Motor stator, motor, and method for manufacturing motor stator

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

[Technical field]

[0001] The present application relates to a stator for a motor, a motor, and a method for manufacturing a stator for a motor. [Background technology]

[0002] In recent years, motors have been known that use the inside of the stator slots as coolant passages to improve cooling efficiency. However, in such motors, there is a possibility that the coolant passing through the inside of the slots may leak out from the inside of the slots through gaps between the laminated steel plates. Therefore, in order to realize such motors, techniques for preventing coolant leakage have been reported.

[0003] For example, Patent Document 1 discloses a technique for preventing refrigerant leakage from the openings and laminated steel plates by filling the slot openings of a core made of laminated steel plates with a mixture of alumina powder and polyimide resin, spraying a ceramic material onto the inner peripheral surface of the core made of laminated steel plates, and applying a thermosetting resin to the inner surfaces of the slots. Patent Document 2 discloses a technique for preventing refrigerant leakage from inside the slots to the rotor by filling the slot openings with a resin mold and applying pressure to the entire inner peripheral surface of the stator with a thin film made of a plastic material by blower molding, spraying, or other methods, and cutting off unnecessary parts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 53-095207 A (Page 2, upper right column, line 11 to lower left column, line 9) [Patent Document 2] JP 2004-129406 A (paragraph 0016, figure 3) Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional techniques such as those described in the above Patent Documents 1 and 2 have the problem that the process required to prevent refrigerant leakage is multi-step and complicated.In addition, when subjected to a cooling / heating cycle, there is a problem that the refrigerant may leak if the adhesion with the core made of laminated steel plates is lost due to deterioration of the resin, thermal expansion, etc.

[0006] The present application has been made to solve the above-mentioned problems, and has an object to provide a motor stator, a motor, and a method for manufacturing a motor stator that reliably prevent refrigerant leakage from laminated steel plates in a relatively simple manner. [Means for solving the problem]

[0007] The motor stator disclosed in the present application comprises 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 plurality of stator cores provided on the outer periphery and inner periphery of the stator core and arranged continuously in the circumferential direction. The plate-like resin layer is oriented parallel to the layer direction. A stator for a motor comprising: a resin layer containing an inorganic filler; and a coil wound around the teeth with an insulating film interposed therebetween. The motor stator disclosed in the present application is characterized in that it comprises a stator core made of laminated steel plate and having slots formed between a plurality of teeth protruding radially from the outer periphery of a circular yoke toward the center, resin layers containing inorganic filler provided on the outer periphery and inner periphery of the stator core and arranged continuously in the circumferential direction, with a first inorganic filler in particulate or plate form arranged on the stator core side and a second inorganic filler in particulate form having an average particle size smaller than that of the first inorganic filler arranged on the opposite side to the stator core side, and a coil wound around the teeth via an insulating film.

[0008] A motor disclosed in the present application includes the above-described motor stator.

[0009] The method of manufacturing a motor stator disclosed in the present application includes a step of applying a resin mixed with an inorganic filler to a substrate, and then drying the substrate to create a resin sheet; and a step of forming a stator core having slots formed between a plurality of teeth that protrude radially from the outer periphery of a circular yoke toward the center of the yoke, the stator core being made of laminated steel sheets. and The method includes a step of attaching the resin surface of the resin sheet continuously in the circumferential direction to the inner circumferential surface, and a step of curing the attached resin sheet. Effect of the Invention

[0010] According to the present application, by covering the outer layer of the stator core with a resin layer filled with inorganic filler, not only can refrigerant leakage be prevented, but also a decrease in adhesion of the resin layer and the occurrence of cracks due to differences in thermal expansion coefficients with the stator core caused by cooling and heating cycles can be suppressed. [Brief description of the drawings]

[0011] [Figure 1] 1 is an enlarged cross-sectional view showing a configuration of a motor stator according to a first embodiment. [Diagram 2] 3 is a cross-sectional view showing a configuration of a resin layer used in the motor stator according to the first embodiment. FIG. [Diagram 3] 5A to 5C are cross-sectional views illustrating a method for manufacturing a resin sheet for forming a resin layer of the motor stator according to the first embodiment. [Figure 4] 5A to 5C are cross-sectional views illustrating a method for manufacturing a resin layer of the motor stator according to the first embodiment. [Diagram 5] 10 is a cross-sectional view showing a configuration of a resin layer used in a motor stator according to a second embodiment. FIG. [Figure 6] 10 is a cross-sectional view showing another configuration of the resin layer used in the motor stator according to the second embodiment. FIG. [Figure 7] 11 is a cross-sectional view showing a configuration of a resin sheet used in a motor stator according to embodiment 3. FIG. [Figure 8] 13 is a cross-sectional view showing another configuration of the resin sheet used in the motor stator according to the third embodiment. FIG. [Figure 9] FIG. 11 is a cross-sectional view showing a configuration of a motor according to a fourth embodiment. [Figure 10] FIG. 4 is a side view for explaining a method of leak evaluation in the examples. [Figure 11] FIG. 4 is a cross-sectional view for explaining a method of leak evaluation in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Embodiment 1 Fig. 1 is an enlarged cross-sectional view showing the configuration of a motor stator 100 according to embodiment 1. As shown in Fig. 1, the motor stator 100 is composed of a stator core 1, resin layers 2a, 2b provided on the outer circumferential surface and / or inner circumferential surface of the stator core 1, insulating films 3a, 3b provided on the inner surfaces of slot portions 1a, 1b of the stator core 1, and a coil 4 wound around a tooth portion 1c of the stator core 1 with the insulating films 3a, 3b sandwiched therebetween.

[0013] The stator core 1 is formed by stacking a plurality of thin plates made of a magnetic material. The 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 protrudes 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 portions 1c of the stator core 1 with insulating films 3a, 3b sandwiched therebetween, and a refrigerant 5 passes through the insides of the slots 1a, 1b of the stator core 1 to directly cool the coil 4.

[0014] The resin layers 2a and 2b are composed of a cured resin and inorganic filler dispersed and filled in the cured resin. Fig. 2 shows a cross-sectional view illustrating the configuration of the 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 composed of a particulate filler layer in which particulate inorganic filler 22 is filled in resin 21.

[0015] The resin layers 2a and 2b may be reinforced by disposing a glass cloth or the like on the outer side opposite to the stator core 1 side.

[0016] <Inorganic filler> The inorganic filler 22 is not particularly limited, and examples thereof include boron nitride (BN), fused silica (SiO2), crystalline silica (SiO2), aluminum oxide (Al2O3), aluminum nitride (AlN), silicon carbide (SiC), calcium carbonate (CaCO3), magnesium oxide (MgO), and the like. These inorganic fillers may be used alone or in combination of two or more. By using a filler with high thermal conductivity such as crystalline silica (SiO2), aluminum oxide (Al2O3), magnesium oxide (MgO), boron nitride (BN), or aluminum nitride (AlN) as the inorganic filler 22, the heat dissipation performance of the core made of laminated steel plates can be improved.

[0017] The inorganic filler 22 preferably has an average particle size of 20 nm or more and 500 μm or less. If the inorganic filler 22 has an average particle size of less than 20 nm, the specific surface area increases and the wettability with the resin decreases, so that the amount of filler cannot be increased, and the leakage prevention effect decreases. On the other hand, if the inorganic filler 22 has an average particle size of more than 500 μm, the layer becomes uneven due to the presence of coarse particles, making it difficult to control the thickness of the resin layer. From the viewpoints of preventing refrigerant leakage, workability, and moldability, the inorganic filler 22 preferably has an average particle size of 0.1 μm or more and 200 μm or less. Furthermore, from the viewpoint of filling the gaps in the laminated steel plates, the inorganic filler 22 preferably has an average particle size of 1 / 2 or less of the gaps in the laminated steel plates.

[0018] 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. If the filling rate is less than 10% by volume, the inorganic filler 22 is not present sufficiently on the inner and outer diameter surfaces of the stator core 1, and the refrigerant leakage prevention effect is reduced. On the other hand, if the filling rate exceeds 90% by volume, it becomes difficult to disperse the inorganic filler 22 in the resin 21, which causes problems in workability and moldability. From the viewpoints of refrigerant leakage prevention, workability, and moldability, the filling amount of the inorganic filler 22 is preferably 30% by volume or more and 75% by volume or less.

[0019] <Resin> The resin 21 used in the resin layers 2a and 2b is not particularly limited, and any resin known in the art 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. From the viewpoints of formability of the resin layers 2a and 2b, adhesion to the core made of laminated steel plates, insulation, and the like, epoxy resin is preferred.

[0020] 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.

[0021] Next, a manufacturing method for motor stator 100 according to embodiment 1 will be described with reference to FIGS. 3A to 3D and 4A to 4C.

[0022] First, there will be described a method for manufacturing a resin sheet for forming a resin layer of the motor stator 100. Figures 3A to 3D are cross-sectional views for explaining the method for manufacturing the resin sheet.

[0023] First, a predetermined amount of resin 21 is mixed with an amount of a curing agent required for curing this resin 21. After adding a solvent to this mixture, inorganic filler 22 is added and mixed to obtain a resin composition 211. If the viscosity of the resin composition 211 is low, it is not necessary to add a solvent. When a coupling agent is added, the coupling agent may be added before the kneading step.

[0024] <Hardening 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 epoxy resin curing agent 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 epoxy resins, such as 1,8-diazabicyclo(5,4,0)undecene and its derivatives. 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 set to 0.1 parts by weight or more and 200 parts by weight or less per 100 parts by weight of the resin.

[0025] <Curing accelerator> In order to increase the curing speed of the resin and the curing agent in the resin composition, a curing accelerator may be included. The type of the curing accelerator is not particularly limited as long as it can accelerate the curing of the resin, and it may be appropriately selected from known curing accelerators. When an epoxy resin is used as the resin, examples of the curing accelerator include tertiary amines such as benzyldimethylamine, imidazoles such as 2-ethyl-4-methylimidazole, and organic metals such as zinc octylate. The curing accelerator may be used alone or in combination of two or more kinds. 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 per 100 parts by weight of the resin.

[0026] <Film-forming agent> In order to improve film formability such as film thickness uniformity and surface smoothness, a film-forming agent can be added as necessary. As the film-forming agent, a phenoxy resin, an acrylic resin, a high molecular weight epoxy resin, etc. are used. These film-forming 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 per 100 parts by weight of the resin.

[0027] <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 the 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.

[0028] <Solvent> The resin composition for producing the resin sheet may contain a solvent from the viewpoint of adjusting the viscosity of the composition. The solvent is not particularly limited, and a known solvent may be appropriately selected according to the type of resin and inorganic filler to be used. Examples of such a solvent include acetone, methanol, ethanol, isopropyl alcohol, toluene, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more. The amount of the solvent is not particularly limited as long as it is an amount that provides a composition viscosity that can be kneaded, and is generally preferably 20 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the total of the resin and the inorganic filler.

[0029] Next, resin sheet 200C (FIG. 3A) in which resin composition 211 mixed with inorganic filler 22 described above is applied to releasable substrate 23, and sheet 200D (FIG. 3B) in which resin composition 211 without inorganic filler is applied to releasable substrate 24 are dried, and then their resin surfaces are brought together (FIG. 3C) and pressed with a predetermined press pressure to produce resin sheets 2A and 2B (FIG. 3D) for forming resin layers 2a and 2b of stator core 1.

[0030] Here, the releasable substrate is not particularly limited, and for example, a known releasable substrate such as a release-treated resin sheet or film can be used.

[0031] The applied resin composition 211 may be dried at ambient temperature, but may be heated to 40° C. or higher and 200° C. or lower, if necessary, in order to promote evaporation of the solvent.

[0032] Next, a description will be given of a method for manufacturing the resin layer of the motor stator 100. Figures 4A to 4C are cross-sectional views for explaining the method for manufacturing the resin layer.

[0033] First, the resin sheets 2A and 2B prepared above are attached to the outer peripheral surface and / or inner peripheral 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 attaching them, the resin on the stator core side of the resin sheets 2A and 2B permeates into the gaps between the laminated steel plates that form the stator core 1.

[0034] When attaching the resin sheets 2A and 2B to the outer peripheral surface and / or inner peripheral surface of the stator core 1, if there are openings and uneven parts on the outer peripheral surface and / or inner peripheral surface of the stator core 1, it is preferable to fill the uneven parts by sealing them with a sealant such as epoxy resin and acrylic resin before attaching the resin sheets. In addition, from the viewpoint of continuously disposing the resin sheets 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 and 2B is large relative to the gap between the rotor and the case disposed on the inner peripheral side or the outer peripheral side of the stator core 1, a process of suppressing the thickness by applying pressure may be added after attaching the resin sheets 2A and 2B. Even if it is not necessary to suppress the thickness, a process of pressing the resin sheets 2A and 2B may be added to improve the adhesion between the resin sheets 2A and 2B and the stator core 1 made of laminated steel sheets.

[0035] After the resin sheets 2A and 2B are attached to the stator core 1, the resin sheets 2A and 2B are cured (FIG. 4B). There are no particular limitations on the curing temperature and curing time, and they may be set appropriately depending on the type of resin composition used. For example, the curing temperature is in the range of 20°C to 300°C, and the curing time is in the range of 1 minute to 100 hours.

[0036] After the resin sheets 2A and 2B are cured, the releasable base material 23 on the outer periphery is peeled off to obtain the stator core 1 having the resin layers 2a and 2b formed thereon (FIG. 4C).

[0037] 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 side of the stator core 1. 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 steps corresponding to Figs. 4A to 4C are performed, whereby 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 can be obtained without a resin layer.

[0038] As described above, motor stator 100 according to the first embodiment includes stator core 1 made of laminated steel plate and having slots 1a, 1b formed between a plurality of teeth 1c protruding radially from the outer periphery toward the center of annular yoke portion 1d, resin layers 2a, 2b provided on the outer periphery and / or inner periphery of stator core 1 and containing inorganic filler 22 arranged continuously in the circumferential direction, and coil 4 wound around teeth 1c with insulating films 3a, 3b interposed therebetween. Further, according to a manufacturing method for motor stator 100 according to the first embodiment, a resin having particulate inorganic filler 22 mixed therein is used as a base material. and drying to create a resin sheet; a process of attaching the resin surfaces of resin sheets 2A, 2B continuously in the circumferential direction to the outer peripheral surface and / or inner peripheral surface of stator core 1 made of laminated steel plate and formed between a plurality of teeth portions 1c protruding radially from the outer periphery to the center of annular yoke portion 1d; and a process of hardening the attached resin sheets 2A, 2B.By covering the outer layer of the stator core with a resin layer filled with inorganic filler, not only can refrigerant leakage be prevented, but also a decrease in adhesion of the resin layer and the occurrence of cracks due to differences in thermal expansion coefficients with the stator core due to cooling and heating cycles can be suppressed.

[0039] Embodiment 2 In the first embodiment, a case where a particulate filler is used as the inorganic filler 22 is described, but in the second embodiment, a case where a plate-shaped filler is used is described.

[0040] Fig. 5 is a cross-sectional view showing the configuration of resin layers 2a and 2b used in motor stator 100 according to embodiment 2. As shown in Fig. 5, resin layers 2a and 2b according to embodiment 2 are made of plate-shaped filler layers in which plate-shaped inorganic filler 25 is filled in resin 21.

[0041] 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. This allows the filler to be 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 inner peripheral surface of the stator core 1, the filler is arranged perpendicular to the gaps between the laminated steel plates, thereby reliably preventing refrigerant leakage.

[0042] Examples of the plate-like inorganic filler 25 include boron nitride (BN), aluminum oxide (Al2O3), mica, etc. When the inorganic filler has a plate-like shape, the average particle size means the length of the long side.

[0043] Other configurations and manufacturing methods of motor stator 100 according to embodiment 2 are similar to those of motor stator 100 according to embodiment 1, so corresponding parts are given the same reference numerals and description thereof will be omitted.

[0044] As described above, according to the motor stator 100 of the second embodiment, the resin layers 2a, 2b are filled with the plate-shaped inorganic filler 25, and by orienting the plate-shaped inorganic filler 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 can reliably prevent 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 cooling and heating cycles.

[0045] In the present embodiment 2, the resin layers 2a and 2b are filled with only the plate-shaped inorganic filler 25, but the present invention is not limited to this. 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.

[0046] Embodiment 3 In the third embodiment, a case will be described in which resin layers filled with inorganic fillers having different average particle sizes are arranged.

[0047] Fig. 7 is a cross-sectional view showing the configuration of a resin sheet 200E used in a motor stator 100 according to embodiment 3. As shown in Fig. 7, the resin sheet 200E according to embodiment 3 is composed of a filler sheet layer 200a in which particulate inorganic filler 22 as a first inorganic filler is mixed into a resin composition 211, and a filler sheet layer 200b in which particulate inorganic filler 26 as a second inorganic filler having an average particle size smaller than that of inorganic filler 22 and an average particle size equal to or less than 1 / 2 of the gaps between the laminated steel plates forming the stator core 1 is mixed.

[0048] 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 disposed on the stator core 1 side, and a filler sheet layer 200a containing particulate inorganic filler 22 is disposed on the outside.

[0049] Other configurations and manufacturing methods of motor stator 100 according to embodiment 3 are similar to those of motor stator 100 according to embodiment 1, so corresponding parts are given the same reference numerals and description thereof will be omitted.

[0050] As a result, a filler sheet layer 200b mixed with particulate inorganic filler 26 having a small average particle size is placed on the stator core 1 side, and the resin composition penetrates into the gaps in the laminated steel plates and fills the gaps in the laminated steel plates with particulate inorganic filler 26 having a small average particle size.This ensures that the filler can reliably stop the leakage of refrigerant from the gaps in the laminated steel plates, which is difficult to prevent using resin alone, and allows the refrigerant to flow through the slots without leakage.

[0051] As described above, according to the motor stator 100 of the third embodiment, the inorganic filler is particulate inorganic filler 22 as the first inorganic filler, and particulate inorganic filler 26 as the second inorganic filler having an average particle size smaller than that of the first inorganic filler and half or less than that of the gaps in the laminated steel plates, and the resin layers 2a, 2b have a layer containing inorganic filler 22 on the outer circumferential surface and / or inner circumferential surface of the stator core 1, and a layer containing inorganic filler 26 is provided in the gaps in the laminated steel plates. Therefore, according to the manufacturing method of the motor stator 100 of the third embodiment, the inorganic filler is particulate inorganic filler 22 as the first inorganic filler, and particulate inorganic filler 26 as the second inorganic filler having an average particle size smaller than that of the first inorganic filler and half or less than that of the gaps in the laminated steel plates. In the resin sheet 200E, a filler sheet layer 200b containing inorganic filler 26 is provided on the stator core 1 side, and a filler sheet layer 200a containing inorganic filler 22 is provided on the outer side. As a result, not only can the same effects as in the first embodiment be obtained, but also the resin composition permeates the gaps in the laminated steel plates and the particulate inorganic filler having a small average particle size is filled in the gaps in the laminated steel plates, so that leakage of the refrigerant from the gaps in the laminated steel plates, which is difficult to prevent with resin alone, is reliably blocked by the filler, and the refrigerant can flow in the slots without leakage.

[0052] In the third embodiment, the particulate inorganic filler 22 is used on the outer side of the 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 those of the second embodiment can be obtained.

[0053] Embodiment 4 In the fourth embodiment, a motor using the motor stator 100 according to the first to third embodiments will be described.

[0054] Fig. 9 shows a cross-sectional view illustrating the configuration of a motor 300 according to embodiment 4. As shown in Fig. 9, motor 300 according to embodiment 4 includes motor stator 100 according to embodiments 1 to 3, a rotor 107, a shaft 108, a frame 109, and two brackets 110. Motor stator 100 is formed in a cylindrical shape having a central axis C.

[0055] As described above, the motor according to the fourth embodiment is provided with the motor stator 100 described in any one of the first to third embodiments, and therefore it is possible to obtain a motor that can not only prevent refrigerant leakage from the motor stator, but also suppresses 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 cooling and heating cycles. EXAMPLES

[0056] The present application will be described in detail below with reference to examples and comparative examples, but the present application is not limited thereto.

[0057] Table 1 shows the constituent materials and their blending ratios of the resin layer, particulate filler layer, and plate-like filler layer used in Examples 1 to 13 and Comparative Example 2.

[0058] [Table 1]

[0059] <Preparation 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) were added with 50 parts by mass of methyl ethyl ketone which is a solvent, 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 doctor blade method on a PET film which had been subjected to a release treatment with a thickness of 50 μm, and was heated and dried at 80° C. for 10 minutes to prepare a resin sheet with a thickness of 80 μm.

[0060] <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) were added with 100 parts by mass of methyl ethyl ketone which is a solvent, and stirred until dissolved. Next, 5 parts by weight of imidazole catalyst (2E4MZ: manufactured by Shikoku Kasei) were added and stirred until uniformly dissolved. 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 blended into this mixture as a particulate filler to prepare a resin composition with a particulate filler filling rate of 60% by volume. Thereafter, this resin composition was applied onto a release-treated PET film by the doctor blade method in the same manner as when the resin layer was produced, and then subjected to a heat drying treatment at 80°C for 10 minutes to produce a particulate filler sheet 1 having a thickness of 100 μm.

[0061] The particulate filler sheet 2 was prepared in the same manner as the particulate filler layer 1, except that the particulate filler was a mixture of 93 parts by mass of spherical alumina having an average particle size of 5 μm (DAW05: manufactured by Denka) and 140 parts by mass of spherical alumina having an average particle size of 45 μm (DAW45: manufactured by Denka) so that the filling rate of the particulate filler was 40 volume %.

[0062] Particulate filler sheet 3 was prepared in the same manner as particulate filler 1, except that 140 parts by mass of spherical alumina (DAW05: manufactured by Denka) having an average particle size of 5 μm and 210 parts by mass of spherical alumina (DAW45: manufactured by Denka) having an average particle size of 45 μm were mixed as the particulate filler, so that the filling rate of the particulate filler was 50 volume %.

[0063] <Preparation 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) were added to 150 parts by mass of methyl ethyl ketone which is a solvent, 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 weight of mica (manufactured by Okabe Mica) with an average particle size of 400 μm was blended into this mixture as a plate-like filler to prepare a resin composition with a filling rate of the plate-like filler of 50% by volume. Thereafter, in the same manner, the mixture was applied by the doctor blade method onto a PET film which had been subjected to a release treatment, and heated and dried at 80 degrees for 10 minutes to prepare a plate-like filler sheet 1 having a thickness of 100 μm.

[0064] Plate-like filler sheet 2 was prepared in the same manner as plate-like filler sheet 1, except that 236 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 50 volume %, and the amount of solvent methyl ethyl ketone added was 180 parts by mass.

[0065] The plate-like filler sheet 3 is made of plate-like alumina (AH-1) having an average particle size of 9 μm. Plate-like filler sheet 3 was prepared in the same manner as plate-like filler sheet 1, except that 625 parts by mass of methyl ethyl ketone (manufactured by Denka) was added so that the filling rate of the plate-like filler was 60 volume %, and the amount of methyl ethyl ketone solvent added was 220 parts by mass.

[0066] Plate-like filler sheet 4 was prepared 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 %.

[0067] 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.

[0068] When the cross sections of the above plate-like filler sheets 1 to 5 were observed under an electron microscope, it was confirmed that the plate-like fillers were all oriented in the horizontal direction.

[0069] Table 2 shows the configurations 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.

[0070] [Table 2]

[0071] [Example 1] The particulate filler sheet 1 was heated at 80° C. for 10 minutes under reduced pressure and a pressing pressure of 2 MPa to obtain a resin sheet of the particulate filler sheet 1 of Example 1.

[0072] [Example 2] The particulate filler sheet 2 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 2 of Example 2.

[0073] [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.

[0074] [Example 4] The plate-like filler sheet 1 was heated at 80° C. for 10 minutes under reduced pressure and a pressing pressure of 5 MPa to obtain a resin sheet of the plate-like filler sheet 1 of Example 4.

[0075] [Example 5] The plate-like filler sheet 2 was heated at 80° C. for 10 minutes under reduced pressure and a pressing pressure of 5 MPa to obtain a resin sheet of the plate-like filler sheet 2 of Example 5.

[0076] [Example 6] The plate-like filler sheet 3 was heated at 80° C. for 10 minutes under reduced pressure and a pressing pressure of 5 MPa to obtain a resin sheet of the plate-like filler sheet 3 of Example 6.

[0077] [Example 7] The resin sheet and the particulate filler sheet 1 were overlapped and heated at 80° C. for 10 minutes under reduced pressure and a press pressure of 2 MPa to obtain a resin sheet having a resin sheet layer and a particulate filler sheet layer of Example 7.

[0078] [Example 8] A 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 then superimposed on the plate-shaped filler sheet 5 obtained, and heated at 80°C for 10 minutes under reduced pressure at a press pressure of 2 MPa to obtain a resin sheet having a resin sheet layer and a plate-shaped filler sheet layer of Example 8.

[0079] [Example 9] The plate-like filler sheet 4 was heated at 80°C for 10 minutes under reduced pressure at a press 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 press 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.

[0080] [Example 10] The particulate filler sheet 3 obtained in Example 3 and the plate-like filler sheet obtained in Example 5 were stacked together and heated at 80°C for 10 minutes under reduced pressure and a press pressure of 4 MPa to obtain a resin sheet having a particulate filler sheet layer and a plate-like filler sheet layer of Example 10.

[0081] [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.

[0082] [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 were stacked in the order of resin sheet, particulate filler sheet 2, plate-like filler sheet 1, and heated at 80°C for 10 minutes under reduced pressure and a pressing pressure of 2 MPa to obtain a resin sheet having three layers, namely, a resin sheet layer, a particulate filler sheet layer, and a plate-like filler sheet layer, of Example 12.

[0083] [Example 13] The resin sheet, the particulate filler sheet 2 and the plate-like filler sheet 4 obtained in Example 2 were heated at 80°C for 10 minutes under reduced pressure and a press pressure of 3 MPa, and the plate-like filler sheet 4 obtained was superimposed in the order of resin sheet, particulate filler sheet 2 and plate-like filler sheet 4, and heated at 80°C for 10 minutes under reduced pressure and a press pressure of 2 MPa to obtain a resin sheet having three layers, that is, a resin sheet layer, a particulate filler sheet layer and a plate-like filler sheet layer of Example 13.

[0084] [Comparative Example 2] The resin sheet was heated at 80° C. for 30 minutes under reduced pressure and a pressing pressure of 0.1 MPa to obtain a resin sheet of Comparative Example 2.

[0085] The resin sheets of Examples 1 to 13 and Comparative Example 2 were attached to the outer periphery of a motor stator and heated to 150°C for hardening to obtain a resin layer 2a. When attaching the resin sheets to the stator, the resin sheets of Examples 7, 8, 12, and 13, which include a resin sheet layer, were arranged so that the resin sheet layer was on the stator core 1 side (filler sheet layer on the outside). Also, the resin sheets that were a combination of a particulate filler sheet layer and a plate-like filler sheet layer were arranged so that the particulate filler sheet layer was on the stator core 1 side (plate-like filler sheet layer on the outside). In the stator evaluation, a motor stator that did not have a resin layer 2a on the outer periphery of the stator core 1 was used as Comparative Example 1.

[0086] <Leakage evaluation> The stator provided with the resin layer 2a was subjected to 10 repeated heat cycles of -10°C and 100°C, and then a coolant was made to flow through the stator to evaluate the leakage of the coolant from the stator provided with the resin sheet.

[0087] Fig. 10A and Fig. 10B are diagrams for explaining the method of leakage evaluation in this embodiment, Fig. 10A shows the front side of the stator, Fig. 10B shows the back side. Fig. 11A shows a cross-sectional view taken along the line XX in Fig. 10A, Fig. 11B shows a cross-sectional view taken along the line YY in Fig. 10A, and Fig. 11C shows a cross-sectional view taken along the line ZZ in Fig. 10A.

[0088] As shown in Figures 10A and 10B and Figures 11A and 11B, a cylindrical inner lid 6 is placed on the inner circumference of the stator, an upper lid 7 with a refrigerant inlet 11 and outlet 12 is placed on the surface of the stator, and a lower lid 8 is placed on the back surface of the stator, and the refrigerant is injected at a constant flow rate so that the refrigerant flows on three sides excluding the partitions above and below each coil. O-rings 13 are placed on the inside of the upper lid 7 and the lower lid 8 to prevent the refrigerant from leaking from the lids. The refrigerant inlet 11 and outlet 12 may be placed on the lower lid 8.

[0089] Partition plates 9 and 10 filled with an acrylic resin-based sealant were installed on either the top or bottom of the coil 4, except between the adjacent inlet 11 and outlet 12, to block the passage of the refrigerant. The opposite side of the passage of the refrigerant blocked by the partition plates 9 and 10 was made into a flow path through which the refrigerant flows. These were arranged alternately above and below for each coil, and the refrigerant was made to flow in a bellows-like manner so that the refrigerant would flow reliably into all slots. As shown in FIG. 11C, both the partition plates 9 and 10 were arranged on the coil 4 between the adjacent inlet 11 and outlet 12 to block the flow of the refrigerant and prevent backflow. The refrigerant was passed through the stator for evaluating leakage thus produced, and the presence or absence of refrigerant leakage from the outer periphery side where the resin layer was provided was visually confirmed.

[0090] 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, the refrigerant leaked out from the gaps in the laminated steel plates when it was flowing between the coils. In addition, when only a resin layer not filled with filler was provided as in Comparative Example 2, cracks occurred in the resin layer that had hardened during the heat cycle of the stator, and when the refrigerant was flowed, the refrigerant leaked out from the cracks. With only the resin layer, there was a large difference in the thermal expansion coefficient between the core and the resin layer during the heat cycle, which caused cracks to occur in the resin layer.

[0091] On the other hand, in the 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 during the heat cycle of the stator, and cracks do not occur. In addition to being able to suppress cracks in the resin layer, the particulate filler and plate-like filler suppress the outflow of the refrigerant to the outer diameter, so that the refrigerant leakage can be prevented. In terms of the effect of suppressing the outflow of the refrigerant to the outside, it is more effective if the plate-like filler is oriented perpendicular to the radial direction.

[0092] Although various exemplary embodiments and examples are described in this application, various features, aspects, and functions described in one or more embodiments are not limited to the application of a specific embodiment, but can be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are expected within the scope of the technology disclosed in this specification. For example, the following are included: when at least one component is modified, added, or omitted, and further, when at least one component is extracted and combined with a component of another embodiment. [Explanation of symbols]

[0093] 1 stator core, 1a, 1b slot portion, 1c teeth portion, 1d yoke portion, 2a, 2b resin layer, 4 coil, 22 inorganic filler, 100 motor stator.

Claims

1. 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 resin layer including an inorganic filler, the resin layer being provided on an outer peripheral surface and an inner peripheral surface of the stator core and being continuously arranged in a circumferential direction; a coil wound around the teeth via an insulating film; A stator for a motor comprising:

2. A stator for a motor as described in claim 1, characterized in that the average particle size of the inorganic filler is 20 nm or more and 500 μm or less.

3. A stator for a motor as described in claim 1, characterized in that the average particle size of the inorganic filler is less than 1 / 2 of the gap between the laminated steel plates.

4. A stator for a motor as described in claim 1, characterized in that the resin layer contains a coupling agent.

5. 2. The motor stator according to claim 1, wherein the inorganic filler is in the form of particles or / and plates.

6. A stator for a motor as described in Claim 5, characterized in that the plate-shaped inorganic filler is oriented parallel to the layer direction of the resin layer.

7. The stator for a motor according to claim 1, characterized in that the inorganic filler is a first filler in a particulate or plate-like form and a second filler in a particulate form having an average particle size smaller than that of the first filler and less than half the average particle size of the gaps in the laminated steel plates, the resin layer has a layer containing the first filler on the outer peripheral surface and / or inner peripheral surface of the stator core, and a layer containing the second filler is provided in the gaps in the laminated steel plates.

8. A motor comprising the motor stator according to any one of claims 1 to 7.

9. A step of applying the resin mixed with the inorganic filler to a substrate and then drying the applied resin to produce a resin sheet; a step of attaching a resin surface of the resin sheet continuously in a circumferential direction to an outer peripheral surface and an inner peripheral surface of a stator core made of laminated steel plates and having slots formed between a plurality of teeth protruding radially from the outer periphery to the center of an annular yoke; A step of curing the attached resin sheet; A method for manufacturing a stator for a motor, comprising:

10. 10. The method for manufacturing a motor stator according to claim 9, wherein the inorganic filler is in a particulate or / and plate shape.

11. The method for manufacturing a stator for a motor as described in claim 10, characterized in that the inorganic filler is a first filler in a particulate or plate-like form and a second filler in a particulate form having an average particle size smaller than that of the first filler and less than half the average particle size of the gaps in the laminated steel plates, and the resin sheet is provided with a sheet layer containing the second filler on the stator core side and a sheet layer containing the first filler on the outside.