Manufacturing system and process for the manufacture of a stator and / or a rotor of an electric machine, as well as a computer program product

Abstract

Manufacturing system (1) for the manufacture of a stator (2) and / or a rotor (3) of an electric machine (4), comprising: wherein a holding tool (5) for receiving a plurality of stacked annular disc-shaped electrical steel sheets (6), wherein the holding tool (6) has a clamping mandrel (7) for fixing the electrical steel sheets (6) to the inner diameter (8) of the clamping mandrel (7), and a base plate (10) at a first axial end (9) of the clamping mandrel (7) and a cover plate (12) at a second axial end (11), wherein an axial stress can be introduced into the electrical steel sheets (6) arranged on the clamping mandrel (7) via the base plate (10) and / or the cover plate (11); a baking lacquer tool (20) into which the holding tool (5) equipped with the electrical steel sheets (6) can be inserted and adjusted to a baking lacquer temperature; a transfer molding tool (30) into which the holding tool (5) equipped with the electrical steel sheets (6) can be inserted and adjusted to a molding temperature, characterized in that the holding tool (5) comprises a injection geometry which, in a state inserted into the transfer molding tool (30), influences the shaping and / or the flow of the plastic during the transfer molding process.

Description

[0001] The present invention relates to a manufacturing system for producing a stator and / or a rotor of an electric machine. The invention further relates to a method for producing a stator and / or a rotor of an electric machine, as well as a computer program product.

[0002] Electric motors are increasingly being used for propulsion in motor vehicles to create alternatives to combustion engines that require fossil fuels. Considerable efforts have already been made to improve the everyday usability of electric drives and to offer users the familiar driving comfort.

[0003] In the manufacturing process of rotors for electric machines, such as those used in the drive trains of electric vehicles, electrical steel sheets are first stamped to form the basis of the rotor stacks. These stamped sheets are then carefully stacked, and a special baking varnish is applied. This varnish serves both to insulate the individual sheets and to optimize the magnetic and mechanical properties of the stack. This baking varnish can be applied to or incorporated into the stack, for example, by dip impregnation or trickle impregnation.

[0004] In the next step, the stacked and enamelled lamination stacks are placed in a special mold and heated. This baking process hardens the enamel and firmly bonds the individual laminations together, contributing to the structural integrity of the rotor. After this process is complete and the stacks have cooled, the lamination stacks with the hardened enamel are transferred to a new mold. At this stage of the process, the magnets, essential for generating the magnetic poles in the rotor, can be inserted into the formed rotor body. This rotor body, now equipped with the magnets, is then subjected to another heating process. Subsequently, in the transfer molding process, a special molding material, typically a thermoplastic or thermoset, is introduced into the structure of the rotor body.This material helps to fix the magnets in the magnet pockets of the rotor body, to seal the rotor and to ensure its geometric shape and mechanical strength.

[0005] RU 2 390 905 C1 discloses a method for manufacturing a valve induction generator. The method comprises manufacturing the magnetic cores of the stator and rotor by bonding and pressing slotted electrical steel laminations into stacks, and installing the stator and rotor in the generator housing. Furthermore, the windings are inserted into the slots of the stator magnetic coils and insulated within the housing. The electrical steel laminations are bonded together using silicone lacquer to improve the reliability and service life of the generator.

[0006] DE 10 2021 111 346 A1 discloses a method for manufacturing a laminated core of an electric machine. This method comprises providing laminations, applying an adhesive to these laminations, and arranging a defined initial number of adhesive-coated laminations into a partial stack. The adhesive is then activated, and the partial stack is punched to produce a punched partial laminated core. Subsequently, several of these partial laminated cores are arranged into a stack, which is heated, pressed, and joined while a molding compound is simultaneously injected to bond the partial laminated cores and form the final laminated core.

[0007] US 4,093,413 A discloses an apparatus for the automated production of perforated composite articles in repetitive cycles. The apparatus comprises a machine that applies molten material around an insert by die casting or injection molding, a plurality of mandrels for forming temporary mandrel-with-insert and mandrel-with-composite combinations, and an unloading station for unloading composites and a loading station for loading the mandrels. A loading system with holding means enables the performance of a series of operations in suitable temporal sequences, including the extraction of a mandrel with composite and the loading of a mandrel with insert at a common loading / unloading position of the machine.

[0008] The object of the invention is to provide a manufacturing system for producing a stator and / or a rotor of an electric machine that allows for particularly energy-efficient production of the rotor and / or stator. It is further an object of the invention to provide an energy-optimized method for producing a stator and / or a rotor of an electric machine. A further object of the invention is to provide a correspondingly improved computer program.

[0009] This task is solved by a manufacturing system for producing a stator and / or a rotor of an electric machine, comprising: - A holding tool for receiving a plurality of stacked ring-shaped electrical steel sheets, wherein the holding tool has a clamping mandrel for fixing the electrical steel sheets to the inner diameter of the clamping mandrel, and a base plate at a first axial end of the clamping mandrel and a cover plate at a second axial end, wherein an axial tension can be introduced into the electrical steel sheets arranged on the clamping mandrel via the base plate and / or the cover plate; - A baking lacquer tool into which the holding tool equipped with the electrical steel sheets can be inserted and which can be set to a baking lacquer temperature; - A transfer molding tool into which the holding tool equipped with the electrical steel sheets can be inserted and adjusted to a molding temperature.

[0010] The manufacturing system according to the invention thus allows, in particular, the integration of the thermal processes in the two production steps of baking and transfer molding by the holding tool. This offers the advantage of providing a manufacturing system in which multiple heating of the rotor during its production is avoided, leading to corresponding savings in energy costs and plant investments, and ultimately contributing to a more efficient and cost-effective production of an electric machine.

[0011] A key element of the manufacturing system according to the invention is the holding tool, which can also be referred to as the tool core. The holding tool comprises a mandrel for fixing the electrical steel sheets to its inner diameter, as well as a base plate and a cover plate, which can, for example, apply axial tension to the electrical steel sheets via spring elements. This holding tool thus serves, among other things, to hold the electrical steel sheets, for handling between the back-coating tool and the transfer molding tool, and preferably also for shaping by means of an injection geometry for the molding process.

[0012] It is further provided that the holding tool includes a gate geometry which, when inserted into the transfer molding tool, influences the shaping and / or the flow of the plastic during the transfer molding process. This allows the electrical steel sheets 6 to remain in the holding tool throughout the process chain and does not need to be transferred to a separate injection mold. The holding tool thus forms part of the transfer molding tool.

[0013] According to an advantageous embodiment of the invention, the transfer molding tool and / or the holding tool can be provided with a temperature sensor for determining the temperature of the electrical steel sheets, thus enabling very precise thermal management of the manufacturing process. It is particularly advantageous to arrange the temperature sensor in the holding tool, as it then "travels" with the process chain and no separate sensors need to be provided in the backcoat tool and / or transfer molding tool.

[0014] The object of the invention is further achieved by a method for manufacturing a stator and / or a rotor of an electrical machine, comprising the following steps: - Provision of a holding tool for receiving a plurality of stacked annular disc-shaped electrical steel sheets, wherein the holding tool has a clamping mandrel for fixing the electrical steel sheets to the inner diameter of the clamping mandrel, and a base plate at a first axial end of the clamping mandrel and a cover plate at a second axial end, wherein an axial tension can be introduced into the electrical steel sheets arranged on the clamping mandrel via the base plate and / or the cover plate; a) Placing the electrical steel sheets onto the mandrel of the holding tool; b) Applying an axial stress to the electrical steel sheets arranged on the mandrel by means of the base plate and / or the cover plate; c) Inserting the mandrel into a baking varnish tool; wherein steps a) can be performed in any order; d) Adjusting the electrical steel sheets fixed to the holding tool to a baking lacquer temperature; e) Removal of the holding tool from the back lacquer tool; f) Inserting the holding tool into a transfer molding tool; g) Setting the electrical steel sheets fixed to the holding tool to a molding temperature; the steps eg may be carried out in any order; h) Overmolding the electrical steel sheets in the transfer molding tool with a plastic.

[0015] Furthermore, it is planned that the electrical steel sheets fixed to the holding tool will be set to a molding temperature lower than the baking lacquer temperature. This eliminates the need for reheating and the introduction of thermal energy during transfer molding, which is naturally very energy-efficient and therefore highly preferred.

[0016] Electrical steel sheets can be stacked using various methods. For example, they can be stacked, where the individual sheet laminations are simply stacked on top of each other. This is the simplest and most cost-effective type of stacking, but it can lead to increased magnetic loss. To reduce this loss, a sheet stack can also be configured as a layered stack, where the sheet laminations are arranged in layers, with each layer rotated by a specific angle. This reduces eddy current losses and improves the magnetic properties.It is also conceivable to package the electrical steel sheets using segmented packaging, in which the sheet laminations are divided into segmented parts that are then assembled into a complete stack. This can contribute to precise control of the magnetic properties and a reduction in eddy current losses. Alternatively, the electrical steel sheets could be produced using skew-cut or angled packaging, in which the sheet laminations are cut at an angle and then reassembled into a stack. This can reduce unwanted noise and vibration. Finally, the sheet stack arrangement could be configured as step-lap packaging, in which the sheet laminations are arranged so that their ends overlap, thereby increasing mechanical stability and reducing magnetic losses.

[0017] The application of the baking varnish to the electrical steel sheets can be carried out in various ways. Preferably, the baking varnish is applied to the electrical steel sheets using a method selected from the group consisting of dipping, spraying, rolling, impregnation and / or powder coating processes.

[0018] In the dipping process, the stacked electrical steel sheets are immersed in the curing lacquer. After dipping, the excess lacquer is drained off, and the sheets undergo a thermal curing process in which the lacquer hardens, bonding and insulating the sheets together. In a spraying process, the curing lacquer is sprayed onto the electrical steel sheets. This allows for precise application of the lacquer to the desired areas. After the lacquer is applied, the stack of electrical steel sheets is thermally cured to ensure a strong bond and insulation. In the roller coating process, the lacquer is applied to the electrical steel sheets using rollers. This allows for an even distribution of the lacquer across the entire surface of the electrical steel sheets. After the lacquer is applied, the thermal curing process takes place to fix and insulate the sheets.In the impregnation process, the stacked electrical steel sheets are soaked with liquid enamel, allowing the enamel to penetrate the spaces between the sheets. After impregnation, the sheets are thermally cured, causing the enamel to harden and form a solid, insulating layer between the sheets. In a powder coating process, a powder coating is electrostatically applied to the electrical steel sheets and then thermally baked. This creates a continuous, insulating layer that effectively bonds the sheets.

[0019] It is understood that the application of the baking lacquer to the electrical steel sheets preferably takes place before the electrical steel sheets, fixed to the holding tool, are brought to a baking lacquer temperature. Preferably, the application of the baking lacquer to the electrical steel sheets is carried out before the mandrel with the electrical steel sheets is inserted into a baking lacquer tool.

[0020] The baking lacquer tool includes, in particular, a thermal energy source for heating the electrical steel sheets coated with the baking lacquer to the required baking lacquer temperature for the lacquer to harden. In its simplest form, the baking lacquer tool can be an oven.

[0021] During the thermal curing of the bonding lacquer in the bonding tool, also known as "baking," the lacquer is hardened by heating to bond and insulate the electrical steel sheets. The curing temperature of the bonding lacquer depends on the specific type of lacquer used and its chemical properties. Preferably, the curing temperature of the bonding lacquer is between 150°C and 200°C. During the curing process, the temperature should be controlled as precisely as possible to ensure that the lacquer cures uniformly and achieves the desired mechanical and electrical properties. Therefore, it may be advantageous for the bonding tool and / or the holding tool to have a temperature sensor. The curing process can last from a few minutes to several hours, again depending on the specific lacquer formulation and the process requirements.

[0022] A baking varnish can, for example, be selected from the group of epoxy resins, polyester resins, polyurethane resins, alkyd resins, silicone resins, acrylic resins, phenolic resins, melamine resins.

[0023] According to a further particularly preferred embodiment of the invention, the removal of the holding tool from the baking lacquer tool can take place at a temperature of the electrical steel sheets that is between 0.5 and 1.0 times the baking lacquer temperature. This achieves, in particular, the effect that the heat content of the electrical steel sheets and / or the holding tool is still sufficiently high to reduce or even completely prevent the reintroduction of thermal energy during the subsequent transfer molding process.

[0024] Furthermore, the invention can also be further developed such that the insertion of the holding tool into a transfer molding tool takes place at a temperature of the electrical steel sheets that is between 0.5 and 1.0 times the baking lacquer temperature. The advantage of this embodiment is also that the thermal energy content of the electrical steel sheets and / or the holding tool from the baking of the electrical steel sheets is still so high that the introduction of additional thermal energy can be reduced or even completely dispensed with.

[0025] It can also be advantageous to further develop the invention such that the transfer molding tool and / or the holding tool has a temperature sensor for determining the temperature of the electrical steel sheets, and the overmolding of the electrical steel sheets with the plastic in the transfer molding tool only takes place when a signal representing the molding temperature is present at a process control unit of the transfer molding tool via the temperature sensor. The advantage that can be achieved in this way is that very precise thermal management of the manufacturing process is enabled. It is particularly advantageous to arrange the temperature sensor in the holding tool, since it then "travels with" the process chain and no separate sensors need to be provided in the backcoat tool and / or transfer molding tool.

[0026] According to a further preferred embodiment of the invention, it can be provided that after placing the electrical steel sheets on the mandrel of the holding tool and before applying axial tension to the electrical steel sheets arranged on the mandrel by means of the base plate and / or the cover plate, a plurality of permanent magnets are inserted into the corresponding magnetic pockets of the electrical steel sheets.

[0027] Finally, the problem of the invention can also be solved by a computer program product stored on a machine-readable medium, or a computer data signal embodied by an electromagnetic wave, with a computer program code suitable for carrying out a method according to one of claims 4-9.

[0028] The invention will now be explained in more detail with reference to figures, without limiting the general concept of the invention.

[0029] It shows: Fig. 1. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a first manufacturing step in a schematic representation. Fig. 2. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a second manufacturing step in a schematic representation. Fig. 3. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a third manufacturing step in a schematic representation. Fig. 4. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a fourth manufacturing step in a schematic representation. Fig. 5. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a fifth manufacturing step in a schematic representation. Fig. 6. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a sixth manufacturing step in a schematic representation. Fig. 7. The manufacturing system for producing a stator and / or a rotor of an electrical machine in a seventh manufacturing step in a schematic representation. Fig. 8. A schematic representation of a stator and / or a rotor of an electrical machine after an eighth manufacturing step, Fig. 9 an electric machine with a rotor and a stator in a schematic axial section view.

[0030] The Fig. Figures 1-7 show a manufacturing system 1 for the production of a stator 2 and / or a rotor 3 of an electric machine 4 in various manufacturing steps.

[0031] Fig. Figure 1 shows a plurality of already stamped and stacked ring-shaped electrical steel sheets 6, from which a stator 2 or a rotor 3 of an electric machine 4 is to be manufactured. Such an electric machine 4 is shown as an example in the Fig. 9 shown.

[0032] The manufacturing system 1 comprises a holding tool 5 for receiving the stacked ring-shaped electrical steel sheets 6, wherein the holding tool 6 has a clamping mandrel 7 for fixing the electrical steel sheets 6 to the inner diameter 8 of the clamping mandrel 7, and a base plate 10 at a first axial end 9 of the clamping mandrel 7. The electrical steel sheets 6 are then placed onto the clamping mandrel 7 of the holding tool 6 and rest axially against the base plate 10 on one side. This condition is in the Fig. 2 shown.

[0033] In this state, a cover plate 12 is then arranged at the second axial end 11 of the holding tool 5, whereby an axial tension is introduced into the electrical steel sheets 6 arranged on the clamping mandrel 7 via the base plate 10 and / or the cover plate 11, which contributes to improved stacking of the electrical steel sheets 6. In this, in the Fig. 3. In the manufacturing state shown, the liquid baking lacquer can then be applied to or introduced into the stack of electrical steel sheets 6.

[0034] How to use the Fig. 4 recognizes, the manufacturing system 1 also has a baking lacquer tool 20, into which the holding tool 5 equipped with the wetted electrical steel sheets 6 is inserted and set to a baking lacquer temperature, so that the baking lacquer thermally hardens.

[0035] After the electrical steel sheets 6 are placed on the mandrel 7 of the holding tool 6 and before axial tension is applied to the electrical steel sheets 6 by means of the base plate 10 and / or the cover plate 11, a plurality of permanent magnets are inserted into the corresponding magnetic pockets of the electrical steel sheets 6. This is possible because the stack of electrical steel sheets 6 equipped with the permanent magnets remains in the holding tool 5 during the subsequent process steps, in particular up to and during the transfer molding. The temperature sensor can then also determine when the electrical steel sheets 6 have cooled sufficiently from the coating temperature to reach the molding temperature, which is usually slightly below the coating temperature. When the molding temperature is reached, the injection of the plastic 31 is triggered in the molding tool and the electrical steel sheets are overmolded with the plastic 31.

[0036] The holding tool 5 is therefore removed from the baking lacquer tool 20 after baking and inserted into a transfer molding tool 30, where it is set to the molding temperature. The electrical steel sheets 6 are then overmolded with a plastic 31 in the transfer molding tool 30, which results in the Fig. 5-6 can be seen. For thermal process control, the transfer molding tool 30 and / or the holding tool 5 can have a temperature sensor to determine the temperature of the electrical steel sheets 6. The Fig. It can also be inferred from figures 5-6 that the holding tool 5 includes a injection geometry which, in a state inserted into the transfer molding tool 30, influences the shaping and / or the flow of the plastic during the transfer molding process.

[0037] After transfer molding, the holding tool 5 with the electrical steel sheets 6 is removed from the transfer molding tool 30, which is in the Fig. Figure 7 shows that the rotor 3 or the stator 2 is then removed from the holding tool 5, as shown in the figure. Fig. 8 can be seen.

[0038] The rotor 3 or the stator 2 can then be used in an electric machine 4, for example a radial flux machine, as used in the Fig. 9 is outlined.

[0039] The invention is not limited to the embodiments illustrated in the figures. The foregoing description is therefore not to be considered limiting, but rather explanatory. The following claims are to be understood as meaning that a named feature is present in at least one embodiment of the invention. This does not preclude the presence of further features. Insofar as the claims and the foregoing description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing any hierarchy. Reference symbol list 1 Manufacturing system 2 Stator 3 Rotor 4 electric machine 5 Holding tool 6 electrical steel sheets 7 mandrel 8 inner diameter 9 End 10 Base plate 11 End 12 Cover plate 20 Baking varnish tools 30 Transfer Molding Tools 31 Plastic

Claims

[1] Manufacturing system (1) for manufacturing a stator (2) and / or a rotor (3) of an electric machine (4), comprising: wherein a holding tool (5) for receiving a plurality of stacked annular disc-shaped electrical steel sheets (6), wherein the holding tool (6) has a clamping mandrel (7) for fixing the electrical steel sheets (6) to the inner diameter (8) of the clamping mandrel (7), and a base plate (10) at a first axial end (9) of the clamping mandrel (7) and a cover plate (12) at a second axial end (11), wherein an axial stress can be introduced into the electrical steel sheets (6) arranged on the clamping mandrel (7) via the base plate (10) and / or the cover plate (11); a baking lacquer tool (20) into which the holding tool (5) equipped with the electrical steel sheets (6) can be inserted and adjusted to a baking lacquer temperature; a transfer molding tool (30) into which the holding tool (5) equipped with the electrical steel sheets (6) can be inserted and adjusted to a molding temperature, characterized by , that the holding tool (5) includes a injection geometry which, in a state inserted into the transfer molding tool (30), influences the shaping and / or flow of the plastic during the transfer molding process. [2] Manufacturing system (1) according to claim 1, characterized by , that the transfer molding tool (30) and / or the holding tool (5) has a temperature sensor for determining the temperature of the electrical steel sheets (6). [3] Method for manufacturing a stator (2) and / or a rotor (3) of an electrical machine (4), comprising the following steps: • Provision of a holding tool (5) for receiving a plurality of stacked annular disc-shaped electrical steel sheets (6), wherein the holding tool (6) has a clamping mandrel (7) for fixing the electrical steel sheets (6) to the inner diameter (8) of the clamping mandrel (7), and a base plate (10) at a first axial end (9) of the clamping mandrel (7) and a cover plate (12) at a second axial end (11), wherein an axial stress can be introduced into the electrical steel sheets (6) arranged on the clamping mandrel (7) via the base plate (10) and / or the cover plate (11); a) Placing the electrical steel sheets (6) onto the mandrel (7) of the holding tool (6); b) Applying an axial stress to the electrical steel sheets (6) arranged on the mandrel (7) by means of the base plate (10) and / or the cover plate (11); c) Inserting the mandrel (7) into a baking varnish tool (20); • where steps a)-c) can be performed in any order; d) Adjusting the electrical steel sheets (6) fixed to the holding tool (5) to a baking lacquer temperature; e) Removal of the holding tool (5) from the back lacquer tool (20); f) Inserting the holding tool (5) into a transfer molding tool (30); g) Adjusting the electrical steel sheets (6) fixed to the holding tool (5) to a moulding temperature; • where steps e)-g) can be performed in any order; h) Overmolding the electrical steel sheets (6) in the transfer molding tool (30) with a plastic, characterized by , that the electrical steel sheets (6) fixed to the holding tool (5) are set to a moulding temperature which is lower than the baking lacquer temperature; [4] Method according to claim 3, characterized by , that the removal of the holding tool (5) from the baking lacquer tool (20) takes place at a temperature of the electrical steel sheets (6) that is between 0.5-1.0 times the baking lacquer temperature; . [5] Method according to claim 3 or 4, characterized by , that the insertion of the holding tool (5) into a transfer molding tool (30) takes place at a temperature of the electrical steel sheets (6) that is between 0.5-1.0 times the baking lacquer temperature; [6] Method according to any one of claims 3 to 5, characterized by , that the transfer molding tool (30) and / or the holding tool (5) has a temperature sensor for determining the temperature of the electrical steel sheets (6) and that the overmolding of the electrical steel sheets (6) in the transfer molding tool (30) with the plastic only takes place when a signal representing the molding temperature is present at a process control of the transfer molding tool (30) via the temperature sensor. [7] Method according to any one of claims 3 to 6, characterized by, that after placing the electrical steel sheets (6) on the mandrel (7) of the holding tool (6) and before applying axial tension to the electrical steel sheets (6) arranged on the mandrel (7) by means of the base plate (10) and / or the cover plate (11), a plurality of permanent magnets are inserted into the corresponding magnet pockets of the electrical steel sheets (6). [8] Computer program product stored on a machine-readable medium or computer data signal embodied by an electromagnetic wave, comprising computer program code suitable for carrying out a method according to any one of claims 3 to 7.

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