JP2006014490A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine which can enhance heat dissipation properties by improving thermo-conductive performance while maintaining the insulation reliability. <P>SOLUTION: Within a core 2 slot 2a in a stator 1, a winding 7 using an adhesive electric wire 6 is stored via a slot insulation article 3 and a wedge member 12 is driven into the opening part of the slot 2a. Furthermore, the inside of the slot 2a and the coil end parts are impregnated with varnish 12 by varnish treatment, and are thermoset to integrally fix and form the winding 7 with the adhesive layer 10 of the adhesive electric wire 6 and the varnish 12. Then, a first and a second filling agents are contained and are used in each member constituting the insulation structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotating electrical machine having an improved stator insulation structure.

FIG. 11 shows a general insulation structure of a stator of a rotating electrical machine. In the iron core 101 of the stator 100, a plurality of slots 101a are concentrically arranged at equal intervals. A U-shaped slot insulator 102 using calendered aramid paper or the like is mounted in the slot 101a, and a synthetic resin enamel such as polyamide imide enamel copper wire is placed inside the slot insulator 102. A winding 103 using a wire 103a is accommodated and wrapped with a slot insulator 102, and then a wedge material 104 formed of, for example, a calendered aramid paper or the like into a half-U shape is driven into the winding 103. Fixed. In addition, interphase paper is inserted between the phases at the coil end portion (not shown) of the winding 103 to melt the phases. Furthermore, the winding 103 accommodated in the slot 101a is impregnated with varnish 106 in the slot 101a and the coil end portion by varnish treatment, and is heat-cured and integrally fixed (see Patent Document 1).
JP-A-9-308158 (FIG. 10)

  Conventionally, devices that use a rotating electrical machine are often controlled at a variable speed by an inverter in order to increase energy efficiency. The inverter is driven at a frequency of about 2 kHz to several tens of kHz, for example, a PWM pulse. A surge voltage is generated every time. The surge voltage is a phenomenon in which a voltage higher than the output voltage of the inverter is applied under the influence of the surrounding electrical system such as the length of the cable and the presence or absence of a capacitor. Further, since the pulse waveform is steep, partial discharge is likely to occur in the enameled wire 103a used in the winding 103, so that a local temperature rise occurs or occurs in the coating film of the enameled wire 103a. The ozone that has been applied acts in a complex manner, causing the insulation of the enamel film to deteriorate at an accelerated rate, thereby shortening the life of the equipment. Furthermore, in recent years, rotating electrical machines are also becoming smaller, and the winding temperature tends to increase more and more. For this reason, measures are taken to improve the heat resistance deterioration of the insulating material used in each part, or the thermal conductivity of each part is improved.

  In order to increase the durability due to this surge voltage, it is possible to increase the space factor by increasing the enamel coating film or increasing the amount of impregnating resin in the winding 103 of the rotating electrical machine. In addition to problems such as a decrease in efficiency and an increase in expenses, there are many cases where the desired reliability cannot be obtained even if these measures are taken. For this purpose, an enameled wire coating having excellent characteristics with respect to the inverter surge voltage and an insulation structure with high resistance against the surge voltage are required.

  In addition, in order to cope with the temperature rise of the winding 103, it is possible to improve the heat resistance deterioration of the insulating material relatively easily, but the cost of the material itself is large, and the temperature range is limited. There is also. And as a measure to increase the thermal conductivity, there is usually a method to increase the heat dissipation effect by reducing the thickness of organic materials with poor thermal conductivity such as resin, but the reduction in thickness directly leads to a decrease in insulation performance In many cases, it is difficult to achieve both heat conduction performance and insulation performance in an insulating material.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotating electrical machine capable of improving heat dissipation by improving heat conduction performance while maintaining insulation reliability. Objective.

According to the first aspect of the present invention, the first filler having a thermal conductivity of at least 1.0 W / mK or more as a treatment varnish for a winding of a rotating electrical machine is compared with the first filler having a particle size. It is characterized by using a resin uniformly containing a second filler that is 0.15 times or less.
According to such a configuration, the second filler having a particle size of 0.15 times or less with respect to the first filler is compared with the first filler having a thermal conductivity of 1.0 W / mK or more. By containing uniformly, the processing varnish which improved the heat-dissipating property by improving heat-conducting performance, maintaining insulation reliability, can be used for a rotary electric machine.

According to a second aspect of the present invention, there is provided a first filler having a thermal conductivity of at least 1.0 W / mK as a slot insulator inserted between the rotating electrical machine winding and the iron core for ground insulation. The use of a single material of the sheet material uniformly containing the second filler having a particle size of 0.15 times or less compared to the first filler, or a pasting material with another sheet material It is characterized by.
According to such a structure, the slot insulator which has the same effect as Claim 1 can be used for a rotary electric machine.

The invention according to claim 3 uses an adhesive electric wire formed by applying an adhesive layer of a B stage on the surface of an enameled wire as a magnet wire of a winding of a rotating electrical machine. The first filler having a thermal conductivity of not less than / mK and the second filler having a particle size of 0.15 times or less compared to the first filler are uniformly contained. To do.
According to such a configuration, the bonded electric wire having the same effect as that of the first aspect can be used for the rotating electrical machine.

According to a fourth aspect of the present invention, there is provided a first filler having a thermal conductivity of at least 1.0 W / mK or more as a wedge material for a rotating electrical machine, and a particle size of 0.15 compared to the first filler. It is characterized by using a single sheet material that uniformly contains a second filler that is twice or less, or a laminate material with another sheet material.
According to such a configuration, a wedge material having an effect similar to that of the first aspect can be used for the rotating electrical machine.

  ADVANTAGE OF THE INVENTION According to this invention, the rotary electric machine which can improve the heat dissipation can be provided by improving a heat conductive performance, maintaining insulation reliability.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
First, FIG. 1 is a partial cross-sectional view of a stator of a rotating electrical machine. As shown in FIG. 1, a plurality of slots 2a are arranged concentrically at equal intervals in the iron core 2 of the stator 1 of the rotating electrical machine. The slot 2a has a substantially trapezoidal shape. A U-shaped slot insulator 3 is inserted into the slot 2a.

  As shown in FIG. 2, the slot insulator 3 is made of, for example, a film of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide or the like, or a sheet material 4 made of synthetic paper such as aramid. Has been configured. In the synthetic resin 5, boron nitride or magnesium oxide as a first filler and a second filler deposited by a sol-gel method using a metal alkoxide as a raw material are uniformly contained.

  FIG. 5 shows a method for producing the synthetic resin 5 by the sol-gel method. In FIG. 5, the synthetic resin 5 is composed of, for example, tetraethoxysilane (30 ml) having high purity as metal alkoxide and polydimethylsiloxane ( 20 ml), isopropyl alcohol (15 ml) and tetrahydrofuran (10 ml) are stirred and mixed with a stirrer at room temperature and normal pressure for 2 hours to obtain liquid A. Then, a solution obtained by stirring and mixing 2N hydrochloric acid (10 ml) and distilled water (30 ml) was added dropwise to the solution A with stirring, and the mixed liquid was kept in a sealed state at 70 ° C. for 48 hours. Warm for hours to obtain solution B.

  Further, 60 vol% of hexagonal boron nitride (or magnesium oxide) as a first filler having a thermal conductivity of 1.0 W / mK or more is filled in this liquid B, and stirred and mixed at 300 ° C. Is dried and cured to form a plate-shaped synthetic resin. Here, since the synthetic resin 5 is laminated as a slot insulator 3 on one side of the sheet material 4 in a prepreg state, the synthetic resin 5 is mixed with stirring and dried and cured at 300 ° C. It is applied as a state, and as a result, it is configured as being attached to the slot insulator 3.

As shown in FIG. 2, the slot insulator 3 is inserted into the slot 2 a so that the side of the synthetic resin 5 bonded in the prepreg state is in contact with the inner wall of the slot 2 a of the iron core 2.
Subsequently, as shown in FIG. 1, a winding 7 is formed by inserting an adhesive wire 6 as a magnet wire inside the slot insulator 3. The winding 7 is, for example, a three-phase winding composed of R, S, and T phases and is star-connected, and each phase winding includes a plurality of windings connected in series corresponding to a plurality of poles. It is connected to an inverter (not shown) via a power supply lead wire.

  As shown in FIG. 3, the bonded electric wire 6 is formed by applying a synthetic resin 10a to the surface of an enamel layer 9 around the conductor 8 (the conductor 8 and the enamel layer 9 constitute an enameled wire that is a normal magnet wire). The formed adhesive layer 10 is formed. When the adhesive wire 6 is heated at a predetermined temperature, the adhesive layer 10 is fused, the adhesive wires 6 are bonded to each other, and the winding 7 constituted by the adhesive wire 6 is integrated. The synthetic resin 10a (adhesive layer 10) is the same material as the synthetic resin 5 in the case of the slot insulator 3, and is formed as the adhesive layer 10 when it is stirred and mixed and dried and cured at 300 ° C.

  Then, as shown in FIG. 1, a wedge material 11 in which a sheet material is formed in a semi-U shape is driven into the opening of the slot 2 a of the iron core 2, and the winding 7 is fixed. The sheet material used as the wedge material 11 is composed of, for example, a synthetic resin such as polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, or other synthetic paper such as aramid, and the synthetic resin is made of a slot insulator 3. The same material as that of the synthetic resin 5 is formed.

  Subsequently, the winding 7 housed in the slot 2a is subjected to a process of impregnating with a varnish 12 for integrally fixing and molding. This treatment is, for example, a dripping impregnation varnish treatment. While rotating the stator 1, the varnish 12 is dropped from both sides of the coil end portions 7 </ b> R to 7 </ b> T (see FIG. 4) of the winding 7 with the nozzles, A process in which the winding 7 in the slot 2a is filled with the varnish 12 by capillary action, and the varnish 12 is impregnated in the slot 2a and the coil end portions 7R to 7T, and then heat-cured (corresponding to the B stage). It is. The impregnated varnish 12 is made of a synthetic resin, and this synthetic resin is the same material as that of the slot insulator 3, and is stirred and mixed, filled in the slot 2a, and dried and cured.

Then, a rotor (not shown) is arranged in the stator 1 having an insulating structure to constitute a rotating electric machine.
Thus, the rotation speed of the rotor is changed by PWM control of the winding 7 of the stator 1 by the inverter.

The operation of the present invention will be described below with reference to FIGS.
First, experimental results regarding the correlation between the particle size and the heat transfer coefficient will be described with reference to FIGS.
FIG. 6 shows the change in thermal conductivity when a mixture of boron nitride and isopropylene elastomer having the same shape as mica is filled with carbon black having an average particle size of 90 nm. The vertical axis indicates the thermal conductivity ( W / mK), and the horizontal axis represents the volume ratio (vol%) between the composite of boron nitride and isopropylene-based elastomer and carbon black.
The thermal conductivity was measured by a laser flash method. Here, the filling amount of boron nitride was constant at a volume amount 0.6 times (60 vol%) with respect to the volume sum of boron nitride and isopropylene elastomer.

  From FIG. 6, the thermal conductivity is increased by filling with carbon black. Compared with the case where carbon black is not filled and the case where carbon black is filled with 10 vol%, the thermal conductivity is about 3.7 W / mK, which is nearly four times higher. I was able to get it. This is because the elastic modulus of the resin between the boron nitrides is increased due to the uniform presence of the carbon black particles between the boron nitride particles, and as a result, the heat flow between the boron nitride particles is improved. It is thought that it improved.

  FIG. 7 shows changes in thermal conductivity when a mixture of boron nitride and isopropylene elastomer is filled with alumina having an average particle size of 70 nm instead of carbon black. According to this, a further increase in thermal conductivity was observed as compared with carbon black, and a thermal conductivity of about 4.7 W / mK could be obtained when alumina was filled at about 12.5 vol%.

FIG. 8 shows the change in thermal conductivity when a mixture of boron nitride and isopropylene elastomer is filled with alumina having different particle sizes, the vertical axis shows the thermal conductivity (W / mK), and the horizontal axis Indicates the particle size ratio of boron nitride as the first filler and alumina as the second filler.
It can be seen from FIG. 8 that the thermal conductivity increases in the range where the particle size ratio is smaller than about 0.1 times. Thus, a material having high thermal conductivity can be obtained by setting the particle size of the second filler to 0.15 times or less of the particle size of the first filler.

  As described above, the point of increasing the thermal conductivity is that the second filler is dispersed in the first filler. In order to further improve the thermal conductivity, the filler is chemically separated. It can be seen that it is important that they are connected by bonding or evenly dispersed. Therefore, if a method of precipitating the second filler by applying the sol-gel method as a method for uniformly dispersing the second filler in the first filler is applied between the first fillers. Uniform dispersion of the two fillers is possible.

  According to such a configuration, the resin used as the adhesive layer 10 of the bonded electric wire 6 includes boron nitride (or magnesium oxide) as the first filler having a thermal conductivity of 1.0 W / mK or more, and metal alkoxide. Since the second filler deposited by the sol-gel method using tetraethoxysilane as a raw material is uniformly dispersed, the thermal conductivity is improved while maintaining the insulation reliability against the inverter surge voltage when the inverter is driven. Thus, heat dissipation can be improved. Furthermore, hexagonal boron nitride and magnesium oxide, which are the first fillers, have a low Mohs hardness and are soft, and thus can prevent damage to the base material and enamel wire.

  In the varnish 12, boron nitride (or magnesium oxide) as the first filler and the second filler deposited by the sol-gel method using tetraethoxysilane as a raw material are uniformly dispersed. While maintaining the insulation reliability of the varnish 12, it is possible to improve the heat transfer property, and furthermore, the varnish 12 and the adhesive layer 10 are integrated by the heat-curing process. By efficiently transferring heat to the iron core 2 side, heat dissipation can be enhanced. Furthermore, damage to the substrate and enameled wire can be prevented by the hexagonal boron nitride and magnesium oxide as the first filler.

  Further, in the synthetic resin 5 constituting the slot insulator 3, boron nitride (or magnesium oxide) as a first filler and a second filler deposited by a sol-gel method using tetraethoxysilane as a raw material are uniform. Therefore, the heat transfer coefficient can be improved while maintaining the insulation reliability of the slot insulator 3 at the bonded portion between the slot insulator 3 and the iron core 2. Since it is in close contact with the iron core 2, the heat dissipation can be enhanced by efficiently transmitting the Joule heat generated in the bonded electric wire 6 to the iron core 2 side. Furthermore, damage to the substrate and enameled wire can be prevented by the hexagonal boron nitride and magnesium oxide as the first filler.

  Further, in the synthetic resin constituting the wedge material 11, boron nitride (or magnesium oxide) as the first filler and the second filler deposited by the sol-gel method using tetraethoxysilane as a raw material are uniformly dispersed. Therefore, while maintaining the insulation reliability of the wedge material 11, it is possible to improve heat dissipation by improving the heat transfer performance of the wedge material portion, which has been a large thermal resistance in the past. Furthermore, damage to the substrate and enameled wire can be prevented by the hexagonal boron nitride and magnesium oxide as the first filler.

  Therefore, while maintaining the insulation reliability against the inverter surge voltage generated by the inverter drive, the heat dissipation performance can be improved by improving the heat conduction performance of the entire rotating electric machine, and thus the entire rotating electric machine. The temperature can be reduced.

(Second embodiment)
FIG. 9 and FIG. 10 show a second embodiment of the present invention, and different points from the first embodiment will be described. In the first embodiment, the synthetic resin 5 is formed using the sol-gel method containing isopropyl alcohol (isopropyl elastomer), but the synthetic resin is formed using the sol-gel method using an epoxy resin. Explain the case. In this case, the sol-gel method involves stirring tetraethoxysilane (30 ml), silane coupling agent A187 (10 ml), distilled water (5 ml), and ethanol (10 ml) with a 200 ml beaker for 10 minutes, while stirring. A liquid in which diethyleneamine (0.6 ml) was dropped was used as a B liquid, and 60 vol% boron nitride (or magnesium oxide) was filled in the B liquid. The resin filled with these is dried and cured at 350 ° C. to obtain a synthetic resin. Other configurations are the same as those in the above embodiment.

Next, experimental results regarding the correlation between the particle size and the heat transfer coefficient will be described with reference to FIGS.
FIG. 9 shows changes in thermal conductivity when a composite of boron nitride and epoxy resin is filled with carbon black having an average particle size of 90 nm, and the vertical axis shows thermal conductivity (W / mK). The horizontal axis represents the volume ratio (vol%) between the composite of boron nitride and epoxy resin and carbon black. The thermal conductivity was measured by a laser flash method. Here, the filling amount of boron nitride was constant at a volume amount 0.6 times (60 vol%) with respect to the volume sum of boron nitride and epoxy resin.

  From FIG. 9, the thermal conductivity is increased by filling with carbon black, and the thermal conductivity of about 6.5 W / mK, which is more than twice that of the case of not filling carbon black and the case of filling 1 vol% of carbon black. Could get. This is because, as in the first embodiment, the carbon black particles are uniformly present between the boron nitride particles, whereby the elastic modulus of the resin between the boron nitrides is increased. As a result, the heat between the boron nitride particles is increased. It is thought that the heat conduction performance was improved because the flow was improved.

FIG. 10 shows a change in thermal conductivity when a composite of boron nitride and an epoxy resin is filled with alumina having an average particle size of 70 nm instead of carbon black. A further increase in thermal conductivity was observed compared to carbon black, and a thermal conductivity of about 7.4 W / mK could be obtained when 4 vol% alumina was filled.
According to the rotating electrical machine having the above-described insulating configuration, the same effect as in the first embodiment can be obtained.

(Modification)
The present invention is not limited to the above embodiment, but can be modified or expanded as follows.
In the first embodiment, the varnish treatment is the dripping impregnation varnish treatment, but the immersion impregnation varnish treatment may be performed. Further, the impregnation operation of the varnish 12 may be performed in a vacuum container. According to this, since the varnish 12 is impregnated in a reduced pressure state, the varnish 12 is surely secured to a narrow space between the bonded electric wires 6 of the winding 7, between the winding 7 and the slot 2a, and between the slot insulator 3 and the slot 2a. Impregnated. In the immersion impregnation varnish treatment, the stator 1 is immersed and impregnated in a container in which the varnish 12 is accommodated, and the excess varnish 12 is removed by dropping it by leaving it naturally, and then heating furnace Inside, the varnish 12 impregnated in the stator 1 is cured by heating.

In the above-described embodiment, the slot insulator 3 and the wedge material 11 are configured such that the synthetic resin 5 is applied to, for example, one surface of the film or synthetic paper that is the sheet material 4. The synthetic resin 5 may be applied to both sides of the paper.
The slot insulator 3 and the wedge material 11 are configured by applying the synthetic resin 5 to the sheet material. However, it is not necessary to apply the synthetic resin 5 to the sheet material, and the synthetic resin formed by the sol-gel method is formed into a sheet shape. However, the slot insulator 3 and the wedge member 11 may be configured by using them themselves.

  Further, the synthetic resin 5 is applied to the sheet material 4, but the sheet material used as the slot insulator 3 is a film such as polyethylene terephthalate, polyethylene naphthalate or polyphenylene sulfide, or a synthetic paper such as aramid. Or it is a bonding material with other sheet | seat materials, and it is good also as a structure by which the 1st filler and the 2nd filler are previously contained in the raw material of these films or synthetic paper.

In the above embodiment, the second filler is deposited by a sol-gel method using metal alkoxide (tetraethoxysilane) as a raw material, but carbon black or alumina is contained in the resin as the second filler. May be.
In the first embodiment, the first insulator and the second filler are contained in all the members of the slot insulator 3, the adhesive wire 6, the wedge material 11 and the varnish 12, but all the members are used. It is not necessary to use it contained in a member. For example, it may be used contained in one member or two or more members.

1 is a partial longitudinal sectional view of a stator showing a first embodiment of the present invention. Partial cross-sectional perspective view of slot portion Diagram showing coil end Cross section of bonded wire Chart showing the sol-gel method Diagram showing the change in thermal conductivity when filled with carbon black Fig. 6 equivalent when alumina is added Figure showing the change in thermal conductivity depending on the particle size ratio of boron nitride and alumina 6 equivalent diagram 7 equivalent diagram Fig. 1 equivalent diagram showing conventional technology

Explanation of symbols

In the drawings, 1 is a stator, 2 is an iron core, 2a is a slot, 3 is a slot insulator, 4 is a sheet material, 5 is a synthetic resin, 6 is an adhesive wire, 7 is a winding, 10 is an adhesive layer, and 11 is a wedge. The material, 12 indicates varnish.

Claims (7)

  As a treatment varnish for a winding of a rotating electrical machine, a first filler having a thermal conductivity of at least 1.0 W / mK and a particle size of 0.15 times or less compared to the first filler. A rotating electrical machine characterized by using a resin that uniformly contains two fillers.   As a slot insulator inserted for ground insulation between the winding of the rotating electrical machine and the iron core, a first filler having a thermal conductivity of at least 1.0 W / mK or more and a particle size of the first filler A rotating electrical machine characterized by using a single sheet material uniformly containing a second filler that is 0.15 times or less compared to a filler, or a laminate material with another sheet material.   As a magnet wire for a winding of a rotating electric machine, an adhesive electric wire formed by applying an adhesive layer of a B stage on the surface of an enameled wire is used. A rotating electrical machine characterized by uniformly containing a first filler having and a second filler having a particle size of 0.15 times or less that of the first filler.   As a wedge material of a rotating electrical machine, a first filler having a thermal conductivity of at least 1.0 W / mK and a second filling having a particle size of 0.15 times or less compared to the first filler A rotating electrical machine characterized by using a single sheet material uniformly containing a material or a laminate material with another sheet material.   The rotating electrical machine according to any one of claims 1 to 4, wherein the first filler is boron nitride or magnesium oxide.   The rotating electrical machine according to claim 1, wherein the second filler is carbon black or alumina. 5. The rotating electrical machine according to claim 1, wherein the second filler is precipitated and dispersed by a sol-gel method using a metal alkoxide as a raw material.

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