removed, particularly by the fact that winding the second length section onto the spool pulls on the third length section, thus at least reducing or removing the fold or wave, and in particular smoothing it out.The third length range is thus used as a buffer or length reserve, which makes it possible to wind the second length range onto the spool, while relative movements between the first length range and the tool, in particular relative movements between the tool and the first length range as a whole, are prevented.

[0021] After trimming at least one edge area, for example, the first length section is moved translationally in the direction of movement relative to the tool and thereby moved out of the tool, and for example, a fourth length section of the strip, adjoining the first length section in the opposite direction, is moved into the tool, whereby, for example, a fold or wave and thus a length allowance is formed from the first length section in order to then, for example, wind the third length section onto the spool, while the fourth length section is arranged in the tool and while movements of the fourth length section in the direction of movement and relative to the tool do not occur.The preceding explanations regarding the first length range can readily be applied to the fourth length range, so that, for example, the fourth length range, or rather its edge range, is trimmed by the tool in the same way as the first length range or its edge range. Moving the belt in the direction of travel is also referred to as belt tension or feed, whereby, for example, the belt is moved in the direction of travel, particularly relative to the tool, by means of a conveying device also known as a feed unit.Preferably, the tool provides for an incremental or stepwise movement, in particular a pulling motion, of the strip, for example, into the tool, so that the strip is incrementally, i.e., stepwise and thus gradually, trimmed at its first end or on its first side by means of the tool, while the respective length section of the strip arranged in the tool does not move in the direction of movement relative to the tool. This prevents, for example, the strip from buckling in the tool, which is designed, for example, as a punching tool. This is particularly advantageous when the strip has a very thin wall. Especially when the strip is formed from a sheet, the wall thickness is also referred to as the sheet thickness. Preferably, the wall thickness is at most 1 mm and at least 0.04 mm.This incremental movement or pulling of the strip is particularly advantageous when the strip is provided with recesses, for example, holes, especially through holes, in order to form at least one groove and / or at least one magnetic pocket and / or at least one cooling channel in the strip or the sheet metal stack. By providing the strip with at least one recess in this way, also referred to as perforation, the strip, whose wall thickness is already very thin, is further weakened, and undesirable deformations, such as buckling of the strip, can be avoided by the incremental or stepwise movement of the strip into the tool.

[0022] Finally, it has proven particularly advantageous to additionally trim the first length section and thereby provide it with at least one recess, which may be designed as a through-hole or as a blind hole. This additional trimming of the first length section creates the aforementioned at least one recess, from which at least one cooling channel through which a coolant can flow for cooling the laminated core and / or at least one receptacle for receiving at least one magnet, in particular a permanent magnet, and / or for receiving a winding is produced.

[0023] This allows for a particularly high component quality to be achieved in a particularly time- and cost-effective manner.

[0024] Finally, it has proven particularly advantageous if the first length section is additionally trimmed after the trimming of at least one edge area, so that the creation of the recess preferably takes place after the trimming of at least one edge area. This allows the sheet metal stack to be manufactured with a particularly high component quality.

[0025] Preferably, the strip is made of a soft magnetic material. For example, the strip is a grain-oriented electrical steel sheet or a non-grain-oriented electrical steel sheet, wherein the grain-oriented or non-grain-oriented electrical steel sheet is the aforementioned soft magnetic material. Furthermore, it is conceivable that the strip is made of a soft magnetic composite material such as SMC (Sheet Moulding Compound). It is also conceivable that the laminated core is made of an electrically and magnetically conductive material such as a bipolar plate.

[0026] The invention allows at least the following advantages to be realized: - one-sided or preferably two-sided and preferably incremental trimming of the strip by high-speed shear cutting (HGSS) - lowest width tolerance (2 IT classes better than slit tape) - less edge indentation and therefore a larger active area compared to the air gap - no degree and therefore less risk of short circuits between the layers - No post-processing such as facing - Lower electromagnetic losses (remagnetization losses are smaller due to lower edge hardening) and higher efficiency of the electric machine, thus requiring less cooling power. - no imperfections at the strip edge due to storage, transport, etc. - No corrosion or contamination of the strip edges in the finished product (including the joining surface to the rotor carrier), as inline processing takes place directly after trimming. - Improvement of the cut surface quality, resulting in improved form, dimensional and positional tolerances. - Improved cut surface quality, resulting in improved mechanical strength due to a reduction in notch stress through the cut surface - advantageous adaptation of the technology, among other things, for battery and fuel cell components

[0027] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0028] The drawing shows: Fig. 1 a schematic representation of a method for manufacturing a laminated core for an electric machine, in particular for an axial flux machine; Fig. 2 a further schematic representation of the procedure; Fig. 3 a schematic cross-sectional view of a strip from which the sheet metal stack is manufactured; and Fig. 4 another schematic cross-sectional view of the band.

[0029] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0030] Fig. Figure 1 shows a schematic representation of a method for manufacturing a laminated core 10 for an electric machine, in this case an axial flux machine (AFM). The axial flux machine is also referred to as an axial flux motor. In its fully manufactured state, the axial flux machine has a rotor and a stator, by means of which the rotor can be driven and thus rotated about a machine axis relative to the stator. The axial flux machine is used, for example, to drive a motor vehicle, particularly a passenger car, electrically. The axial flux machine can, for example, provide drive torques via its rotor for the purely electrical drive of the motor vehicle.The laminated core 10 is used, for example, as a laminated core for the rotor and thus as a rotor laminated core, or as a laminated core for the stator and thus as a stator laminated core.

[0031] In this process, a strip 12, for example made of sheet metal, in particular electrical steel, is wound around an imaginary winding axis 14 to form a coil 16 such that respective length ranges L of the strip 12 form layers 18 arranged one above the other in the radial direction of the laminated core 10. The radial direction of the laminated core 10, whose axial direction is perpendicular to the radial direction of the laminated core 10 and coincides with the winding axis 14 in this case, is illustrated by a double arrow 20. In the fully manufactured state of the electrical machine, whose axial direction coincides with the machine's axis of rotation, the axial direction of the laminated core 10 coincides with the axial direction of the electrical machine, whose radial direction is perpendicular to the axial direction of the electrical machine.Thus, in the fully manufactured state of the electric machine, the radial direction of the laminated core 10 coincides with the radial direction of the electric machine.

[0032] Out of Fig. Figure 2 shows that the strip 12 has two opposite ends E1 and E2, and terminates at these ends, which are opposite each other when viewed along the winding axis 14. Thus, the ends E1 and E2 are located on opposite sides S1 and S2 of the strip 12, with sides S1 and S2 opposite each other along the winding axis 14. As will be explained in more detail below, the process involves trimming on both sides, that is, trimming the strip 12 laterally on both sides, E1 and E2. The process will be explained below using the example of end E1, and thus side S1. However, the preceding and following explanations regarding side S1 and end E1 can readily be applied to side S2 and end E2, and vice versa.

[0033] In this process, a first edge region R1 of the strip 12, which ends at the first edge region R1 when viewed along the winding axis 14, is trimmed by high-speed shearing at a cutting speed of more than 2.2 meters per second. The edge region R1 is located on side S1, i.e., at end E1. A further edge region of the strip 12, opposite edge region R1 along the winding axis 14 and thus located at end E2, i.e., on side S2, is designated WR. This further edge region WR, at which the strip 12 ends when viewed along the winding axis 14, is also trimmed by high-speed shearing at a cutting speed of more than 2.2 meters per second. In particular, the edge regions R1 and WR are trimmed simultaneously. The preceding and following explanations regarding edge region R1 can readily be applied to the further edge region WR, and vice versa.

[0034] Fig. Figure 2 shows a schematic top view of band 12. From Fig. Figure 1 shows that the tape 12 is unwound from a second spool 22 and, in particular, is moved translationally in a direction of movement illustrated by an arrow 24, especially at a speed also referred to as the feed rate v. In the embodiment shown in the figures, the edge region R1 is trimmed in a state in which the edge region R1 has not yet been wound onto the spool 16 and has already been unwound from the spool 22. In particular, the edge region R1 is trimmed in a state in which the edge region R1 is flat and thus lies in a plane, with the winding axis 14 running parallel to or in the plane.

[0035] In the embodiment shown in the figures, the first edge region R1 extends only over a first part of the entire longitudinal extent of the strip 12, which runs perpendicular to the winding axis 14 and whose longitudinal extent is illustrated by a double arrow 26. The first edge region R1 is trimmed, while a second edge region R2 of the strip 12, which extends only over a second part of the entire longitudinal extent of the strip 12, which runs perpendicular to the winding axis 14 and directly adjoins the first edge region R1 along the longitudinal extent of the strip 12, is not trimmed. Viewed along the winding axis 14, the second edge region R2 ends at the second edge region R2. Like the edge region R1, the edge region R2 is also located at the end E1 and thus on side S1. Therefore, for example, the edge regions R1 and R2 are respective parts of the end E1. Fig. Figure 2 illustrates a third edge region of the tape 12, R3, which, viewed along the winding axis 14, terminates at the third edge region R3. Edge region R3 is also located at end E1 and thus on side S1, so that edge regions R1, R2, and R3 are located at the same end E1 and thus on the same side S1 of the tape 12. Edge region R3 lies in front of edge region R1 in the direction of movement, with edge region R1 adjoining edge region R3 along the length of the tape 12 and opposite to the direction of movement. Edge region R1 is trimmed, while edge region R3 is already trimmed. In other words, edge region R3 lies between edge regions R2 and R3 along the length of the tape 12, each of which adjoins edge region R1 directly.Accordingly, for example, the further edge region WR lies between two edge regions arranged at end E2 and thus on side S2, which each connect directly to the further edge region WR along the longitudinal extent of the strip 12. The preceding and following explanations regarding the edge regions R2 and R3 can readily be applied to the edge regions between which the edge region WR lies.

[0036] In the embodiment shown in the figures, the first edge region R1 is a first part of a first length region L1 of the strip. Thus, for example, the further edge region WR is also part of the first length region L1. In other words, for example, the length region L1 comprises the edge regions R1 and WR.

[0037] The edge regions R1 and WR are trimmed, particularly simultaneously, by means of a tool 28, which is preferably a punching tool. For this purpose, the first length region L1 is moved translationally in the direction of movement (arrow 24) relative to the tool 28 and thereby moved into the tool 28. The edge regions R1 and WR are trimmed, particularly simultaneously, by means of the tool 28 while the first length region L1 is arranged in the tool 28 and while a movement of the first length region L1, and thus of the edge regions R1 and WR, in the direction of movement and relative to the tool 28 does not occur. The edge region R2 is, for example, a component or part of a second length region L2 of the strip 12, wherein, for example, the second length region L2 adjoins the length region L1 directly opposite the direction of movement.The edge region R3, for example, is a component or part of a third length region L3 of the strip 12, wherein, for example, the second length region L1 adjoins the third length region L3 directly opposite the direction of movement. Thus, for example, a first of the edge regions arranged at the end E2, between which the further edge region WR is arranged, is a component of the length region L2, and, for example, a second of the edge regions arranged at the end E2, between which the further edge region WR lies or is arranged, is a component of the third length region L3.The edge areas R1 and WR are trimmed, for example, by means of the tool 28, while the first length area L1 is arranged in the tool 28, and while the length areas L2 and L3 are arranged outside the tool 28, and, for example, while movements of the length areas L2 and L3 in the direction of movement and relative to the tool 28 do not occur.

[0038] To produce the sheet metal stack 10 in a particularly time- and cost-effective manner while maintaining high component quality, it is provided, for example, that the edge regions R1 and WR are trimmed using the tool 28, while a fourth length region L4 of the strip 12, running in the direction of movement (arrow 24) in front of the first length region L1 and, for example, also in front of the third length region L3, is wound onto the spool 16. The trimming of length region L1 and the winding of length region L4 thus occur simultaneously, but are decoupled from each other, since length region L4 is wound onto the spool 16, while length region L1 does not move relative to the tool 28 and in the direction of movement.This is realized, for example, in such a way that the length range L3 and / or a further length range of the strip 12 arranged between the length ranges L3 and L4 forms a length allowance, for example in the form of a fold or a wave, wherein, for example, by winding the length range L4 to the coil 16 pulse space dimension, while movements of the length range L1 relative to the tool 28 and in the direction of movement are omitted, the length allowance, i.e. the fold or wave, is reduced or eliminated.

[0039] A second tool, designated 30, is provided in addition to tool 28. Tool 30, which is designed, for example, as a punching tool, can be used to trim the strip 12, thereby creating, for example, recesses 32 in the strip. The recesses 32 are also referred to as holes or perforations, whereby, for example, each recess 32 is not produced as a through-hole, but rather as a blind hole. Thus, for example, after the length range L1, i.e., the edge regions R1 and WR, has been trimmed by tool 28, the length range L1 is additionally trimmed by tool 30, thereby creating at least one of the recesses 32 in the length range L1.For example, at least one cooling channel through which a coolant flows for cooling the laminated core 10, or a receptacle (also referred to as a magnet pocket) for receiving a magnet, in particular a permanent magnet, or a receptacle for receiving a winding, is formed from the recess 32. In particular, it is conceivable that the at least one recess 32 is formed in the edge region R1.

[0040] Fig. Figure 3 shows the band 12 in a schematic cross-sectional view, while the band 12 is trimmed in its edge areas R1 and WR using tool 28. Fig. Figure 4 shows a schematic cross-sectional view of band 12 after trimming of band 12 in the edge regions R1 and WR. Fig. 3 and Fig.Figure 4 shows that by trimming the edge areas R1 and WR using high-speed shear cutting, excessive deformations, and in particular excessive edge inward curling, can be avoided. This ensures a particularly high component quality for the sheet metal stack 10. Reference symbol list 10 sheet metal packages Volume 12 14 winding axis 16 coil 18 layers 20 Double Arrow 22 coil 24 Arrow 26 Double Arrow 28 tools 30 second tool E1 first end E2 second end L Length ranges L1 first length range L2 second length range L3 third length range L4 fourth length range R1 first boundary area R2 second boundary area R3 third boundary area S1 first page S2 second page QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2021 003 706 A1

[0002] DE 10 2007 019 911 A1

[0002] EP 2 355 313 ​​A1

[0002] WO 2016 / 113567 A1

[0002] EP 3 245 719 A0

[0002] US 2010 / 0090555 A1

[0002] DE 10 2016 207 944 A1

[0002] JP 2019 - 1655519 A1

[0002]

Claims

[1] Method for producing a laminated core (10) for an electrical machine, in which a strip (12) is wound around a winding axis (14) to form a coil (16) in such a way that respective length regions (L) of the strip (12) form layers (18) arranged one on top of the other in the radial direction (20) of the laminated core (10), characterized by that at least one edge region (R1) of the strip (12), which ends along the winding axis (14) at the at least one edge region (R1), is trimmed by high-speed shear cutting at a cutting speed of more than 2.2 meters per second. [2] Method according to claim 1, characterized by that the at least one edge region (R1) is trimmed in a state in which the at least one edge region (R1) has not yet been wound into the coil (16). [3] Method according to claim 1 or 2, characterized bythat the at least one edge region (R1) extends over the entire longitudinal extent (26) of the band (12) running perpendicular to the winding axis (14). [4] Method according to claim 1 or 2, characterized by in that the at least one edge region (R1) extends over a first part of the entire longitudinal extent (26) of the strip (12) running perpendicular to the winding axis (14), wherein the at least one edge region (R1) is trimmed, while a second edge region (R2) of the strip (12) extending over a second part of the entire longitudinal extent (26) of the strip (12) running perpendicular to the winding axis (14) and directly adjoining the at least one edge region (R1) along the longitudinal extent (26) of the strip (12), the first edge region (R2) and second edge region (R2) of which are arranged at the same end (E1) of the strip (12), is omitted, which second edge region ends along the winding axis (14) at the second edge region (R2). [5] Method according to claim 4, characterized by that after trimming the at least one edge region (R1), the second edge region (R2) is also trimmed by high-speed shear cutting at a cutting speed of more than 2.2 meters per second. [6] Method according to one of the preceding claims, characterized by that the at least one edge region (R1) is part of a first length region (L1) of the band (12). [7] Method according to claim 6, characterized by , that: - the at least one edge region (R1) is trimmed by means of a tool (28); - the first length region (L1) is moved translationally in a direction of movement (24) relative to the tool (28) and is thereby moved into the tool (28); and - the at least one edge region (R1) is trimmed while the first length region (L1) is arranged in the tool (28) and while a movement of the first length region (L1) in the direction of movement (24) and relative to the tool (28) is omitted. [8] Method according to claim 7, characterized by that the at least one edge region (R1) is trimmed, while a second length region (L4) of the band (12), which runs in front of the first length region (L1) as viewed in the direction of movement (24), is wound around the winding axis (14) to the reel (16). [9] Method according to one of claims 6 to 8, characterized bythat the first length region (L1) is additionally trimmed, whereby at least one recess (32) is produced in the first length region (L1), from which at least one cooling channel through which a coolant can flow for cooling the laminated core (10) and / or at least one receptacle for receiving a magnet and / or for receiving a winding is produced. [10] Method according to claim 9, characterized by that the first length region (L1) is additionally trimmed after trimming the at least one edge region (R1).

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