JP7459389B1 - Motor stator, motor, and manufacturing method of motor stator - Google Patents

Abstract

The motor stator 100 includes a stator core (1) made of laminated steel plates and having slots (1a, 1b) formed between a plurality of teeth (1c) protruding radially from the outer periphery toward the center of a circular yoke portion (1d), resin layers (2a, 2b) containing inorganic filler (22) provided on the outer periphery and/or inner periphery of the stator core (1), and a coil (4) wound around the teeth (1c) via insulating films (3a, 3b). Covering the outer layer of the stator core with the resin layer filled with inorganic filler prevents refrigerant leakage.

Description

This application relates to a motor stator, a motor, and a method for manufacturing a motor stator.

BACKGROUND ART In recent years, motors have been known that use the inside of a stator slot as a coolant passage from the viewpoint of improving cooling efficiency. However, in the motor, there is a possibility that the refrigerant passing through the slot may leak out from the slot through the gap between the laminated steel plates. Therefore, in order to realize the above-mentioned motor, a technique for preventing refrigerant leakage has been reported.

For example, Patent Document 1 discloses a process of filling the slot opening of a core made of laminated steel plates with a mixture of alumina powder and polyimide resin, a process of thermally spraying a ceramic material on the inner peripheral surface of the core made of laminated steel plates, and a process of thermally hardening the inner surface of the slot. A technique is disclosed in which refrigerant leakage from openings and laminated steel plates is prevented by a process of applying a synthetic resin. Furthermore, in Patent Document 2, unnecessary portions are removed by filling the slot openings with a resin mold and applying pressure to the entire inner circumferential surface of the stator using a method such as blow molding or spraying to apply a thin film made of a plastic material. A technique is disclosed that prevents refrigerant from leaking from the inside of the slot to the rotor side through a cutting process.

JP-A-53-095207 (page 2, upper right column, line 11 to lower left column, line 9) JP 2004-129406 (Paragraph 0016, Figure 3)

However, the conventional techniques such as those disclosed in Patent Document 1 and Patent Document 2 described above have a problem in that the steps required to prevent refrigerant leakage are multi-step and complicated. Furthermore, there is a problem in that when a cooling/heating cycle is applied, the refrigerant may leak if adhesion with the core made of laminated steel plates is lost due to resin deterioration, thermal expansion, etc.

The present application has been made to solve the above-mentioned problems, and aims to provide a motor stator, a motor, and a method for manufacturing a motor stator that reliably prevents refrigerant leakage from laminated steel plates in a relatively simple manner.

The stator for a motor disclosed in the present application is made of laminated steel plates, and includes a stator core having slots formed between a plurality of teeth protruding radially from the outer periphery of an annular yoke toward the center, and an outer peripheral surface of the stator core. and a resin layer including a plate-shaped inorganic filler provided on the inner peripheral surface and continuously arranged in the circumferential direction and oriented parallel to the layer direction of the resin layer , and an insulating film on the teeth. A stator for a motor, comprising: a coil wound through the coil;
Moreover, the stator for a motor disclosed in the present application is made of laminated steel plates, and includes a stator core having slots formed between a plurality of teeth protruding radially from the outer periphery of an annular yoke toward the center; A particulate or plate-shaped first inorganic filler is provided on the outer peripheral surface and the inner peripheral surface and is continuously arranged in the circumferential direction on the stator core side, and the first inorganic filler is arranged on the side opposite to the stator core side. A resin layer containing an inorganic filler in which a second inorganic filler in the form of particles having a smaller average particle size than the inorganic filler is arranged, and a coil wound around the teeth with an insulating film interposed therebetween. .

The motor disclosed in the present application is characterized by including the above-mentioned motor stator.

The manufacturing method of a stator for a motor disclosed in the present application is characterized by including a process of applying a resin mixed with an inorganic filler to a substrate, followed by drying to create a resin sheet, a process of attaching the resin surface of the resin sheet continuously in the circumferential direction to the outer and inner peripheral surfaces of a stator core made of laminated steel plates and having slots formed between a plurality of teeth protruding radially from the outer periphery of a circular yoke toward the center, and a process of hardening the attached resin sheet.

According to the present application, by covering the outer layer of the stator core with a resin layer filled with an inorganic filler, it is possible to not only prevent refrigerant leakage, but also reduce the adhesion of the resin layer due to the difference in thermal expansion coefficient with the stator core during cooling and heating cycles. The generation of cracks can be suppressed.

1 is an enlarged cross-sectional view showing the configuration of a motor stator according to Embodiment 1. FIG. 4 is a cross-sectional view showing a configuration of a resin layer used in the motor stator according to the first embodiment. FIG. FIG. 3 is a cross-sectional view for explaining a method of manufacturing a resin sheet for forming a resin layer of a motor stator according to Embodiment 1. 5A to 5C are cross-sectional views for illustrating a method for manufacturing a resin layer of the motor stator according to the first embodiment. FIG. 3 is a cross-sectional view showing the structure of a resin layer used in a motor stator according to a second embodiment. 11 is a cross-sectional view showing another configuration of the resin layer used in the motor stator according to the second embodiment. FIG. FIG. 7 is a cross-sectional view showing the structure of a resin sheet used in a motor stator according to Embodiment 3. FIG. 7 is a cross-sectional view showing another configuration of a resin sheet used in a motor stator according to Embodiment 3. FIG. 7 is a cross-sectional view showing the configuration of a motor according to a fourth embodiment. FIG. 3 is a side view for explaining a leakage evaluation method in an example. FIG. 3 is a cross-sectional view for explaining a leakage evaluation method in an example.

Embodiment 1.
FIG. 1 is an enlarged cross-sectional view showing the configuration of a motor stator 100 according to the first embodiment. As shown in FIG. 1, the motor stator 100 includes a stator core 1, resin layers 2a and 2b provided on the outer circumferential surface and/or inner circumferential surface of the stator core 1, and inner surfaces of slot portions 1a and 1b of the stator core 1. The coil 4 is wound around the teeth portion 1c of the stator core 1 with the insulating films 3a and 3b sandwiched therebetween.

The stator core 1 is formed by laminating a plurality of thin plates made of magnetic material. Stator core 1 has a yoke portion 1d and a plurality of teeth portions 1c. The yoke portion 1d has an annular shape. Each of the plurality of teeth portions 1c projects radially inward from the yoke portion 1d. The plurality of teeth portions 1c are arranged at equal intervals in the circumferential direction. The coil 22 is wound around the teeth 1c of the stator core 1 with insulating films 3a, 3b interposed therebetween, and the refrigerant 5 passes through the slots 1a, 1b of the stator core 1, thereby directly cooling the coil 4.

The resin layers 2a and 2b are composed of a cured resin and an inorganic filler dispersed and filled in the cured resin. FIG. 2 shows a cross-sectional view showing the structure of resin layers 2a and 2b used in the motor stator 100 according to the first embodiment. As shown in FIG. 2, the resin layers 2a and 2b are comprised of particulate filler layers in which a resin 21 is filled with particulate inorganic filler 22. As shown in FIG.

Note that the resin layers 2a and 2b may be reinforced by arranging glass cloth or the like on the outside opposite to the stator core 1 side.

<Inorganic filler>
The inorganic filler 22 includes, but is not particularly limited to, boron nitride (BN), fused silica (SiO ₂ ), crystalline silica (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), and silicon carbide (SiC). , calcium carbonate (CaCO ₃ ), magnesium oxide (MgO), and the like. Further, these inorganic fillers may be used alone or in combination of two or more. By using a highly thermally conductive filler such as crystalline silica (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), boron nitride (BN), or aluminum nitride (AlN) as the inorganic filler 22, , it is possible to improve the heat dissipation performance of the core made of laminated steel plates.

The average particle size of the inorganic filler 22 is preferably 20 nm or more and 500 μm or less. If the average particle size of the inorganic filler 22 is less than 20 nm, the specific surface area becomes large and the wettability with the resin decreases, so the filling amount of the filler cannot be increased, and the leakage prevention effect decreases. On the other hand, if the average particle size of the inorganic filler 22 exceeds 500 μm, the presence of coarse particles increases the unevenness of the layer, making it difficult to control the thickness of the resin layer. From the viewpoint of preventing refrigerant leakage, workability, and moldability, the average particle size of the inorganic filler 22 is preferably 0.1 μm or more and 200 μm or less. Furthermore, from the viewpoint of filling the gaps between the laminated steel plates, the average particle size of the inorganic filler 22 is preferably 1/2 or less of the gap between the laminated steel plates.

The filling rate of the inorganic filler 22 in the resin layers 2a and 2b (the proportion of the inorganic filler in the resin layer) is preferably 10% by volume or more and 90% by volume or less. When the filling rate is less than 10% by volume, the inorganic filler 22 is not sufficiently present on the inner diameter surface and the outer diameter surface of the stator core 1, and the refrigerant leak prevention effect is reduced. On the other hand, when the filling rate exceeds 90% by volume, it becomes difficult to disperse the inorganic filler 22 in the resin 21, causing problems in workability and moldability. From the viewpoint of prevention of refrigerant leakage, workability, and moldability, the filling amount of the inorganic filler 22 is preferably 30% by volume or more and 75% by volume or less.

<Resin>
The resin 21 used for the resin layers 2a and 2b is not particularly limited, and resins known in the technical field can be used. Examples of the resin 21 include epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, silicone resin, polyimide resin, acrylic resin, polycarbonate, polyethylene terephthalate, polyphenylene sulfide, and the like. These resins may be used alone or in combination of two or more. Epoxy resin is preferred from the viewpoints of moldability of the resin layers 2a, 2b, adhesion to the core made of laminated steel plates, insulation properties, etc.

Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, alicyclic aliphatic epoxy resins, glycidyl-aminophenol type epoxy resins, epoxy resins containing a naphthalene skeleton, anthracene skeleton, or isocyanuric acid skeleton, novolac type epoxy resins such as phenol novolac type epoxy resins and cresol novolac type epoxy resins, triphenol alkane type epoxy resins such as triphenol methane type epoxy resins and triphenol propane type epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, biphenyl aralkyl type epoxy resins, and heterocyclic type epoxy resins. These epoxy resins may be used alone or in combination of two or more.

Next, a manufacturing method for the motor stator 100 relating to embodiment 1 will be described with reference to Figures 3A to 3D and Figures 4A to 4C.

First, a method for manufacturing a resin sheet for forming the resin layer of the motor stator 100 will be described. 3A to 3D are cross-sectional views for explaining a method of manufacturing a resin sheet.

First, a predetermined amount of resin 21 and an amount of curing agent required to harden this resin 21 are mixed. After adding a solvent to this mixture, an inorganic filler 22 is added and mixed to obtain a resin composition 211. When the viscosity of the resin composition 211 is low, it is not necessary to add a solvent. In addition, when blending a coupling agent, the coupling agent may be added before the kneading step.

<Curing Agent>
The resin composition for producing the resin sheet may contain a curing agent to cure the resin. The curing agent is not particularly limited, and may be appropriately selected from known curing agents according to the type of resin. For example, in the case where an epoxy resin is used, examples of the curing agent for the epoxy resin include amine-based curing agents such as ethylenediamine, polyamidoamine, diaminodiphenylmethane (DDM), and diaminodiphenylsulfone (DDS); acid anhydride-based curing agents such as phthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, tetrabromophthalic anhydride, methylnadic anhydride, dodecenylsuccinic anhydride, and pyrrolimetic anhydride; phenol-based curing agents such as novolac phenolic resins and cresol novolac phenolic resins; tertiary amines such as dicyandiamide and benzyldimethylamine; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole; and curing agents that promote self-polymerization of the epoxy resin, such as 1,8-diazabicyclo(5,4,0)undecene and derivatives thereof. These curing agents may be used alone or in combination of two or more. The amount of the curing agent may be appropriately adjusted depending on the type of resin and the type of curing agent used, and is generally 0.1 parts by weight to 200 parts by weight per 100 parts by weight of the resin.

<Curing accelerator>
In order to increase the curing speed of the resin and curing agent in the resin composition, a curing accelerator may be included. The type of curing accelerator is not particularly limited as long as it can promote curing of the resin, and may be appropriately selected from known curing accelerators. When an epoxy resin is used as the resin, examples of curing accelerators include tertiary amines such as benzyldimethylamine, imidazoles such as 2-ethyl-4-methylimidazole, and organic metals such as zinc octylate. It will be done. The curing accelerator may be used alone or in combination of two or more types. The content of the curing accelerator may be appropriately adjusted depending on the type of resin and curing agent used, and is generally 0.1 to 100 parts by weight based on 100 parts by weight of the resin.

<Film-forming agent>
In order to improve film formability such as film thickness uniformity and surface smoothness, a film formability imparting agent may be included as necessary. As the film-forming agent, phenoxy resin, acrylic resin, high molecular weight epoxy resin, etc. are used. These film formability imparting agents may be used alone or in combination of two or more. The content of the film-forming agent may be appropriately adjusted depending on the type of resin used, and is generally 5 to 200 parts by weight based on 100 parts by weight of the resin.

<Coupling Agent>
The resin composition for producing the resin sheet may contain a coupling agent from the viewpoint of improving the adhesive strength at the interface between the resin and the inorganic filler. The coupling agent is not particularly limited, and a known one may be appropriately selected according to the type of resin and inorganic filler. Examples of such coupling agents include γ-glycidoxypropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane. These coupling agents may be used alone or in combination of two or more. The amount of the coupling agent may be appropriately set according to the type of resin and coupling agent used, and is generally preferably 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the resin.

<Solvent>
The resin composition for manufacturing the resin sheet can contain a solvent from the viewpoint of adjusting the viscosity of the composition. The solvent is not particularly limited, and any known solvent may be appropriately selected depending on the type of resin and inorganic filler used. Examples of such solvents include acetone, methanol, ethanol, isopropyl alcohol, toluene, methyl ethyl ketone, and the like. These solvents may be used alone or in combination of two or more. The amount of the solvent blended is not particularly limited as long as it provides a viscosity of the composition that can be kneaded, and is generally 20 parts by mass or more and 200 parts by mass based on the total of 100 parts by mass of the resin and inorganic filler. It is preferable that the amount is less than 100%.

Next, resin sheet 200C (Fig. 3A) in which resin composition 211 mixed with the above-mentioned inorganic filler 22 is applied to a releasable substrate 23, and sheet 200D (Fig. 3B) in which resin composition 211 without inorganic filler is applied to a releasable substrate 24 are dried, and then the resin surfaces are brought together (Fig. 3C) and pressed with a predetermined press pressure to create resin sheets 2A and 2B (Fig. 3D) for forming resin layers 2a and 2b of stator core 1.

Here, the releasable substrate is not particularly limited, and any known releasable substrate such as a release-treated resin sheet, film, etc. can be used.

The applied resin composition 211 may be dried at ambient temperature, but from the viewpoint of promoting volatilization of the solvent, it may be heated to a temperature of 40° C. or more and 200° C. or less, if necessary.

Next, a method for manufacturing the resin layer of the motor stator 100 will be described. FIGS. 4A to 4C are cross-sectional views for explaining a method of manufacturing a resin layer.

First, the resin sheets 2A and 2B created above are attached to the outer circumferential surface and/or inner circumferential surface of the stator core 1 by peeling off the releasable base material 24 on the side to be attached to the stator core 1 (FIG. 4A). By pasting, the resin on the stator core side of the resin sheets 2A and 2B permeates into the gaps between the laminated steel plates forming the stator core 1.

When pasting the resin sheets 2A, 2B on the outer circumferential surface and/or inner circumferential surface of the stator core 1, if there are openings or uneven parts on the outer circumferential surface and/or inner circumferential surface of the stator core 1, please apply epoxy resin and acrylic sheets in advance. It is best to close the uneven portions with a sealing material such as resin and then paste the resin sheet. Moreover, from the viewpoint of arranging the resin sheets continuously in the circumferential direction of the stator core 1, the resin sheets 2A and 2B may be partially overlapped. If the thickness of the resin sheets 2A, 2B is large in relation to the gap between the rotor and the case, which are arranged on the inner or outer circumference side of the stator core 1, after pasting the resin sheets 2A, 2B, apply pressure to reduce the thickness. A process for suppressing this may be added. Furthermore, even when there is no need to reduce the thickness, a step of pressurizing the resin sheets 2A, 2B may be added in order to improve the adhesion between the resin sheets 2A, 2B and the stator core 1 made of laminated steel plates.

After attaching the resin sheets 2A and 2B to the stator core 1, the resin sheets 2A and 2B are cured (FIG. 4B). The curing temperature and curing time are not particularly limited and may be appropriately set depending on the type of resin composition used. For example, the curing temperature ranges from 20°C to 300°C, and the curing time ranges from 1 minute to 100 hours.

After the resin sheets 2A, 2B are cured, the releasable base material 23 on the outer circumferential side is peeled off to obtain the stator core 1 on which the resin layers 2a, 2b are formed (FIG. 4C).

In addition, when the entire stator is coated with varnish for the purpose of fixing the coil wound with electric wire, the resin sheets 2A and 2B do not require a layer of resin only on the stator core 1 side. Instead of the resin sheets 2A and 2B, a resin sheet 200C (200CA, 200CB) in which a resin composition 211 mixed with an inorganic filler 22 shown in FIG. 3A is applied to a releasable base material 23 is attached to the outer peripheral surface and/or inner peripheral surface of the stator core 1, and the process corresponding to FIG. 4A to FIG. 4C is performed, so that the varnish permeates the gaps between the laminated steel plates that form the stator core 1, and a stator core 1 in which the resin layers 2a and 2b are formed is obtained without a resin layer.

As described above, according to the motor stator 100 according to the first embodiment, the teeth portions 1c are made of laminated steel plates and protrude radially from the outer periphery of the annular yoke portion 1d toward the center. A stator core 1 having slot portions 1a and 1b formed therein; resin layers 2a and 2b containing an inorganic filler 22 provided on the outer circumferential surface and/or inner circumferential surface of the stator core 1 and continuously arranged in the circumferential direction; Since the teeth part 1c is provided with the coil 4 wound through the insulating films 3a and 3b, according to the method for manufacturing the motor stator 100 according to the first embodiment, particulate A step of applying a resin mixed with an inorganic filler 22 to a base material and drying it to create a resin sheet, and a plurality of sheets made of laminated steel plates and protruding radially from the outer periphery of the annular yoke portion 1d toward the center. A step of continuously pasting the resin surfaces of the resin sheets 2A, 2B in the circumferential direction on the outer peripheral surface and/or the inner peripheral surface of the stator core 1 formed between the teeth portions 1c of the stator core 1, and the pasted resin sheets 2A, 2B. This method not only prevents refrigerant leakage by covering the outer layer of the stator core with a resin layer filled with an inorganic filler, but also prevents refrigerant leakage due to the difference in thermal expansion coefficient between the stator core and the stator core due to the cooling/heating cycle. Decrease in adhesion of the resin layer and generation of cracks can be suppressed.

Embodiment 2.
In the first embodiment, a case where a particulate filler is used as the inorganic filler 22 is explained, but in a second embodiment, a case is explained where a plate-like filler is used.

FIG. 5 shows a cross-sectional view showing the structure of resin layers 2a and 2b used in the motor stator 100 according to the second embodiment. As shown in FIG. 5, the resin layers 2a and 2b of the second embodiment are plate-shaped filler layers in which a resin 21 is filled with a plate-shaped inorganic filler 25. As shown in FIG.

In the resin sheets 2A and 2B of the second embodiment, the plate-shaped inorganic filler 25 is oriented parallel to the sheet surface direction during the pressing process. As a result, the filler is oriented in the radial direction of the stator core 1, and when the resin sheets 2A and 2B are attached to the outer peripheral surface and/or the inner peripheral surface of the stator core 1, the filler is oriented perpendicularly to the gap between the laminated steel plates. By arranging the refrigerant, it is possible to reliably prevent refrigerant leakage.

Examples of the plate-shaped inorganic filler 25 include boron nitride (BN), aluminum oxide (Al ₂ O ₃ ), mica, and the like. In addition, when the shape of an inorganic filler is plate-like, an average particle diameter means the length of a long side.

Other configurations and manufacturing methods of the motor stator 100 according to the second embodiment are the same as those of the motor stator 100 according to the first embodiment, and corresponding parts are given the same reference numerals and explanations thereof will be omitted.

As described above, according to the motor stator 100 of the second embodiment, the resin layers 2a and 2b are filled with the plate-shaped inorganic filler 25. By orienting the plate-shaped inorganic filler so that it is parallel to the sheet surface direction, the filler is oriented in the radial direction of the stator core, and when the resin sheet is attached to the outer peripheral surface and/or inner peripheral surface of the stator core, the filler is arranged perpendicular to the gaps in the laminated steel sheets, which reliably prevents refrigerant leakage. In addition, it is possible to suppress the deterioration of adhesion of the resin layer and the occurrence of cracks due to the difference in thermal expansion coefficient with the stator core caused by the cooling and heating cycle.

In the present embodiment 2, the resin layers 2a and 2b are filled with only the plate-shaped inorganic filler 25, but this is not limited thereto. As shown in FIG. 6, the resin layers 2a and 2b may include a filler layer 20A filled with the plate-shaped inorganic filler 25 and a filler layer 20B filled with the particulate inorganic filler 22. In this case, the same effect as above can be obtained. In this configuration, it is preferable to arrange the filler layer 20B filled with the particulate inorganic filler 22 on the stator core 1 side and arrange the filler layer 20A filled with the plate-shaped inorganic filler 25 on the outside.

Embodiment 3.
In Embodiment 3, a case will be described in which resin layers filled with inorganic fillers having different average particle sizes are arranged.

FIG. 7 shows a cross-sectional view showing the configuration of a resin sheet 200E used in the motor stator 100 according to the third embodiment. As shown in FIG. 7, the resin sheet 200E of the third embodiment includes a filler sheet layer 200a in which a resin composition 211 is mixed with a particulate inorganic filler 22 as a first inorganic filler, and a filler sheet layer 200a in which a particulate inorganic filler 22 as a first inorganic filler is mixed into a resin composition 211. Filler sheet layer 200b mixed with particulate inorganic filler 26 as a second inorganic filler having a small average particle size and an average particle size of 1/2 or less of the gap between the laminated steel plates forming stator core 1. It consists of and.

In this configuration, a filler sheet layer 200b containing particulate inorganic filler 26 having an average particle size smaller than that of inorganic filler 22 is arranged on the stator core 1 side, and a filler sheet layer 200a containing particulate inorganic filler 22 is arranged on the outside.

The other configuration and manufacturing method of the motor stator 100 according to the third embodiment are the same as those of the motor stator 100 according to the first embodiment, and corresponding parts are given the same reference numerals and the explanation thereof will be omitted.

As a result, the filler sheet layer 200b mixed with the particulate inorganic filler 26 having a small average particle size is arranged on the stator core 1 side, and the resin composition permeates into the gaps between the laminated steel plates, and the particulate inorganic filler 26 having a small average particle size is mixed with the filler sheet layer 200b. By filling the gap between the laminated steel plates with the filler 26, the leakage of refrigerant from the gap between the laminated steel plates, which is difficult to prevent with resin alone, can be surely dammed up by the filler, and the refrigerant can flow into the slot without leakage.

As described above, according to the motor stator 100 according to the third embodiment, the inorganic filler has an average particle size larger than that of the particulate inorganic filler 22 as the first inorganic filler. It is a particulate inorganic filler 26 as a second inorganic filler that is small and has an average particle size of 1/2 or less of the gap between the laminated steel plates, and the resin layers 2a and 2b are formed on the outer peripheral surface of the stator core 1 or / Since the layer containing the inorganic filler 22 is provided on the inner peripheral surface and the layer containing the inorganic filler 26 is provided in the gap between the laminated steel plates, the method for manufacturing the motor stator 100 according to the third embodiment According to , the inorganic filler includes a particulate inorganic filler 22 as a first inorganic filler, and an average particle size smaller than that of the first inorganic filler and an average particle size of 1/2 or less of the gap between the laminated steel plates. The resin sheet 200E is provided with a filler sheet layer 200b containing the inorganic filler 26 on the stator core 1 side and containing the inorganic filler 22 on the outside. Since the filler sheet layer 200a is provided, not only the same effects as in the first embodiment can be obtained, but also the resin composition can penetrate into the gaps between the laminated steel plates and the inorganic filler in the form of particles with a small average particle size can be absorbed. By filling the gaps between the laminated steel plates, the filler reliably dams up leakage of refrigerant from the gaps between the laminated steel plates, which is difficult to prevent with resin alone, and allows the refrigerant to flow into the slots without leakage.

Note that in the third embodiment, particulate inorganic filler 22 is used on the outside of resin sheet 200E, but the present invention is not limited to this. As shown in FIG. 8, a plate-shaped inorganic filler 26 may be used. In this case, in addition to the above effects, the same effects as in the second embodiment can also be obtained.

Embodiment 4.
In Embodiment 4, a motor using the motor stator 100 according to Embodiments 1 to 3 will be described.

FIG. 9 shows a cross-sectional view showing the configuration of a motor 300 according to the fourth embodiment. As shown in FIG. 9, a motor 300 according to the fourth embodiment includes the motor stator 100 according to the first to third embodiments, a rotor 107, a shaft 108, a frame 109, and two brackets 110. Equipped with The motor stator 100 is formed into a cylindrical shape having a central axis C.

As described above, since the motor according to the fourth embodiment includes the motor stator 100 according to any one of the first to third embodiments, the refrigerant from the motor stator is It is possible to obtain a motor that can not only prevent leakage but also suppress deterioration in adhesion of the resin layer and generation of cracks due to the difference in thermal expansion coefficient with the stator core due to cooling and heating cycles.

The details of the present application will be explained below with reference to Examples and Comparative Examples, but the present application is not limited by these.

Table 1 shows the constituent materials and their mixing ratios of the resin layer, particulate filler layer, and plate-like filler layer used in Examples 1 to 13 and Comparative Example 2.

<Production of resin sheet>
70 parts by mass of liquid bisphenol A type epoxy resin (jER828US: manufactured by Mitsubishi Chemical) which is a thermosetting resin, 30 parts by mass of solid bisphenol A type epoxy resin (jER1007: manufactured by Mitsubishi Chemical), and 50 parts by mass of methyl ethyl ketone which is a solvent. was added and stirred until dissolved. Next, 20 parts by weight of phenoxy resin (1256B40, manufactured by Mitsubishi Chemical) and 5 parts by weight of imidazole catalyst (2E4MZ, manufactured by Shikoku Kasei) were added and stirred until uniformly dissolved to prepare a resin composition. This resin composition was applied by a doctor blade method onto a release-treated PET film having a thickness of 50 μm, and was heated and dried at 80° C. for 10 minutes to produce a resin sheet having a thickness of 80 μm.

<Preparation of particulate filler sheet>
70 parts by mass of liquid bisphenol A type epoxy resin (jER828US: manufactured by Mitsubishi Chemical) which is a thermosetting resin, 30 parts by mass of solid bisphenol A type epoxy resin (jER1001: manufactured by Mitsubishi Chemical), and 100 parts by mass of methyl ethyl ketone which is a solvent. was added and stirred until dissolved. Next, 5 parts by weight of an imidazole catalyst (2E4MZ: manufactured by Shikoku Kasei) was added and stirred until uniformly dissolved. To this mixture, 210 parts by mass of spherical alumina (DAW05: manufactured by Denka) with an average particle size of 5 μm and 315 parts by mass of spherical alumina (DAW45: manufactured by Denka) with an average particle size of 45 μm were added as particulate filler. A resin composition having a filling rate of 60% by volume was prepared. Thereafter, this resin composition was applied onto the release-treated PET film using the doctor blade method in the same manner as when the resin layer was prepared, and heat-dried at 80°C for 10 minutes to reduce the thickness. A particulate filler sheet 1 having a diameter of 100 μm was produced.

Particulate filler sheet 2 was prepared in the same manner as particulate filler layer 1, except that the particulate filler was a mixture of 93 parts by mass of spherical alumina (DAW05: manufactured by Denka) having an average particle size of 5 μm and 140 parts by mass of spherical alumina (DAW45: manufactured by Denka) having an average particle size of 45 μm, so that the filling rate of the particulate filler was 40 volume %.

The particulate filler sheet 3 contains, as particulate fillers, 140 parts by mass of spherical alumina (DAW05: manufactured by Denka) with an average particle size of 5 μm and 210 parts by mass of spherical alumina (DAW45: manufactured by Denka) with an average particle size of 45 μm. Particulate filler sheet 3 was produced in the same manner as particulate filler 1 except that the particulate filler was blended so that the filling rate was 50% by volume.

<Production of plate-shaped filler sheet>
70 parts by mass of liquid bisphenol A type epoxy resin (jER828US: manufactured by Mitsubishi Chemical) which is a thermosetting resin, 30 parts by mass of solid bisphenol A type epoxy resin (jER1007: manufactured by Mitsubishi Chemical), and 150 parts by mass of methyl ethyl ketone which is a solvent. was added and stirred until dissolved. Next, 20 parts by weight of phenoxy resin (1256B40, manufactured by Mitsubishi Chemical) and 5 parts by weight of imidazole catalyst (2E4MZ, manufactured by Shikoku Kasei) were added and stirred until uniformly dissolved to prepare a resin composition. 292 parts by mass of mica (manufactured by Okabe Mica) having an average particle size of 400 μm was added to this mixture as a plate-shaped filler to prepare a resin composition having a filling rate of plate-shaped filler of 50% by volume. Thereafter, in the same manner, it was coated on a PET film that had been subjected to a mold release treatment using a doctor blade method, and was heated and dried at 80 degrees for 10 minutes to produce a plate-shaped filler sheet 1 with a thickness of 100 μm.

The plate-shaped filler sheet 2 contains 236 parts by mass of flaky boron nitride BN (UHP-1: manufactured by Showa Denko) with an average particle size of 10 μm as a plate-shaped filler, so that the filling rate of the plate-shaped filler is 50% by volume. A plate-shaped filler sheet 2 was prepared in the same manner as the plate-shaped filler sheet 1 except that the amount of the solvent methyl ethyl ketone added was 180 parts by mass.

The plate-shaped filler sheet 3 is made of plate-shaped alumina (AH-1) with an average particle size of 9 μm as a plate-shaped filler.
0: manufactured by Denka) was blended so that the filling rate of the plate-shaped filler was 60% by volume, and the amount of the solvent methyl ethyl ketone added was 220 parts by mass. A plate-like filler sheet 3 was produced.

Plate-like filler sheet 4 was produced in the same manner as plate-like filler sheet 1, except that 101 parts by mass of flake-like boron nitride BN (UHP-1: manufactured by Showa Denko) with an average particle size of 10 μm was blended as the plate-like filler so that the filling rate of the plate-like filler was 30 volume %.

Plate-like filler sheet 5 was prepared in the same manner as plate-like filler sheet 1, except that 552 parts by mass of flake-like boron nitride BN (UHP-1: manufactured by Showa Denko) having an average particle size of 10 μm was blended as the plate-like filler so that the filling rate of the plate-like filler was 70 volume %, and the amount of solvent methyl ethyl ketone added was 270 parts by mass.

When the cross sections of the plate-shaped filler sheets 1 to 5 were observed using an electron microscope, it was confirmed that the plate-shaped fillers were all oriented in the horizontal direction.

Table 2 shows the configuration of the resin layers used in Examples 1 to 13 and Comparative Examples 1 and 2, and the stator characteristics when the resin layers were provided on the outer periphery of the stator.

[Example 1]
Particulate filler sheet 1 was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 2 MPa to obtain a resin sheet of particulate filler sheet 1 of Example 1.

[Example 2]
The particulate filler sheet 2 was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 1 MPa to obtain a resin sheet of the particulate filler sheet 2 of Example 2.

[Example 3]
The particulate filler sheet 3 was heated at 80° C. for 10 minutes under reduced pressure and a pressing pressure of 1 MPa to obtain a resin sheet of the particulate filler sheet 3 of Example 3.

[Example 4]
The plate-shaped filler sheet 1 was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 5 MPa to obtain a resin sheet of the plate-shaped filler sheet 1 of Example 4.

[Example 5]
The plate-shaped filler sheet 2 was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 5 MPa to obtain a resin sheet of the plate-shaped filler sheet 2 of Example 5.

[Example 6]
The plate-shaped filler sheet 3 was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 5 MPa to obtain a resin sheet of the plate-shaped filler sheet 3 of Example 6.

[Example 7]
The resin sheet and the particulate filler sheet 1 were overlapped and heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 2 MPa to obtain a resin sheet having the resin sheet layer of Example 7 and the particulate filler sheet layer.

[Example 8]
The plate-shaped filler sheet 5 was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 6 MPa, and a resin sheet was superimposed on the obtained plate-shaped filler sheet 5, and heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 2 MPa. Thus, a resin sheet having the resin sheet layer of Example 8 and a plate-shaped filler sheet layer was obtained.

[Example 9]
The plate-like filler sheet 4 was heated at 80°C for 10 minutes under reduced pressure at a pressing pressure of 3 MPa to obtain a plate-like filler sheet 4, which was then superimposed on the particulate filler sheet 1 obtained in Example 1 and heated at 80°C for 10 minutes under reduced pressure at a pressing pressure of 3 MPa to obtain a resin sheet having a particulate filler sheet layer and a plate-like filler sheet layer of Example 9.

[Example 10]
The particulate filler sheet 3 obtained in Example 3 and the plate-like filler sheet obtained in Example 5 were overlapped and heated at 80° C. for 10 minutes under reduced pressure with a press pressure of 4 MPa to obtain the particulate filler sheet of Example 10. A resin sheet having a filler sheet layer and a plate-like filler sheet layer was obtained.

[Example 11]
The plate-like filler sheet 5 was heated at 80°C for 10 minutes under reduced pressure at a pressing pressure of 6 MPa to obtain a plate-like filler sheet 5, which was then superimposed on the particulate filler sheet 2 obtained in Example 2 and heated at 80°C for 10 minutes under reduced pressure at a pressing pressure of 2 MPa to obtain a resin sheet having a particulate filler sheet layer and a plate-like filler sheet layer of Example 11.

[Example 12]
The resin sheet, the particulate filler sheet 2 obtained in Example 2, and the plate-like filler sheet 1 obtained in Example 4 are stacked in the order of resin sheet, particulate filler sheet 2, and plate-like filler sheet 1, The resin sheet was heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 2 MPa to obtain a resin sheet having three layers: the resin sheet layer of Example 12, a particulate filler sheet layer, and a plate-like filler sheet layer.

[Example 13]
The resin sheet, the particulate filler sheet 2 obtained in Example 2, and the plate-like filler sheet 4 were heated at 80° C. for 10 minutes under reduced pressure at a press pressure of 3 MPa. The shaped filler sheet 2 and the plate-shaped filler sheet 4 were stacked in this order and heated at 80°C for 10 minutes under reduced pressure at a press pressure of 2 MPa to form the resin sheet layer, particulate filler sheet layer and plate-shaped filler sheet of Example 13. A resin sheet having three layers was obtained.

[Comparative example 2]
The resin sheet was heated at 80° C. for 30 minutes under reduced pressure at a press pressure of 0.1 MPa to obtain a resin sheet of Comparative Example 2.

The resin sheets of Examples 1 to 13 and Comparative Example 2 were attached to the outer peripheral side of a motor stator and cured by heating to 150° C. to obtain a resin layer 2a. When attaching the resin sheet to the stator, the resin sheets of Examples 7, 8, 12, and 13 that included a resin sheet layer were arranged so that the resin sheet layer was on the stator core 1 side (the filler sheet layer was on the outside). Further, in the resin sheet having a combination of a particulate filler sheet layer and a plate-like filler sheet layer, the particulate filler sheet layer was arranged on the stator core 1 side (the plate-like filler sheet layer was on the outside). In the stator evaluation, a motor stator in which the resin layer 2a was not provided on the outer circumferential side of the stator core 1 was designated as Comparative Example 1.

<Leakage evaluation>
After the stator provided with the resin layer 2a was heat cycled 10 times at −10° C. and 100° C., refrigerant was flowed through the stator to evaluate leakage of the refrigerant from the stator provided with the resin sheet.

10A and 10B are diagrams for explaining the leakage evaluation method in this embodiment, with FIG. 10A showing the front side of the stator and FIG. 10B showing the back side. 11A is a sectional view taken along the XX arrow in FIG. 10A, FIG. 11B is a sectional view taken along the YY arrow in FIG. 10A, and FIG. 11C is a sectional view taken along the ZZ arrow in FIG. 10A.

As shown in FIGS. 10A and 10B and FIGS. 11A and 11B, a cylindrical inner lid 6 is placed on the inner peripheral side of the stator, and an upper lid 7 and a stator are provided with a refrigerant inlet 11 and an outlet 12 on the surface of the stator. A lower lid 8 was installed on the back side of the coil, and the refrigerant was injected at a constant flow rate so that the refrigerant flowed on three sides of each coil except for the upper and lower partitions. O-rings 13 are provided inside the upper lid 7 and lower lid 8 to prevent refrigerant from leaking from the lid portions. Note that the refrigerant inlet 11 and outlet 12 may be provided in the lower lid 8.

Partition plates 9 and 10 filled with acrylic resin sealant are installed on either the top or bottom of the coil 4 except between the adjacent inlet 11 and outlet 12 to block the path of the refrigerant. . The opposite side where the passage of the refrigerant was blocked by the partition plates 9 and 10 was used as a flow path for the refrigerant. These were arranged alternately up and down for each coil, so that the refrigerant would flow in a bellows shape to ensure that the refrigerant would flow into all the slots. As shown in FIG. 11C, both a partition plate 9 and a partition plate 10 were placed in the coil 4 between the adjacent inlet 11 and outlet 12 to block the flow of the refrigerant and prevent backflow. A refrigerant was flowed through the thus prepared stator for evaluating leakage, and the presence or absence of refrigerant leakage from the outer peripheral side where the resin layer was provided was visually confirmed.

As shown in Table 2, it was confirmed that when a resin sheet was not placed on the outer periphery of the stator as in Comparative Example 1, when the refrigerant was flowed between the coils, the refrigerant leaked out from the gaps between the laminated steel plates. In addition, when only a resin layer without filler is provided as in Comparative Example 2, cracks occur in the resin layer hardened by the heat cycle of the stator, and when the refrigerant is poured, the refrigerant leaks outside through the cracks. It leaked out. The resin layer alone has a large difference in thermal expansion coefficient from the core during heat cycling, which causes cracks to occur in the resin layer.

On the other hand, in a resin layer having a filler layer filled with particulate filler and plate-like filler, the difference in thermal expansion coefficient with the core is suppressed by filling the filler with the heat cycle of the stator, and cracks do not occur. In addition to being able to suppress cracks in the resin layer, it was also possible to prevent refrigerant leakage because the particulate filler and plate-like filler suppressed the refrigerant from flowing out to the outside diameter. In terms of the effect of suppressing the flow of refrigerant to the outside, it is more effective if the plate-shaped filler is oriented perpendicularly to the radial direction.

Although various exemplary embodiments and examples are described in this application, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but can be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are expected within the scope of the technology disclosed in this specification. For example, this includes cases in which at least one component is modified, added, or omitted, and even cases in which at least one component is extracted and combined with components of other embodiments.

1 stator core, 1a, 1b slot portion, 1c teeth portion, 1d yoke portion, 2a, 2b resin layer, 4 coil, 22 inorganic filler, 100 stator for motor.

Claims (7)

a stator core made of laminated steel plates and having slots formed between a plurality of teeth that protrude radially from the outer periphery of an annular yoke toward the center;
a resin layer that is provided on the outer peripheral surface and the inner peripheral surface of the stator core and includes a plate-shaped inorganic filler that is continuously arranged in the circumferential direction and is oriented in parallel to the layer direction ;
a coil wound around the teeth with an insulating film interposed therebetween;
A stator for a motor characterized by comprising: The motor stator according to claim 1, characterized in that the average particle size of the inorganic filler is 20 nm or more and 500 μm or less. The motor stator according to claim 1, wherein the resin layer contains a coupling agent. a stator core made of laminated steel plates and having slots formed between a plurality of teeth protruding radially from the outer periphery of an annular yoke toward the center;
A particulate or plate-shaped first inorganic filler is provided on the outer circumferential surface and the inner circumferential surface of the stator core and is continuously arranged in the circumferential direction. a resin layer containing an inorganic filler in which a second inorganic filler in the form of particles having a smaller average particle size than the first inorganic filler is arranged ;
a coil wound around the teeth with an insulating film interposed therebetween;
A stator for a motor characterized by comprising: A motor comprising the motor stator according to any one of claims 1 to 4 . A step of applying a resin mixed with an inorganic filler to a base material and then drying it to create a resin sheet;
The resin is applied continuously in the circumferential direction to the outer and inner circumferential surfaces of the stator core, which is made of laminated steel plates and has slots formed between a plurality of teeth that protrude radially from the outer periphery of the annular yoke toward the center. The process of pasting the resin side of the sheet,
a step of curing the pasted resin sheet;
A method of manufacturing a stator for a motor, the method comprising: 7. The method for manufacturing a motor stator according to claim 6 , wherein the inorganic filler is in the form of particles and/or plates.

Images