Method for assembling a rotor

Abstract

Method for assembling a rotor (1) for an electrical machine, which comprises a shaft (11), an inner laminated core (12), a plurality of outer laminated cores (13), and a plurality of inner magnets (14) each arranged between the inner laminated core (12) and an outer laminated core (13), characterized in that outer laminated core masses of the outer laminated cores (13) are determined and, based on the outer laminated core masses, an assembly position is defined for each outer laminated core (13).

Description

[0001] The present invention relates to a method for assembling a rotor for an electrical machine, which comprises a shaft, an inner laminated core, a plurality of outer laminated cores, and a plurality of internal magnets each arranged between the inner laminated core and an outer laminated core.

[0002] A method according to the preamble of claim 1 is described in DE 10 2019 127 583 A1. Since many quality characteristics of an electrical machine are directly related to rotor imbalance, a balancing process is generally performed at the end of the rotor assembly. The rotor imbalance is determined and compensated by selectively applying balancing masses or selectively removing sacrificial material. However, appropriate installation space must be provided for both the balancing masses and the sacrificial material.

[0003] From US 2004 / 0 187 294 A1 a method for assembling a rotor for an electrical machine is known, wherein the rotor comprises a shaft, an inner laminated core, a plurality of outer laminated cores and windings each arranged on an outer laminated core, and wherein outer laminated core masses of the outer laminated cores are determined.

[0004] From DE 10 2017 123 703 A1 a method for assembling a rotor for an electrical machine is known, wherein the rotor comprises a shaft, laminated core segments arranged axially stacked on the shaft and magnets arranged in pockets of the laminated core segments, and wherein the laminated core segments and the magnets are measured and, based thereon, assembly positions for the laminated cores and the magnets are calculated.

[0005] From JP H09-294 358 A a method for assembling a rotor for an electrical machine is known, wherein the rotor comprises a shaft, an iron core fastened to the shaft and magnets fastened to the outer circumference of the iron core, and wherein masses of the magnets are determined.

[0006] From DE 10 2021 112 815 A1 a method for assembling a rotor for an electrical machine is known, wherein the rotor comprises a shaft, laminated core segments arranged axially stacked on the shaft and magnets arranged in pockets of the laminated core segments, and wherein the shaft and the laminated cores are measured and relative positions are determined based thereon.

[0007] Against this background, the task is to create a relatively compact rotor for an electric machine.

[0008] This object is achieved according to the invention by a method for assembling a rotor for an electrical machine having the features of claim 1.

[0009] Since the outer lamination stacks have a relatively large mass on the one hand and relatively large mass fluctuations on the other, the outer lamination stack masses of the outer lamination stacks are determined by measurement, preferably by weighing, and an unbalance-optimized mounting position is defined for each outer lamination stack based on the outer lamination stack masses. Specifically, the mounting positions of the outer lamination stacks are defined such that the rotor exhibits the lowest possible unbalance by mounting the outer lamination stacks at the defined mounting positions before the final balancing process. Consequently, ideally no balancing masses are required, but in any case only relatively light and thus compact balancing masses are required to balance the rotor, thereby creating a relatively compact rotor for an electrical machine.Preferably, the internal magnet masses of the internal magnets are also determined by measurement and, based on the internal magnet masses, an unbalance-optimized mounting position is determined for each internal magnet in such a way that the rotor has the lowest possible unbalance by mounting the internal magnets at the specified mounting positions before the final balancing process.

[0010] In a preferred embodiment, the rotor comprises a plurality of surface magnets, each arranged on the radial outer side of an outer laminated core. Preferably, the surface magnet masses of the surface magnets are determined by measurement, and based on the surface magnet masses, an unbalance-optimized mounting position is determined for each surface magnet such that the rotor exhibits the lowest possible unbalance by mounting the surface magnets at the specified mounting positions before the final balancing process.

[0011] Typically, during rotor assembly, a corresponding stock is provided for each rotor component, with the stocks each comprising a number of rotor components that allows for the assembly of multiple rotors. Advantageously, therefore, the outer lamination stack masses of all outer lamination stacks in an outer lamination stack stock and / or the inner magnet masses of all inner magnets in an inner magnet stock and / or the surface magnet masses of all surface magnets in a surface magnet stock are determined by measurement, and the outer lamination stacks and / or the inner magnets and / or the surface magnets are selected from the corresponding stock based on their respective masses in such a way that they can be used to create a rotor that is as unbalance-free as possible.

[0012] Preferably, the shaft imbalance and the inner lamination stack imbalance are determined separately by measurement, and an unbalance-optimized rotational alignment of the inner lamination stack relative to the shaft is determined based on the shaft imbalance and the inner lamination stack imbalance. Specifically, the rotational alignment of the inner lamination stack is determined such that the shaft imbalance and the inner lamination stack imbalance compensate each other as much as possible when the inner lamination stack is attached to the shaft with the specified rotational alignment.

[0013] In a preferred embodiment, the rotor comprises several axially stacked inner lamination stacks. Preferably, an inner lamination stack imbalance of each inner lamination stack is determined, and a rotational alignment for each inner lamination stack is determined based on the shaft imbalance and the inner lamination stack imbalances. Through the targeted rotational alignment of the multiple inner lamination stacks, the shaft imbalance can be compensated particularly effectively.

[0014] Preferably, the inner lamination stack unbalances of all inner lamination stacks in an inner lamination stack stock are determined by measurement, and each inner lamination stack is selected from the inner lamination stack stock based on its inner lamination stack unbalance in such a way that the shaft unbalance of the shaft can be compensated particularly effectively.

[0015] Preferably, the determination of the assembly positions and / or the determination of the rotational orientation and / or the selection from the respective inventory is carried out with the help of an artificial intelligence system. The artificial intelligence system can be trained to recognize and consider specific relationships that cannot be mapped otherwise.

[0016] Typically, the outer lamination stacks, the inner magnets, and, if present, the surface magnets, are cast and / or bonded together with the inner lamination stack. A rotor imbalance is determined during a final balancing process after casting and / or bonding. Due to the different weights and therefore generally different sizes of the rotor components, different cavities of different sizes can be created in the rotor and different radial expansions of the rotor can occur. This can cause a significant imbalance during the casting and / or bonding process.Preferably, therefore, the determined rotor imbalance is provided to the artificial intelligence system and the artificial intelligence system is configured to learn relationships between mounting positions and masses of the outer laminated cores and / or the inner magnets and / or, if applicable, the surface magnets as well as the rotor imbalance, so that the artificial intelligence system can take these relationships into account when determining the mounting positions of the outer laminated cores and / or the inner magnets and / or, if applicable, the surface magnets.

[0017] An embodiment of the present invention is described below with reference to the accompanying figures. Herein: Fig. 1 schematically shows a rotor for an electric machine mounted according to a method according to the invention, and Fig. 2 schematically an inner laminated core, an outer laminated core, two inner magnets arranged between the inner laminated core and the outer laminated core, as well as a surface magnet of the rotor made of Fig. 1 in an exploded view.

[0018] Fig. 1 shows a rotor 1 for an electrical machine (not shown). The rotor 1 comprises a shaft 11, a plurality of inner laminated cores 12 secured axially one above the other on the shaft 11, a plurality of outer laminated cores 13, a plurality of inner magnets 14 arranged between an inner laminated core 12 and an outer laminated core 13, and a plurality of surface magnets 15 arranged on the radial outer side of an outer laminated core 13.

[0019] The outer lamination stacks 13, the inner magnets 14 and the surface magnets 15 are firmly connected to the inner lamination stacks 12 by a casting material 16 and a bandage 17. Unlike in Fig.1, the potting material 16 actually fills all the cavities between the inner lamination stacks 12, the outer lamination stacks 13, the inner magnets 14 and the surface magnets 15.

[0020] To assemble the rotor 1, a shaft stock with a plurality of shafts 11, an inner laminated core stock with a plurality of inner laminated cores 12, an outer laminated core stock with a plurality of outer laminated cores 13, an inner magnet stock with a plurality of inner magnets 14, and a surface magnet stock with a plurality of surface magnets 15 are provided. The number of each rotor component 11-15 in the corresponding stock is greater than the number of each rotor component 11-15 in the rotor 1, so that multiple rotors 1 can be assembled from the stocks.

[0021] For each shaft 11 of the shaft stock, a shaft unbalance is measured, for each inner lamination stack 12 of the inner lamination stack stock, an inner lamination stack unbalance is measured, for each outer lamination stack 13 of the outer lamination stack stock, an outer lamination stack mass is measured, for each inner magnet 14 of the inner magnet stock, and a surface magnet mass is measured.

[0022] During assembly of a rotor 1, a shaft 11 is taken from the shaft stock and a number of inner lamination stacks 12 required for assembly of the rotor 1 is taken from the inner lamination stack stock, wherein the shaft 11 and the inner lamination stacks 12 are selected based on their shaft unbalance or their respective inner lamination stack unbalance with the aid of an artificial intelligence system.

[0023] With the help of the artificial intelligence system, a rotational alignment relative to the removed shaft 11 is determined for each removed inner lamination pack 12 based on the shaft unbalance of the removed shaft 11 and the inner lamination pack unbalances of the removed inner lamination packs 12.

[0024] The artificial intelligence system is configured or trained to select the shaft 11 and the inner lamination stacks 12 and to determine the rotational orientations of the inner lamination stacks 12 in such a way that a shaft-inner lamination stack assembly, which is created by attaching the removed inner lamination stacks 12 with the respective rotational orientation to the removed shaft 11, has the lowest possible assembly imbalance.

[0025] After the removed inner lamination packs 12 have been attached to the shaft 11, the assembly unbalance of the shaft inner lamination pack assembly is determined by measurement.

[0026] Subsequently, the number of outer lamination stacks 13, inner magnets 14 and surface magnets 15 required for the assembly of the rotor 1 is taken from the corresponding stock, whereby these are selected based on the determined assembly unbalance, the outer lamination stack masses, the inner magnet masses and the surface magnet masses with the aid of the artificial intelligence system.

[0027] With the help of the artificial intelligence system, an assembly position is determined for each removed outer laminated core 13, for each removed inner magnet 14, and for each removed surface magnet 15 based on the assembly unbalance, the outer laminated core masses, the inner magnet masses, and the surface magnet masses.

[0028] The artificial intelligence system is configured or trained to select the outer laminated cores 13, the inner magnets 14 and the surface magnets 15 and to determine the mounting positions of the outer laminated cores 13, the inner magnets 14 and the surface magnets 15 in such a way that the rotor 1 has the lowest possible rotor imbalance after subsequent casting and bandaging.

[0029] The outer laminated cores 13, inner magnets 14 and surface magnets 15 arranged at the respective mounting positions are cast and bandaged together with the inner laminated cores 12 in order to firmly connect them to the inner laminated cores 12 fastened to the shaft 11 via the casting material 16 and the bandage 17.

[0030] After casting and bandaging, a final balancing process is performed, during which any rotor imbalance of rotor 1 is measured and, if necessary, compensated by attaching appropriately designed balancing masses. Due to the unbalance-optimized assembly, ideally no balancing masses are required, but in any case only relatively small balancing masses are required.

[0031] The rotor imbalance determined in this way is fed to the artificial intelligence system, which is designed to learn relationships between the respective mounting positions and masses of the outer laminated cores 13, the inner magnets 14 and the surface magnets 15 as well as the rotor imbalance.

Claims

[1] Method for assembling a rotor (1) for an electrical machine, which comprises a shaft (11), an inner laminated core (12), a plurality of outer laminated cores (13), and a plurality of inner magnets (14) each arranged between the inner laminated core (12) and an outer laminated core (13), characterized by that outer sheet stack masses of the outer sheet stacks (13) are determined and, based on the outer sheet stack masses, an assembly position is determined for each outer sheet stack (13). [2] Method according to claim 1, wherein internal magnet masses of the internal magnets (14) are determined and a mounting position is determined for each internal magnet (14) based on the internal magnet masses. [3] Method according to one of the preceding claims, wherein the rotor (1) comprises a plurality of surface magnets (15) each arranged on the radial outside of an outer laminated core (13), and wherein surface magnet masses of the surface magnets (15) are determined and a mounting position is determined for each surface magnet (15) based on the surface magnet masses. [4] Method according to one of the preceding claims, wherein the outer lamination stacks (13) and / or the inner magnets (14) and / or the surface magnets (15) are selected from a corresponding stock based on their respective mass. [5] Method according to one of the preceding claims, wherein a shaft unbalance of the shaft (11) and an inner laminated core unbalance of the inner laminated core (12) are determined and, based on the shaft unbalance and the inner laminated core unbalance, a rotational alignment of the inner laminated core (12) relative to the shaft (11) is determined. [6] Method according to claim 5, wherein the rotor (1) comprises a plurality of axially stacked inner lamination stacks (12), wherein an inner lamination stack imbalance of each inner lamination stack (12) is determined, and wherein a rotational alignment for each inner lamination stack (12) is determined based on the shaft imbalance and the inner lamination stack imbalances [7] Method according to claim 5 or 6, wherein each inner core stack (12) is selected from a stock of inner core stacks based on its core stack imbalance. [8] Method according to one of the preceding claims, wherein the determination of the mounting positions and / or the determination of the rotational orientation and / or the selection from the respective stock is carried out with the aid of an artificial intelligence system. [9] Method according to claim 8, wherein the outer laminated cores (13) and the inner magnets (14) are cast and / or bandaged together with the inner laminated core (12), wherein after the casting and / or bandaging a rotor imbalance of the rotor (1) is determined, and wherein the artificial intelligence system is set up to learn relationships between mounting positions and masses of the outer laminated cores (13) and / or the inner magnets (14) and the rotor imbalance.

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