JP2024006524A - Rotor of rotary electric machine and manufacturing method for the same - Google Patents

Abstract

To provide a highly reliable rotor of a rotary electric machine having high crack resistance in a slot for a magnet under a heat cycle environment by efficiently mitigating stress to resin and a manufacturing method for the same.SOLUTION: A rotor 100 of a rotary electric machine includes a rotor core 1 provided with slots 2 for a magnet along the circumferential direction, a permanent magnet 3 located in the slots 2 for the magnet and fixed with a magnet fixing resin 5, and a stress relaxation layer formed on the surface of the permanent magnet 3 and in which a part of the magnet fixing resin 5 is modified.SELECTED DRAWING: Figure 2

Description

The present application relates to a rotor of a rotating electric machine and a method of manufacturing the same.

As a rotating electrical machine, an IPM motor (Interior Permanent Magnet Motor) is known which has a structure in which permanent magnets are embedded in magnet slots provided in a rotor. In addition to the electrification of automobiles, with the recent technological advances in industrial robots and railways, the IPM motors that control them are also required to be highly efficient and precise.

Generally, in the rotor of an IPM motor, a permanent magnet is inserted into a magnet slot formed in a laminated core made by laminating multiple core pieces and joined together by caulking or welding, and then a resin is inserted into the slot. It is manufactured by fixing a permanent magnet to a laminated core by injecting it and curing it.

The rotor of an IPM motor is required to have high heat cycle resistance. Rare earth permanent magnets used in IPM motors have high electrical conductivity, and when an alternating magnetic field is applied to the permanent magnets, energy loss called eddy current loss occurs. At this time, the temperature of the permanent magnets in the magnet slots provided in the core rotor increases. In addition, assuming use in cold regions, it is necessary to adapt to environments as low as -40°C.

The resin, the laminated core, and the permanent magnet each have different coefficients of thermal expansion. Therefore, under the above-mentioned heat cycle environment, there is a risk that cracks will occur in the resin part due to the stress generated due to the difference in linear expansion coefficient, and that the resin will scatter as the rotor rotates at high speed. Ta.

As a countermeasure against cracks, for example, in Patent Document 1, one end face of the permanent magnet and one end face of the laminated core constitute the same plane, and the permanent magnet is exposed to the end face of the laminated core, causing cracks to occur in the permanent magnet. A method of fixing a permanent magnet is disclosed in which displacement is released to the outside of a laminated core and stress generated within the resin is alleviated.

In addition, in Patent Document 2, the surface of the permanent magnet is covered with an insulating non-woven fabric, and the non-woven fabric deforms in its thickness direction to alleviate the thermal expansion and contraction of the permanent magnet, causing cracks in the resin. A method for suppressing this is disclosed.

JP 2017-22886 (Paragraph 0036, Figure 11) JP 2019-140773 (Paragraph 0024, Figure 3)

However, although the method of relieving stress on the resin is an effective means for suppressing cracks, the rotor described in Patent Document 1 requires a special tool to move the magnets to the ends of the rotor. There was a problem with becoming. Further, the rotor described in Patent Document 2 has a problem in that it requires a step of providing a clearance for the nonwoven fabric and uniformly pasting the nonwoven fabric covering the magnets.

The present application was made in order to solve the above-mentioned problems, and provides a reliable material that efficiently relieves stress on the resin and has high crack resistance in the magnet slot under a heat cycle environment. An object of the present invention is to provide a rotor for a rotating electrical machine with high performance and a method for manufacturing the same.

A rotor of a rotating electric machine disclosed in the present application includes a rotor core having slots provided along the outer circumferential direction, a permanent magnet arranged in the slot and fixed with resin, and a surface of the permanent magnet. and a stress relaxation layer in which a portion of the resin is modified.

The method for manufacturing a rotor for a rotating electric machine disclosed in the present application includes the steps of forming a coating layer on the surface of a permanent magnet, inserting the permanent magnet into a slot provided in a rotor core, and inserting the permanent magnet into a slot provided in a rotor core. Injecting a resin between the permanent magnets and fixing the permanent magnets in the slots by heat treatment, and forming a stress relaxation layer in which a portion of the resin is modified by the coating layer. It is characterized by including the following.

According to the rotor of a rotating electric machine disclosed in the present application, a stress relaxation layer can be efficiently introduced onto the surface of a magnet without using special tools or securing extra clearance. Furthermore, it is possible to suppress the occurrence of cracks in the resin under a heat cycle environment.

1 is a plan view showing the configuration of a rotor of a rotating electric machine according to Embodiment 1. FIG. FIG. 2 is a partially enlarged cross-sectional view of a magnet slot portion showing the configuration of a rotor of the rotating electrical machine according to the first embodiment. FIG. 2 is a perspective view showing the configuration of permanent magnets in the rotor of the rotating electric machine according to the first embodiment. FIG. 3 is a cross-sectional view showing changes in the magnet slots before and after heat treatment of the permanent magnets in the rotor of the rotating electrical machine according to the first embodiment. FIG. 3 is a perspective view showing another configuration of permanent magnets in the rotor of the rotating electric machine according to the first embodiment. FIG. 3 is a flowchart showing the steps of a manufacturing process in a method for manufacturing a rotor of a rotating electric machine according to the first embodiment.

Embodiment 1.
Hereinafter, preferred embodiments of the rotor of the rotating electric machine of the present application will be described using the drawings. FIG. 1 is a plan view showing the configuration of a rotor 100 of a rotating electrical machine according to Embodiment 1 of the present application. FIG. 2 is a sectional view taken along the line AA in FIG. FIG. 3 is a perspective view showing the configuration of the permanent magnet 3 provided in the rotor 100 of the rotating electrical machine.

As shown in FIGS. 1 and 2, a rotor 100 of a rotating electric machine according to the first embodiment includes a rotor core 1 and permanent magnets 3 embedded in magnet slots 2 provided in the rotor core 1. and has. Furthermore, a shaft slot 4 is provided in the center of the rotor core 1. A plurality of magnet slots 2 are provided along the circumferential direction of the rotor core 1. In addition, in FIG. 1, the number of magnet slots 2 is four, and a case of a four-pole rotor in which a permanent magnet 3 is embedded in each magnet slot 2 is illustrated, but the number of poles of the rotor is not particularly limited. Further, the magnet slot 2 may be provided with a protruding structure for defining the position of the magnet or a flux barrier for preventing generation of leakage magnetic flux. Although FIG. 1 illustrates a rectangular shape, the shape of the magnet slot 2 is not particularly limited.

As shown in FIG. 3A, the permanent magnet 3 is usually provided in the shape of a rectangular parallelepiped, and is subjected to surface treatment such as plating or epoxy resin coating (not shown). In the first embodiment, as shown in FIG. 3(b), the coating layer 6 of the permanent magnet 3 is coated with these surface treatment layers before the permanent magnet 3 is inserted into the magnet slot 2. It is pre-applied to the upper layer. The coating layer 6 is provided so as to cover a total of six sides of the rectangular parallelepiped-shaped permanent magnet 3, that is, two sides each of the wide front and back sides, the narrow vertical side, and the wide horizontal side. Although it is preferable that it is, it is not limited to this. From the viewpoint of workability during magnet insertion, the permanent magnet 3 may have a shape that covers at least eight vertices of the rectangular parallelepiped, as shown in FIG. 3(c), instead of all six sides. The material of the coating layer 6 may be liquid resin or oil.

A permanent magnet 3 is placed in the magnet slot 2. A magnet fixing resin 5 is filled between the rotor core 1 and the coating layer 6. The magnet fixing resin 5 may be in a liquid state when filled, and may be hardened when the rotor is used to fix the permanent magnet 3, and may be a thermosetting resin such as an epoxy resin.

The method of filling the magnet fixing resin 5 is not particularly limited, and any method known in the technical field can be used. For example, there may be a method of directly pouring the resin from the upper part of the magnet slot 2, or a method of pouring the resin while applying pressure using a mold having a casting spout.

After being filled, the magnet fixing resin 5 is heated to be cured. Although the heat treatment conditions for the magnet fixing resin 5 are not particularly limited, the treatment is performed at, for example, 120° C. for 2 hours so that the rotor core 1 and the permanent magnets 3 can be adhesively fixed.

FIG. 4 is a cross-sectional view showing changes in the magnet slot 2 before and after heat treatment in the rotor 100 of the rotating electrical machine according to the first embodiment, FIG. 4(a) shows before heat treatment, FIG. 4(b) shows indicates after heat treatment. As shown in FIGS. 4(a) and 4(b), the magnet fixing resin 5 and the coating layer 6 are mixed or reacted and hardened near the magnet surface, thereby forming a stress relaxation layer 7.

The stress relaxation layer 7 has a composition based on the composition of the magnet fixing resin 5 and incorporates the components of the coating layer 6. Since the coating layer 6 has a long-chain hydrocarbon-based chemical structure, it has the effect of modifying and plasticizing the magnet fixing resin 5. Therefore, the stress relaxation layer 7 exhibits a lower elastic modulus than the magnet fixing resin 5.

As described above, the rotor 100 of the rotating electrical machine according to the first embodiment includes the rotor core 1 laminated with circular electromagnetic steel sheets, the magnet slots 2 penetrating the rotor core 1 in the axial direction, and the magnet slots 2. It consists of a resin part consisting of a permanent magnet 3 inserted into a slot 2 and a magnet fixing resin 5 that fixes the permanent magnet 3. By providing a stress relaxation layer 7 on the surface of the permanent magnet 3, - The stress generated in the resin part by cycling is alleviated by the stress relaxation layer, making it possible to prevent the occurrence of cracks.

The materials used for the rotor 100 of the rotating electric machine according to the first embodiment will be described below.
The rotor core 1 is not particularly limited, and may include a steel plate laminate formed by laminating electromagnetic steel sheets, soft magnetic metal powder such as iron, iron-silicon alloy, iron-carbon alloy, or soft magnetic metal oxide. It can be obtained by molding a powder magnetic core made of magnetic powder coated with a resin binder such as silicone resin, or a high-density powder magnetic core. The forming method is not particularly limited, and a method of cutting out material, a method of laminating electromagnetic steel sheets pressed into a desired shape, and the like can be used. Among them, the rotor core 1 obtained by forming a steel plate laminate made of laminated silicon steel plates is preferable.In particular, from the viewpoint of preventing eddy current loss, the rotor core 1 is preferably made by laminating silicon steel plates with an insulating film formed on the surface. More preferably, the rotor core 1 is obtained by molding a steel plate laminate. The thickness of the silicon steel plate is not particularly limited, but is generally 0.2 mm to 0.5 mm.

Examples of the permanent magnet 3 include rare earth magnets, ferrite magnets, alnico magnets, etc. Among them, rare earth magnets are preferred because they can provide high output. Examples of rare earth magnets include neodymium-iron-boron magnets and samarium-iron-nitrogen magnets. Among these, neodymium-iron-boron based sintered magnets are preferred because of their excellent performance as magnets. In addition, neodymium-iron-boron based sintered magnets use a diffusion method that diffuses dysprosium, terbium, etc. along the interfaces between crystals (grain boundaries), dispersing only the neodymium at the grain boundaries. The coercive force of grain boundaries may be strengthened by substitution with prosium or terbium. In addition, as a surface treatment, plating with zinc, chromium, nickel, tin, gold, silver, rhodium, chrome-zinc, etc., or coating with epoxy resin, polyimide resin, polyamide resin, fluororesin, etc. is performed.

One type of permanent magnet 3 can be selected from various types of magnets, and a plurality of magnets may be used in combination in order to obtain desired motor characteristics of the rotating electric machine. The permanent magnet 3 embedded in the magnet slot 2 may be a single permanent magnet 3 pre-formed into a predetermined shape, but from the viewpoint of reducing eddy current and temperature, the permanent magnet 3 is divided into a plurality of pieces. The magnet 3 may be used, or a plurality of divided permanent magnets 3 (3a, 3b, 3c) joined and integrated may be used (see FIG. 5). Alternatively, a permanent magnet 3 with slits may be used.

The magnet fixing resin 5 is preferably a thermosetting resin so that the gap between the rotor core 1 and the permanent magnet 3 can be filled. Examples of thermosetting resins include epoxy resins, acrylic resins, phenolic resins, and silicone resins. These resins can be used alone or in combination of two or more, but among them, in order to form the stress relaxation layer 7, an epoxy resin that exhibits suitable miscibility and reactivity with the coating layer 6 is used. Particularly preferred.

Examples of the coating layer 6 include epoxy resin, phenol resin, polyamide resin, silicone, etc., as long as it is mixed with the magnet fixing resin 5 and reacts with heat treatment. Examples include resins and mixtures of two or more thereof. Particularly preferred among these are those having a long-chain hydrocarbon structure in the molecule, such as epoxidized soybean oil, epoxidized linseed oil, epoxidized fatty acid isobutyl epoxidized unsaturated fatty acid ester, and epoxidized fatty acid 2 - Ethylhexyl, alicyclic epoxy, di2-ethylhexyl 4,5-epoxycyclohexane-1,2-dicarboxylate, di(9,10-epoxystearyl) 4,5-epoxycyclohexane-1,2-dicarboxylate, silane As a system, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3 - Glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldiethoxysilane Roxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- Aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3- Examples of trimethoxysilylpropylsuccinic anhydride and modified silicone resins include amino-modified, epoxy-modified, carboxy-modified, and phenol-modified silicone resins. The modified silicone resin may be amino-modified, epoxy-modified, carboxy-modified, or phenol-modified at either the side chain, one end, both ends, or both ends of the side chain.

In addition, fats and oils without reactive groups can also be applied to the coating layer 6, and examples of aliphatic dibasic acids include bis-2-ethylhexyl adipate, bisisononyl adipate, bisisodecyl adipate, and bis-azelaate. 2-Ethylhexyl, bis-2-ethylhexyl sebacate, phthalate esters, di-2-ethylhexyl phthalate, trimethyl esters, tri-2-ethylhexyl phthalate, phosphate esters , butyl phosphate, tris-2-ethylhexyl phosphate and the like. These fats and oils may be used alone or in combination of two or more.

The rotor 100 of the rotating electric machine according to the first embodiment manufactured as described above can be used in various environments. For example, a rotating electric machine used in a cold region may be exposed to an environment of about -40°C, but the rotor 100 of the rotating electric machine according to the first embodiment has magnet slots even in a low-temperature environment. Since the permanent magnet 3 can be adhesively fixed within the resin without cracking, it can be used stably. Further, the operating temperature range of a rotating electric machine is normally 150°C or higher due to temperature rise of members (for example, rotor core, permanent magnet), eddy current, etc., but in this embodiment The rotor 100 of the rotating electric machine according to No. 1 can be used even in a high-temperature environment because the permanent magnet 3 can be adhesively fixed within the magnet slot 2 without cracking the resin.

Next, examples will be shown. However, the present application is not limited to the following examples unless the gist of the present application is exceeded.

(Example 1)
FIG. 6 is a flowchart showing the steps of the manufacturing process in the method for manufacturing the rotor 100 of a rotating electric machine according to the first embodiment.

First, a rotor core 1 (diameter 140 mm, height 40 mm) having magnet slots was fabricated by laminating silicon steel plates (0.3 mm) with an insulating film formed on their surfaces and mechanically caulking them. (Step S601). As the magnet slots 2, four magnet slots 2 each having a width of 45 mm and a length of 8 mm were provided as shown in FIG.

Subsequently, an acid anhydride-curing epoxy resin having a viscosity of 2 to 3 Pa·s at 60° C. was prepared as the magnet fixing resin 5 for fixing the magnet (step S602). This epoxy resin can be cured by standing in a 120°C environment for 2 hours, and has a glass transition temperature of 160°C to 170°C and a flexural modulus of 15 to 20GPa after curing.

Next, epoxy, which is a liquid resin, is applied as a coating layer 6 on six sides of a rectangular parallelepiped-shaped (42 mm x 7.5 mm x 38 mm) neodymium-iron-boron sintered permanent magnet 3 whose surface is galvanized. Chemical linseed oil was applied in an amount that would not drip (step S603).

Subsequently, after preheating the rotor core 1 to 80° C., the permanent magnet 3 coated with epoxidized linseed oil was inserted into the magnet slot 2 (step S604).

Next, an acid anhydride-curing epoxy resin is injected into the magnet slot 2 so that it is flush with the upper surface of the rotor core 1 (step S605).

Finally, sample 1, which will become rotor 100 of a rotating electric machine, was completed by heat treatment at 120° C. for 2 hours.

(Example 2)
In Sample 1 described above, Sample 2 was prepared by applying epoxidized linseed oil, which is a liquid resin, as a coating layer 6 to eight vertices of the magnet, as illustrated in FIG. 3(c). Note that the other configurations of the rotor 100 of this rotating electrical machine other than the location where the coating layer 6 is applied are the same as those of the sample 1 described above.

(Example 3)
Sample 3 was prepared in which the coating layer 6 of Sample 1 was changed from epoxidized linseed oil, which is a liquid resin, to epoxidized fatty acid isobutyl, which is a fatty acid ester, which is a liquid resin. Note that, in the rotor 100 of this rotating electric machine, the other configurations other than the type of coating layer 6 are the same as in Sample 1 described above.

(Example 4)
Sample 4 was prepared by changing the coating layer 6 from epoxidized linseed oil, which is a liquid resin, to silane-based 3-glycidoxypropylmethyldiethoxysilane, which is a liquid resin, in Sample 1 described above. Note that, in the rotor 100 of this rotating electric machine, the other configurations other than the type of coating layer 6 are the same as in Sample 1 described above.

(Example 5)
In the above sample 1, the coating layer 6 is made of epoxidized linseed oil, which is a liquid resin, and amine-modified silicone, which is a liquid resin and has both ends of a modified silicone resin-based polysiloxane modified with amines. Sample 5 was created using a different resin. Note that, in the rotor 100 of this rotating electric machine, the other configurations other than the type of coating layer 6 are the same as in Sample 1 described above.

(Example 6)
Sample 6 was prepared by changing the coating layer 6 from epoxidized linseed oil, which is a liquid resin, to bis-2-ethylhexyl adipate, which is an aliphatic dibasic acid oil, in Sample 1 described above. Note that, in the rotor 100 of this rotating electric machine, the other configurations other than the type of coating layer 6 are the same as in Sample 1 described above.

(Example 7)
In sample 1, the permanent magnet was divided into three parts (14 mm x 7.5 mm x 38 mm), and each of the six sides was coated with epoxidized linseed oil as a coating layer 6, and arranged in rows in the magnet slot 2. (See FIG. 5) to create sample 7. When coated with epoxidized linseed oil, there was no need for an adhesive to attach the magnets in the divided parts, and the magnets could be inserted into the designated areas. Normally, in order to increase the accuracy of the magnet insertion position, adhesive is used to temporarily fix the divided magnets. This time, we have confirmed that split magnets can be temporarily fixed using only a coating layer. In addition, in the rotor 100 of this rotating electric machine, the other structure is the same as the above-mentioned sample 1 except that the permanent magnet 3 is divided into three parts.

(Comparative example 1)
For comparison, a sample 8 was prepared in which the coating layer 6 was not provided on the surface of the permanent magnet 3 in the sample 1 described above. The rotor of this rotating electric machine has the same structure as Sample 1 described above except that there is no coating layer.

Using Samples 1 to 7 of Examples 1 to 7 and Sample 8 of Comparative Example 1, the formation of stress relaxation layers and resistance to heat cycles were confirmed. The stress relaxation layer was formed as follows. Samples 1 to 8 were cut along the AA cross section in FIG. 1, and the surface condition of the permanent magnet 3 was observed. Samples 1 to 7 showed elasticity with respect to the resin part for fixing the magnet, as determined by discoloration in the portion corresponding to the stress relaxation layer and palpation using a needle.

In samples 1, 2, and 7, epoxidized linseed oil, which is a liquid resin, was used as the coating layer. Epoxidized linseed oil has a plurality of epoxy groups and a plurality of hydrocarbon groups each having seven carbon atoms in its molecular skeleton. It has been found that the magnet fixing resin 5 reacts with the epoxy groups of the epoxidized linseed oil used as the coating layer 6, and the hydrocarbon groups impart plasticity to the reaction product.

In sample 3, epoxidized fatty acid isobutyl, which is a liquid resin, was used as the coating layer 6. Epoxidized fatty acid isobutyl has an epoxy group and a plurality of hydrocarbon groups each having 7 carbon atoms in its molecular skeleton. It was found that the magnet fixing resin 5 reacts with the epoxy group of the epoxidized fatty acid isobutyl used as the coating layer 6, and the hydrocarbon group imparts plasticity to the reaction product.

In sample 4, silane-based 3-glycidoxypropylmethyldiethoxysilane, which is a liquid resin, was used as the coating layer 6. 3-Glycidoxypropylmethyldiethoxysilane is known to be used as a silane coupling agent. 3-Glycidoxypropylmethyldiethoxysilane has an epoxy group in its molecular skeleton and a linear molecular structure with 7 carbon atoms and 1 silicon. The magnet fixing resin 5 reacts with the epoxy group of 3-glycidoxypropylmethyldiethoxysilane used as a coating layer, and the linear chemical structure consisting of carbon and silicon imparts plasticity to the reaction product. I understand.

In sample 5, the coating layer 6 was a liquid resin, and an amine-modified silicone resin in which both ends of a modified silicone resin-based polysiloxane were amine-modified was used. Amine-modified silicone resin has an amino group that reacts with an epoxy resin and a polysiloxane structure in its molecular skeleton. It was found that the magnet fixing resin 5 reacts with the amino groups of the amine-modified silicone resin used as the coating layer 6, and the polysiloxane skeleton imparts plasticity to the reaction product.

In sample 6, bis-2-ethylhexyl adipate was used as the oil in coating layer 6. Bis-2-ethylhexyl adipate has 22 carbon atoms and has ethylhexyl groups at both ends of the molecule. It has been found that when the magnet fixing resin 5 is mixed with bis-2-ethylhexyl adipate used as the coating layer 6, the reaction product is plasticized.

On the other hand, in Sample 8, no discoloration or change in elasticity as in Samples 1 to 7 was observed at the interface between the permanent magnet 3 and the magnet fixing resin 5.

Next, crack resistance was evaluated using Samples 1 to 8 described above. In the test, the rotor of the created rotating electric machine was placed in a heat cycle test tank and left to stand for 200 cycles at -40℃ to 160℃, after which the appearance of the rotor was checked to see if there were any cracks. did. In Samples 1 to 7, no cracks were observed around the magnet fixing resin, but in Sample 8, minute cracks were observed around the magnet fixing resin.

From the above results, it can be seen that the coating layer 6 is formed on the surface of the permanent magnet 3, and the magnet fixing resin 5 that fixes the coating layer 6 and the permanent magnet 3 is heated in the magnet slot 2. It has been found that by providing the stress relaxation layer 7, it is possible to suppress the occurrence of cracks in the magnet fixing resin.

As described above, according to the rotor 100 of the rotating electric machine according to the first embodiment, the rotor core 1 has the magnet slots 2 provided along the outer circumferential direction, and the rotor core 1 has the magnet slots 2 disposed in the magnet slots 2. Since the permanent magnet 3 is fixed with the magnet fixing resin 5 and the stress relaxation layer is formed on the surface of the permanent magnet 3 and a part of the magnet fixing resin 5 is modified, According to the method for manufacturing a rotor of a rotating electrical machine according to the first embodiment, the process of forming the coating layer 6 containing a long-chain hydrocarbon material on the surface of the permanent magnet 3, and the step of forming the coating layer 6 containing a long-chain hydrocarbon material on the surface of the permanent magnet 3, The permanent magnet 3 is inserted into the magnet slot 2 by inserting the permanent magnet 3 into the magnet slot 2, injecting the magnet fixing resin 5 between the magnet slot 2 and the permanent magnet 3, and performing heat treatment. Since the structure includes the step of fixing the magnet in the magnet and forming a stress relaxation layer 7 in which a part of the magnet fixing resin 5 is modified by the coating layer 6, it is possible to efficiently introduce the stress relaxation layer to the magnet surface. . Furthermore, it is possible to provide a rotor for a highly reliable rotating electrical machine that can suppress the occurrence of cracks in the magnet fixing resin under a heat cycle environment and firmly fix permanent magnets with adhesive.

Although this application describes various exemplary embodiments, the various features, aspects, and functions described in the embodiments are not limited to the application of particular embodiments, and are not intended to be used alone. , or can be applied to the embodiments in various combinations. Accordingly, countless variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, this includes cases in which at least one component is modified, added, or omitted, and cases in which at least one component is extracted and combined with other components.

1 rotor core, 2 slot for magnet, 3 permanent magnet, 5 resin for fixing magnet, 6 coating layer, 6 coating layer, 7 stress relaxation layer, 100 rotor of rotating electric machine.

Claims (10)

a rotor core with slots provided along the outer circumference;
a permanent magnet disposed within the slot and fixed with resin;
a stress relaxation layer formed on the surface of the permanent magnet and partially modified with the resin;
A rotor for a rotating electrical machine characterized by comprising: The rotor of a rotating electrical machine according to claim 1, wherein the stress relaxation layer has a lower elastic modulus than the resin other than the stress relaxation layer. 3. The rotor of a rotating electric machine according to claim 1, wherein the stress relaxation layer includes a long-chain hydrocarbon material. forming a coating layer on the surface of the permanent magnet;
inserting the permanent magnet into a slot provided in the rotor core;
A resin is injected between the slot and the permanent magnet, and heat treatment is performed to fix the permanent magnet in the slot, and a portion of the resin is modified by the coating layer to form a stress relaxation layer. The process of
A method of manufacturing a rotor for a rotating electrical machine, the method comprising: 5. The method of manufacturing a rotor for a rotating electric machine according to claim 4, wherein the stress relaxation layer has a lower elastic modulus than the resin. 6. The method of manufacturing a rotor for a rotating electric machine according to claim 5, wherein the coating layer includes a long-chain hydrocarbon material. 7. The method for manufacturing a rotor of a rotating electrical machine according to claim 4, wherein the coating layer is formed by applying a liquid resin. 7. The method for manufacturing a rotor of a rotating electric machine according to claim 4, wherein the coating layer is formed by applying oil or fat. 8. The method of manufacturing a rotor for a rotating electric machine according to claim 7, wherein the stress relaxation layer is formed by being modified by reacting the coating layer with the liquid resin. 9. The method of manufacturing a rotor for a rotating electrical machine according to claim 8, wherein the stress relaxation layer is formed by being modified by mixing the coating layer and the oil or fat.

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