Manufacturing system and method for producing a stator and / or a rotor of an electric machine, and computer program product

Abstract

The invention relates to a manufacturing system (1) for producing a stator (2) and / or a rotor (3) of an electric machine (4), said system comprising: 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) on the inner diameter (8) of the clamping mandrel (7) and has a bottom plate (10) at a first axial end (9) of the clamping mandrel (7) and a top plate (12) at a second axial end (11), wherein axial stress can be introduced, via the bottom plate (10) and / or the top plate (11), into the electrical steel sheets (6) arranged on the clamping mandrel (7); a self-bonding varnish tool (20) into which the holding tool (5) equipped with the electrical steel sheets (6) can be inserted and set to a self-bonding varnish temperature; and a transfer moulding tool (30) into which the holding tool (5) equipped with the electrical steel sheets (6) can be inserted and set to a moulding temperature.

Description

[0001] Manufacturing system and method for producing a stator and / or a rotor of an electrical machine and computer program product

[0002] The present invention relates to a manufacturing system for producing a stator and / or a rotor of an electrical machine. The invention further relates to a method for producing a stator and / or a rotor of an electrical machine, as well as a computer program product.

[0003] Electric motors are increasingly being used to power motor vehicles, creating alternatives to combustion engines that require fossil fuels. Considerable efforts have already been made to improve the everyday suitability of electric drives and also to provide users with the same level of driving comfort they are accustomed to.

[0004] In the manufacturing process of rotors for electrical machines, such as those used in the drivetrains of electric vehicles, electrical laminations are first punched, forming the basis for the rotor stacks. These punched laminations are then carefully stacked, and a special bonding varnish is applied. This serves both to insulate the individual laminations and to optimize the magnetic and mechanical properties of the stack. This bonding varnish can be applied to the stack, for example, by dip impregnation or drip impregnation.

[0005] In the next step, the stacked laminated cores, coated with the bonding varnish, are placed in a special tool and heated. This baking process serves to harden the bonding varnish and firmly bond the individual laminations together, which contributes to the structural integrity of the rotor. After this process is complete and the stacks have cooled, the laminated cores with the hardened bonding varnish are transferred to a new tool. At this stage of the process, for example, the magnets, which are 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, a special molding material, typically a thermoplastic or thermoset, is introduced into the structure of the rotor body in the transfer molding process.This material helps to fix the magnets in the magnet pockets of the rotor body, seal the rotor and ensure its geometric shape and mechanical strength.

[0006] The object of the invention is to provide a manufacturing system for producing a stator and / or a rotor of an electrical machine that allows for particularly energy-efficient production of the rotor and / or stator. Furthermore, the object of the invention is to provide an energy-optimized method for producing a stator and / or a rotor of an electrical machine. Furthermore, the object of the invention is to provide a correspondingly improved computer program product.

[0007] This object is achieved by a manufacturing system for producing a stator and / or a rotor of an electrical machine, comprising:

[0008] - A holding tool for receiving a plurality of stacked annular disk-shaped electrical sheets, wherein the holding tool has a clamping mandrel for fixing the electrical sheets to the inner diameter of the clamping mandrel, as well as 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 sheets arranged on the clamping mandrel via the base plate and / or the cover plate;

[0009] - A baking varnish tool into which the holding tool equipped with the electrical sheets can be inserted and which can be set to a baking varnish temperature;

[0010] A transfer molding tool into which the holding tool equipped with the electrical steel sheets can be inserted and adjusted to a molding temperature. The manufacturing system according to the invention thus allows, in particular, the merging of the thermal processes in the two production steps of baking and transfer molding through the holding tool. This provides the advantage of providing a manufacturing system that avoids repeated heating of the rotor during its production, leading to corresponding savings in energy costs and equipment investments and ultimately contributing to more efficient and cost-effective production of an electrical 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 clamping mandrel for securing the electrical sheets at its inner diameter, as well as a base plate and a cover plate, which can apply axial tension to the electrical sheets, for example, via spring elements. This holding tool thus serves, among other things, for holding the electrical sheets, for handling between the self-bonding varnish tool and the transfer molding tool, and preferably also for shaping them using an injection molding geometry for the molding process.

[0012] 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 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 "moves" through the process chain and no separate sensors need to be provided in the self-bonding varnish tool and / or transfer molding tool.

[0013] According to a further preferred development of the invention, it can also be provided that the holding tool comprises an injection molding geometry that, when inserted into the transfer molding tool, influences the shaping and / or flow of the plastic during the transfer molding process. This allows the electrical sheets 6 to remain in the holding tool during the process chain and does not need to be transferred to a separate injection molding tool. The holding tool thus forms part of the transfer molding tool.

[0014] The object of the invention is further achieved by a method for producing a stator and / or a rotor of an electrical machine, comprising the following steps:

[0015] - Providing a holding tool for receiving a plurality of stacked annular disk-shaped electrical sheets, wherein the holding tool has a clamping mandrel for fixing the electrical sheets to the inner diameter of the clamping mandrel, as well as 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 sheets arranged on the clamping mandrel via the base plate and / or the cover plate; a) placing the electrical sheets onto the clamping mandrel of the holding tool; b) introducing an axial tension into the electrical sheets arranged on the clamping mandrel by means of the base plate and / or the cover plate; c) inserting the clamping mandrel into a self-baking tool; wherein steps ac can be carried out in any desired order; d) setting the electrical sheets fixed to the holding tool to a self-baking temperature; e) removing the holding tool from the self-baking tool;f) inserting the holding tool into a transfer molding tool; g) adjusting the electrical sheets fixed to the holding tool to a molding temperature; wherein steps e)g can be carried out in any order; h) overmolding the electrical sheets in the transfer molding tool with a plastic.

[0016] The electrical laminations can be stacked using various methods. For example, the electrical laminations can be designed as stacked laminations, in which the individual laminations are simply stacked on top of one another. This is the simplest and most cost-effective type of lamination, but it can lead to increased magnetic loss. To reduce this, a lamination stack arrangement can also be configured as a layered lamination, in which the laminations are arranged in layers, with each layer rotated by a specific angle. This reduces eddy current losses and improves magnetic behavior.It is also conceivable to package the electrical laminations using segmented packaging, in which the laminations are divided into segmented parts that are then assembled into a complete package. This can contribute to precise control of the magnetic properties and a reduction of eddy current losses. It would also be possible to design the electrical laminations using skew packaging, in which the laminations are cut at an angle and then reassembled into a package, which can reduce unwanted noise and vibration. Finally, it would also be possible to configure the lamination stack arrangement as step-lap packaging, in which the laminations are arranged so that their ends overlap, which can increase mechanical stability and reduce magnetic losses.

[0017] The bonding varnish can be applied to the electrical sheets in various ways. The bonding varnish is preferably applied to the electrical sheets using a method selected from the group of baptism processes, spraying processes, roller processes, impregnation processes and / or powder coating processes. In the baptism process, the stacked electrical sheets are dipped into the bonding varnish. After dipping, the excess varnish is drained off, and the sheets are subjected to the thermal curing process, during which the varnish hardens and bonds the sheets together and insulates them. In a spray process, the bonding varnish is sprayed onto the electrical sheets. This allows the varnish to be applied precisely to the desired areas. After the varnish has been applied, the stack of electrical sheets is thermally cured to ensure a strong bond and insulation. In the roller process, the varnish is applied to the electrical sheets using rollers.This allows for an even distribution of the paint over the entire surface of the electrical sheets. After the paint is applied, a thermal curing process follows to bond and insulate the sheets. In the impregnation process, the stacked electrical sheets are soaked with the liquid bonding varnish, allowing the paint to penetrate the spaces between the sheets. After impregnation, the sheets are thermally cured, which hardens the paint and forms a solid, insulating layer between the sheets. In a powder coating process, a powder coating is electrostatically applied to the electrical sheets and then thermally baked. This forms a continuous, insulating layer that effectively bonds the sheets.

[0018] It is understood that the application of the bonding varnish to the electrical sheets preferably takes place before the electrical sheets secured to the holding tool are heated to a bonding varnish temperature. The application of the bonding varnish to the electrical sheets is preferably carried out before the clamping mandrel with the electrical sheets is inserted into a bonding varnish tool.

[0019] The self-bonding varnish tool comprises, in particular, a thermal energy source for heating the electrical sheets coated with the self-bonding varnish to the required temperature for curing the self-bonding varnish. In its simplest form, the self-bonding varnish tool can be an oven.

[0020] During thermal curing of the bonding varnish in the bonding varnish tool, also known as a "bake," the bonding varnish is hardened by heating to bond and insulate the electrical sheets. The curing temperature of the bonding varnish depends on the specific type of varnish used and its chemical properties. The curing temperature of the bonding varnish is preferably between 150°C and 200°C. During the curing process, the temperature should be controlled as precisely as possible to ensure that the varnish cures evenly and the desired mechanical and electrical properties are achieved. Therefore, it may be preferable for the bonding varnish tool and / or the holding tool to have a temperature sensor. The curing process can take from a few minutes to several hours, again depending on the specific varnish formulation and process requirements.

[0021] 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.

[0022] According to another particularly preferred embodiment of the invention, the holding tool can be removed from the self-bonding varnish tool at a temperature of the electrical sheets that is between 0.5 and 1.0 times the self-bonding varnish temperature. This can, in particular, achieve the effect that the heat content of the electrical sheets and / or the holding tool is still sufficiently high to reduce or even completely prevent a renewed introduction of thermal energy during the subsequent transfer molding.

[0023] Furthermore, the invention can also be further developed such that the insertion of the holding tool into a transfer molding tool occurs at a temperature of the electrical steel sheets that is between 0.5 and 1.0 times the baking varnish 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 sufficiently high that the introduction of additional thermal energy can be reduced or even completely eliminated.

[0024] In a likewise preferred embodiment of the invention, it can also be provided that the electrical steel sheets fixed to the holding tool are set to a molding temperature that is lower than the baked enamel temperature. This eliminates the need for reheating and the introduction of thermal energy during transfer molding, which is naturally particularly advantageous in terms of energy and therefore particularly preferred.

[0025] It may 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 sheets, and the plastic is only injected around the electrical sheets in the transfer molding tool when the temperature sensor sends a signal representing the molding temperature to a process control of the transfer molding tool. The advantage that can be realized 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 "moves along" through the process chain and no separate sensors need to be provided in the self-bonding tool and / or transfer molding tool.

[0026] According to a further preferred embodiment of the subject matter of the invention, it can be provided that after the electrical sheets have been placed on the clamping mandrel of the holding tool and before an axial tension is introduced into the electrical sheets arranged on the clamping 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 sheets.

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

[0028] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept. It shows:

[0029] Figure 1 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a first manufacturing step in a schematic representation,

[0030] Figure 2 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a second manufacturing step in a schematic representation,

[0031] Figure 3 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a third manufacturing step in a schematic representation,

[0032] Figure 4 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a fourth manufacturing step in a schematic representation,

[0033] Figure 5 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a fifth manufacturing step in a schematic representation,

[0034] Figure 6 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a sixth manufacturing step in a schematic representation,

[0035] Figure 7 shows the manufacturing system for producing a stator and / or a rotor of an electrical machine in a seventh manufacturing step in a schematic representation,

[0036] Figure 8 shows a stator and / or a rotor of an electrical machine after an eighth manufacturing step in a schematic representation, Figure 9 shows an electrical machine with a rotor and a stator in a schematic axial sectional representation.

[0037] Figures 1-7 show a manufacturing system 1 for producing a stator 2 and / or a rotor 3 of an electrical machine 4 in various manufacturing steps.

[0038] Figure 1 shows a plurality of already punched and stacked annular electrical sheets 6, from which a stator 2 or a rotor 3 of an electrical machine 4 is to be produced. Such an electrical machine 4 is shown as an example in Figure 9.

[0039] The manufacturing system 1 comprises a holding tool 5 for receiving the stacked annular disk-shaped electrical sheets 6, wherein the holding tool 6 has a clamping mandrel 7 for fixing the electrical sheets 6 to the inner diameter 8 of the clamping mandrel 7, as well as a base plate 10 at a first axial end 9 of the clamping mandrel 7. The electrical sheets 6 are then placed on the clamping mandrel 7 of the holding tool 6 and rest axially on one side against the base plate 10. This state is shown in Figure 2.

[0040] In this state, a cover plate 12 is then arranged on the holding tool 5 at its second axial end 11, wherein axial tension is introduced into the electrical 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 sheets 6. In this manufacturing state, which can be seen in Figure 3, the liquid baking varnish can then be applied to or introduced into the stack of electrical sheets 6.

[0041] As can be seen from Figure 4, the production system 1 further comprises a baking varnish tool 20, into which the holding tool 5 equipped with the wetted electrical steel sheets 6 is inserted and set to a baking varnish temperature so that the baking varnish thermally cures. After the electrical steel sheets 6 have been placed on the clamping mandrel 7 of the holding tool 6 and before axial tension is applied by means of the base plate 10 and / or the cover plate 11 to the electrical steel sheets 6 arranged on the clamping mandrel 7, 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 transfer molding.The temperature sensor can then also determine when the electrical sheets 6 have cooled sufficiently from the baked enamel temperature to reach the molding temperature, which is typically slightly below the baked enamel temperature. When the molding temperature is reached, the injection of the plastic 31 is triggered in the molding tool, and the electrical sheets are overmolded with the plastic 31.

[0042] After baking, the holding tool 5 is removed from the baking varnish tool 20 and inserted into a transfer molding tool 30, where it is adjusted to the molding temperature. The electrical sheets 6 are then overmolded in the transfer molding tool 30 with a plastic 31, as can be seen in Figures 5-6. For thermal process control, the transfer molding tool 30 and / or the holding tool 5 can have a temperature sensor for determining the temperature of the electrical sheets 6. Figures 5-6 also show that the holding tool 5 comprises an injection molding geometry which, when inserted into the transfer molding tool 30, influences the shaping and / or flow of the plastic during the transfer molding process.

[0043] After transfer molding, the holding tool 5 with the electrical sheets 6 is removed from the transfer molding tool 30, as shown in Figure 7. Finally, the rotor 3 or the stator 2 is removed from the holding tool 5, as shown in Figure 8.

[0044] The rotor 3 or the stator 2 can then be used in an electrical machine 4

[0045] be used, for example a radial flux machine as sketched in Figure 9.

[0046] The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be considered restrictive, but rather explanatory. The following claims are to be understood in such a way that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. Where the claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority.

[0047] List of reference symbols

[0048] 1 manufacturing system

[0049] 2 Stator

[0050] 3 Rotor

[0051] 4 electric machine

[0052] 5 Holding tool

[0053] 6 electrical sheets

[0054] 7 tension dome

[0055] 8 inner diameter

[0056] 9 End

[0057] 10 Base plate

[0058] 11 End

[0059] 12 Cover plate

[0060] 20 baking varnish tools

[0061] 30 transfer molding tools

[0062] 31 plastic

Claims

Claims 1. A manufacturing system (1) for producing a stator (2) and / or a rotor (3) of an electrical machine (4), comprising: characterized in that a holding tool (5) for receiving a plurality of stacked annular disk-shaped electrical sheets (6), wherein the holding tool (6) has a clamping mandrel (7) for fixing the electrical sheets (6) to the inner diameter (8) of the clamping mandrel (7), as well as 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 tension can be introduced into the electrical sheets (6) arranged on the clamping mandrel (7) via the base plate (10) and / or the cover plate (11); a baking varnish tool (20) into which the holding tool (5) equipped with the electrical sheets (6) can be inserted and which can be adjusted to a baking varnish temperature;a transfer molding tool (30) into which the holding tool (5) equipped with the electrical sheets (6) can be inserted and adjusted to a molding temperature; 2. Manufacturing system (1) according to claim 1, characterized in that the transfer molding tool (30) and / or the holding tool (5) has a temperature sensor for determining the temperature of the electrical sheets (6).

3. Manufacturing system (1) according to claim 1 or 2, characterized in that the holding tool (5) comprises an injection geometry which, when inserted into the transfer molding tool (30), enables the shaping and / or influences the flow of the plastic during the transfer molding process.

4. A method for producing a stator (2) and / or a rotor (3) of an electrical machine (4), comprising the following steps: • Providing a holding tool (5) for receiving a plurality of stacked annular disk-shaped electrical sheets (6), wherein the holding tool (6) has a clamping mandrel (7) for fixing the electrical sheets (6) to the inner diameter (8) of the clamping mandrel (7), as well as 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 tension can be introduced into the electrical sheets (6) arranged on the clamping mandrel (7) via the base plate (10) and / or the cover plate (11); a) placing the electrical sheets (6) on the clamping mandrel (7) of the holding tool (6); b) introducing an axial tension by means of the base plate (10) and / or the cover plate (11) into the electrical sheets (6) arranged on the clamping mandrel (7); c) inserting the clamping mandrel (7) into a baking varnish tool (20); • wherein steps a)-c) can be carried out in any order; d) setting the electrical sheets (6) fixed to the holding tool (5) to a baking varnish temperature; e) removing the holding tool (5) from the baking varnish tool (20); f) inserting the holding tool (5) into a transfer molding tool (30); g) setting the electrical sheets (6) fixed to the holding tool (5) to a molding temperature; • wherein steps e)-g) can be carried out in any order; h) overmolding the electrical sheets (6) in the transfer molding tool (30) with a plastic.

5. Method according to claim 4, characterized in that the removal of the holding tool (5) from the baking varnish tool (20) takes place at a temperature of the electrical sheets (6) which is between 0.5 and 1.0 times the baking varnish temperature; 6. Method according to claim 4 or 5, characterized in that the insertion of the holding tool (5) into a transfer molding tool (30) takes place at a temperature of the electrical sheets (6) which is between 0.5-1.0 times the baking varnish temperature; 7. Method according to one of claims 4-6, characterized in that the setting of the electrical sheets (6) fixed to the holding tool (5) takes place to a molding temperature which is lower than the baking varnish temperature; 8. Method according to one of claims 4-7, characterized in that the transfer molding tool (30) and / or the holding tool (5) has a temperature sensor for determining the temperature of the electrical sheets (6) and the injection molding of the electrical sheets (6) in the transfer molding tool (30) with the plastic only takes place when the temperature sensor A signal representing the moulding temperature is applied to a process control of the transfer moulding tool (30).

9. Method according to one of claims 4-8, characterized in that after placing the electrical sheets (6) on the clamping mandrel (7) of the Holding tool (6) and before introducing an axial tension by means of the base plate (10) and / or the cover plate (11) into the electrical sheets (6) arranged on the clamping mandrel (7), a plurality of permanent magnets are inserted into the corresponding magnetic pockets of the electrical sheets (6).

10. A computer program product stored on a machine-readable medium or a computer data signal embodied by an electromagnetic wave, comprising a computer program code suitable for carrying out a method according to any one of claims 4-9.

Images