JP2023092752A - Prepreg mica tape, rotary electric machine, and manufacturing method for rotary electric machine - Google Patents

Abstract

To provide a prepreg mica tape, a rotary electric machine, and a manufacturing method for the rotary electric machine that suppress the generation of electrical discharge during charging by suppressing the generation of a gap between a coil and an iron core slot, and by suppressing the generation of bubbles in the process of heating and curing a thermosetting resin in the prepreg mica tape.SOLUTION: A prepreg mica tape 35 has a configuration in which a substrate 33, mica paper 31, and a varnish layer 34 in a semi-cured state are stacked on top of each other, and an antifoaming agent is added to the varnish layer 34.SELECTED DRAWING: Figure 3B

Description

TECHNICAL FIELD The present invention relates to a prepreg mica tape, a rotating electric machine, and a method for manufacturing a rotating electric machine.

Thermosetting resins with high electrical insulation (insulation reliability) and excellent mechanical properties are widely used to insulate and fix coils used in electrical equipment (generators, motors, transformers, etc.). be.

A mica insulation system with high insulation reliability is used for insulation of high-voltage rotating electric machines such as generators and electric motors. In particular, this mica insulation system is used in stator windings that constitute rotating electric machines, and there are, for example, the following manufacturing methods (three conventional methods).

(1) Integrated injection method (total impregnation method)
First, a dry mica tape is wound around a conductor covered with insulation to manufacture a single coil. This coil unit is then assembled into the core slot along with the slot liner and the in-slot insulation, the wedges are installed, and they are secured to the core slot to produce the stator windings. Next, the stator winding is immersed in an insulating resin (varnish), and the varnish is vacuum-impregnated (vacuum pressure injection) into the stator winding. Finally, the stator windings are heated to thermally cure the varnish and produce the stator windings.

(2) Single injection method When very large stator windings are used, such as high-voltage, large-capacity generators used in power plants and substations, fixed Vacuum-impregnating the entire child winding with varnish is practically difficult in terms of equipment. For this reason, in many cases, the stator winding is manufactured by incorporating the single coil into the core slot after the varnish has hardened.

That is, first, a dry mica tape is wound around a conductor covered with insulation to manufacture a single coil. Next, this coil unit is immersed in varnish, and the varnish is vacuum-impregnated (vacuum pressure injection) into this coil unit. Next, this coil unit is heated to thermally harden the varnish to produce a coil unit. Finally, the coil unit is assembled into the core slot along with the slot liner and in-slot insulation, the wedges are installed and they are secured to the core slot to produce the stator windings.

(3) Prepreg method In this method, a mica tape is pre-impregnated with varnish and the varnish is semi-cured to use a prepreg mica tape. First, a prepreg mica tape is wound around a conductor covered with insulation to manufacture a single coil. Next, this coil unit is heated and pressurized to thermally harden the varnish to produce a coil unit. Finally, the coil unit is assembled into the core slot along with the slot liner and in-slot insulation, the wedges are installed and they are secured to the core slot to produce the stator windings. In the prepreg method, vacuum impregnation (vacuum pressure injection) of varnish is not required.

The integrated injection method is suitable for medium-voltage and medium-capacity medium-sized electric motors (e.g., vehicle electric motors and industrial electric motors), while the single injection method and prepreg method are suitable for high-voltage, high-capacity large generators (e.g., , large power generators), etc.

Japanese Patent Laid-Open Publication No. 2002-300000 describes a prepreg technique suitable for large-sized power generators. Patent Document 1 discloses a reinforcing base material 22, a low dielectric constant heat conductive layer 23 formed on one surface of the reinforcing base material 22, and a mica layer 21 formed on the other surface of the reinforcing base material 22. and According to Patent Document 1, it is possible to provide an electrical insulating member, a stator coil for a rotating electrical machine, and a rotating electrical machine that can exhibit excellent electrical insulation properties and high thermal conductivity even in a high-humidity environment. .

Further, in Patent Document 2, a conductor covered with an insulating coating is wound to form a winding, the winding is accommodated in a molded body, the molded body is evacuated, and an epoxy resin is injected to form the coil. In the coil for an induction appliance, a coil for an induction appliance is disclosed in which a surfactant is added to the epoxy resin. It is said that the epoxy resin can easily permeate into the minute space and the generation of voids can be prevented.

JP 2010-158113 A JP-A-9-246066

In the manufacture of a rotating electric machine, if there is a gap between the stator coil and the stator slot after the stator coil is accommodated in the stator slot, there is a risk that discharge will occur in this gap when an electric current is applied. In the integral injection method described above, the varnish is impregnated in a vacuum with the stator coils installed in the stator slots. Since the stator coils are installed in the stator slots after forming a varnish layer on the stator coils, a gap may occur between the stator coils and the stator slots. The aforementioned Patent Literature 1 does not describe reducing the gap between the stator coils and the stator slots.

Further, Patent Document 2 describes that adding a surfactant to an epoxy resin makes it easier for the epoxy resin to permeate into microspaces and prevents the generation of voids. No mention is made of adding a surfactant to the thermosetting resin therein. Furthermore, in the process of injecting the epoxy resin into the molded body, heating, and curing, there is a risk that new air bubbles will be generated or that the generated air bubbles will remain, but there is no description of measures to deal with such problems. .

Therefore, in view of the above circumstances, the present invention suppresses the generation of a gap between the coil and the core slot, and suppresses the generation of air bubbles in the process of heating and curing the thermosetting resin in the prepreg mica tape. The present invention provides a prepreg mica tape, a rotating electric machine, and a method for manufacturing a rotating electric machine, which suppress the occurrence of discharge during charging.

One aspect of the present invention for achieving the above object has a configuration in which a base material, mica paper, and a semi-cured varnish layer are laminated, and an antifoaming agent is added to the varnish layer. A prepreg mica tape characterized by

Another aspect of the present invention for achieving the above object is a rotating electric machine having a stator winding having a stator core in which core slots are formed, and a single coil having a conductor formed with a mica insulating layer. The mica insulating layer has a configuration in which a base material, mica paper, and a semi-cured varnish layer are laminated, and is composed of a prepreg mica tape in which an antifoaming agent is added to the varnish layer. A rotating electrical machine characterized by:

Another aspect of the present invention for achieving the above object is a rotating electric machine comprising a stator winding having a stator core having core slots and a coil unit having a conductor formed with a mica insulating layer. A manufacturing method of , wherein a mica tape obtained by bonding a base material and mica paper with an adhesive is impregnated with a varnish to which an antifoaming agent is added, and the varnish to which an antifoaming agent is added is semi-cured, A varnish layer to which a semi-cured antifoaming agent is added is held on the outermost surface of the mica tape to form a varnish layer to produce a prepreg mica tape, the prepreg mica tape is wound around a conductor, and a mica insulating layer is formed. is formed, a coil unit is manufactured, the coil unit is inserted into the core slot together with a slot liner that protects the coil unit and an in-slot insulating material that insulates the coil unit, and the coil unit, the slot liner, and the in-slot insulating material are fixed in core slots to manufacture intermediate stator windings.

According to the present invention, it is possible to suppress the formation of a gap between the coil and the core slot, suppress the formation of air bubbles in the process of heating and curing the thermosetting resin in the prepreg mica tape, and Provided are a prepreg mica tape, a rotating electric machine, and a method for manufacturing a rotating electric machine, which suppress the occurrence of electric discharge.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

FIG. 2 is a cross-sectional view schematically showing an example of the configuration of the stator windings of the rotary electric machine of the present invention; FIG. 2 is a cross-sectional view schematically showing an example of the coil unit 12 of FIG. 1; Cross-sectional schematic diagram of conventional prepreg mica tape Schematic cross-sectional view showing a first example of the prepreg mica tape of the present invention Schematic cross-sectional view showing a second example of the prepreg mica tape of the present invention Schematic cross-sectional view showing a third example of the prepreg mica tape of the present invention 2 is a perspective view schematically showing the configuration of the stator winding 10 of FIG. 1; FIG. Cross-sectional view schematically showing a coil using conventional prepreg mica tape A cross-sectional view schematically showing a coil using the prepreg mica tape of the present invention. Cross-sectional view schematically showing the outermost surface of the prepreg mica tape of the present invention (in the case of a single layer) Cross-sectional view schematically showing the outermost surface of the prepreg mica tape of the present invention (in the case of multiple layers) A graph schematically showing the temperature profile of the varnish flowing and curing process by heating the stator winding 10 of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. In addition, substantially the same or similar configurations are denoted by the same reference numerals, and the description may be omitted if the description is redundant.

[Prepreg mica tape]
FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a stator winding of a rotary electric machine according to the present invention. As shown in FIG. 1 , the stator winding 10 has a stator core 11 having a plurality of core slots 13 and coil units 12 accommodated (inserted) in the core slots 13 . Although not shown, the stator winding 10 has a single coil 12 wound between core slots 13 .

The rotating electric machine has rotor coils (not shown) inside the stator windings 10 described above. In this way, the stator winding 10 and the rotor coil are used to constitute a rotating electric machine such as a generator or an electric motor. When the rotating electrical machine is a generator, the rotor coils can be rotated by external power to extract current from the stator windings 10 . Further, when the rotating electric machine is an electric motor, it is possible to supply power to the outside by supplying current to the stator winding 10 to rotate the rotor coil. That is, the rotor coils installed inside the stator winding 10 are driven (rotated) to function as a rotating electric machine.

Next, the configuration of the coil unit 12 will be described more specifically. FIG. 2 is a cross-sectional view schematically showing an example of the coil unit 12 of FIG. In addition, (A) shows the overall structure of the coil unit 12, and (B) shows a partial enlargement of the coil unit 12. As shown in FIG. The coil unit 12 described in this embodiment is formed by being tied (twisted) at both ends of the coil unit 12, as shown in FIG. 2(A). That is, one end (for example, the left side of the paper surface in FIG. 2) is formed by being tied (twisted) and is present outside the stator winding 10 . The other end (for example, the right side of the paper surface in FIG. 2) is formed by tying (twisting) the coil unit 12 and exists outside the stator winding 10 .

The conductor 21 is exposed at either end of the coil unit 12 , and the conductor 21 is exposed outside the stator winding 10 . This end is connected to an external power supply or storage battery.

In addition, the coil unit 12 is inserted into the core slot 13 at its vertically elongated portion in FIG. 2(A). That is, the coil unit 12 shown in FIG. 2(A) shows the state of the stator winding 10 viewed from the radial direction.

In addition, as shown in FIG. 2B, the coil unit 12 has a conductor 21 (for example, a metal wire) having a rectangular cross section and a mica insulating layer 22 covering the conductor 21 .

The conductors 21 and 21 are insulated from each other by, for example, a resin material. A plurality of conductors 21 insulated from each other (coated with insulation) are formed inside the mica insulating layer 22 . A prepreg mica tape is used for the mica insulating layer 22 .

That is, the mica insulating layer 22 is formed from a prepreg mica tape. The coil unit 12 is formed of a conductor 21 covered with insulation and a mica insulation layer 22, and the coil unit 12 is formed by winding a prepreg mica tape (mica insulation layer 22) around the conductor 21 covered with insulation. .

Next, the details of the structure of the prepreg mica tape will be described. FIG. 3A is a schematic cross-sectional view of a conventional prepreg mica tape, and FIGS. 3B to 3D are schematic cross-sectional views showing first to third examples of the prepreg mica tape of the present invention, respectively. Both the conventional prepreg mica tape 30 and the prepreg mica tapes 35 to 37 of this embodiment have a tape shape and a shape that can be easily wound around the conductor 21 .

As shown in FIG. 3A, the conventional prepreg mica tape 30 has a structure in which a base material 33 and mica paper 31 are adhered (bonded and fixed) by an adhesive layer 32 . Since the mica paper 31 is usually brittle, the mica paper 31 is adhered to the base material 33 for reinforcement. Note that mica is so-called "mica". The form of mica is not particularly limited. Laminated mica is widely used as mica for the mica paper 31 . Note that flake mica may be used as the mica depending on the application, the method of manufacturing the insulating material, and the like. In addition, the particle size of the mica constituting the laminated mica and the flake mica is also set according to the application, the manufacturing method of the insulating material, and the like.

The base material 33 reinforces the fragile mica paper 31 . That is, the base material 33 is used as a reinforcing base material for the mica paper 31 . For the base material 33, for example, an inorganic base material such as glass cloth, or an organic base material such as polyethylene terephthalate film, polyimide film, cellulose paper, aramid paper, or non-woven fabric is used depending on heat resistance and insulation properties. Also, as for the shape thereof, for example, a sheet shape, a tape shape, or the like is used.

The adhesive 32 bonds the mica paper 31 and the base material 33 together. Therefore, the adhesive 32 contains a material (component) capable of bonding the mica paper 31 and the base material 33 together.

Then, the conventional prepreg mica tape 30 is produced by impregnating the mica paper 31 with varnish and semi-curing the impregnated varnish.

The adhesive 32 may be varnish with which the mica paper 31 is impregnated. In other words, the mica paper 31 and the base material 33 may be adhered by semi-curing the impregnated varnish.

The prepreg mica tapes 35 , 36 , 37 of this embodiment form (hold) a semi-cured varnish layer 34 on the outermost surface of the conventional prepreg mica tape 30 . This varnish layer 34 contains an antifoaming agent. The varnish layer 34 may be formed on the surface of the mica paper 31 (FIG. 3A), may be formed on the surface of the substrate 33 (FIG. 3B), or may be formed on the surfaces of both the mica paper 31 and the substrate 33. may be formed (Fig. 3C). The semi-cured varnish layer 34 preferably contains a filler.

As the base material 33, when using an inorganic base material such as glass cloth, or an organic base material such as polyethylene terephthalate film, polyimide film, cellulose paper, aramid paper, non-woven fabric, etc., the surface of the base material 33 is half It is preferable to form a cured varnish and fill the voids in the substrate.

Thermosetting resins such as epoxy resins, unsaturated polyester resins and silicone resins are used as semi-cured varnishes. Among these, the curing reaction of the silicone resin is roughly divided into a condensation reaction, such as dehydration condensation, which produces a low-molecular-weight compound, and a hydrosilylation reaction (addition reaction). Particularly in the case of a condensation reaction, if a low-molecular-weight compound remains in the insulating layer, voids may be formed, resulting in insulation defects. Moreover, shrinkage during curing may increase due to the release of low-molecular-weight compounds from the insulating layer. Therefore, when a silicone resin is used as the varnish, it is preferable to use an addition-curable varnish that cures through a hydrosilylation reaction.

In the prepreg mica tape of the present invention, an antifoaming agent is added to this semi-cured varnish. For example, when the surfactant described in Patent Document 2 is added to the varnish, it exerts a remarkable effect on surface or interfacial phenomena. By adding a surfactant to the varnish, the surface tension of the varnish can be greatly reduced, and the wettability and permeability of the varnish can be improved. At the same time, however, adding a surfactant that improves the wettability and permeability of the varnish will increase the foamability of the varnish and facilitate the stabilization of the generated bubbles. For this reason, while the varnish tends to penetrate narrow gaps, there is a concern that air bubbles are generated and the generated air bubbles tend to remain. In contrast, the antifoaming agent added in the present invention does not significantly lower the surface tension of the varnish, but destroys or suppresses the formation of air bubbles.

For example, when an epoxy resin is used as the varnish, one of the conditions for the antifoaming agent to be added, which destroys air bubbles, or suppresses the formation of air bubbles, is that the surface tension is lower than that of the varnish. As such an antifoaming agent, silicone, silicone to which silica is added, or the like can be preferably used. Polyoxyethylene/polyoxypropylene block copolymers, derivatives of fluorocarbons, tributyl phosphate, etc., may also be used as long as they have a lower surface tension than the varnish used and can be uniformly dissolved or dispersed in this varnish. can also be used. The same applies when unsaturated polyester, imide ester, or the like is used as the varnish.

When a silicone resin is used as the varnish, the silicone resin itself exhibits antifoaming properties, and the surface tension of the silicone resin itself is very low. For this reason, compared with thermosetting resins having a relatively high surface tension, such as epoxy resins and unsaturated polyester resins, the effect obtained by adding an antifoaming agent is small. However, when using a resin having a higher surface tension than a normal silicone resin, such as a silicone resin modified with an epoxy resin, the effect of adding an antifoaming agent increases.

These antifoaming agents may be added in small amounts, usually about 1% by mass. Moreover, since it is not an ionic compound, it is possible to suppress the generation of air bubbles without impairing the insulating performance of the finally formed insulating layer.

Thus, the prepreg mica tapes 35, 36, 37 of this embodiment are produced by the following steps.

(1) First, the base material 33 and the mica paper 31 are adhered with the adhesive 32, and the varnish is applied to the mica tape (the base material 33 and the mica paper 31 fixed with the adhesive 32) to be bonded and fixed. The impregnated varnish (impregnated varnish) is brought to a semi-cured state.

(2) Then, a semi-cured varnish (additional varnish) 34 containing a filler is formed on the outermost surface of this mica tape.

That is, the prepreg mica tape of the present invention includes a mica tape impregnated with a semi-cured varnish (impregnated varnish), a semi-cured varnish (additional varnish) held on the outermost surface of the mica tape and containing a filler, have

As the filler contained in the additional varnish, inorganic particles used for insulating materials such as silica, alumina, and boron nitride are preferable. By adjusting the type, shape, particle size, and content of this filler, the viscosity of the additional varnish can be adjusted.

By adjusting the type, shape, particle size, and content of this filler, the viscosity of the additional varnish during heating can be lowered, that is, the fluidity of the additional varnish can be increased, and the prepreg mica can be Additional varnish can be facilitated to flow from the tape.

In order to maintain the tape shape of the prepreg mica tape of the present invention, the impregnated varnish and the additional varnish are brought to a semi-cured state, that is, B-stage so that they do not flow before heating.

On the other hand, when the prepreg mica tape is wound around the conductor 21 covered with insulation, the hardening degrees of the impregnating varnish and the additional varnish are adjusted in order to give the prepreg mica tape the necessary flexibility. The viscosities (fluidity) of the impregnating varnish and the additional varnish during heating differ depending on the degree of curing of the impregnating varnish and the additional varnish.

The impregnating varnish and the additional varnish come to exude (flow or flow out) in the initial stage of the flow and curing process of the varnish by heating.

The fluidity of the impregnated varnish and the additional varnish, that is, the viscosity at the time of heating due to the difference in the degree of hardening differs depending on the size and shape of the coil unit 12 and the core slot 13, and therefore is adjusted as appropriate. The amount of the impregnated varnish and additional varnish and the degree of semi-hardened state are adjusted according to the size and shape of the coil unit 12 and the core slot 13 . Furthermore, the temperature profile of the varnish flowing and curing process by heating the stator winding 10 is adjusted.

Further, the degree of hardening of the impregnated varnish and the degree of hardening of the additional varnish may be the same or different. For example, the degree of cure of the additional varnish is less than the degree of cure of the impregnating varnish. This makes the viscosity of the additional varnish lower than that of the impregnated varnish when heated, that is, the fluidity of the additional varnish higher than that of the impregnated varnish, making it easier to flow the additional varnish from the prepreg mica tape. can do.

Thus, the prepreg mica tape in this embodiment consists of a mica tape in which the base material 33 and the mica paper 31 are adhered with the adhesive 32, and a semi-cured varnish 34 held on the outermost surface of the mica tape. and have The semi-cured varnish 34 preferably contains a filler. The mica paper 31 or the base material 33 and the mica paper 31 are preferably impregnated with semi-cured varnish. That is, of the base material 33 and the mica paper 31, at least the mica paper 31 is preferably impregnated with semi-cured varnish.

In the method of manufacturing the prepreg mica tape in this embodiment, the mica tape obtained by bonding the base material 33 and the mica paper 31 with the adhesive 32 is impregnated with varnish, and after the varnish is semi-cured, the mica tape is formed. A semi-cured varnish 34 is held on the outermost surface.

[Rotating electric machine and manufacturing method of the rotating electric machine]
Next, a rotating electric machine using the prepreg mica tape of the present invention described above and a manufacturing method thereof will be described. FIG. 4 is a perspective view schematically showing the configuration of the stator winding 10 of FIG. 1. As shown in FIG. As shown in FIG. 4 , the stator winding 10 has a stator core 11 and coil units 12 . The stator winding 10 has three types of insulation: (a) phase-to-phase insulation, (b) ground insulation, and (c) winding turn-to-turn insulation.

The stator core 11 has core slots 13, which are rectangular grooves extending in the axial direction (laminating direction), formed at regular intervals on the outer circumference of a cylindrical laminated steel plate in which circular steel plates are laminated.

FIG. 5A is a cross-sectional view schematically showing a coil using a conventional prepreg mica tape, and FIG. 5B is a cross-sectional view schematically showing a coil using the prepreg mica tape of the present invention. 5A and 5B are views in plane H of FIG.

The core slot 13 has a position where the two coil units 12 are sandwiched between the two stacked coil units 12 and groove sidewalls on the sides of the two coil units 12 (in the circumferential direction of the stator winding 10). and three in-slot insulating materials 43 installed so as to sandwich the two coil units 12 vertically (in the radial direction of the stator winding 10). Furthermore, a wedge 41 is installed on the in-slot insulating material 43 (in the radial direction of the stator winding 10).

That is, in the core slot 13 into which the slot liner 42 is inserted, the two coil units 12 are sandwiched between the three in-slot insulating materials 43 .

The wedge 41 fixes the coil unit 12 , the in-slot insulating material 43 , and the slot liner 42 to the core slot 13 . A wedge 41 is installed in the core slot 13 in a wedge shape. That is, after the coil unit 12, the slot liner 42, and the in-slot insulating material 43 are inserted into the core slot 13, the wedge 41 moves the coil unit 12, the slot liner 42, and the in-slot insulating material 43 into the core slot 13. Fixed.

Thus, the coil unit 12 is inserted into the core slot 13 together with the slot liner 42 and the slot insulating material 43, and the coil unit 12 is fixed by the wedge 41 together with the slot liner 42 and the slot insulating material 43. .

The slot liner 42 reinforces insulation between the conductor 21 (coil unit 12) and the stator core 11 and protects the mica insulating layer 22 (coil unit 12). For the slot liner 42, an organic base material such as polyethylene terephthalate film, polyimide film, cellulose paper, aramid paper, or non-woven fabric is used.

The in-slot insulating material 43 provides insulation between the conductor 21 (the single coil 12) and the conductor 21 (the single coil 12), insulation between the conductor 21 (the single coil 12) and the stator core 11, and insulation between the conductor 21 (the single coil 12 ) and the wedge 41 are reinforced. A laminated composite material of glass cloth and resin is used for the in-slot insulating material 43 .

The wedge 41 fixes the coil unit 12 , the slot liner 42 and the in-slot insulating material 43 to the core slot 13 . For the wedge 41, a laminated composite material of glass cloth and resin is used.

When the conventional prepreg mica tape 30 is used, a gap 44 is formed between the two coil units 12 and the three in-slot insulating materials 43 inserted into the core slot 13 and the inner wall (groove side wall) of the core slot 13. may be formed. In other words, a gap 44 may be formed between the mica insulating layer 22 on the surface of the conductor 21 and the core slot 13 . If the gap 44 is formed in this way, there is a risk that discharge will occur in this gap 44 during charging.

FIG. 5B is a cross-sectional configuration when using the prepreg mica tapes (35, 36, 37) of this embodiment on the plane H of FIG. It is an explanatory view explaining.

When using the prepreg mica tape of the present invention, as shown in FIG. The gap 44 that is formed is smaller. This is because the varnish exuded from the mica insulating layer 22 (the prepreg mica tape of the present invention) in this embodiment coats the surface of the mica insulating layer 22 by the flow and curing process of the varnish, which will be described later. to fill the That is, the varnish 45 (varnish 45 filling the gap 44 ) is formed in the gap 44 .

In addition, it is preferable that the varnish 45 completely fills the gap 44 . This makes it possible to completely suppress the discharge occurring in the gap 44 during charging. However, by making the gap 44 smaller without completely filling the gap 44 with the varnish 45, the discharge generated in the gap 44 during charging can be suppressed.

In the above-described three conventional methods, a corona prevention layer (d) or an electric field relaxation layer (e) may be provided in the stator winding 10 in order to suppress the generation of discharge in the gap 44 ( See Figure 4). In particular, in a high-voltage and high-capacity generator such as a large power generator, the stator winding 10 is provided with a corona prevention layer (d) and an electric field relaxation layer (e).

On the other hand, the rotating electrical machine described in this embodiment has a stator winding 10 and a rotor coil, and the stator winding 10 is formed with core slots 13, in contrast to these three conventional systems. It has a stator core 11 and a coil unit 12 having an insulation-coated conductor 21 and a special mica insulation layer 22 (coil unit 12 having a mica insulation layer 22 formed on the insulation-coated conductor 21). That is, the rotating electric machine described in this embodiment has a stator core 11 in which core slots 13 are formed, and a stator winding having a single coil 12 in which a special mica insulating layer 22 is formed on a conductor 21 coated with insulation. It has line 10 .

This special mica insulating layer 22 is held on the mica tape impregnated with the semi-cured varnish (impregnated varnish) and the outermost surface of the mica tape. , a semi-cured varnish containing a filler (additional varnish), and a prepreg mica tape.

That is, the coil unit 12 has a mica insulating layer 22 with an impregnating varnish and an additional varnish applied to an insulating coated conductor 21 .

Further, the stator winding 10 is inserted into the core slot 13 together with the coil unit 12, and includes a slot liner 42 that protects the coil unit 12, an in-slot insulating material 43 that insulates the coil unit 12, a coil unit 12, and an inner slot. a wedge 41 securing the slot liner 42 to the core slot 13;

A gap 44 formed by the coil unit 12, the slot liner 42, and the in-slot insulating material 43 is impregnated into the mica insulating layer 22 and held in the gap 44 formed between the mica insulating layer 22 and the core slot 13. and forms a varnish exuded from the mica insulating layer 22 .

That is, by heating the stator winding 10, the impregnating varnish and the additional varnish seep out from the mica insulating layer 22, and the gaps 44 formed between the mica insulating layer 22 and the core slots 13 are filled with these varnishes. , the stator winding 10 is produced. This suppresses the occurrence of discharge in the gap 44 during charging.

Next, a method for manufacturing a rotating electric machine, particularly a method for manufacturing the stator winding 10, using the prepreg mica tapes (35, 36, 37) of this embodiment will be described.

In other words, the manufacturing method of the rotating electric machine described in this embodiment particularly includes the stator core 11 having the core slot 13 formed therein and the coil unit 12 having the conductor 21 formed with the mica insulating layer 22. This is a method for manufacturing the wire 10, and includes STEP 1 to the following.

STEP 1: A prepreg mica tape having an impregnating varnish (semi-cured state) and an additional varnish (semi-cured state) is wound around a conductor 21 covered with insulation to form a mica insulation layer 22 to produce a coil unit 12 .

That is, in STEP 1, the mica tape obtained by bonding the base material 33 and the mica paper 31 with the adhesive 32 is impregnated with varnish, and the varnish is semi-cured. The cured varnish is held, the prepreg mica tape of the present invention is produced, the prepreg mica tape is wound around the conductor 21, the mica insulating layer 22 is formed, and the coil unit 12 is manufactured.

STEP 2: Together with the coil unit 12 manufactured in STEP 1, the slot liner 42 and the in-slot insulating material 43 are inserted into the core slot 13, and then the wedge 41 is installed. A coil unit 12, a slot liner 42, and an in-slot insulating material 43 are fixed by a wedge 41 to manufacture the intermediate stage stator winding 10 (the stator winding 10 before heating).

That is, in STEP 2, the coil unit 12 is inserted into the core slot 13 together with the slot liner 42 that protects the coil unit 12 and the in-slot insulating material 43 that insulates the coil unit 12. Insulation 43 is secured in core slot 13 by wedge 41 to produce intermediate stage stator winding 10 .

STEP 3: After that, by heating the intermediate stage stator winding 10 manufactured in STEP 2, the impregnating varnish and the additional varnish of the mica insulating layer 22 are made to flow.

Then, the varnish impregnated and held in the mica insulating layer 22 is injected (the varnish flows) into the gap 44 formed between the mica insulating layer 22 and the core slot 13 , and the varnish 45 fills the gap 44 . A fill varnish 45 is formed in the gap 44 . The varnish 45 filled in the gap 44 is then cured.

That is, in STEP 3, the stator winding 10 in the intermediate stage is heated to flow the varnish impregnated and held in the mica insulating layer 22, thereby forming the coil unit 12, the slot liner 42, and the in-slot insulating material 43. , forming a fluidized varnish that is impregnated and held in the mica insulating layer 22 in the gap 44 formed between the mica insulating layer 22 and the core slot 13, is cured, and the stator winding 10 ( A heated stator winding 10 and a final stage stator winding 10) are manufactured.

In this way, when the prepreg mica tape of the present invention is used to manufacture the stator winding 10, the prepreg mica tape is wound around the conductor 21 coated with insulation to form the mica insulating layer 22, and the coil The single unit 12 is manufactured, the coil unit 12, the slot liner 42, and the in-slot insulating material 43 are inserted into the core slot 13, and the coil unit 12, the slot liner 42, and the in-slot insulating material 43 are fixed by the wedge 41 and fixed. A child winding 10 is manufactured.

Then, the stator winding 10 is heated based on the varnish flowing and curing process, and the impregnated varnish and the additional varnish are flowed and cured to manufacture the stator winding 10 . The flowing impregnating varnish and additional varnish seep out from the surface of the mica insulating layer 22 and fill the gaps 44 that existed before heating. That is, varnish 45 is formed in gap 44 .

As a result, the gap 44 becomes smaller, or the gap 44 is completely filled, and discharge that may occur in this gap 44 during charging can be suppressed.

Next, a cross section of the outermost surface of the mica insulating layer 22 formed on the conductor 21 of the coil unit 12 described in this embodiment will be schematically described.

6A and 6B are cross-sectional views schematically showing the outermost surface of the prepreg mica tape of the present invention, FIG. 6A being a single layer and FIG. 6B being a double (multiple) layer. The case of using the prepreg mica tape 35 having the varnish layer 34 as the mica tape 31 described above is shown. However, the same applies when using the prepreg mica tape 36 or the prepreg mica tape 37 .

In STEP 1, the prepreg mica tape is wound around the conductor while partially overlapping like a bandage (spiral band). Therefore, in STEP 3, when the stator winding 10 is heated, the varnish impregnated into the prepreg mica tape (impregnated varnish) and the varnish containing the filler formed on the outermost surface of the prepreg mica tape 35 (additional varnish) are From the surface and end face of the prepreg mica tape, it seeps out to the surface of the K mica tape 31 and the gap 46 between the prepreg mica tapes.

In other words, the semi-cured impregnated varnish and additional varnish whose viscosity is lowered by heating seep from the surface of the prepreg mica tape 35 to the surface of the mica insulating layer 22 in the initial stage of the flow and curing process of the varnish by heating. Along with this, as shown in FIG. 6B, the prepreg mica tape also seeps into the gap 46 between the prepreg mica tape and the prepreg mica tape 35 from the end face of the prepreg mica tape.

Thus, the impregnating varnish and the additional varnish bleed from the prepreg mica tape onto the surface of the mica insulating layer 22 and into the gaps 46 between the prepreg mica tapes and the prepreg mica tapes to bleed the surface of the mica insulating layer 22. and in the gap 46 between the prepreg mica tape and the prepreg mica tape, a thermosetting resin layer containing a filler is formed. Accordingly, it is possible to suppress discharge that may occur during charging.

In particular, as shown in FIG. 6B, when prepreg mica tapes are laminated in multiple layers, the prepreg mica tape 35 has high insulation in the lamination direction. However, gaps 46 are formed at the interface between the laminated prepreg mica tapes and the prepreg mica tapes, which may cause insulation defects.

Therefore, in this embodiment, particularly when prepreg mica tapes are laminated in multiple layers (when prepreg mica tapes are wound in multiple layers), the impregnated varnish and the additional varnish are applied from the end face of the prepreg mica tape to the prepreg mica tape. It seeps into the gap 46 between the prepreg mica tape.

Thus, according to this embodiment, a thermosetting resin layer containing a filler can be formed in the gap 46 between the prepreg mica tapes. As a result, the partial discharge resistance of the interface between the prepreg mica tape and the prepreg mica tape can be improved.

Note that the impregnated varnish and the additional varnish seep out from the end face of the prepreg mica tape 35 to the surface of the mica insulating layer 22 as well.

In addition, the prepreg mica tape of this embodiment can also be used in a method of manufacturing a rotating electric machine using the prepreg method, particularly in a method of manufacturing the stator winding 10 .

The manufacturing method of the stator winding 10 in this case has the following steps.

In STEP 1, a mica tape in which a base material 33 and a mica paper 31 are adhered with an adhesive 32 is impregnated with varnish to make the varnish a semi-cured state. varnish, prepare prepreg mica tapes 35, 36, 37, wind the prepreg mica tapes 35, 36, 37 around the conductor 21, form the mica insulating layer 22, and manufacture the coil unit 12 in the intermediate stage. do.

In STEP 2, the coil unit 12 in the intermediate stage is heated and pressurized to thermally harden the varnish, thereby manufacturing the coil unit 12 in the final stage.

In STEP 3, the coil unit 12 at the final stage is inserted into the core slot 13 together with the slot liner 42 and the in-slot insulating material 43, and the coil unit 12, the slot liner 42, and the in-slot insulating material 43 are inserted into the core slot 13. The wedges secure and produce the stator windings 10 .

As a result, the impregnated varnish and the additional varnish seep out from the end face of the prepreg mica tape 35 to the surface of the mica insulating layer 22 and the gap 46 between the prepreg mica tapes 35 and 35 .

Then, a thermosetting resin layer containing a filler can be formed in the gap 46 between the prepreg mica tapes 35 and the prepreg mica tapes 35 . Thereby, the partial discharge resistance characteristic of the interface between the prepreg mica tape 35 and the prepreg mica tape 35 can be improved.

Next, the temperature profile of the varnish flow/hardening process by heating the stator winding 10 described in this embodiment will be schematically described.

FIG. 7 is an explanatory diagram schematically illustrating the temperature profile of the varnish flowing and curing process by heating the stator winding 10 described in this embodiment.

In STEP 3, as the temperature of the semi-cured varnish rises, the viscosity of the varnish decreases and the varnish gels. When the temperature rises further, the varnish begins to harden, and finally the entire varnish hardens. That is, in the initial stage of heating, due to the temperature rise of the varnish, the viscosities of the impregnated varnish and the additional varnish of the mica insulating layer 22 decrease, and the varnish spreads over the surface of the mica insulating layer 22 and the prepreg mica tape 35 and the prepreg mica tape. 35 , and flows inside the core slot 13 .

In particular, when the stator winding 10 is heated, by rotating the stator winding 10 about its axis, the oozing varnish can flow more easily inside the core slots 13 . As a result, the oozing varnish fills the gaps 44 and gaps 46 that existed before heating. That is, the oozing varnish is formed in the gaps 44 and 46 . As a result, discharge that may occur in the gap 44 or the gap 46 during charging can be suppressed.

<At least one of the slot liner 42, the in-slot insulating material 43, and the wedge 41 holds a varnish to which a semi-cured antifoaming agent is added>
In this embodiment, the mica insulating layer 22 is impregnated with a semi-cured varnish and held therein, and at least one of the slot liner 42, the in-slot insulating material 43, and the wedge 41 is coated with a semi-cured defoaming agent. A varnish to which agents have been added may be retained.

Note that the varnish may be retained only on the slot liner 42 , the in-slot insulating material 43 only, or the wedge 41 only. The varnish to which the antifoaming agent is added is held by the slot liner 42 and the wedge 41, held by the slot liner 42 and the in-slot insulating material 43, and held by the wedge 41 and the in-slot insulating material 43. may

After the coil unit 12, the slot liner 42, the in-slot insulating material 43, and the wedge 41 are installed in the core slot 13, the stator winding 10 is heated to flow the varnish to which the antifoaming agent is added. - May be cured.

That is, in this embodiment, by heating the stator winding 10, the varnish containing the antifoaming agent that is impregnated and held in the mica insulating layer 22 flows, and furthermore, the slot liner 42 and the inside of the slot flow. When the insulating material 43 and the wedge 41 also hold the varnish containing the antifoaming agent, by heating the stator winding 10, the varnish containing the antifoaming agent contained in these can be removed. The viscosity of the varnish is also reduced, and the antifoaming agent-added varnish retained by them also flows inside the core slot 13 .

When the slot liner 42 retains the varnish to which the antifoaming agent is added, the varnish to which the antifoaming agent is added is applied (held) on the surface of the film or paper (the surface of the slot liner 42). , is impregnated (held) in the voids (inside) of the film or paper (the voids of the slot liner 42).

In the case where the slot insulating material 43 retains the varnish containing the antifoaming agent, the varnish containing the antifoaming agent is applied to the surface of the slot insulating material 43 , particularly the slot insulating material 43 . It is applied (held) on the surface facing the coil unit 12 .

If the wedge 41 retains the antifoaming varnish, the antifoaming varnish may be applied to the surfaces of the wedges 41, particularly the surfaces of the wedges 41, and the in-slot insulation. It is applied (held) on the surface facing 43 .

Depending on the size and shape of the coil unit 12 and the core slot 13, the amount of antifoaming agent-added varnish held in the slot liner 42, the in-slot insulating material 43, and the wedge 41 and the degree of semi-hardening state to adjust. Also, the temperature profile of the flow and curing process of the varnish to which the antifoaming agent is added by heating the stator winding 10 is adjusted.

Also, the core slot 13 may be replenished with a varnish containing an antifoaming agent. The varnish is not limited to be held on the slot liner 42, the in-slot insulating material 43, and the wedge 41, and the coil unit 12 may be replenished by directly applying varnish containing an antifoaming agent.

The antifoaming agent-added varnish used for at least one of the slot liner 42, the in-slot insulating material 43, and the wedge 41 may be epoxy resin, unsaturated polyester resin, similar to the varnish used for the prepreg mica tape. Thermosetting resins such as silicone resins are preferred, and the same varnishes used for the impregnation varnish and the additional varnish are preferably used.

In addition, as in the case of the varnish used for the prepreg mica tape, it is necessary to add an antifoaming agent having a lower surface tension than the varnish used. Silicone or the like can be preferably used. Moreover, an appropriate antifoaming agent can be used according to the type of varnish used.

The stator winding 10 in this case includes a slot liner 42 inserted into the core slot 13 together with the coil unit 12, an in-slot insulating material 43, a coil unit 12, a slot liner 42, and an in-slot insulating material 43. and a wedge 41 for fixing to the core slot 13, and a semi-cured antifoaming agent is added to at least one of the coil unit 12, the slot liner 42, the in-slot insulating material 43, and the wedge 41. hold.

A gap 44 formed between the mica insulating layer 22 and the core slot 13 is filled with a varnish added with an antifoaming agent impregnated and held in the mica insulating layer 22, a slot liner 42, and a slot liner 42. The antifoaming agent-added varnish held on at least one of the insulating material 43 and the wedge 41 is allowed to flow.

That is, the stator winding 10 in this case includes the coil unit 12 having the mica insulating layer 22 impregnated with the varnish to which the antifoaming agent is added in advance and holding the varnish to which the antifoaming agent is added in advance. The coil unit 12, the slot liner 42, and the in-slot insulating material 43 are inserted into the core slot 13, and the wedge 41 holds them together. It may be fixed.

The manufacturing method of the stator winding 10 in this case has the following steps.

In STEP 1, a mica tape in which a base material 33 and a mica paper 31 are adhered with an adhesive 32 is impregnated with varnish to make the varnish a semi-cured state. varnish is retained, prepreg mica tapes (35, 36, 37) are produced, the prepreg mica tapes (35, 36, 37) are wound around the conductor 21, the mica insulating layer 22 is formed, and the coil unit 12 is formed. manufacture.

In STEP 2, at least one of the slot liner 42, the in-slot insulating material 43, and the wedge 41 that fixes the slot liner 42 and the in-slot insulating material 43 to the core slot 13 is held with semi-hardened varnish in advance. Let

Then, the coil unit 12 is inserted into the core slot 13 together with the slot liner 42 and the in-slot insulating material 43, and the coil unit 12, the slot liner 42, and the in-slot insulating material 43 are fixed to the core slot 13 by wedges. , to manufacture the intermediate stage stator windings 10 .

In STEP 3, the intermediate stage stator winding 10 is heated to remove the varnish impregnated and retained in the mica insulation layer 22 and at least one of the slot liner 42, the in-slot insulation 43, and the wedge 41. Allow the varnish held in to flow.

Then, the flowing varnish is formed in the gap 44 formed by the coil unit 12, the slot liner 42, and the in-slot insulating material 43, and formed between the mica insulating layer 22 and the core slot 13, It is cured to produce the stator winding 10 (heated stator winding 10, final stage stator winding 10).

<Effect of this embodiment>
According to this embodiment, the use of the prepreg mica tapes (35, 36, 37) of this embodiment eliminates the need for manufacturing equipment and manufacturing processes for injecting varnish under vacuum and pressure.

According to this embodiment, the gap 44 formed between the mica insulating layer 22 and the core slot 13 is filled with varnish 45 (impregnated varnish oozing from the mica insulating layer 22 (prepreg mica tapes (35, 36, 37)). and additional varnish) to form a filler-containing thermosetting resin layer in the gaps 44 . Because the antifoaming agent is added to this semi-cured varnish, bubbles are generated when the varnish in the prepreg mica tape is heated and cured, and the varnish seeps out and flows to fill the gaps. can be suppressed. Even if bubbles are generated, it is possible to suppress the generated bubbles from remaining. Thereby, the occurrence of discharge in the gap 44 formed between the mica insulating layer 22 and the core slot 13 can be suppressed.

According to this embodiment, a filler-containing thermosetting resin layer with few voids can be formed on the surface of the mica insulating layer 22 and in the gap 46 between the prepreg mica tapes. can. As a result, the partial discharge resistance of the interface between the prepreg mica tape and the prepreg mica tape can be improved.

If voids remain in the mica insulating layer 22, there is a risk of electrical discharge occurring during charging. Therefore, in the integral injection method and the single injection method, the varnish is injected into the fine gaps of the dry mica tape so that voids do not remain in the mica insulating layer 22 . Usually, the fine voids of the dry mica tape are vacuum impregnated (vacuum pressurized injection) over a long period of time. In this embodiment, it is not necessary to vacuum impregnate (vacuum pressurize) the varnish into the fine voids of the dry mica tape over a long period of time.

Moreover, unlike the prepreg method, the coil unit 12 can be manufactured by curing the varnish without pressurizing the coil unit 12 . Therefore, the manufacturing time can be shortened.

Moreover, unlike the integral injection method, the stator winding 10 does not need to be immersed in varnish, so that excess varnish does not adhere to unnecessary portions. This makes it possible to reduce the amount of varnish used. Further, for example, when varnish adheres to the inner circumference of the stator winding 10, the gap between the stator winding 10 and the rotor coil is affected, and the varnish adheres to the outer circumference of the stator winding 10. If so, the cooling efficiency of the stator winding 10 may be affected.

As described above, according to the present embodiment, it is possible to suppress the occurrence of discharge in the voids of the mica insulating layer 22, the gaps 46, and the gaps 44 in future rotary electric machines, and to provide rotary electric machines with high insulation reliability. .

Moreover, according to the present embodiment, it is possible to simplify manufacturing equipment and manufacturing processes for manufacturing the rotary electric machine (stator winding 10), and shorten the manufacturing time.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments are specifically described in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

DESCRIPTION OF SYMBOLS 10... Stator winding, 11... Stator core, 12... Single coil, 13... Core slot, 21... Conductor, 22... Mica insulating layer, 30... Conventional prepreg mica tape, 31... Mica paper, 32... Adhesive, 33 Base material 34 Antifoaming agent added varnish 35 Prepreg mica tape of the present example 36 Prepreg mica tape of the present example 37 Prepreg mica tape of the present example 41 Wedge , 42... slot liner, 43... insulating material in slot, 44... gap, 45... varnish filling gap 44, 46... gap.

Claims (15)

Having a structure in which a base material, mica paper, and a semi-cured varnish layer are laminated,
A prepreg mica tape, wherein an antifoaming agent is added to the varnish layer. The prepreg mica tape according to claim 1, wherein the varnish layer contains a filler. 2. The prepreg mica tape according to claim 1, wherein the varnish layer is formed on at least one of the surface of the mica paper and the surface of the base material. The prepreg mica tape according to any one of claims 1 to 3, wherein at least one of the base material and the mica paper is coated with a semi-cured varnish. The prepreg mica tape according to any one of claims 1 to 3, wherein the varnish layer constitutes the outermost surface of the mica paper. The prepreg mica tape according to any one of claims 1 to 3, further comprising an adhesive layer between the base material and the mica paper. A rotating electric machine having a stator winding having a stator core in which core slots are formed and a coil unit having a mica insulating layer formed on a conductor,
The mica insulating layer has a configuration in which a base material, mica paper, and a semi-cured varnish layer are laminated, and is composed of a prepreg mica tape in which an antifoaming agent is added to the varnish layer. A rotating electrical machine characterized by: The rotating electric machine according to claim 7, wherein the varnish layer contains filler. The stator winding has a slot liner that is inserted into the core slot together with the coil unit and protects the coil unit, and an in-slot insulating material that insulates the coil unit,
A component of the varnish layer of the mica insulating layer is formed in a gap formed between the mica insulating layer and the core slot, which is formed by the coil unit, the slot liner, and the in-slot insulating material. 8. The rotating electrical machine of claim 7, comprising: At least one of the slot liner, the in-slot insulating material, and the wedge fixing the coil unit, the slot liner, and the in-slot insulating material to the core slot is semi-hardened to which an antifoaming agent is added. a gap formed between the mica insulation layer and the core slot containing components of at least one of the varnish layer of the slot liner, the in-slot insulation, and the wedge. The rotary electric machine according to claim 7, characterized in that: A method for manufacturing a rotating electric machine comprising a stator winding having a stator core having core slots and a single coil having a mica insulating layer formed on a conductor, the method comprising:
A mica tape obtained by bonding a base material and mica paper with an adhesive is impregnated with a varnish containing an antifoaming agent, and the varnish containing an antifoaming agent is semi-cured,
A varnish layer to which a semi-cured antifoaming agent is added is held on the outermost surface of the mica tape to form a varnish layer to produce a prepreg mica tape,
winding the prepreg mica tape around the conductor to form the mica insulating layer to manufacture the coil unit;
inserting the coil unit into the core slot together with a slot liner that protects the coil unit and an in-slot insulating material that insulates the coil unit;
A method of manufacturing a rotating electric machine, comprising a step of fixing the coil unit, the slot liner, and the in-slot insulating material to the core slot to manufacture an intermediate stator winding. heating the intermediate stage stator winding to flow the varnish impregnated and retained with the defoamer added to the mica insulation layer;
The mica insulating layer is impregnated and held in a gap formed between the mica insulating layer and the core slot, and is formed by the coil unit, the slot liner, and the in-slot insulating material. 12. The method of manufacturing a rotating electric machine according to claim 11, wherein a varnish to which an antifoaming agent is added is formed and cured to manufacture the stator windings. A semi-hardened antifoaming agent is added in advance to at least one of the slot liner, the in-slot insulating material, the iron core slot, and at least one of the coil unit, the slot liner, and the wedge that fixes the in-slot insulating material. to retain the varnish that has been applied,
a varnish impregnated and held in the mica insulation layer in the gap formed between the mica insulation layer and the core slot by heating the intermediate stage stator winding, and the slot liner and the slot; 12. The electric rotating machine according to claim 11, wherein a varnish containing an antifoaming agent held on at least one of the inner insulating material and the wedges is flowed and cured to manufacture the stator winding. manufacturing method. 12. The method of manufacturing a rotating electrical machine according to claim 11, wherein the semi-cured antifoaming agent-added varnish held by the prepreg mica tape contains a filler. A method for manufacturing a rotating electric machine having a stator winding having a stator core having core slots and a coil unit having a mica insulating layer formed on a conductor, the method comprising:
A mica tape obtained by bonding a base material and mica paper with an adhesive is impregnated with a varnish containing an antifoaming agent, and the varnish containing an antifoaming agent is semi-cured,
Thereafter, a semi-cured antifoaming agent-added varnish is held on the outermost surface of the mica tape to prepare a prepreg mica tape,
winding the prepreg mica tape around the conductor to form the mica insulating layer to produce an intermediate coil unit;
Heating and pressurizing the intermediate stage coil unit to manufacture the final stage coil unit,
A method of manufacturing a rotating electrical machine, comprising: inserting the coil unit at the final stage into a core slot together with a slot liner for protecting the coil unit and an insulating material in the slot for insulating the coil unit, thereby manufacturing a stator winding. .

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