WO2024052961A1

WO2024052961A1 - Method for manufacturing stator coil, stator coil, and rotary machine

Info

Publication number: WO2024052961A1
Application number: PCT/JP2022/033280
Authority: WO
Inventors: 貴裕馬渕
Original assignee: 三菱電機株式会社
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2024-03-14

Abstract

This method for manufacturing a stator coil comprises: a first step for winding a mica tape (7) on a coil conductor (5); a second step for winding a prepreg tape (9) on the coil conductor (5) on which the mica tape (7) has been wound; a third step for winding a thermal shrinkage tape on the outer circumference of the coil conductor (5) on which the mica tape (7) and the prepreg tape (9) have been wound; a fourth step for heating the coil conductor (5) and curing a resin included in the prepreg tape while compressing the mica tape (7) and the prepreg tape (9) by a shrinking force of the thermal shrinkage tape (8); a fifth step for removing the thermal shrinkage tape (8) and impregnating the mica tape (7) with a liquid resin (10); and a sixth step for heating the coil conductor (5) and curing the liquid resin (10). By using said method, a stator coil having excellent electricity resistance and heat dissipation ability can be provided.

Description

Stator coil manufacturing method, stator coil and rotating machine

The present disclosure relates to a method for manufacturing a stator coil, a stator coil using the same, and a rotating machine.

Large high-pressure rotating machines used for turbine generators, industrial motors, etc. are made of a coil insulation material (called a coil insulating material) on the inner periphery of the stator core. In recent years, there has been an increasing demand for smaller size and higher output for rotating machines, and in order to achieve this, coil insulating materials are required not only to withstand voltage but also to efficiently transfer heat from the coil conductor to the iron core. High heat dissipation is desired.

The method for manufacturing the coil insulating material involves wrapping a mica tape, which is a mica sheet with a fiber reinforcing material such as glass cloth, around the coil conductor several times, and applying a low-viscosity liquid curable resin composition (hereinafter referred to as liquid resin) under reduced pressure. Vacuum impregnation method, in which semi-cured resin is placed on an insulating tape, and the tape with semi-cured resin placed on the insulating material is wrapped around a coil conductor and heated and pressed. A resin rich method etc. are commonly used. Among these, the vacuum impregnation method is suitable for manufacturing large-scale high-voltage rotating machines that are expected to operate for a long time because voids that become insulation defects are less likely to occur inside the coil insulating material. In addition, in the vacuum impregnation method, before the heating process, a coil wrapped with mica tape containing liquid resin is fitted into a mold and compressed under pressure. It is possible to drain from the end. By heating the coil in this state to harden the liquid resin, the content of mica in the coil insulating material increases, making it possible to improve voltage resistance.

However, in this method, during the process of heating and curing the liquid resin, the liquid resin is heated before the curing reaction begins, causing its viscosity to temporarily decrease and leaking out from the gaps between the mica tapes. In some cases, voids, which become insulation defects, occur on the surface of the coil insulating material.

On the other hand, Patent Document 1 discloses that mica tape is wound around the surface of the coil conductor to a predetermined thickness to form a main insulating base material layer, and the outside of the main insulating base material layer at the coil end portion is heated. A method is described in which a finishing tape made by bonding a shrinkable cloth tape and a heat-shrinkable film tape is wrapped, and vacuum impregnation with resin and heat treatment are performed. By performing vacuum impregnation and heat treatment of the resin of the coil insulating material using the manufacturing method of Patent Document 1, the finishing tape shrinks due to heat during the heat curing treatment of the resin, making it possible to prevent the resin from leaking from the coil end portion. Therefore, it is possible to suppress the generation of voids in the coil insulating material and improve the voltage resistance.

Japanese Patent Application Publication No. 5-30695

However, with the method of wrapping mica tape around the coil conductor, wrapping finishing tape on the outside, and vacuum impregnating the resin with heat treatment, the liquid resin between the mica tapes is not sufficiently discharged, so the mica tape is It cannot be compressed, the mica content in the coil insulation material is low, and the electrical resistance tends to decrease. In addition, there is a problem that the amount of resin with low thermal conductivity increases, and the heat dissipation of the coil deteriorates.

The present disclosure has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing a stator coil that can improve voltage resistance and heat dissipation.

A method for manufacturing a stator coil according to the present disclosure includes a first step of wrapping a mica tape around a coil conductor in which a conductor is wound into a coil shape, and a second step of wrapping a prepreg tape around the coil conductor wrapped with the mica tape. , a third step of wrapping a heat shrink tape around the outer periphery of the coil conductor wrapped with the mica tape and the prepreg tape, heating the coil conductor and compressing the mica tape and the prepreg tape with the shrinkage force of the heat shrink tape; A fourth step of curing the resin contained in the tape, a fifth step of removing the heat shrink tape and impregnating the mica tape with liquid resin, and a sixth step of heating the coil conductor and curing the liquid resin. Equipped with.

A stator coil according to the present disclosure includes a coil conductor, a first insulating layer containing mica tape and a cured liquid resin on the outer periphery of the coil conductor, and a prepreg tape on the outer periphery of the first insulating layer, without overlapping each other. A second insulating layer is wound around the prepreg tape and a resin contained in the prepreg tape is cured.

According to the method for manufacturing a stator coil according to the present disclosure, the mica tape and the prepreg tape are compressed with a heat shrink tape before being impregnated with the liquid resin of the mica tape, and the resin contained in the prepreg tape is cured and compressed. By maintaining this state, it is possible to suppress the inclusion of excess liquid resin between the mica tapes, and therefore it is possible to improve the voltage resistance and heat dissipation properties of the stator coil.

FIG. 1 is a perspective view showing a schematic configuration of a stator of a rotating machine according to Embodiment 1 of the present disclosure. FIG. 2 is a front view showing a schematic configuration of a coil end portion of a stator coil according to Embodiment 1 of the present disclosure. 1 is a flowchart showing each step of a method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. FIG. 3 is a cross-sectional view showing a coil conductor in a first step of the method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. FIG. 3 is a cross-sectional view showing a coil conductor in a second step of the method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. FIG. 7 is a cross-sectional view showing a coil conductor in a third step of the method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. FIG. 7 is a cross-sectional view showing a coil conductor in a fourth step of the method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. FIG. 7 is a cross-sectional view showing a coil conductor in a fifth step and a sixth step of the method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. FIG. 3 is a cross-sectional view showing a coil insulating material according to Embodiment 2 of the present disclosure. FIG. 7 is a cross-sectional view along the rotation axis of a rotating machine according to Embodiment 3 of the present disclosure. FIG. 3 is a sectional view showing a rotating machine according to Embodiment 3 of the present disclosure.

Embodiment 1.
FIG. 1 is a perspective view showing a schematic configuration of a stator of a rotating machine according to Embodiment 1 of the present disclosure. As shown in FIG. 1, in the stator of a rotating machine, two stages of stator coils 3 are housed inside slots 2 of a stator core 1. A spacer (not shown) is inserted between the two stages of stator coils 3, and a wedge 4 for fixing the stator coil 3 is arranged at the open end of the slot 2. . The wedge 4 suppresses vibrations based on electromagnetic force generated from the stator coil 3 during operation of the rotating machine. Here, an example is shown in which two stages of stator coils 3 are housed inside the slots 2 of the stator core 1, but the number of stator coils 3 housed in the slots 2 is not limited in the present disclosure. shall be taken as a thing.

FIG. 2 is a front view showing a schematic configuration of a coil end portion of a stator coil according to Embodiment 1 of the present disclosure. As shown in FIG. 2, the coil end portion has a curved shape in which the coil conductor 5 serving as the conductor portion of the stator coil 3 is curved. The coil conductor 5 may be, for example, a bundle of rectangular metal wires. The periphery of the coil conductor 5 is covered with a coil insulating material 6 to form ground insulation with the stator core. The coil insulating material 6 is made of mica tape, prepreg tape, and liquid resin impregnated into mica tape. Here, in this embodiment, a rectangular metal wire is used as an example of the cross-sectional shape of the coil conductor 5, but the cross-sectional shape of the coil conductor may be circular or the like.

FIG. 3 is a flowchart showing each step of the method for manufacturing a stator coil according to Embodiment 1 of the present disclosure. As shown in FIG. 3, the method for manufacturing a stator coil includes steps from step S1 to step S6. Step S1 is the first step of wrapping the mica tape 7 around the coil conductor 5. Step S2 is a second step of wrapping the prepreg tape 9 around the coil conductor 5 around which the mica tape 7 is wound. Step S3 is the third step of wrapping the heat shrink tape 8 around the outer periphery of the coil conductor 5 around which the mica tape 7 and the prepreg tape 9 are wound. Step S4 is a fourth step in which the coil conductor 5 is heated and the resin contained in the prepreg tape 9 is cured while the mica tape 7 and the prepreg tape 9 are compressed by the shrinkage force of the heat-shrinkable tape 8. Step S5 is a fifth step in which the heat shrink tape 8 is removed and the mica tape 7 is impregnated with the liquid resin 10. Step S6 is a sixth step in which the coil conductor 5 is heated and the liquid resin 10 is cured.

FIG. 4 is a cross-sectional view showing a coil conductor in the first step of the stator coil manufacturing method according to Embodiment 1 of the present disclosure. In the first step, the mica tape 7 is wound around the coil conductor 5 several times in a half-overlap manner. Here, the mica tape 7 used in the present disclosure has a structure in which mica and a reinforcing material such as a glass cloth or a resin film are bonded together using an epoxy resin or a silicone resin. When wrapping the mica tape 7 around the coil conductor 5, the mica layer of the mica tape 7 is wound around the coil conductor 5 side, but a fluidized resin layer such as glass cloth is separately provided on the mica layer side in order to improve resin impregnation. The impregnating properties of the resin may also be improved. Since the innermost layer of mica tape tends to be difficult to be impregnated with resin, it is possible to improve the impregnation property by, for example, placing glass cloth or the like on the conductor side and wrapping it around the innermost layer.

Furthermore, when winding the mica tape 7 around the coil conductor 5, it is desirable to apply tension to the mica tape 7 while winding it so as to avoid wrinkles. This is because if winding wrinkles occur, the mica may break, causing the mica to become unoriented, and the withstand voltage properties may decrease. A method for effectively suppressing winding wrinkles is to heat the coil conductor 5 and the mica tape 7 in advance to increase the flexibility of the mica tape 7 when wrapping the mica tape 7 while applying tension. , a method in which the mica tape 7 is stored after being stored in a humidified atmosphere, and the like.

FIG. 5 is a cross-sectional view showing a coil conductor in the second step of the stator coil manufacturing method according to Embodiment 1 of the present disclosure. In the second step, a prepreg tape 9 using mica as a tape base material, for example, is wrapped around the outer periphery of the coil conductor 5 around which the mica tape 7 is wound. Here, the prepreg tape 9 used in the present disclosure is a tape containing a semi-cured thermosetting resin. For example, glass cloth, mica, film, nonwoven fabric, insulating paper, cloth base material, etc. can be used as the tape base material, but since glass cloth and mica have high mechanical strength, the prepreg tape 9 of the present disclosure can be used. suitable for As in the present disclosure, when the prepreg tape 9 is used to enhance voltage resistance, it is desirable to use mica.

The prepreg tape 9 preferably has a mica mass of 30 to 100 g/m ² per m ² from the viewpoint of voltage resistance, and a thickness of 0.1 mm or more and 2 mm or less from the viewpoint of ease of wrapping. In the present disclosure, an epoxy resin, a silicone resin, a phenol resin, or a polyester resin can be used as the thermosetting resin in a semi-cured state, and in particular, the epoxy resin has excellent adhesiveness to the mica tape 7.

A thermosetting resin in a semi-cured state is cured by heating, and after curing, its elastic modulus increases and it is necessary to have insulation properties. Further, it is desirable that the curing start temperature of the thermosetting resin is higher than the shrinkage start temperature of the heat shrinkable tape 8 in the present disclosure. The curing start temperature of the thermosetting resin can be measured by DSC (differential scanning calorimetry), and can be defined as the peak starting temperature of the exothermic reaction accompanying the curing reaction. The curing initiation reaction can be controlled by the curing catalyst contained in the prepreg tape 9. When using an epoxy resin, curing catalysts include aromatic polyamines, aliphatic polyamines, imidazole derivatives, tertiary amine salts, etc. Can be used. Further, the thermosetting resin may be combined with a metal soap composed of a bond between a metal and a long-chain fatty acid to adjust the curing start time.

As with the mica tape 7, the prepreg tape 9 can be wrapped in a manner such as a method of wrapping it multiple times in the tape width direction in a half-overlap manner, a method of wrapping it in the tape width direction so as not to overlap, etc. When the prepreg tape is wound multiple times in the tape width direction in a half-overlap manner, the prepreg tape becomes two layers and becomes thicker, so that the mechanical strength increases after the prepreg tape 9 is cured. However, in the fifth step of the present disclosure, when the prepreg tapes 9 overlap in the cross-sectional direction of the coil, the overlapping part is difficult to be impregnated with the liquid resin, and if there are voids in the overlapping part, insulation defects may occur. . In order to prevent this insulation defect, it is desirable to provide a plurality of holes in advance in the prepreg tape 9 to serve as resin impregnation channels.

Furthermore, when the prepreg tape 9 is wound so as not to overlap in the tape width direction, the prepreg tape 9 becomes one layer. In this case, since the prepreg tapes 9 do not overlap, there is an advantage that the liquid resin 10 is easily impregnated. For this reason, the coil insulating material 6 does not generate voids that would cause insulation defects, and thus improves voltage resistance. The mechanical strength after the prepreg tape 9 is cured is lower than when the tape is wrapped in an overlapping manner in the width direction, but by using mica or glass cloth as the base material of the prepreg tape 9, the mechanical strength required for practical use is reduced. Mechanical strength can be imparted.

In the second step as well, it is desirable to wind the prepreg tape 9 while applying tension to prevent winding wrinkles from occurring. If the thickness of the prepreg tape is less than 0.1 mm, it will deform when tension is applied during winding, and the tape will easily break. Moreover, if the thickness of the prepreg tape 9 exceeds 0.3 mm, it becomes difficult to wrap it along the outer periphery of the mica tape 7, and winding wrinkles are likely to occur. Therefore, the thickness of the prepreg tape 9 is preferably 0.1 mm or more and 0.3 mm or less in order to make it easier to wind.

If the amount of resin contained in the prepreg tape 9 is less than 20 g, the mechanical strength of the prepreg tape 9 after curing will be low and it will be easily deformed. Furthermore, if the amount of resin exceeds 200 g, the resin of the prepreg tape 9 may flow out onto the mica tape 7 when the prepreg tape 9 is cured while generating the shrinkage force of the heat-shrinkable tape 8 in the fourth step. It hardens. Therefore, the content of the resin impregnated in the fifth step may decrease. Therefore, in order to obtain the mechanical strength of the prepreg tape 9 after curing, the amount of resin contained in the prepreg tape 9 is preferably 20 g or more and 200 g or less per 1 m ² of tape.

FIG. 6 is a cross-sectional view showing a coil conductor in the third step of the stator coil manufacturing method according to Embodiment 1 of the present disclosure. In the third step, a heat shrink tape 8 is wrapped around the outer periphery of the coil conductor 5 wrapped around the mica tape 7 and the prepreg tape 9. The heat shrink tape 8 is wound so that it can be removed before performing the fifth step. Moreover, by arranging a plate-shaped backing plate around the outer periphery of the prepreg tape 9, the surface of the prepreg tape 9 can be made smooth when the heat shrink tape 8 is wound.

As the material for the heat shrink tape 8, polyester tape or polyamide tape can be used. Furthermore, in addition to these materials, it is also possible to use a material for the heat-shrinkable tape 8 that is made of a composite material such as glass fiber to increase the strength of the tape. A heat-shrinkable tape is a tape in which a resin fixed in a stretched and oriented state shrinks in a direction that releases the orientation when heated, and in the present disclosure, the shrinkage start temperature is in the range of 50°C to 130°C. desirable. Moreover, it is preferable that the shrinkage rate of the heat-shrinkable tape 8 is 3% or more. The shrinkage start temperature can be determined by checking the presence or absence of shrinkage deformation when the heat-shrinkable tape 8 is stored at a constant temperature, and the shrinkage rate can be determined by measuring the length of the tape before and after storage.

FIG. 7 is a cross-sectional view showing a coil conductor in the fourth step of the stator coil manufacturing method according to Embodiment 1 of the present disclosure. In the fourth step, the coil conductor 5 that has been subjected to the third step is heated for the first time to harden the prepreg tape 9 while generating the shrinkage force of the heat-shrinkable tape 8. By heating the heat-shrinkable tape 8 within the shrinkage start temperature range, the heat-shrinkable tape 8 contracts, and the shrinkage force of the heat-shrinkable tape 8 compresses the mica tape 7 and the prepreg tape 9 in the direction of the coil conductor 5. . Further, due to this first heating, the curing reaction of the prepreg tape 9 progresses and mechanical strength is developed, so that the mica tape 7 is maintained in a compressed state.

Since the gap between the mica tape 7 is air, it is easily compressed by the contraction force of the heat shrink tape 8 in the fourth step. Furthermore, although a reaction force opposite to the compression direction is generated in the compressed mica tape 7, the prepreg tape 9 is compressed along the cross section of the mica tape 7 and hardened. Therefore, the prepreg tape 9 having high mechanical strength receives the reaction force, and the compressed state of the mica tape 7 is maintained.

In this way, by compressing the mica tape 7 before impregnation with the liquid resin, compression becomes easy because there is no resin between the tapes before impregnation. In addition, since the stator coil manufacturing method of the present disclosure can be applied to the coil end portions where pressure compression molding is difficult, the stator coil end portions have better voltage resistance and heat dissipation than conventional manufacturing methods. It is possible to improve performance.

FIG. 8 is a cross-sectional view showing the coil conductor in the fifth step and sixth step of the stator coil manufacturing method according to Embodiment 1 of the present disclosure. In the fifth step, the prepreg tape 9 is cured while generating the shrinkage force of the heat-shrinkable tape 8, and the liquid resin 10 is applied to the mica tape 7 in a reduced pressure atmosphere using a coil with the mica tape 7 compressed. Impregnate. After impregnating with the liquid resin 10, it is possible to pressurize with a gas such as air or nitrogen to impregnate the gap between the mica tapes 7 with the liquid resin 10, thereby suppressing the generation of voids that cause insulation defects. Since it is necessary to prevent the generation of voids, the liquid resin 10 preferably does not contain a solvent. Furthermore, as the type of resin, epoxy resin, silicone resin, unsaturated polyester resin, and alkyd resin can be used. Reactive diluents can be added to these resins since the lower the viscosity, the higher the impregnability. Reactive diluents include acrylate monomers, methacrylate monomers, styrene, vinyltoluene, diallylphthalate, monoepoxides, and the like. It is preferable that the liquid resin 10 used in the fifth step has a different curing temperature from the resin contained in the prepreg tape 9 in the second step, so it is preferable to use a different resin from the prepreg tape 9. may also be used.

In the sixth step, in the second heating, the coil impregnated with the liquid resin 10 is heated to advance the curing reaction of the liquid resin 10, the liquid resin 10 is cured, and the mica tape 7 and the coil conductor 5 are integrated. . The second heating is performed in a temperature range of 90° C. to 180° C. under normal pressure in order to thermally cure the liquid resin 10. In this manner, the stator coil according to the present embodiment can be obtained through the first to sixth steps.

As described above, the stator coil manufacturing method of the present disclosure includes the first to sixth steps. Before impregnating the mica tape 7 with the liquid resin 10, the mica tape 7 and the prepreg tape 9 are compressed with a heat shrink tape 8, and the resin contained in the prepreg tape 9 is cured and maintained in the compressed state. Since it is possible to suppress the excess liquid resin 10 from being included between the tapes 7 and the generation of voids due to leakage of the liquid resin 10, it is possible to improve the voltage resistance and heat dissipation properties of the stator coil. It is possible.

In addition, in the stator coil manufacturing method of the present disclosure, in order to compress the mica tape 7 in advance and fix the state with the prepreg tape 9 before impregnating with the liquid resin 10, The step of compressing the mica tape 7 can be omitted. In the conventional stator coil manufacturing method, the excess liquid resin contained between the mica tapes 7 is discharged from the gaps between the mica tapes, so the flow path for the liquid resin is narrow with only the gaps between the mica tapes 7, and the excess liquid resin is discharged through the gaps between the mica tapes 7. However, the stator coil manufacturing method of the present disclosure can shorten the manufacturing time of the stator coil 3.

Embodiment 2.
In the second embodiment, the same reference numerals are used for the same components as in the first embodiment of the present disclosure, and descriptions of the same or corresponding parts are omitted. Hereinafter, a stator coil according to a second embodiment will be described with reference to the drawings.

FIG. 9 is a cross-sectional view showing a coil insulating material according to Embodiment 2 of the present disclosure. The first insulating layer 11 and the second insulating layer 12 shown in FIG. 9 are made by impregnating the gap between the mica tapes 7 with liquid resin 10 and hardening it in the second heating process, and are different from those in the first embodiment. This is obtained by the stator coil manufacturing method based on the above method. As shown in FIG. 9, in the sixth step, the liquid resin 10 is heated and cured to become a cured product 15 of liquid resin. Further, the prepreg tape 9 includes a resin 13 and mica 14. The resin contained in the second insulating layer 12 is one in which mica 14 is hardened by heating before impregnating the coil, and hardened again when the liquid resin 10 forming the first insulating layer 11 is heated.

In the stator coil according to Embodiment 2 of the present disclosure, the second insulating layer 12 on the outermost surface of the stator coil 3 is composed of mica 14 wound so as not to overlap in the tape width direction, and It is characterized by high smoothness. Similar to the first insulating layer 11 of the present invention, the outermost surface of a typical coil is composed of mica tape 7 wrapped so as to overlap in the tape width direction, and the thickness of each tape layer is stepped. There is. When the surface of the stator coil 3 is smooth like the stator coil of the present disclosure, when the stator coil 3 is inserted into the slot 2, it can be placed in close contact with the surface of the slot 2, thereby improving heat dissipation. be able to. In this case, a semiconductive sheet or a nonlinear resistance material may be placed on the surface of the slot 2 to alleviate the electric field between the coil and the iron core.

If the mica tape 7 of the first insulating layer 11 is wrapped only around the outermost circumference so as not to overlap in the tape width direction and impregnated with the liquid resin 10 without using the prepreg tape 9, the liquid resin 10 will leak out during heating and curing. , voids that become insulation defects occur on the surface of the stator coil 3. In addition, if a film tape or the like is wrapped to prevent this, the heat dissipation will decrease depending on the thickness of the film tape, and the adhesion at the interface between the film tape and the mica tape 7 will be poor, causing the body of the device to Peeling failure occurs.

When the prepreg tape 9 is wrapped around the second insulating layer 12 of the present disclosure so as not to overlap in the tape width direction, the resin 13 is uniformly melted, so the liquid resin 10 will not leak out during heating and curing. In order for the resin 13 to melt uniformly, the resin 13 must have a curing reactivity different from that of the liquid resin 10 used for the first insulating layer 11, a higher curing reactivity than the liquid resin 10, and a temperature that is half-melted at room temperature. It is desirable that the resin is in a hardened state and that the curing reaction proceeds while melting at a lower temperature than the liquid resin 10 during heating. Further, the liquid resin 10 used for the first insulating layer 11 is a liquid at room temperature, and is cured after being impregnated into the mica tape 7. In order to suppress leakage of the liquid resin 10, it is desirable that the resin 13 is cured first during heating, so the first insulating layer 11 and the second insulating layer 12 of the present disclosure have resin compositions with different curing start temperatures. is suitable. Examples of these resins include epoxy resins from the viewpoint of adhesive properties.

Embodiment 3.
In Embodiment 3, a stator coil will be described using the same reference numerals for the same components as in Embodiment 1 of the present disclosure.

FIG. 10 is a cross-sectional view along the rotation axis of a rotating machine according to Embodiment 3 of the present disclosure. The rotating machine 16 of the present disclosure includes a stator core 17, a tightening member 18, a retaining ring 19, a frame 20, an intermediate member 21, and an elastic support member 22. The tightening members 18 are a plurality of members that are provided on the outer periphery of the stator core 17 at predetermined intervals in the circumferential direction and tighten the stator core 17 in the axial direction. The retaining rings 19 are provided on the outer periphery of the stator core 17 at predetermined intervals in the axial direction, and tighten the stator core 17 from the outer periphery of the core tightening member 18 in the rotation axis direction. A cylindrical frame 20, an intermediate frame member 21, and an elastic support member 22 are provided around the stator core 17 in which the retaining ring 19 is disposed. The middle frame members 21 are a plurality of ring-shaped members that protrude in the axial direction from the inner surface of the frame 20 at predetermined intervals in the axial direction. The elastic support member 22 is fixed to the adjacent middle frame members 21 and consists of a spring plate fixed to the retaining ring 19 at its axial center. FIG. 10 shows an example in which four retaining rings 19 are arranged on the outer periphery of the stator core 17, and five middle frame members 21 are provided on the inner surface of the frame 20 at predetermined intervals in the axial direction.

FIG. 11 is a sectional view showing a rotating machine according to Embodiment 3 of the present disclosure. As shown in FIG. 11, the rotating machine 16 includes a rotor (not shown), a stator 17 that is arranged coaxially with the rotor and has slots 2 on the surface facing the rotor, and This is a rotating machine in which a stator coil 3 is housed in a slot 2. Further, FIG. 11 is a cross-sectional view taken along the dashed line A-A' in FIG. FIG. 11 shows an example in which eight core tightening members 18 are provided on the outer periphery of the stator 17 in a rotating machine 16, and four elastic support members 22 are arranged between the retaining ring 19 and the middle frame member 21. It shows.

The rotating machine shown here constitutes, for example, the armature of a turbine generator. A predetermined number of slots formed in the axial direction are provided in the circumferential direction on the inner peripheral portion of the stator core 17, and the stator coil 3 is disposed within the slot. Since the rotary machine including the stator coil 3 according to

Embodiments

1 and 2 of the present disclosure can have a high withstand voltage of the stator coil, it is possible to achieve higher output and further miniaturization. When the configuration of the rotating machine of the present disclosure is applied to a turbine generator, increasing the voltage resistance of the coil insulating material 6 makes it possible to reduce the thickness of the insulating material used in the rotating machine, reducing heat generation in the coil conductor 5. Therefore, the output efficiency of the generator can be improved.

Note that the configuration shown in the above embodiments shows an example of the contents of the present disclosure, and can be combined with other known techniques. Furthermore, it is also possible to omit or change a part of the configuration without departing from the gist of the present disclosure.

1 Stator core, 2 Slot, 3 Stator coil, 4 Wedge, 5 Coil conductor, 6 Coil insulation material, 7 Mica tape, 8 Heat shrink tape, 9 Prepreg tape, 10 Liquid resin, 11 First insulating layer, 12 second insulating layer, 13 resin, 14 mica, 15 cured liquid resin, 16 rotating machine, 17 stator, 18 core tightening member, 19 retaining ring, 20 frame, 21 middle frame member, 22 elastic support member

Claims

A first step of wrapping a mica tape around a coil conductor in which the conductor is wound into a coil shape;
a second step of wrapping a prepreg tape around the coil conductor wrapped with the mica tape;
a third step of wrapping a heat shrink tape around the outer periphery of the coil conductor around which the mica tape and the prepreg tape are wound;
a fourth step of heating the coil conductor and curing the resin contained in the prepreg tape while compressing the mica tape and the prepreg tape with the shrinkage force of the heat-shrinkable tape;
a fifth step of removing the heat shrink tape and impregnating the mica tape with a liquid resin;
a sixth step of heating the coil conductor and curing the liquid resin;
A method for manufacturing a stator coil comprising:
2. The method of manufacturing a stator coil according to claim 1, wherein the second step is a step of winding the prepreg tape in the width direction of the tape without overlapping.
3. The method of manufacturing a stator coil according to claim 1, wherein the second step is a step of wrapping the prepreg tape around a coil end portion of the coil conductor.
The method for manufacturing a stator coil according to any one of claims 1 to 3, wherein the prepreg tape has a thickness of 0.1 mm or more and 0.3 mm or less.
The method for manufacturing a stator coil according to any one of claims 1 to 4, wherein the amount of resin contained in the prepreg tape is 20 g or more and 200 g or less per m 2 of tape.
a coil conductor;
a first insulating layer containing mica tape and a cured liquid resin around the outer periphery of the coil conductor;
a second insulating layer in which a prepreg tape is wound around the outer periphery of the first insulating layer without overlapping each other, and a resin contained in the prepreg tape is cured;
A stator coil comprising:
The stator coil according to claim 6, wherein the first insulating layer and the second insulating layer are made of resins having different compositions.
rotor and
a stator core disposed coaxially with the rotor and having a slot provided on a surface facing the rotor;
A rotating machine in which the stator coil according to claim 6 or 7 is housed in the slot of the stator core.