Stator and rotating electric machine

Abstract

The invention provides a stator which suppresses reduction of a duty factor of a stator coil inserted into a slot and has excellent oil-resistant adhesion. The stator is provided with: an annular stator core; a plurality of slots arranged side by side in the circumferential direction of the inner circumferential side of the stator core and penetrating in the axial direction; an insulator which is in the form of a multi-layer sheet in which the layers are bonded by a first bonding method, and which is wound in a cylindrical shape along the inner walls of the grooves in each of the plurality of grooves; and a plurality of stator coils inserted into an inner side of the insulator, a first surface of the insulator being bonded to an inner wall of the slot by a second bonding method, and a second surface on an opposite side of the first surface being bonded to the stator coils by the second bonding method, a portion of the insulator is folded back in a direction perpendicular to the axial direction, an inner wall of the groove facing the second surface of the folded back portion has three or less surfaces, and at least a portion of the second surface of the folded back portion is bonded to the inner wall of the groove by the second bonding method.

Description

Technical Field

[0001] The invention relates to a stator and a rotating electric machine. Background Art

[0002] In a rotating electrical machine for an automobile, insulation between the stator core and the stator coil is achieved by sandwiching an insulator between inner walls of slots provided in the stator core and the stator coil inserted into the slots.

[0003] Patent Document 1 is known as a technique related to an insulator provided between an inner wall of a slot provided in a stator core and a stator coil inserted into the slot.

[0004] In Patent Document 1, in paragraphs 0035 and Figure 5 It states that "an insulating sheet member 24 is sandwiched between the inner wall surface of each slot 25 of the stator core 22 and the conductor segment 23. The insulating sheet member 24 is formed by winding a rectangular insulating paper into a square tube shape in accordance with the cross-sectional shape in the direction perpendicular to the axis of the slot 25, and is arranged along the inner wall surface of each slot 25." And, in paragraphs 0036 and Figure 8 It is recorded in Figure 8 As shown, at the end portion on the other axial end side of the insulating sheet member 24, that is, the side where the inclined portion 23e is formed (the second coil end group 21b side (see Figure 2 )) is formed at the end portion thereof with a folded portion 24b which is folded back axially toward the radial outside more than once (once in the present embodiment). Therefore, the insulating paper becomes double-layered at the portion where the folded portion 24b is formed. The insulating sheet member 24 is configured in a state where at least a portion of the folded portion 24b is accommodated in the groove 25".

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2014-168330 Summary of the invention

[0008] Problems to be solved by the invention

[0009] That is, in the technology described in Patent Document 1, Figure 5 As described, in the folded portion 24b, the entire circumference of the stator coil is surrounded by a double-layer insulator.

[0010] However, there is a demand for rotating electrical machines to be smaller and have higher outputs. To achieve high outputs using a small stator, it is necessary to increase the space factor of the stator coils inserted into the slots.

[0011] Therefore, in Patent Document 1 Figure 5In the described structure, there is a problem that the thickness of the insulator increases and the space factor decreases, which hinders the miniaturization and high output of the rotating electrical machine.

[0012] Therefore, an object of the present invention is to provide a stator and a rotating electric machine which suppress a decrease in the space factor of a stator coil inserted into a slot and have excellent oil-resistant adhesion.

[0013] Solutions to Solve Problems

[0014] In order to solve the above-mentioned problems, the stator of the present invention, for example, comprises: a stator core in the shape of an annular ring; a plurality of slots arranged in the circumferential direction of the inner circumferential side of the stator core and penetrating in the axial direction; an insulator, which is a multi-layer sheet in which each layer is bonded by a first bonding method, and is wound into a cylindrical shape along the inner wall of the slot in each of the plurality of slots; and a plurality of stator coils, which are inserted into the inner side of the insulator, a first surface of the insulator is bonded to the inner wall of the slot by a second bonding method, and a second surface on the opposite side of the first surface is bonded to the stator coil by the second bonding method, a portion of the insulator is folded back in a direction perpendicular to the axial direction, the inner wall of the slot opposite to the second surface of the folded back portion is less than three surfaces, and at least a portion of the second surface of the folded back portion is bonded to the inner wall of the slot by the second bonding method.

[0015] Furthermore, a rotating electrical machine according to the present invention includes, for example, the above-described stator.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide a stator and a rotating electrical machine which can suppress a decrease in the space factor of a stator coil inserted into a slot and have excellent oil-resistant adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of the stator.

[0019] Figure 2 It is a figure explaining the shape of a groove.

[0020] Figure 3 It is a diagram for explaining the folding back of the insulator in the slot.

[0021] Figure 4 It is a diagram for explaining another example of the shape of the stator coil.

[0022] Figure 5 This is a diagram for explaining another example of the folding direction of the insulator in the slot.

[0023] Figure 6 is a cross-sectional view of a rotating electrical machine.

[0024] Figure 7It is a figure explaining the insulator concerning the comparative example of the strength test.

[0025] Figure 8 It is a figure explaining the insulator concerning Example 1 of a strength test.

[0026] Fig. 9 It is a figure explaining the insulator concerning Example 2 of the strength test.

[0027] Fig.10 It is a figure explaining the insulator concerning Example 3 of a strength test.

[0028] Fig.11 It is a graph showing the results of the strength test. DETAILED DESCRIPTION

[0029] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, the present invention is not limited to the embodiments described below. These embodiments are merely illustrative, and the present invention can be implemented in various ways with various changes and improvements based on the knowledge of those skilled in the art. In addition, in the drawings used in the following description, the same symbols are marked for the common devices and equipment, and the description of the devices, equipment and actions that have been described is sometimes omitted.

[0030] (Rotating electric machine using insulator)

[0031] Figure 1 is a three-dimensional diagram of the stator. In the following description, "axial direction", "circumferential direction" and "radial direction" refer to Figure 1 The axial direction of the annular stator 20 shown is Figure 1 The “inner circumference” refers to the radial inner side (inner diameter side) of the stator 20, and the “outer circumference” refers to the opposite direction, that is, the radial outer side (outer diameter side) of the stator 20.

[0032] Figure 2 3 is a diagram for explaining the shape of the slots. Specifically, it is a part of a cross-sectional view of the stator core 21 in a state where the insulator 301 and the stator coil 60 are not inserted, cut along a plane perpendicular to the axial direction. Figure 3 It is a diagram for explaining the folding back of the insulator in the slot.

[0033] Specifically, it is a part of the cross-sectional view of the stator core in a state where the insulator 301 and the stator coil 60 are inserted into the slot 15. Figure 2 and Figure 3 The structure is the same in any slot 15 provided in the stator core 21. In addition, in the following description, the stator used for the rotating electric machine of the hybrid vehicle is described, but it is not limited to this.

[0034] like Figure 1As shown, the stator 20 has slots 15 , a stator core 21 , and a stator coil 60 .

[0035] The stator core 21 has an annular shape and is made by laminating thin silicon steel plates, for example.

[0036] like Figure 1 As shown in FIG. 1 , a plurality of slots 15 are arranged in a circumferential direction on the inner circumference of the stator core 21. In addition, the slots 15 penetrate the stator core 21 in the axial direction. Figure 2 As shown, the groove 15 has an opening on the inner circumference. Figure 2 In the embodiment, the long side direction of the slot 15 corresponds to the radial direction of the stator 20 , and the short side direction of the slot 15 corresponds to the circumferential direction of the stator 20 .

[0037] like Figure 1 As shown, the stator coil 60 is wound in a wave winding manner on a plurality of slots 15 provided on the inner circumference side of the stator core 21. In the present embodiment, the wave winding method is adopted as the winding method, but it is not limited to this as long as it is a distributed winding winding method. It should be noted that in the present embodiment, the inner transformation in which the slot 15 is located on the inner circumference side of the stator core 21 is described, but the outer transformation in which the slot 15 is located on the outer circumference side of the stator core 21 is also applicable.

[0038] In addition, if Figure 3 As shown, a conductor such as a copper wire having an insulating coating with a substantially rectangular cross section is used for the stator coil 60. By using a coil with a substantially rectangular cross section, the space factor in the slot 15 is improved.

[0039] in addition, Figure 4 A diagram showing another example of the shape of the stator coil is shown. Specifically, Figure 4 FIG. 1 is a cross-sectional view of a portion of a stator core in which an insulator 301 and a stator coil 60 are inserted into a slot 15. Figure 4 As shown, round enameled wires can also be used as stator coils 60 .

[0040] like Figure 3 As shown, the insulator 301 has a surface material 401 forming a first surface and a core material 402 forming a second surface, and the surface material 401 and the core material 402 are bonded by a first bonding method. In addition, as the first bonding method for bonding the surface material 401 and the core material 402, there are bonding based on heat fusion, bonding based on adhesives, etc.

[0041] The insulator 301 is wound into a cylindrical shape along the inner wall of the slot 15. At this time, the insulator 301 is folded back in a direction perpendicular to the axial direction, and the inner wall of the slot 15 facing the core material 402 of the folded back portion is less than three sides. Figure 3In FIG. 1 , as an example of the insulator 301 , a part of the insulator 301 is folded back in the circumferential direction perpendicular to the axial direction, and the inner wall of the groove 15 facing the core material 402 of the folded back part is one surface. Figure 3 , an example is shown in which both one end of the insulator 301 and the folded-back portion of the core material 402 face the same surface of the inner wall of the groove 15 , but the present invention is not limited to this.

[0042] Figure 5 is a diagram illustrating another example of the folding direction of the insulator in the slot. Figure 3 Similarly, FIG. 1 is a cross-sectional view of a portion of a stator core in a state where an insulator 301 and a stator coil 60 are inserted into the slot 15. The insulator 301 may be Figure 3 The folded back portion of the core material 402 is opposed to the inner wall of the short side direction of the groove 15 as shown. Figure 5 As shown in FIG. 1 , the core material 402 of the folded-back portion faces the inner wall of the slot 15 in the longitudinal direction. However, by providing the insulator 301 in such a manner that the folded-back portion of the insulator 301 to form a double layer is reduced, the space factor can be improved. For example, if Figure 3 The insulator 301 and Figure 5 Compared with the insulator 301, Figure 3 The insulator 301 has a smaller double layer portion, so that Figure 3 The insulator 301 is arranged in this way, so that the space factor can be better than Figure 5 composition.

[0043] like Figure 3 to Figure 5 As shown, after the stator coil 60 and the insulator 301 are inserted into the slot 15, the stator coil 60 and the insulator 301 and the inner wall of the slot 15 and the insulator 301 are bonded by a second bonding method. As the second bonding method, as described later, the stator coil 60 and the insulator 301 and the inner wall of the slot 15 and the insulator 301 can be bonded by a fixing varnish, or a foaming adhesive can be used for bonding. When the fixing varnish is used, the fixing varnish is impregnated between the stator coil 60 and the insulator 301 and the inner wall of the slot 15 and the insulator 301, and then heated and cured. In addition, when the foaming adhesive is used, the foaming adhesive is applied between the stator coil 60 and the insulator 301 and between the inner wall of the slot 15 and the insulator 301, and one or both of induction heating and electric heating of the stator coil are performed to heat and cure the foaming adhesive.

[0044] In this way, by arranging the insulator 301 in each slot 15 , electrical insulation between the stator core 21 and the stator coil 60 can be ensured.

[0045] In addition, if Figure 3 to Figure 5As shown, the insulator 301 is formed into a square shape in a manner of wrapping the stator coil 60 along the inner wall of the slot 15, and the stator coil 60 is opposed to the core material 402. In addition, the insulator 301 is configured such that: it is folded back in a direction perpendicular to the axial direction, and the core material 402 of the folded back portion becomes less than three surfaces of the inner wall of the opposed stator core 21. With this structure, since the insulator 301 is folded back to form a double layer, the portion where the thickness of the insulator 301 is increased is no longer the entire circumference of the stator coil 60, so that the reduction in the space factor can be suppressed.

[0046] In addition, if Figure 1 As shown, the stator 20 may also have an annular insulating paper 300 .

[0047] Figure 6 The rotating electrical machine 10 includes a rotor 11 , a housing 50 , and a liquid cooling jacket 130 in addition to the stator 20 described above.

[0048] The rotor 11 is rotatably supported on the inner peripheral side of the stator 20. The rotor 11 includes a rotor core 12, a rotating shaft 13, permanent magnets 18, and end rings (not shown).

[0049] The rotor core 12 is made by laminating thin plates of silicon steel plates. The rotating shaft 13 is fixed to the center of the rotor core 12. The rotating shaft 13 is rotatably held by bearings 144 and 145 mounted on the liquid cooling jacket 130, and rotates at a predetermined position in the stator 20 and at a position opposite to the stator 20.

[0050] The housing 50 is fixed to the outer circumference of the stator 20. The housing 50 is formed into a cylindrical outer skin of the motor by cutting iron materials such as carbon steel, casting or pressing cast steel or aluminum alloy. The housing 50 is also called a frame or a frame.

[0051] A liquid cooling jacket 130 is fixed to the outer peripheral side of the housing 50. A refrigerant passage 153 for a liquid refrigerant RF such as oil is formed by the inner peripheral wall of the liquid cooling jacket 130 and the outer peripheral wall of the housing 50, and the refrigerant passage 153 is formed to prevent liquid leakage. The liquid cooling jacket 130 accommodates the bearings 144 and 145 and is also called a bearing bracket.

[0052] The refrigerant RF flows through the refrigerant passage 153 and flows out from the refrigerant outlets 154 and 155 toward the stator 20 to cool the stator 20. A portion of the refrigerant RF flowing out to the stator 20 flows into the refrigerant passage 153 via the refrigerant storage space 150. Such a cooling method is called direct liquid cooling. In addition, oil can be exemplified as the refrigerant RF. Hereinafter, the refrigerant RF is described as oil.

[0053] Heat generated from the stator coil 60 is transferred to the housing 50 via the stator core 21 , and is dissipated by the refrigerant RF flowing through the liquid cooling jacket 130 .

[0054] The rotating electrical machine is assembled by inserting the stator 20 into the housing 50 and attaching it to the inner wall of the housing 50, and then inserting the rotor 11 into the stator 20. Next, the bearings 144 and 145 are fitted to the rotating shaft 13 and assembled to the liquid cooling jacket 130.

[0055] Such direct liquid cooling has the advantage of high cooling efficiency, but on the other hand, since the oil as the refrigerant RF is transferred to the insulator 301 located between the inner wall of the slot 15 and the stator coil 60, the insulator 301 needs to have oil resistance. If the oil resistance of the insulator 301 is low, that is, if an adhesive that is hydrolyzed by the moisture in the oil is used for bonding the surface material 401 and the core material 402, the bonding force between the surface material 401 and the core material 402 will be reduced.

[0056] Figure 7 This is a diagram for explaining an insulator according to a comparative example of a strength test described later, and is a diagram showing an example of an insulator 301 that is not folded back. In addition, as described later, 210 is stainless steel that imitates the stator core 21. Figure 7 The insulator 301 shown has a structure in which a surface material 401 is arranged on the outer periphery of the insulator 301 , and a core material 402 is arranged on the inner periphery of the insulator 301 .

[0057] Will Figure 7 The insulator 301 shown is inserted into Figure 2 In the slot 15 of the stator core 21 shown in the figure, when the stator coil 60 is inserted and bonded inside the inserted insulator 301, the inner wall of the stator core 21 is bonded to the surface material 401, and the stator coil 60 is bonded to the core material 402. Figure 7 In the structure of the insulator 301 shown, if the bonding strength between the surface material 401 and the core material 402 decreases, the core material 402 peels off from the surface material 401 , and thus the stator coil 60 bonded to the core material 402 cannot be fixed to the inner wall of the stator core 21 .

[0058] but, Figure 3 In the insulator 301 shown, the core material 402 is bonded to the stator coil 60 by a second bonding method with high oil resistance, and both the surface material 401 and the core material 402 are bonded to the inner wall of the stator core 21 by a second bonding method with high oil resistance. With such a configuration, even if the bonding force between the surface material 401 and the core material 402 is reduced and the core material 402 is peeled off from the surface material 401, the bonding between the stator coil 60 and the inner wall of the stator core 21 can be ensured.

[0059] In addition, when the inner wall of the groove 15 facing the core material 402 of the folded back portion is one surface, as shown in FIG. Figure 3 to Figure 5 As shown, it is preferred that the folded-back portion of the core material 402 is opposed to the inner wall of the groove 15 without an opening. Thus, the bonding force between the folded-back portion of the core material 402 and the inner wall of the groove 15 can be ensured. In addition, when the inner wall of the groove 15 opposed to the folded-back core material 402 is three-sided, that is, when the inner wall of the groove 15 opposed to the surface material 401 is one-sided, it is preferred that the surface material 401 is opposed to the inner wall of the groove 15 without an opening. Thus, the bonding force between the surface material 401 and the inner wall of the groove 15 can be ensured.

[0060] In addition, when the inner wall of the groove 15 facing the folded-back core material 402 is two or three sides, the contact area between the folded-back core material 402 and the inner wall of the groove 15 is large, so there is no problem even if the folded-back core material 402 faces the inner wall of the groove 15 having an opening. The same is true for the surface material 401.

[0061] (Composition of Insulator)

[0062] The specific configuration example of the insulator 301 is described. The surface material 401 is formed of a thermoplastic resin film or a nonwoven fabric made of a thermoplastic resin. The thermoplastic resin used as the surface material 401 is not particularly limited, and for example, vinyl resins such as polyethylene and polypropylene, polylactide, polycaproic acid, polybutylene succinate, polyethylene terephthalate, polybutylene terephthalate, and polyester resins such as polyethylene naphthalate can be used. In addition, polyamide resins such as NOMEX (registered trademark), nylon 6, nylon 66, and nylon 6T composed of m-phenylenediamine and isophthalic acid can also be used. In addition, various engineering plastics such as polyphenylene sulfide, polyetheretherketone, and polyimide can also be used. Among them, from the viewpoint of heat resistance, polyamide resins (aromatic polyamide resins) formed from aromatic compounds, such as NOMEX (registered trademark), etc., are preferred.

[0063] The core material 402 is formed of a thermoplastic resin film. The thermoplastic resin used is not particularly limited, and for example, vinyl resins such as polyethylene and polypropylene, polyester resins such as polylactide, polycaproic acid, polybutylene succinate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate can be used. In addition, various engineering plastics such as polyphenylene sulfide, polyetheretherketone, and polyimide can also be used. Among them, polyester resins and polyimide resins having aromatic compounds such as polyethylene terephthalate and polyethylene naphthalate are preferred from the viewpoint of processability and heat resistance.

[0064] In addition, other types of thermoplastic resin films or nonwoven fabrics made of thermoplastic resins can also be applied to the surface of the core material 402 that is not in contact with the surface material 401. The thermoplastic resin used is not particularly limited, and for example, vinyl resins such as polyethylene and polypropylene, polylactide, polycaproic acid, polybutylene succinate, polyethylene terephthalate, polybutylene terephthalate, and polyester resins such as polyethylene naphthalate can be used. In addition, polyamide resins such as NOMEX (registered trademark), nylon 6, nylon 66, and nylon 6T composed of m-phenylenediamine and isophthalic acid can also be used. In addition, various engineering plastics such as polyphenylene sulfide, polyetheretherketone, and polyimide can also be used. The method of applying other types of thermoplastic resin films or nonwoven fabrics made of thermoplastic resins to the surface of the core material 402 that is not in contact with the surface material 401 is not particularly limited, and preferably thermal fusion, bonding using an adhesive, etc.

[0065] (Composition of Foaming Adhesive)

[0066] The foaming adhesive used between the insulator 301 (thermoplastic resin layer) and the stator coil 60, and between the insulator 301 and the inner wall of the stator core 21 is composed of a thermosetting resin and a microcapsule-type foaming agent. Examples of the thermosetting resin include epoxy resins, unsaturated polyester resins, vinyl ester resins, and polyurethane resins. From the viewpoint of heat resistance and oil resistance, epoxy resins, unsaturated polyester resins, and vinyl ester resins are preferred.

[0067] The epoxy resin is not particularly limited, and examples thereof include bisphenol-type epoxy resins such as bisphenol A type, bisphenol F type, dimer acid-modified bisphenol A type, phenol novolac type, cresol novolac type, novolac type epoxy resins such as biphenyl type epoxy resins, triphenylmethane type epoxy resins, etc. These epoxy resins can be used alone or in combination of two or more. In addition, as a curing agent for the epoxy resin, anhydrides, phenol, phenol novolac, dicyandiamide, etc. can be cited.

[0068] The unsaturated polyester resin is not particularly limited, and can be obtained by dissolving a condensate obtained from a dibasic acid and a polyol in a free radical polymerizable monomer. As the dibasic acid used as the raw material of the unsaturated polyester resin, α,β-unsaturated dibasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,10-decanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic anhydride, 4,4'-biphenyldicarboxylic acid, and saturated dibasic acids such as dialkyl esters thereof can be used. However, it is not particularly limited to these compounds. These dibasic acids and the like may be used alone or in combination of two or more.

[0069] As the polyols used as the raw material of unsaturated polyester resin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 2-methyl--1,3-propylene glycol, 1,3-butylene glycol, the adduct of bisphenol A and propylene oxide or ethylene oxide, glycerine, trimethylolpropane, 1,3-propylene glycol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, p-xylene glycol, dicyclohexyl--4,4'-diol, 2,6-decanediol, tris(2-hydroxyethyl)isocyanurate etc. can be used. However, it is not particularly limited to these compounds. In addition, amino alcohols such as ethanolamine can also be used. These polyols can be used only one, or two or more can be appropriately mixed. In addition, as needed, dicyclopentadiene compounds can be introduced into the resin skeleton.

[0070] As the epoxy compound used as a raw material of the vinyl ester resin, a compound having at least two epoxy groups in the molecule can be used. Examples of such epoxy compounds include Epi-Bis glycidyl ether epoxy resins obtained by condensation reaction of bisphenols such as bisphenol A, bisphenol F, and bisphenol S with epihalohydrin, novolac glycidyl ether epoxy resins obtained by condensation reaction of novolac, which is a condensate of phenols such as phenol, cresol, and bisphenol, with epihalohydrin, glycidyl ester epoxy resins obtained by condensation reaction of tetrahydrophthalic acid with epihalohydrin, or by condensation reaction of hexahydrophthalic acid with epihalohydrin, or glycidyl ether epoxy resins obtained by condensation reaction of at least one of 4,4′-biphenol, 2,6-naphthalenediol, and hydrogenated bisphenol with epihalohydrin, or by condensation reaction of diols with epihalohydrin, amine-containing glycidyl ether epoxy resins obtained by condensation reaction of hydantoin with epihalohydrin, or by condensation reaction of cyanuric acid with epihalohydrin, etc. However, the epoxy compounds are not particularly limited to these compounds. These epoxy compounds may be used alone or in combination of two or more.

[0071] As the unsaturated monobasic acid used as the raw material of the vinyl ester resin, for example, acrylic acid, methacrylic acid, crotonic acid, etc. can be used. In addition, half esters of maleic acid, itaconic acid, etc. can also be used. However, it is not particularly limited to these. These unsaturated monobasic acids can be used alone, or two or more can be appropriately mixed and used.

[0072] Other optional components may be added to the above resin composition as needed. Examples of the optional components include radical polymerizable monomers, polymerization initiators, curing accelerators, polymerization inhibitors, and adhesion enhancers.

[0073] Examples of free radical polymerizable monomers include styrene, vinyl toluene, vinyl naphthalene, α-methyl styrene, vinyl pyrrolidone, acrylamide, acrylonitrile, allyl alcohol, allyl phenyl ether, (meth) acrylate, vinyl acetate, vinyl pyrrolidone, (meth) acrylamide, maleic acid diester, fumaric acid diester, etc. However, it is not particularly limited to these compounds. Preferably, styrene, vinyl toluene, (meth) acrylate (e.g., methacrylate, acrylate) is used. Examples of the (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, methoxylated cyclotriene (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, alkoxypolypropylene glycol (meth)acrylate, and the like. Acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycidyl (meth)acrylate, caprolactone-modified tetrafurfuryl (meth)acrylate, ethoxycarbonylmethyl (meth)acrylate, 2-ethylhexylcarbitol acrylate, 1,4-butanediol (meth)acrylate, acrylonitrile butadiene methacrylate, dicyclopentenyloxyethyl methacrylate, 2-methacryloyloxyethyl isocyanate, 2-methacryloyloxyethoxyethyl isocyanate and other (meth)acrylates having an isocyanate group; 2-(0-[1'methylpropyleneamino]carboxylamino)ethyl methacrylate, 2-(1'[2,4-dimethylpyrazolyl]carboxylamino)ethyl methacrylate and other (meth)acrylates having an isocyanate derivative group having thermal latency. These compounds may be used alone or in combination of two or more. Preferably, the (meth)acrylates are highly reactive and do not hinder the decomposition of the photopolymerization initiator.

[0074] The polymerization initiator can use benzoyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, tert-amyl perbenzoate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxyisobutyrate, di-tert-butyl peroxide, dicumyl peroxide, cumene hydroperoxide, 1,1-di(tert-butylperoxy)cyclohexane, 2,2-di(tert-butylperoxy)butane, tert-butyl hydroperoxide, di-sec-butyl peroxycarbonate, methyl ethyl ketone peroxide, etc. These compounds can be used alone or in combination of two or more. Among these compounds, from the viewpoint of curing temperature, compounds such as 1,1-di(tert-butylperoxy)cyclohexane having a half-life temperature of 100°C to 150°C are preferred.

[0075] Examples of the curing accelerator include metal salts of cyclohexane acid or octanoic acid (metal salts of cobalt, zinc, zirconium, manganese, calcium, etc.), which may be used alone or in combination of two or more.

[0076] Examples of the polymerization inhibitor include quinones such as hydroquinone, p-tert-butylcatechol, and pyrogallol. These may be used alone or in combination of two or more.

[0077] Examples of the adhesion improver include p-phenylvinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. These may be used alone or in combination of two or more.

[0078] The microcapsule-type foaming agent is not particularly limited, and may be, for example, a core-shell structure in which a volatile solvent is encapsulated by an acrylic resin. The synthesis method is also not particularly limited, and an interfacial polymerization method, an in-situ method, etc. may be used.

[0079] Furthermore, in order to improve heat resistance and strength, silica, alumina, etc. may be added as a filler.

[0080] (Verification of folded shape)

[0081] Using NOMEX (registered trademark), which is an aromatic polyimide resin nonwoven fabric, as the surface material 401, and utilizing an insulator 301 using insulating paper NHN made by Rui'an Insulation, which is a polyimide film, as the core material 402, the folding back effect of the insulator 301 was verified by comparing Examples 1 to 3 with the comparative example.

[0082] (Example 1)

[0083] Figure 8 It is a figure explaining the insulator concerning Example 1 of a strength test. Figure 8 The folding back method of the insulator 301 shown is similar to Figure 3The folding method shown is the same. Stainless steel 210 is used to simulate the stator core 21. Specifically, stainless steel 210 is a rectangular block of stainless steel with a length of 100 mm in the z-axis direction, and has a concave cutout that penetrates in the z-axis direction. In addition, in order to facilitate the test, the opening of stainless steel 210 is set to a different structure from that of stator core 21. The structure of stainless steel 210 is the same in Example 2, Example 3 and Comparative Example. A folding method is set in the concave cutout of such stainless steel 210. Figure 8 Insulator 301 of the shape. In addition, Figure 8 As shown, the folded position is the bottom of the concave shape. Then, an enameled wire (not shown) with a cross section of a substantially rectangular shape and a length of 200 mm is inserted into the inner side of the insulator 301. A liquid obtained by mixing 100 parts by weight of Showa Denko Materials fixing varnish WP-2008 and 1.5 parts by weight of polymerization initiator CT-50 is applied and heated and cured at 130°C for 1 hour to prepare a test piece of Example 1 in which the stainless steel 210, the insulator 301 and the enameled wire are fixed.

[0084] (Example 2)

[0085] Fig. 9 1 is a diagram illustrating an insulator according to Example 2 of a strength test. Fig. 9 In the example, only one end of the insulator 301 is folded back, and the core material 402 of the folded back portion is entirely opposed to one side of the inner wall of the groove 15. Fig. 9 The test piece of Example 2 was made under the same conditions as Example 1 except for the folding method of the insulator 301.

[0086] (Example 3)

[0087] Fig.10 1 is a diagram illustrating an insulator according to Example 3 of a strength test. Fig.10 In the example, both ends of the insulator 301 are folded back, and both sides of the core material 402 of the folded back portion face the same surface of the inner wall of the groove 15. Fig.10 The insulator 301 of the shape of . In addition, the folded position is the bottom of the concave shape. The test piece of Example 3 is under the same conditions as Example 1 except for the folding method of the insulator 301.

[0088] (Comparative Example)

[0089] As mentioned above, Figure 7 It is a figure explaining the insulator concerning the comparative example of the strength test. Figure 7The insulator 301 shown is not folded back. Figure 7 The test piece of the comparative example was subjected to the same conditions as those of the first embodiment except that the insulator 301 was not folded back.

[0090] The test pieces of Examples 1 to 3 and the comparative example were immersed in DEXRON (registered trademark)-VI automatic transmission fluid manufactured by ACDelco to which 0.2 wt % of water was added, and heated at 180° C. for 1000 hours. The test pieces were subjected to a pull-out test at a tensile speed of 50 mm / min using a universal testing machine AG-X manufactured by Shimadzu Corporation, and the pull-out strength was compared. Fig.11 Indicates the results of the strength test. In addition, Fig.11 The N in stands for Newton.

[0091] In Examples 1, 2, and 3, even after the oil resistance test, the same pull-out strength as in the initial stage was shown, and damage occurred between the stainless steel 210 and the insulator 301. On the other hand, in the comparative example, the pull-out strength was reduced, and damage occurred at the interface between the surface material 401 and the core material 402.

[0092] From the above, it was confirmed that the oil-resistant adhesiveness was improved by using the shapes of Examples 1 to 3.

[0093] The above description is based on a permanent magnet type rotating electrical machine, but the characteristics of the present invention relate to the insulation of the stator coil, so the rotor is not a permanent magnet type, and it can also be applied to an induction type, synchronous reluctance type, claw pole type, etc.

[0094] Explanation of symbols

[0095] 10 rotating electrical machine; 11 rotor; 12 rotor core; 13 rotating shaft; 15 slot; 18 permanent magnet; 20 stator; 21 stator core; 50 housing; 60 stator coil; 61 coil end on the opposite side of welding; 62 coil end on the welding side; 130 liquid cooling jacket; 144 bearing; 145 bearing; 150 refrigerant (oil) storage space; 153 refrigerant passage; 154 refrigerant outlet; 155 refrigerant outlet; 210 stainless steel; 300 annular insulating paper; 301 insulator; 401 surface material; 402 core material; RF refrigerant.

Claims

1. A stator, characterized in that: have: A ring-shaped stator core; A plurality of slots arranged in a circumferential direction on the inner circumference of the stator core and penetrating in an axial direction; an insulator in the form of a multi-layer sheet in which each layer is bonded by a first bonding method, and is wound into a cylindrical shape along the inner wall of each of the plurality of grooves; and a plurality of stator coils which are inserted inside the insulator, The first surface of the insulator is bonded to the inner wall of the slot by a second bonding method, and the second surface on the opposite side of the first surface is bonded to the stator coil by the second bonding method, A portion of the insulator is folded back in a direction perpendicular to the axial direction, the second surface of the folded back portion faces less than three inner walls of the groove, and at least a portion of the second surface of the folded back portion is bonded to the inner wall of the groove by the second bonding method.

2. The stator according to claim 1, characterized in that: The inner wall of the groove facing the second surface of the folded-back portion of the insulator is one surface.

3. The stator according to claim 2, characterized in that: The cross section of the groove perpendicular to the axial direction is rectangular, and the short side direction is the circumferential direction. A portion of the insulator is folded back along the circumferential direction.

4. The stator according to claim 2, characterized in that: The cross section of the groove perpendicular to the axial direction is rectangular, and the short side direction is the circumferential direction. A portion of the insulator is folded back in a radial direction of the stator core.

5. The stator according to claim 2, characterized in that: The groove has an opening on the inner peripheral side, The first surface of the insulator is in contact with the opening.

6. The stator according to claim 1, characterized in that: The first bonding method is bonding using an adhesive that is hydrolyzed by water contained in a refrigerant that cools the stator coil.

7. The stator according to claim 1, characterized in that: The second surface has any one of polyimide, polyphenylene sulfide, and polyester resin.

8. The stator according to claim 1, characterized in that: The first surface is an aromatic polyamide resin.

9. The stator according to claim 1, characterized in that: The second bonding method is bonding using a thermosetting resin.

10. A rotating electrical machine, characterized in that: A stator according to any one of claims 1 to 9.

11. The rotating electrical machine according to claim 10, characterized in that A liquid cooling jacket is provided on the outer peripheral side of the stator and allows a refrigerant to flow toward the stator to cool the stator.

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