Method for producing insulated covered conductor, impregnation agent used in same, and method for producing rotary electric machine

Abstract

Disclosed is a method for producing an insulated covered conductor, the method including: a step in which an insulating material (6) with which a conductor (7) is to be covered is impregnated or coated with a first impregnation agent (3) that contains an organic acid metal salt (1); a step in which the conductor covered with the insulating material that has been impregnated or coated with the first impregnation agent is immersed in a second impregnation agent (4) that contains an epoxy resin, an acid anhydride, and a metal ion trapping compound (2) that traps metal ions of the organic acid metal salt, so that the insulating material is impregnated with the second impregnation agent; and a step in which the conductor covered with the insulating material that has been impregnated with the second impregnation agent is heated so as to form an insulated covered conductor in which the conductor is covered with the insulating material and a cured product (61) that is obtained by curing the second impregnation agent. By causing the curing reaction of the epoxy resin to progress using the organic acid ions as a catalyst in the heat curing step, while suppressing an undesirable increase in the viscosity of the resin composition, the curing reaction can be caused to progress with an appropriate viscosity.

Description

Manufacturing method of insulated coated conductor, impregnating agent used therein, and manufacturing method of rotating electric machine

[0001] The present disclosure relates to a method for manufacturing an insulated coated conductor, an impregnating agent used therein, and a method for manufacturing a rotating electric machine.

[0002] Insulated coils for rotating electrical machines are formed by impregnating an insulating material wound around a conductor with a liquid resin composition and then heat-curing the impregnated material. During this heat-curing process, low viscosity resin compositions tend to flow, whereas high viscosity resin compositions tend to produce voids. Therefore, it is necessary to ensure that the curing reaction proceeds at an appropriate viscosity. For example, Patent Document 1 discloses a technique in which a conductor is covered with an epoxy resin prepreg containing a metal carboxylate, such as magnesium octoate, which is then vacuum-pressurized and impregnated with a resin composition, followed by heat-curing the impregnated resin composition. This technique allows the metal carboxylate to dissolve in the impregnated resin composition, activating the catalytic activity of the bisphenol epichlorohydrin condensate, resulting in an insulated coil with fewer voids.

[0003] Japanese Unexamined Patent Publication No. 55-079664

[0004] However, when an epoxy resin containing a metal carboxylate is placed on the surface of a coil conductor and then impregnated with a resin composition, the metal carboxylate dissolves in the resin composition in the impregnation tank over time. Because the metal carboxylate exhibits catalytic activity, oligomerization and polymerization of the resin composition in the impregnation tank progresses, resulting in an increased viscosity that is unsuitable for impregnation. This necessitates frequent replacement of the resin composition in the impregnation tank or the addition of a viscosity modifier.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a method for producing an insulated coated conductor that can prevent the resin composition in an impregnation tank from becoming undesirably viscous while achieving good curing in a heat curing step, as well as an impregnating agent and a rotating electric machine to be used therein.

[0006] The method for manufacturing an insulated coated conductor according to the present disclosure includes the steps of impregnating or applying a first impregnating agent containing an organic acid metal salt to an insulating material to be coated on a conductor; immersing the conductor coated with the insulating material impregnated or applied with the first impregnating agent in a second impregnating agent containing an epoxy resin, an acid anhydride, and a metal ion capturing compound that captures metal ions of the organic acid metal salt to impregnate the insulating material with the second impregnating agent; and heating the conductor coated with the insulating material impregnated with the second impregnating agent to form an insulated coated conductor in which the conductor is covered with a cured product formed by curing the insulating material and the second impregnating agent.

[0007] Another method for producing an insulated coated conductor according to the present disclosure includes the steps of: preparing an insulating material impregnated with or coated with a first impregnating agent containing an organic acid metal salt; immersing the insulating material impregnated with or coated with the first impregnating agent in a second impregnating agent containing an epoxy resin, an acid anhydride, and a metal ion capturing compound that captures metal ions of the organic acid metal salt to impregnate the insulating material with the second impregnating agent; coating a conductor with the insulating material impregnated with the second impregnating agent; and heating the conductor coated with the insulating material impregnated with the second impregnating agent to form an insulated coated conductor in which the conductor is covered with a cured product formed by curing the insulating material and the second impregnating agent.

[0008] The impregnating agent according to the present disclosure is a first impregnating agent used in the method for producing an insulated coated conductor according to the present disclosure, and has an organic acid metal salt dispersed therein.

[0009] Another impregnating agent according to the present disclosure is a second impregnating agent used in the method for producing an insulated coated conductor according to the present disclosure, which is a resin composition containing an epoxy resin and an acid anhydride, and a metal ion-capturing compound that captures metal ions of an organic acid metal salt dissolved in the resin composition.

[0010] In addition, the manufacturing method for a rotating electric machine according to the present disclosure includes a step of assembling an insulated coil conductor manufactured by the manufacturing method for an insulated conductor according to the present disclosure into a slot of a stator core to form a stator, and a step of arranging the stator and rotor opposite each other and assembling them.

[0011] According to the present disclosure, the resin composition in the impregnation tank can be prevented from becoming inappropriately thickened, and the curing reaction can proceed at an appropriate viscosity in the heat curing step.

[0012] 11 is a conceptual diagram showing a state in which a conductor coated with an insulating material impregnated with a first impregnating agent according to the first embodiment is impregnated with a second impregnating agent. FIG. 12 is a conceptual diagram showing a state in which an insulating material is wound around a conductor according to the first embodiment. FIG. 13 is a conceptual diagram showing a conductor coated with an insulating material impregnated with the first impregnating agent according to the first embodiment. FIG. 14 is an image showing a state in which metal ions of the first impregnating agent are captured by the metal ion-capturing compound of the second impregnating agent according to the first embodiment. FIG. 15 is a schematic flow chart showing a process for manufacturing an insulation-coated conductor according to the first embodiment. FIG. 16 is a schematic flow chart showing a process for manufacturing an insulation-coated conductor according to the first embodiment. FIG. 17 is a schematic cross-sectional view of an insulation-coated coil conductor according to the first embodiment. FIG. 18 is a conceptual diagram showing a state in which an insulating tape according to the second embodiment is impregnated with the first impregnating agent. FIG. 19 is a conceptual diagram showing an example of an impregnation tank for impregnating a coil conductor coated with an insulating material impregnated with the first impregnating agent according to the second embodiment with the second impregnating agent. FIG. 19 is a schematic diagram showing a part of a stator according to the second embodiment. FIG. 19 is a cross-sectional view showing a rotating electric machine according to the third embodiment. FIG. 19 is a cross-sectional view taken along the line A-A of FIG. 11 showing the rotating electric machine according to the third embodiment.

[0013] Embodiment 1. Embodiment 1 will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing the state in which a conductor 7 coated with an insulating material 6 impregnated with a first impregnating agent 3 according to embodiment 1 is impregnated with a second impregnating agent 4. In FIG. 1, the conductor 7 is coated with the insulating material 6, which is impregnated or coated with the first impregnating agent 3. The first impregnating agent 3 contains an organic acid metal salt 1. The conductor 7 coated with the insulating material 6 impregnated or coated with the first impregnating agent 3 is then immersed in a second impregnating agent 4 stored in an impregnation tank 5, and a resin composition is impregnated into the insulating material 6 and between the insulating material 6 and the conductor 7. The second impregnating agent 4 contains an epoxy resin, an acid anhydride, and a metal ion-trapping compound 2.

[0014] As shown in Fig. 2, a conductor 7 is insulated by wrapping it with, for example, insulating tape, which serves as an insulating material 6. As shown in Fig. 3, the insulating tape is pre-impregnated with a first impregnation agent 3 containing an organic acid metal salt 1. Instead of impregnation, the first impregnation agent 3 may be applied. After the insulating tape is impregnated with or applied with the first impregnation agent 3, it is preferable to dry it at a low temperature or semi-cure it to solidify it.

[0015] Then, the conductor 7 covered with the insulating tape impregnated or coated with the first impregnating agent 3 is immersed in the second impregnating agent 4. At this time, as shown in Fig. 4, the insulating tape containing the organic acid metal salt 1 is present on the conductor 7, and the second impregnating agent 4 containing the epoxy resin, acid anhydride, and metal ion capturing compound 2 is present on the insulating tape.

[0016] The conductor 7 is then removed from the impregnation tank 5 and coated with the insulating material 6 impregnated or coated with the first impregnation agent 3. In the process of heating and curing, the metal ions (M + ) and an anion, organic acid ion (R - ) dissociation reaction becomes active. In particular, organic acid ions (R - ) exhibits strong nucleophilicity and promotes the reaction of epoxy resin with acid anhydride to increase the molecular weight, as shown in the following chemical formula (Chemical Formula 1).

[0017]

[0018] That is, in the heat curing process after impregnation, a reaction occurs in which the organic acid metal salt 1 on the insulating material 6 dissolves in the resin composition, and the metal ions of the organic acid metal salt 1 are captured by the metal ion-trapping compound 2. As a result, the organic acid ions, acting as counter ions, exhibit strong nucleophilicity and catalyze the curing reaction of the epoxy resin. Furthermore, by selecting the substituents of the organic acid, this nucleophilic reactivity can be controlled, and therefore the curing reaction rate can be controlled. Meanwhile, at room temperature, the metal ion-trapping compound 2 exists mostly as a simple substance, and therefore does not exhibit catalytic activity and does not become a factor in thickening the resin composition.

[0019] Therefore, the resin composition can be applied to the area where insulation coating is required with an appropriate viscosity, and the curing reaction can be progressed in a short time while preventing leakage to the outside, resulting in an insulation-coated conductor without voids that can cause insulation defects.

[0020] Here, the epoxy resin includes an epoxy compound having two or more epoxy groups per molecule, such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenol epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol novolac epoxy resin, alicyclic epoxy resin, aliphatic linear epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, hydantoin epoxy resin, isocyanurate epoxy resin, salicylaldehyde novolac epoxy resin, diglycidyl ethers of difunctional phenols, diglycidyl ethers of difunctional alcohols, and halides and hydrogenated versions thereof, and several of these may be used in combination.

[0021] The acid anhydride may be any acid anhydride capable of curing an epoxy resin. Examples include hexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, methylnadic anhydride, methylnorbornane-2,3-dicarboxylic anhydride, norbornane-2,3-dicarboxylic anhydride, dodecenylsuccinic anhydride, α-terpinene, Diels-Alder reaction products of decatrienes such as alloocimene with maleic anhydride, and hydrogenated products thereof. Several of these may also be used in combination. Furthermore, structural isomers or geometric isomers, mixtures thereof, and modified products thereof may also be used.

[0022] The amount of epoxy resin and acid anhydride blended is preferably 0.5 to 1.5 equivalents per total equivalent of epoxy groups in the molecule. If the amount is less than 0.5 equivalents, the proportion of the acid anhydride, which is a low-viscosity component, becomes small, resulting in high viscosity and making impregnation difficult. In this case, the heat resistance and mechanical properties of the cured product also decrease. If the amount exceeds 1.5 equivalents, the heat resistance and mechanical properties of the cured product also decrease.

[0023] The organic acid metal salt 1 is an ionic compound in which the hydrogen atoms of acids such as carboxylic acids, sulfonic acids, oxo acids, and phosphoric acids are replaced with metal ions. Examples include butyrates, cyclohexane salts, cyclohexylpropionates, laurates, caprylates, phenylacetates, and octylates. Since organic acid metal salts are solid at room temperature and therefore difficult to dissolve in the resin composition in the impregnation tank 5, those with high melting points, such as hydrocarbons with long alkyl chains or aromatic rings, are preferred. These may also contain heteroatoms such as nitrogen, oxygen, sulfur, phosphorus, chlorine, iodine, and bromine. Furthermore, the longer the alkyl chain, the greater the electron donating ability, which can enhance the nucleophilicity of the organic acid ion. Therefore, particularly preferred organic acid metal salts 1 are metal laurates and metal caprylates. For example, a metal laurate or a metal caprylate may be dispersed as organic acid metal salt 1 in an adhesive resin component such as epoxy resin, acrylic resin, or methacrylic resin to prepare first impregnating agent 3, which may then be applied to insulating material 6 and dried. Furthermore, reactivity can be controlled by modifying a portion of the organic acid with a substituent. When an electron-donating substituent is bonded to the organic acid of organic acid metal salt 1, the nucleophilicity can strongly catalyze the curing reaction of the resin composition, thereby preventing the resin composition from leaking out of conductor 7 during the heat curing process.

[0024] Examples of metals contained in the organic acid metal salt 1 include Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Zn. In particular, using a metal ion with a large radius and low electronegativity can increase the nucleophilicity of the organic acid ion and enhance the catalytic effect of the curing reaction. The use of Na, Mg, K, Co, Ni, and Zn is preferable because they can improve solubility and reactivity in the resin composition.

[0025] The metal ion-trapping compound 2 is a compound that traps metal ions liberated from the organic acid metal salt 1. Examples include calixarene, cyclic polyketones having repeating units such as 1,3-diketone, and crown ethers that form cyclic polyethers, which trap metal ions by forming non-covalent bonds through acid-base interaction, electrostatic interaction, or the like. Compounds that adsorb metal ions, such as ionophores, may also be used. The metal ion-trapping compound 2 is preferably dissolved and uniformly dispersed in the resin composition.

[0026] Furthermore, from the viewpoint of the usable life of the second impregnating agent 4, it is preferable that the second impregnating agent 4 does not have a catalytic effect on the curing reaction of the resin composition. From this viewpoint, crown ethers that encapsulate metal ions in the central cavity are preferred. Since crown ethers alone do not have a catalytic effect, they do not cause thickening of the resin composition.

[0027] In particular, 18-crown-6, which has an affinity for potassium ions and is represented by the following chemical formula (Chemical Formula 2):

[0028]

[0029] 15-crown-5, which has an affinity for sodium ions and is represented by the following chemical formula (Chemical Formula 3):

[0030]

[0031] 12-crown-4, which specifically forms a complex with lithium ions and is represented by the following chemical formula (Chemical Formula 4):

[0032] It is preferable to use:

[0033] For example, when potassium laurate is used as the organic acid metal salt 1 and 18-crown-6 is used as the metal ion capturing compound 2, the potassium laurate on the insulating material 6 is compatible with the resin composition in the impregnation tank 5, and the potassium ions (K + ) is trapped within 18-crown-6, as shown in the following chemical formula (5).

[0034]

[0035] In the heat curing step after the impregnation, the reaction of the above formula (Chemical Formula 5) is further accelerated, and lauric acid or an organic acid R - serves as a counter ion and catalyzes the curing reaction of the epoxy resin. Even if the organic acid metal salt 1 is solid, the metal ions are captured by the metal ion-capturing compound 2, and the dissolution of the organic acid into the epoxy resin proceeds.

[0036] From the viewpoint of release and capture, it is preferable to use a combination of 18-crown-6 and an organic acid potassium salt, 15-crown-5 and an organic acid sodium salt, or 12-crown-4 and an organic acid lithium salt.

[0037] For example, if the total weight of the second impregnating agent 4 is 100, the organic acid metal salt 1 dispersed in the first impregnating agent 3 may be blended in an amount of about 0.1 to 10 parts by weight.

[0038] Fig. 5 is a schematic flow diagram showing the steps for producing an insulated conductor. As shown in Fig. 5, a first impregnating agent 3 containing an organic acid metal salt 1 is impregnated or applied to an insulating material 6 to be coated onto a conductor 7 (step S101). The conductor 7 coated with the insulating material 6 impregnated or coated with the first impregnating agent 3 is then immersed in a second impregnating agent 4 containing an epoxy resin, an acid anhydride, and a metal ion-capturing compound 2 that captures the metal ions of the organic acid metal salt 1, thereby impregnating the insulating material 6 with the second impregnating agent 4 (step S102). Next, the conductor 7 coated with the insulating material 6 impregnated with the second impregnating agent 4 is heated to form an insulated conductor in which the conductor 7 is covered with a cured product of the insulating material 6 and the second impregnating agent 4 (step S103). These steps allow the production of an insulated conductor.

[0039] The process for producing an insulated conductor may involve first impregnating an insulating material 6 impregnated or coated with a first impregnating agent 3 with a second impregnating agent 4, drying or semi-curing the resulting material, and then coating the conductor 7. Specifically, as shown in FIG. 6 , an insulating material 6 impregnated or coated with a first impregnating agent 3 containing an organic acid metal salt 1 is prepared (step S201). The insulating material 6 thus impregnated or coated with the first impregnating agent 3 is then immersed in a second impregnating agent 4 containing an epoxy resin, an acid anhydride, and a metal ion-capturing compound 2 that captures the metal ions of the organic acid metal salt 1, thereby impregnating the insulating material 6 with the second impregnating agent 4 (step S202). Next, the conductor 7 is coated with the insulating material 6 impregnated with the second impregnating agent 4 (step S203). The conductor 7 coated with the insulating material 6 impregnated with the second impregnating agent 4 is then heated to form an insulated conductor in which the conductor 7 is covered with a cured product of the insulating material 6 and the second impregnating agent 4 (step S204). These steps also allow the production of an insulated conductor.

[0040] In this way, by using a first impregnating agent 3 containing an organic acid metal salt 1 that is applied to or impregnated into the insulating material 6 that is to be coated on the conductor 7, and a second impregnating agent 4 containing an epoxy resin, an acid anhydride, and a metal ion-capturing compound 2 that captures the metal ions of the organic acid metal salt 1 that is impregnated into the insulating material 6 that has been coated or impregnated with the first impregnating agent 3, the reaction in which the metal ions and the organic acid ions dissociate upon heating can be activated, and the curing reaction can proceed with the organic acid ions acting as a catalyst. In other words, the resin composition in the impregnation tank 5 can be prevented from becoming unsuitably thickened, and the curing reaction can proceed at an appropriate viscosity in the heat-curing step.

[0041] Furthermore, when an electron-donating substituent is bonded to the organic acid of the organic acid metal salt 1, the nucleophilicity can strongly catalyze the curing reaction of the resin composition, thereby preventing the resin composition from leaking out of the insulated coil conductor 10 during the heat curing process.

[0042] Furthermore, if the metal ion-capturing compound 2 dissolves in the second impregnating agent 4 at room temperature and the organic acid metal salt 1 is dispersed in the first impregnating agent 3 in a solid state at room temperature, the metal ion-capturing compound 2 can capture the metal ions of the organic acid metal salt 1 in the heat curing step, thereby dissolving the organic acid component of the solid organic acid metal salt 1 in the resin composition.

[0043] In the present embodiment, an example has been shown in which insulating tape is used as the insulating material 6, but the conductor 7 may also be covered with insulating paper, glass cloth, or other materials that are not in the form of tape. Also, while an example has been described in which the conductor 7 is covered with the insulating material 6, the conductor 7 may be the coil conductor 71 or a part that forms the coil conductor 71. A coil assembly may be formed by assembling conductors 7 coated with insulating material 6 that has been impregnated with the first impregnation agent 3, and this may be impregnated with the second impregnation agent 4 and subjected to a heat curing treatment.

[0044] FIG. 7 is a cross-sectional view of an insulation-coated coil conductor 10 in which a coil conductor 71 is formed using a conductor 7. The coil conductor 71 is formed from a long, insulation-coated conductor 7, and an insulating material 6 is disposed between the conductors 7 and on the surface of the coil conductor 71. A cured product 61 is formed inside and on the surface of the insulating material 6, which may be made of, for example, glass fiber, by heat-curing a first impregnating agent 3 and a second impregnating agent 4. When the conductor 7 has a complex shape like this, it is necessary to appropriately reduce the viscosity of the resin composition to allow the resin composition to penetrate into the fine spaces between the conductors 7 and promote the curing reaction. However, even in such cases, the metal ion-capturing compound 2 captures the metal ions, and the remaining organic acid ions allow the curing reaction to proceed at an appropriate viscosity, resulting in the formation of a favorable cured product 61. This makes it possible to manufacture an insulation-coated coil conductor 10 with excellent electrical and mechanical properties.

[0045] Embodiment 2. In Embodiment 2, an example of a method for manufacturing an insulation-coated coil conductor 10, which is an insulation-coated conductor, using the impregnating agent described in Embodiment 1 is described. First, a coil conductor 71, which is a bundle of multiple insulation-coated conductors 7, and an insulating material 6 impregnated with or coated with a first impregnating agent 3 containing an organic acid metal salt 1 are prepared. For example, a long glass fiber insulating tape is used as the insulating material 6, and this insulating tape is immersed in the first impregnating agent 3 while being wound by a winding machine shown in FIG. 8. For example, some of multiple rolls 21 are placed in a tank 22 storing the first impregnating agent 3, and the insulating tape is impregnated with the first impregnating agent 3 containing the organic acid metal salt 1 in the tank 22 and dried. The first impregnating agent 3 may be supplied onto the insulating tape and applied to the surface of the insulating tape.

[0046] Then, an insulating material 6 impregnated or coated with a first impregnation agent 3 containing an organic acid metal salt 1 is wound around the outer periphery of the coil conductor 71, for example, with half of the material overlapping the other, multiple times. Here, the coil conductor 71 is covered with insulating tape, and an organic acid metal salt 1, such as a carboxylate, is disposed on the surface of the insulating tape.

[0047] Next, the coil conductor 71, on which the insulating tape is wound and the organic acid metal salt 1 is disposed, is impregnated with a second impregnating agent 4 containing an epoxy resin, an acid anhydride, and a metal ion-trapping compound 2. For example, a crown ether is used as the metal ion-trapping compound 2. When the insulating tape is wound many times, it is necessary to lower the viscosity of the second impregnating agent 4, so a diluent may be used as appropriate.

[0048] For example, the impregnation method uses a vacuum impregnation tank 51 shown in FIG. 9 . An impregnation tank 5 is provided within the vacuum impregnation tank 51, and a second impregnation agent 4 is supplied to this impregnation tank 5 via a valve 512 from an impregnation resin storage tank 52 provided outside the vacuum impregnation tank 51. The second impregnation agent 4 contains an epoxy resin, an acid anhydride, and a metal ion capture compound 2. A coil conductor 71 wrapped with insulating tape and containing an organic acid metal salt 1 is immersed in the second impregnation agent 4 within the impregnation tank 5, and a pump 511 reduces the pressure within the vacuum impregnation tank 51 to remove air bubbles from the second impregnation agent 4 and to allow the second impregnation agent 4 to penetrate between the conductors 7 of the coil conductor 71 and into the fine spaces within the insulating tape. The valve 512 on the pump 511 side is then closed, and the second impregnation agent 4 is appropriately added from the impregnation resin storage tank 52 to perform pressurized impregnation.

[0049] Then, the coil conductor 71, which has been wrapped with insulating tape, has the organic acid metal salt 1 placed thereon, and is impregnated with the second impregnation agent 4, is removed from the vacuum impregnation tank 51, and the resin composition in the second impregnation agent 4 that has impregnated the insulating material 6 is heated and cured in a temperature range of 90°C to 180°C.

[0050] At this time, as described in the first embodiment, the metal ion capturing compound 2 captures the metal ions, and the uncaptured organic acid ions allow the curing reaction to proceed at an appropriate viscosity, so that a good cured product 61 can be formed.

[0051] Here, an example has been described in which the insulating tape is impregnated with the first impregnation agent 3 and then wound around the coil conductor 71, but the insulating tape may be wound around the coil conductor 71 first and then impregnated with the first impregnation agent 3. The first impregnation agent 3 may also be applied to the insulating tape wound around the coil conductor 71.

[0052] That is, the conductor 7 is a coil conductor 71, and the coil conductor 71 is coated with an insulating material 6 impregnated or coated with a first impregnating agent 3, and is then immersed in a second impregnating agent 4 to impregnate the insulating material 6 with the second impregnating agent 4. The second impregnating agent 4 contains an epoxy resin, an acid anhydride, and a metal ion-capturing compound 2 that captures metal ions of the organic acid metal salt 1. The coil conductor 71 coated with the insulating material 6 impregnated with the second impregnating agent 4 is then heated to cure the epoxy resin contained in the second impregnating agent 4, thereby forming an insulation-coated coil conductor 10 in which the coil conductor 71 is covered with a cured product 61 formed by curing the insulating material 6 and the second impregnating agent 4.

[0053] According to this method, in the heat curing process after impregnation, the metal ions of the organic acid metal salt 1 are captured by the metal ion-capturing compound 2, and the organic acid ions catalyze the curing reaction of the epoxy resin. By controlling this nucleophilic reactivity, the curing reaction rate can be controlled. Meanwhile, the metal ion-capturing compound 2 alone does not exhibit catalytic activity and therefore does not contribute to thickening of the resin composition. Therefore, the resin composition can be distributed to the required areas with an appropriate viscosity while suppressing leakage to the outside, allowing the curing reaction to proceed. As a result, an insulation-coated coil conductor 10 without voids that would cause insulation defects can be obtained. Therefore, it is possible to manufacture an insulation-coated coil conductor 10 with excellent electrical and mechanical properties.

[0054] Furthermore, the obtained insulation-coated coil conductor 10 is placed inside the slot 13 of the stator core 12, for example, and multiple insulation-coated coil conductors 10 are combined to form the stator coil 11, thereby producing the stator 101.

[0055] FIG. 10 is a schematic diagram showing a portion of a stator 101 of a rotating electric machine 100. Here, the coil conductor 71 is, for example, a bundle of rectangular metal wires, and is covered with an insulating material 6. The insulating material 6 provides ground insulation with the stator core 12. The multiple insulation-coated coil conductors 10 in FIG. 10 , together with other insulation-coated coil conductors 10 housed in other slots 13 (not shown) of the stator core 12, form the stator coil 11. Wedges 14 for fixing the insulation-coated coil conductors 10 are inserted into the open ends of the slots 13, and these wedges 14 suppress electromagnetic vibrations generated from the stator coil 11 during operation of the rotating electric machine 100. As a method for manufacturing the insulation-coated coil conductor 10, the process of forming the coil conductor 71 covered with the insulating material 6 and the cured product 61 of the second impregnating agent 4 has been described. However, the resin composition of the second impregnating agent 4 may not be completely cured, and the final curing process of the cured product 61 may be performed after the stator coil 11 is attached to the stator core 12. In this way, a stator 101 having stator coils 11 free of voids that can cause insulation defects can be obtained.

[0056] Embodiment 3 In embodiment 3, an example of a rotating electric machine 100 including the stator 101 described in embodiment 2 will be described. Figures 11 and 12 are schematic diagrams of the rotating electric machine 100 according to embodiment 3. Figure 11 is a cross-sectional view of the rotating electric machine 100 taken along the rotation axis S of the rotor 102, as indicated by the dashed line, and Figure 12 is a cross-sectional view of the rotating electric machine 100 taken along the line A-A indicated by the dashed line in Figure 10.

[0057] 11 and 12 , a rotating electric machine 100 has a cylindrical stator core 12 that houses a rotor 102. The outer periphery of the stator core 12 is provided with a plurality of (eight in this example) core fastening members 103 that are arranged at predetermined intervals in the circumferential direction and fasten the stator core 12 in the direction of the rotation axis S, and a plurality of (four in this example) retaining rings 104 that are arranged at predetermined intervals in the direction of the rotation axis S on the outer periphery of the stator core 12 and that fasten and hold the stator core 12 in the direction of the rotation axis S from the outer periphery of the core fastening members 103. Furthermore, the rotor is provided with a cylindrical frame 105 surrounding the stator core 12 at intervals, a plurality of (five in this example) ring-shaped inner frame members 106 projecting axially at predetermined intervals in the direction of the rotation axis S on the inner surface of the frame 105, and a plurality of (four in this example) elastic support members 107 made of spring plates fixed to adjacent inner frame members 106. The retaining ring 104 serves to fix the elastic support members 107.

[0058] The rotating electric machine 100 constitutes, for example, the armature of a turbine generator. As described in the second embodiment, the inner periphery of the stator core 12 is provided with a predetermined number of slots 13 extending in the direction of the rotation axis S, and the stator coil 11 is disposed within the slots 13. The stator coil 11 is then covered with a cured product 61 formed by impregnating the second impregnating agent 4 and heat-curing the second impregnating agent 4 in the presence of an insulating material 6 and the first impregnating agent 3 described in the first and second embodiments. Specifically, the metal ion-capturing compound 2 in the second impregnating agent 4 captures the metal ions of the organic acid metal salt 1 in the first impregnating agent 3, while the remaining organic acid ions allow the curing reaction to proceed at an appropriate viscosity, resulting in the formation of a good cured product 61 free of void defects. This makes it possible to manufacture a stator coil 11 with excellent electrical and mechanical properties.

[0059] Then, the insulating coated coil conductor 10 having the hardened material 61 described in embodiment 1 is assembled into the slot 13 of the stator core 12 as described in embodiment 2 to produce the stator 101 as the stator coil 11, and the rotating electric machine 100 can be manufactured by arranging this stator 101 and rotor 102 opposite each other.

[0060] The rotating electric machine 100 manufactured in this manner can achieve high output and miniaturization because the stator coil 11 can withstand a high voltage. In particular, when the rotating electric machine 100 is applied to a turbine generator, the high withstand voltage of the stator coil 11 makes it possible to reduce the thickness of the insulating material 6 around the coil conductors 71. Reducing the thickness of the insulating material 6 makes it easier to dissipate heat from the coil conductors 71, and it becomes possible to improve the output efficiency of the generator.

[0061] Furthermore, in the manufacture of the rotating electric machine 100, the usable life of the second impregnating agent 4 with which the stator coil 11 is impregnated can be extended, and the second impregnating agent 4 can be used repeatedly in the impregnation process. This significantly reduces the frequency of replacement of the second impregnating agent 4, even when the stator coil 11 has a large number of parts, thereby improving productivity. Furthermore, the amount of second impregnating agent 4 disposed of can be significantly reduced, thereby reducing the environmental impact.

[0062] The normal temperature described in the first to third embodiments is a temperature that does not exceed the ambient temperature, ie, approximately 15°C to 30°C.

[0063] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0064] 1 organic acid metal salt, 2 metal ion capturing compound, 3 first impregnation agent, 4 second impregnation agent, 5 impregnation tank, 6 insulating material, 7 conductor, 10 insulation coated coil conductor, 11 stator coil, 12 stator core, 13 slot, 14 wedge, 21 roll, 51 vacuum impregnation tank, 52 impregnation resin storage tank, 61 hardened product, 71 coil conductor, 511 pump, 512 valve, 100 rotating electric machine, 101 stator, 102 rotor, 103 iron core clamping member, 104 retaining ring, 105 frame, 106 inner frame member, 107 elastic support member

Claims

1. A method for manufacturing an insulated coated conductor, comprising the steps of: impregnating or applying a first impregnating agent containing an organic acid metal salt to an insulating material to be coated on a conductor; immersing the conductor coated with the insulating material impregnated or applied with the first impregnating agent in a second impregnating agent containing an epoxy resin, an acid anhydride, and a metal ion capturing compound that captures metal ions of the organic acid metal salt, thereby impregnating the insulating material with the second impregnating agent; and heating the conductor coated with the insulating material impregnated with the second impregnating agent to form an insulated coated conductor in which the conductor is covered with a cured product formed by curing the insulating material and the second impregnating agent.

2. A method for manufacturing an insulated coated conductor, comprising the steps of: preparing an insulating material impregnated with or coated with a first impregnating agent containing an organic acid metal salt; immersing the insulating material impregnated with or coated with the first impregnating agent in a second impregnating agent containing an epoxy resin, an acid anhydride, and a metal ion capturing compound that captures metal ions of the organic acid metal salt, thereby impregnating the insulating material with the second impregnating agent; covering a conductor with the insulating material impregnated with the second impregnating agent; and heating the conductor covered with the insulating material impregnated with the second impregnating agent to form an insulated coated conductor in which the conductor is covered with a cured product obtained by curing the insulating material and the second impregnating agent.

3. A method for producing an insulated conductor as described in claim 1 or claim 2, wherein the organic acid metal salt is an ionic compound in which a hydrogen atom that becomes any one of carboxylic acid, sulfonic acid, oxo acid, and phosphoric acid is replaced with a metal ion.

4. A method for producing an insulated conductor as described in claim 1 or claim 2, wherein the metal contained in the organic acid metal salt is at least one of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Zn.

5. A method for producing an insulated conductor according to claim 1 or 2, wherein the organic acid metal salt is at least one of a metal salt of lauric acid and a metal salt of caprylic acid.

6. A method for producing an insulated conductor according to claim 1 or 2, wherein the organic acid metal salt is an organic acid having an electron-donating substituent bonded thereto.

7. A method for producing an insulated conductor as described in claim 1 or claim 2, wherein the metal ion capturing compound is at least one of a cyclic polyether, a cyclic polyketone, and an ionophore.

8. A method for producing an insulated conductor according to claim 1 or claim 2, wherein the metal ion capturing compound is a crown ether.

9. A method for producing an insulated conductor according to claim 1 or 2, wherein the metal ion capturing compound is 18-crown-6, and the organic acid metal salt is a potassium salt.

10. A method for producing an insulated conductor as described in claim 1 or claim 2, wherein the metal ion capturing compound is 15-crown-5, and the organic acid metal salt is a sodium salt.

11. A method for producing an insulated conductor as described in claim 1 or claim 2, wherein the metal ion capturing compound is 12-crown-4, and the organic acid metal salt is a lithium salt.

12. A first impregnating agent for use in the method for producing an insulated coated conductor according to any one of claims 1 to 11, the first impregnating agent having an organic acid metal salt dispersed therein.

13. A second impregnating agent for use in the method for producing an insulated coated conductor according to any one of claims 1 to 11, comprising a resin composition containing an epoxy resin and an acid anhydride, and a metal ion capturing compound that captures metal ions of an organic acid metal salt dissolved in the resin composition.

14. A method for producing an insulated coated conductor as described in claim 1, wherein the conductor is a coil conductor, the method comprising the steps of: immersing the coil conductor coated with the insulating material impregnated or coated with the first impregnating agent in the second impregnating agent to impregnate the insulating material with the second impregnating agent; and heating the coil conductor coated with the insulating material impregnated with the second impregnating agent to form an insulated coated coil conductor in which the coil conductor is covered with a hardened product of the insulating material and the second impregnating agent.

15. A method for manufacturing a rotating electric machine comprising the steps of: assembling an insulated coil conductor manufactured by the method for manufacturing an insulated conductor according to claim 14 into a slot of a stator core to form a stator; and arranging the stator and a rotor opposite each other and assembling them.