Method for producing a laminated core for an electrical machine, in particular for an axial flux machine

Abstract

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 on top of one another 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 at a cutting speed of more than 2.2 meters per second, characterized 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 trimming of a second part of the entire,perpendicular to the winding axis (14) extending longitudinal extent (26) of the band (12) and along the longitudinal extent (26) of the band (12) directly adjoining the at least one edge region (R1), the second edge region (R2) of the band (12), the first edge region (R1) and the second edge region (R2) of which are arranged at the same end (E1) of the band (12), is omitted, which ends along the winding axis (14) at the second edge region (R2).

Description

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

[0002] The generic document DE 10 2021 003 706 A1 discloses a method for producing a rotor for an electrical machine. Furthermore, DE 10 2007 019 911 A1 discloses a method for producing sheet metal parts, in particular electrical sheet metal parts. An axial flux machine, also referred to as an axial flux motor, is known from EP 2 355 313 ​​A1. Furthermore, WO 2016 / 113 567 A1 and EP 3 245 719 A1 disclose an axial flux machine. An axial flux machine is also known from US 2010 / 0 090 555 A1. DE 10 2016 207 944 A1 discloses a package system for an electrical machine. Furthermore, JP 2019 - 165 519 A also states that an axial flux machine is known.

[0003] DE 10 2012 005 005 B4 describes a method and an assembly for producing electrical laminations for iron cores (lamination stacks) of electrical machines. The assembly for carrying out the method comprises a first pair of rollers for joining an endless electrical lamination strip and an endless carrier strip to create a composite, and a second pair of rollers consisting of a punching roller and a separating device for subsequently separating the punched grid from the carrier strip.

[0004] The object of the present invention is to provide a method for producing a laminated core for an electrical machine, in particular for an axial flux machine, so that a high component quality and advantageous mechanical properties of the laminated core can be realized.

[0005] This object is achieved by a method having the features of patent claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] The invention relates to a method for producing a laminated core for an electrical machine, in particular for an axial flux machine also referred to as an axial flux motor. The electrical machine is preferably used in or for a motor vehicle, in particular 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. The electrical machine is preferably a high-voltage component whose electrical voltage, in particular electrical operating or nominal voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and very preferably amounts to several hundred volts. This makes it possible to achieve particularly high electrical outputs for driving the motor vehicle, in particular purely electrically.In its fully manufactured state, the electrical machine, which is preferably designed as an axial flux machine, has at least one stator and at least one rotor. In particular, when the electrical machine is designed as an axial flux machine, at least a part of the stator and at least a part of the rotor are arranged consecutively in the axial direction of the electrical machine, i.e. next to one another, one after the other, or one behind the other, in particular such that an air gap is arranged between the part of the stator and the part of the rotor in the axial direction of the electrical machine. The rotor can be driven by means of the stator and is therefore rotatable relative to the stator about an axis of rotation running in the axial direction of the electrical machine, so that, for example, the electrical machine can provide torque via its rotor for driving the motor vehicle, in particular purely electrically.

[0007] In the method, a strip is wound around a particularly imaginary winding axis to form a coil in such a way that respective lengths of the strip form layers arranged on top of one another in the radial direction of the laminated core, the axial direction of which runs perpendicular to the radial direction of the laminated core. The radial direction of the laminated core runs perpendicular to the winding axis. The axial direction of the laminated core runs parallel to the winding axis or coincides with the winding axis. In the fully manufactured state of the electrical machine, i.e. based on the fully manufactured state of the electrical machine having the laminated core, the axial direction of the laminated core runs in the axial direction of the electrical machine, the radial direction of which runs perpendicular to the axial direction of the electrical machine.Thus, in the fully manufactured state of the electrical machine, the radial direction of the laminated core runs in the radial direction of the electrical machine. The axial direction of the electrical machine coincides with the axis of rotation. In particular, the longitudinal sections are wound around the particularly imaginary winding axis in such a way that, viewed in a sectional plane running perpendicular to the axial direction of the laminated core, the longitudinal sections are wound spirally, thus extending spirally. Preferably, the laminated core is or will be disk-shaped or ring-shaped, so that the laminated core is or will be preferably designed as a ring-shaped laminated core.

[0008] Very preferably, the strip is formed from a metallic material, in particular from sheet metal and very particularly from electrical steel, so that the laminated core wound into the coil can particularly advantageously conduct a magnetic flux or a respective magnetic field that can be provided or is provided by a respective magnet. In particular, it is conceivable that, in the fully manufactured state of the electrical machine, at least the aforementioned magnet, which is designed, for example, as a permanent magnet, is carried by the laminated core. The laminated core can be used for the stator and thus as a stator laminated core of the stator. Furthermore, it is conceivable that the laminated core can be used for the rotor and thus as a rotor laminated core of the rotor.

[0009] In order to achieve particularly high component quality and particularly advantageous mechanical properties of the laminated core, the invention provides that at least one edge region of the strip, which ends at the at least one edge region along the winding axis, is trimmed by high-speed shear cutting (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 reference is made above and below to the edge region or to the at least one edge region, this means the first edge region, unless otherwise stated.Since, with regard to the method for producing the laminated core, the strip ends at the at least one edge region when viewed along the winding axis, the strip ends at the at least one edge region when viewed in the fully manufactured state of the laminated core or in the fully manufactured state of the electrical machine in the axial direction of the laminated core or the axial direction of the electrical machine. By trimming the at least one edge region, for example, an edge of the strip is formed, which, after trimming the at least one edge region, ends at the edge when viewed along the winding axis.Since at least one edge region is trimmed by high-speed shearing, excessive deformations and thus, in particular, excessive edge shrinkage, also referred to as edge shrinkage, can be avoided, so that the edge and thus the strip can be manufactured with particularly high quality. Furthermore, compared to conventional solutions, the invention enables a reduction in magnetic reversal losses, thereby enabling particularly efficient operation of the electrical machine, also referred to as an electrical machine. Since the laminated core is manufactured in such a way that the strip is wound into the coil, the laminated core is a wound laminated core, which is very preferably designed as a wound annular laminated core.

[0010] The invention is based in particular on the following findings and considerations: Axial flux machines (AFM), which are also referred to as axial flux motors, usually have a disc-shaped design, since, for example, at least the aforementioned parts of the stator and the rotor are disc-shaped. This disc-shaped design enables novel drive concepts, in particular axle drive concepts, for motor vehicles compared to conventional electrical machines designed as radial flux machines. Due to installation space constraints, the outer diameter of the axial flux machine is relatively limited, particularly for coaxial applications in passenger cars. For this reason and for reasons of efficiency, an increase in the efficiency of the respective axial flux machine is sought for future large-scale applications compared to conventional solutions.Electrical machines, particularly axial flux machines, with high power density and high speeds or speed capacities typically require high-strength and precise laminated cores, for example in the form of ring laminated cores, made of, in particular, wound strip, in particular electrical steel. Since the strip is preferably made of electrical steel, the strip is then also referred to as electrical steel. Typically, the strip, in particular a starting material from which the strip is formed, is slit in a rolling mill to a particularly predeterminable or predetermined width, whereby the strip is initially produced as a slit strip, after which the strip is typically further processed directly to produce the laminated core from the strip.In this regard, however, a technical problem has been identified, namely that technical restrictions in the rolling mill and during slit strip production, particularly with regard to surface topography, strip width, width tolerances, cut edge characteristics including grade, corrosion protection, packaging traces (impressions), etc., remain directly in the strip from which the laminated core is produced and have a limiting effect on a functional surface, for example, directly delimiting the aforementioned gap, as well as on an adhesive surface between the layers, also referred to as ring layers or designed as ring layers, and on a joining surface on a rear side of the laminated core, which can have a negative impact on efficiency. In particular, it is provided that the layers are bonded to one another using an adhesive, in particular in such a way that the respective layers are bonded to one another via their respective adhesive surfaces using the adhesive.The aforementioned problems and disadvantages can now be avoided by the invention. Especially compared to roller cutting, high-speed shear cutting enables the realization of high-quality edges, while avoiding undesirable hardening of the edge region or the edge.

[0011] In order to ensure a particularly high component quality of the laminated core, it is provided in one embodiment of the invention that the at least one edge region is trimmed in a state in which the at least one edge region is not yet wound up into the coil, so that preferably the at least one edge region is only wound up into the coil after the at least one edge region has been trimmed.

[0012] The invention 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 trimming of 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 directly adjoining the at least one edge region along the longitudinal extent of the strip is omitted, which second edge region of the strip ends along the winding axis at the second edge region.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 strip and thus on the same, in particular first, side of the strip, such that the strip ends at the at least one edge region and at the second edge region in a direction coinciding with the winding axis or running parallel to the winding axis. Thus, the strip ends at the further edge region in a second direction running parallel to the winding axis or coinciding with the winding axis and opposite the direction, such that the further edge region is arranged opposite both the at least one edge region and the second edge region when viewed along the winding axis.If the strip is trimmed in at least one edge region while the second edge region is not trimmed, the strip is not trimmed simultaneously across its entire length in this embodiment. Instead, an incremental trim, also referred to as an open cut, is provided, particularly a side trim. This allows for particularly high component quality.

[0013] In order to produce the laminated core with high quality and in a time- and cost-effective manner, an alternative embodiment can provide for the at least one edge region to extend over the entire longitudinal extent of the strip, running perpendicular to the winding axis. In this embodiment, a complete cut, also referred to as a closed cut, of the strip, for example, formed as a sheet metal strip, is thus provided, since the sheet metal strip is trimmed in its at least one edge region over its entire longitudinal extent, in particular simultaneously.

[0014] Preferably, the at least one edge region, in particular the strip, is trimmed to size by trimming the at least one edge region, i.e., to a particularly predetermined or predeterminable dimension, wherein the dimension extends, for example, along the winding axis or parallel to the winding axis. Thus, for example, the said dimension is a width of the strip running along the winding axis or parallel to the winding axis.

[0015] Very preferably, the at least one edge region is a first lateral edge region of the strip, such that the at least one edge region is arranged on a first side of the strip or at a first end of the strip, viewed along the winding axis. The strip has a second end which lies opposite the first end along the winding axis. The strip has a further edge region at the second end, such that the at least one edge region and the further edge region lie opposite one another, viewed around a winding axis. If, for example, only one-sided trimming is provided, i.e. one-sided trimming of the strip is provided, the strip is trimmed only on or in the at least one edge region with respect to the at least one edge region and the further edge region.If double-sided trimming, i.e. if the strip is to be trimmed on both sides, then both the at least one edge region and the further edge region opposite the at least one edge region along the winding axis are trimmed. The previous and following explanations regarding the at least one edge region can also be readily applied to the further edge region and vice versa. Since the at least one edge region is arranged at the first end and the further edge region at the second end, the at least one edge region and the further edge region lie opposite one another along the winding axis. In this case, the strip, viewed along the winding axis, also ends at the second end and thus also at the further edge region.When reference is made above and below to the edge region or to at least one edge region, this means, unless otherwise stated, the first edge region, i.e. the edge region of the band arranged at the first end.

[0016] High-speed shear cutting allows for the creation of adiabatic shear bands, thus avoiding excessive edge indentation, excessive kerf, and excessive hardening of at least one edge region. As a result, the laminated core can achieve particularly high component quality.

[0017] Since the further edge region is opposite the at least one edge region when viewed along the winding axis and thus in relation to the fully manufactured state of the laminated core in the axial direction of the laminated core, the further edge region or the second end is arranged on a second side of the strip, the second side of which is opposite the first side when viewed along the winding axis.

[0018] It has proven particularly advantageous if, after trimming at least one edge region, the second edge region is also trimmed using high-speed shear cutting at a cutting speed of more than 2.2 meters per second. This allows for particularly high component quality of the laminated core to be achieved.

[0019] 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, in particular when viewed along the winding axis.

[0020] In order to avoid excessive deformations resulting from the trimming of the strip and thus to be able to achieve a 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 longitudinal region 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 longitudinal region is arranged in the tool and while any movement of the first longitudinal region in the direction of movement and relative to the tool is avoided. In particular, it is provided that the at least one edge region is trimmed while relative movements between the first longitudinal region and the tool are avoided. This makes it possible to achieve a particularly high trimming quality.This enables particularly high trimming quality and thus particularly high component quality to be achieved.

[0021] In order to be able to produce the laminated core with particularly high component quality and in a particularly time- and cost-effective manner, a further embodiment of the invention provides that the at least one edge region is trimmed while the first length region is arranged in the tool, while any movement of the first length region in the direction of movement and relative to the tool is avoided, and while a second length region of the strip, which runs in front of the first length region as viewed in the direction of movement, is wound around the winding axis to form the coil. The winding of the second length region and the trimming of the first length region or of the at least one edge region thus proceed simultaneously, i.e. at the same time, but are decoupled from one another by or in such a way that the at least one edge region is trimmed while the second length region is wound onto the coil.This decoupling takes place, for example, in such a way that, viewed in the longitudinal extension of the strip, a third length region is arranged between the first length region and the second length region, which third length region, for example, initially forms a fold or a wave, in particular by the first length region being moved translationally in the direction of movement relative to the tool. If the second length region is wound up into the spool while the first length region is in the tool and the at least one edge region is trimmed, the fold or wave is, for example, at least partially removed, in particular by the third length region being pulled when the second length region is wound up onto the spool, and the fold or wave is thus at least reduced in size or removed and, in the process, in particular, smoothed out.The third length range is thus used as a buffer or length lead, so to speak, which makes it possible to wind the second length range into the coil, while relative movements between the first length range and the tool relative to the tool and in the direction of movement, in particular relative movements between the tool and the first length range as a whole, are avoided.

[0022] After trimming of the at least one edge region, for example, the first length region is moved translationally in the direction of movement relative to the tool and is thereby moved out of the tool, and for example a fourth length region of the strip, which adjoins the first length region in the opposite direction, is moved into the tool, wherein for example a fold or wave and thus a length lead is then formed from the first length region, in order then, for example, to wind up the third length region to the spool, while the fourth length region is arranged in the tool and while movements of the fourth length region in the direction of movement and relative to the tool are avoided.The above and previous statements regarding the first length range can easily be applied to the fourth length range, so that, for example, the fourth length range or its edge region is trimmed by the tool in the same way as the first length range or its edge region. Moving the strip in the direction of movement is also referred to as strip tension or feed, whereby, for example, the strip is moved in the direction of movement, particularly relative to the tool, by means of a conveying device, also referred to as a feed unit.Preferably, an incremental or step-by-step movement, in particular pulling, of the strip formed, for example, from a strip into the tool is provided, so that the strip is incrementally, i.e. step by step and thus gradually trimmed at its first end or on its first side, specifically by means of the tool and while a movement of the respective length region of the strip arranged in the tool in the direction of movement relative to the tool is avoided. This can, for example, prevent buckling of the strip in the tool designed, for example, as a punching tool, which is particularly advantageous when the strip has a particularly small wall thickness. In particular, when the strip is formed from a sheet metal, the wall thickness is also referred to as sheet thickness. The wall thickness is preferably 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 in the form of holes, in particular through-holes, in order to thereby form at least one groove and / or at least one magnetic pocket and / or at least one cooling channel in the strip or in the laminated core, for example. 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, whereby undesirable deformations such as buckling of the strip can be avoided by the incremental or step-by-step movement of the strip into the tool.

[0023] Finally, it has proven particularly advantageous if the first longitudinal region is additionally trimmed and thereby provided, for example, with at least one recess, which is designed, for example, as a through-opening or in the manner of a blind hole. This additional trimming of the first longitudinal region creates the aforementioned at least one recess in the first longitudinal region, 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.

[0024] This enables particularly high component quality to be achieved in a particularly time- and cost-effective manner.

[0025] Finally, it has proven particularly advantageous if the first longitudinal region is additionally trimmed after trimming the at least one edge region, so that the recess is preferably produced after trimming the at least one edge region. This allows the laminated core to be manufactured with a particularly high component quality.

[0026] Preferably, the strip is formed from a soft magnetic material. For example, the strip is a grain-oriented electrical steel sheet or a non-grain-oriented electrical steel sheet, wherein, in particular, the grain-oriented electrical steel sheet or the non-grain-oriented electrical steel sheet is the aforementioned soft magnetic material. Furthermore, it is conceivable for the strip to be formed from a soft magnetic composite material such as SMC (Sheet Moulding Compound). Furthermore, it is conceivable for the laminated core to be formed from an electrically magnetically conductive material such as a bipolar plate.

[0027] The invention can realize at least the following advantages: - single-sided or preferably double-sided and preferably incremental trimming of the strip by high-speed shear cutting (HGSS) - lowest width tolerance (2 IT classes better than slit strip) - less punch edge indentation and thus larger active area compared to air gap - no degree and therefore less risk of short circuits between the layers - No need for post-processing such as facing - lower electromagnetic losses (remagnetization losses smaller, due to lower cutting edge hardening) and higher efficiency of the electrical machine and thus lower cooling capacity required - no defects on 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 cutting surface quality, resulting in improved form, dimensional and position tolerances - Improvement of the cutting surface quality, resulting in improved mechanical strength due to a reduction of the notch load through the cutting surface - advantageous adaptation of the technology for battery and fuel cell components, among others

[0028] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, can be used not only in the respective specified combination, but also in other combinations or on their own, without departing from the scope of the invention.

[0029] The drawing shows: Fig. 1 a schematic representation of a method for producing a laminated core for an electrical machine, in particular for an axial flux machine; Fig. 2 a further schematic representation of the process; Fig. 3 is a schematic cross-sectional view of a strip from which the laminated core is manufactured; and Fig. 4 another schematic cross-sectional view of the belt.

[0030] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0031] Fig. 1 shows a schematic representation of a method for producing a laminated core 10 for an electrical machine, here designed as 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 of rotation relative to the stator. The axial flux machine is used, for example, to drive a motor vehicle, in particular designed as a motor vehicle, more particularly as a passenger car, in particular purely electrically. In this case, the axial flux machine can, for example, provide drive torques for the, in particular purely electrical, drive of the motor vehicle via its rotor.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.

[0032] In the method, a strip 12 made, for example, from sheet metal, in particular from electrical steel, is wound around an imaginary 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 on top of one another in the radial direction of the laminated core 10. The radial direction of the laminated core 10, whose axial direction runs perpendicular to the radial direction of the laminated core 10 and in this case coincides with the winding axis 14, 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 runs perpendicular to the axial direction of the electrical machine.Thus, in the fully manufactured state of the electrical machine, the radial direction of the laminated core 10 coincides with the radial direction of the electrical machine.

[0033] Out of Fig. 2 that the strip 12 has two opposite ends E1 and E2 and ends at the ends E1 and E2, wherein the ends E1 and E2 are opposite one another when viewed along the winding axis 14. Thus, the ends E1 and E2 are arranged on opposite sides S1 and S2 of the strip 12, wherein the sides S1 and S2 are opposite one another along the winding axis 14. As will be explained in more detail below, the method involves bilateral trimming, i.e., bilateral lateral trimming of the strip 12, which is thus trimmed at its two ends E1 and E2 and thus on its two sides S1 and S2. The method is explained below using the example of the end E1 and thus side S1 in particular, wherein the previous and following explanations regarding side S1 and end E1 can easily be transferred to side S2 and thus end E2 and vice versa.

[0034] In the method, a first edge region R1 of the strip 12, which ends at the first edge region R1 as viewed along the winding axis 14, is trimmed by high-speed shear cutting at a cutting speed of more than 2.2 meters per second. The edge region R1 is located on the side S1, thus at the end E1. A further edge region of the strip 12, opposite the edge region R1 along the winding axis 14 and thus located at the end E2, thus on the side S2, is designated WR, wherein the further edge region WR, at which the strip 12 ends as viewed along the winding axis 14, is also trimmed by high-speed shear cutting at a cutting speed of more than 2.2 meters per second. In particular, the edge regions R1 and WR are trimmed simultaneously. The previous and following explanations regarding the edge region R1 can easily be applied to the further edge region WR and vice versa.

[0035] Fig. 2 shows the belt 12 in a schematic plan view. Fig. 1 that the strip 12 is unwound from a second spool 22 and, in particular, is moved translationally in a direction of movement illustrated by an arrow 24, in particular at a speed also referred to as feed speed v. In the exemplary 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 runs in a plane, wherein the winding axis 14 runs parallel to the plane or in the plane.

[0036] In the exemplary 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 running perpendicular to the winding axis 14, the longitudinal extent of which is illustrated by a double arrow 26. The first edge region R1 is trimmed, while a second edge region R2 of the strip 12 extending only over a second part of the entire longitudinal extent of the strip 12 running perpendicular to the winding axis 14 and directly adjoining the first edge region R1 along the longitudinal extent of the strip 12 is omitted, which second edge region R2, viewed along the winding axis 14, ends at the second edge region R2. Like the edge region R1, the edge region R2 is also arranged at the end E1 and thus on the side S1. Thus, for example, the edge regions R1 and R2 are respective parts of the end E1. In Fig. 2, R3 illustrates a third edge region of the belt 12, which, viewed along the winding axis 14, ends at the third edge region R3. The edge region R3 is also arranged at the end E1 and thus on the side S1, so that the edge regions R1, R2 and R3 are arranged at the same end E1 and thus on the same side S1 of the belt 12. The edge region R3 lies in front of the edge region R1, viewed in the direction of movement, wherein the edge region R1 directly adjoins the edge region R3 in the longitudinal extension of the belt 12 and counter to the direction of movement. The edge region R1 is trimmed, while the edge region R3 has already been trimmed. In other words, the edge region R3 lies in the longitudinal extension of the belt 12 between edge regions R2 and R3, which each directly adjoin the edge region R1.Accordingly, for example, the further edge region WR lies between two edge regions arranged at the end E2 and thus on the side S2, which each directly adjoin the further edge region WR along the longitudinal extent of the band 12. The previous and following statements regarding the edge regions R2 and R3 can also be readily applied to the edge regions between which the edge region WR lies.

[0037] In the exemplary embodiment shown in the figures, the first edge region R1 is a first part of a first length range L1 of the strip. Thus, for example, the further edge region WR is also part of the first length range L1. In other words, the length range L1 comprises, for example, the edge regions R1 and WR.

[0038] The edge regions R1 and WR are trimmed, in particular simultaneously, by means of a tool 28, which is preferably a punching tool. For this purpose, the first longitudinal 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, in particular simultaneously, by means of the tool 28, while the first longitudinal region L1 is arranged in the tool 28 and while a movement of the first longitudinal region L1 and thus of the edge regions R1 and WR in the direction of movement and relative to the tool 28 is avoided. The edge region R2 is, for example, a component or part of a second longitudinal region L2 of the strip 12, wherein, for example, the second longitudinal region L2 directly adjoins the longitudinal region L1 opposite to the direction of movement.The edge region R3 is, for example, a component or part of a third length region L3 of the belt 12, wherein, for example, the second length region L1 directly adjoins the third length region L3 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 regions R1 and WR are trimmed, for example, by means of the tool 28, while the first length region L1 is arranged in the tool 28, and while the length regions L2 and L3 are arranged outside the tool 28 and, for example, while movements of the length regions L2 and L3 in the direction of movement and relative to the tool 28 are omitted.

[0039] In order to produce the laminated core 10 in a particularly time- and cost-effective manner and with 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, which runs in front of the first length region L1 and, for example, also in front of the third length region L3 as viewed in the direction of movement (arrow 24), is wound onto the coil 16. The trimming of the length region L1 and the winding of the length region L4 thus take place simultaneously, but are decoupled from one another, since the length region L4 is wound onto the coil 16, while any movement of the length region L1 relative to the tool 28 and in the direction of movement is omitted.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 lead, for example in the form of a fold or a wave, wherein, for example, by the length range L4 being wound up to the coil 16, the length lead, and thus the fold or wave, is reduced or eliminated, while movements of the length range L1 relative to the tool 28 and in the direction of movement are omitted.

[0040] A second tool, provided in particular in addition to the tool 28, is designated by 30. By means of the tool 30, which is designed, for example, as a punching tool, the strip 12 can be trimmed, in particular additionally, whereby, for example, recesses 32 in the strip can be produced. The recesses 32 are also referred to as holes or perforations, wherein, for example, the respective recess 32 is not produced as a through-opening, but in the manner of a blind hole. Thus, it is possible, for example, that after the length region L1, thus the edge regions R1 and WR, have been trimmed by means of the tool 28, the length region L1 is additionally trimmed by means of the tool 30, whereby at least one of the recesses 32 is produced in the length region L1.For example, at least one cooling channel through which a coolant can flow for cooling the laminated core 10, or a receptacle (also referred to as a magnet pocket) for accommodating a magnet, in particular a permanent magnet, or a receptacle for accommodating a winding is produced from the recess 32. In particular, it is conceivable that the at least one recess 32 is produced in the edge region R1.

[0041] Fig. 3 shows the strip 12 in a schematic cross-sectional view, while the strip 12 is trimmed in its edge regions R1 and WR by means of the tool 28. Fig. 4 shows the strip 12 in a schematic cross-sectional view after trimming the strip 12 in the edge regions R1 and WR. Fig. 3 and Fig.Figure 4 shows that by trimming the edge regions R1 and WR using high-speed shear cutting, excessive deformation and, in particular, excessive edge shrinkage can be avoided. This ensures a particularly high component quality of the laminated core 10. List of reference symbols 10 sheet packages 12 volumes 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 ending L length ranges L1 first length range L2 second length range L3 third length range L4 fourth length range R1 first edge area R2 second edge area R3 third edge area S1 first page S2 second page

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), 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 at a cutting speed of more than 2.2 meters per second, characterized byin 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), the at least one edge region (R1) being 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 (R1) 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 at the second edge region (R2) along the winding axis (14). [2] Method according to claim 1, characterized bythat 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 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. [4] 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). [5] Method according to claim 4, 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. [6] Method according to claim 5, 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). [7] Method according to one of claims 4 to 6, 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. [8] Method according to claim 7, characterized by that the first length region (L1) is additionally trimmed after trimming the at least one edge region (R1).

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