JP5579214B2 - Winding body of electrical equipment and manufacturing method thereof - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding body used for electrical equipment such as general industrial and consumer motors, generators, etc., and relates to a winding body for an electrical equipment machine in which a coil is impregnated with an insulating varnish and a method for manufacturing the same. is there.

  Conventionally, stator coils and rotor coils that are formed by winding a conducting wire around an iron core, in addition to improving insulation performance, improve the thermal conductivity from the winding to the iron core to dissipate the heat generated in the coil. For this purpose, an insulating varnish impregnation treatment for filling the gap between the windings with the insulating varnish is performed.

  As such an insulating varnish impregnation method, a dipping impregnation method in which a coil is immersed in an insulating varnish of a thermosetting resin to infiltrate the insulating varnish into the coil, a dripping impregnation method in which the insulating varnish is dropped into the coil and impregnated, or a coil In a vacuum vessel, and a vacuum impregnation method is used in which the coil is immersed in an insulating varnish with the pressure inside the vessel reduced.

In particular, the drop impregnation method is capable of impregnating a necessary portion with a necessary amount of insulating varnish, and is a very excellent impregnation method from the viewpoint of material yield.
On the other hand, in the immersion impregnation method and the vacuum impregnation method, in addition to the capillary phenomenon due to the surface tension of the insulating varnish, the penetration of the insulating varnish into the coil is promoted by applying the hydrostatic pressure of the insulating varnish, while the dripping impregnation In the method, the insulating varnish is infiltrated into the coil mainly by only the capillary phenomenon, so that the permeability of the insulating varnish is lower than the two insulating varnish impregnation methods.
As a result, a gap may remain between the windings, resulting in a decrease in insulation performance and heat dissipation performance.
Therefore, when the insulating varnish is dripped onto the coil, a method of driving the stator with a vibrator to remove the air layer in the coil and promoting the penetration of the insulating varnish (for example, Patent Document 1) or dripping Sometimes the stator is held with the central axis of the core tilted 5 ° to 20 ° with respect to the horizontal, and the insulating varnish is dropped on the end of the coil at the top of the tilt to flow the insulating varnish to promote penetration (for example, patents) Document 2) has been proposed.

JP-A-6-327203 JP-A-9-66258

In recent years, in order to meet the market demand for higher efficiency of rotating electrical machines, instead of the conventional distributed winding method in which the formed coil is inserted into the core slot after winding the wire around the winding frame, the conductor is directly wound around the core. The concentrated winding method is widely adopted.
The concentrated winding method enables higher-density winding than the distributed winding method, and can increase the efficiency of the rotating electrical machine.

In the concentrated winding method, the upper layer winding is sequentially wound around the two to three lower layer windings wound with good alignment. Here, how to improve the alignment of the lower layer windings is the key to high density winding, and various ideas have been studied on the shape of the insulator disposed between the iron core and the windings.
On the other hand, it is easy to make a difference in the alignment between the lower layer winding and the upper layer winding sequentially wound thereon, and when the insulating varnish is dropped on such a coil, the penetration rate V1 of the insulating varnish in the upper layer winding and the lower layer winding A difference V1> V2 is generated between the penetration velocities V2 of the insulating varnish in the winding.
Due to this difference in permeation speed, before the insulating varnish sufficiently penetrates to the center of the coil, the insulating varnish overflows to the outside from the upper winding portion, and a gap remains in the lower winding to leave the insulation performance and heat dissipation of the coil. There was a problem of lowering the performance.
In order to solve such a problem, in the insulating varnish impregnation method of Patent Document 1, since the stator is vibrated during dropping to remove the air layer in the coil, the possibility of remaining voids is reduced. Since this does not affect the surface tension of the coil, it is not possible to equalize the speeds of V1 and V2, and air gaps may remain in the lower layer winding.
Further, in the insulating varnish impregnation method of Patent Document 2, since the penetration speed of the insulating varnish increases due to the flow of the insulating varnish, the penetration of the insulating varnish is promoted, but the speed V1 and V2 cannot be uniformed. The air gap may still remain in the lower layer winding.

  The present invention has been made in order to solve the above-described problems, and sufficiently fills the insulating varnish without any gaps at the center of the coil of the winding body formed by the concentrated winding method. Thus, an object of the present invention is to provide a winding body of an electrical device excellent in insulation and heat dissipation and a method for manufacturing the same.

The winding body of the electric device according to the present invention is
In a winding body of an electric device including an iron core and a coil wound around the iron core,
The coil has an upper layer portion in which the element wire is liquid-repellent processed with a liquid repellent and a lower layer portion that is not liquid-repellent processed,
The entire coil is impregnated with an insulating varnish.

According to the present invention, a method for manufacturing a winding body of an electrical device includes:
A coil winding process in which a wire is wound by winding a wire around an iron core;
A preheating step of preheating the winding body around which the coil is wound to a predetermined temperature;
A liquid repellent impregnation step of impregnating the liquid repellent from the surface layer of the coil of the wound body after the preheating step to a predetermined layer;
After the liquid repellent impregnation step, an insulating varnish impregnation step of impregnating the entire coil with the insulating varnish is provided.

The winding body of the electric device according to the present invention is
In a winding body of an electric device including an iron core and a coil wound around the iron core,
The coil has an upper layer portion in which the element wire is liquid-repellent processed with a liquid repellent and a lower layer portion that is not liquid-repellent processed,
Since the entire coil is impregnated with insulating varnish,
A sufficient amount of insulating varnish can be uniformly filled in the coil, and a winding body of an electrical device having excellent insulation performance and heat dissipation performance can be provided.

According to the present invention, a method for manufacturing a winding body of an electrical device includes:
A coil winding process in which a wire is wound by winding a wire around an iron core;
A preheating step of preheating the winding body around which the coil is wound to a predetermined temperature;
A liquid repellent impregnation step of impregnating the liquid repellent from the surface layer of the coil of the wound body after the preheating step to a predetermined layer;
After the liquid repellent impregnation step, it has an insulating varnish impregnation step for impregnating the entire coil with the insulating varnish,
The penetration rate of the insulating varnish in the upper layer winding is reduced, and the penetration rate in the lower layer winding can be made uniform.
As a result, the insulating varnish can be sufficiently permeated into the entire coil, and a winding body of an electric device having excellent insulation performance and heat dissipation performance can be provided.

It is a schematic diagram which shows the formation process of the winding body of the electric equipment which concerns on Embodiment 1 of this invention. It is a cross-sectional schematic diagram which shows the formation state of the winding body of the electric equipment by the concentrated winding method which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the osmosis | permeation rate at the time of dripping an insulation varnish to the coil formed by the concentrated winding method which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the state of the insulating varnish which osmose | permeates the coil which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the flow of the insulation process of the winding body which concerns on Embodiment 1 of this invention. It is a schematic cross section which shows the osmosis | permeation range of the liquid repellent after dripping a liquid repellent to the winding body of the electric equipment which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the osmosis | permeation rate at the time of dripping an insulating varnish to the winding body of the electric machine by which the liquid repellent process which concerns on Embodiment 1 of this invention was carried out. It is a schematic diagram which shows the structure of the test | inspection apparatus for evaluating the heat dissipation characteristic of the application example A of the winding body of the electric equipment machine which concerns on Embodiment 1 of this invention, the application example B, and a comparative example.

Embodiment 1 FIG.
Hereinafter, a winding body of an electric appliance according to Embodiment 1 of the present invention and a manufacturing method thereof will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a process of forming a winding body 1 of an electric appliance according to Embodiment 1 of the present invention.
The winding body 1 includes an iron core 11 and a coil 12.
The coil 12 is formed by winding an element wire 2 made of an enameled wire or a polyesterimide copper wire around an iron core 11 in a plurality of layers.
The coil 12 formed by the method shown in FIG. 1 is preheated at a temperature of 100 degrees Celsius or higher in order to remove moisture adsorbed on the strand 2 and distortion of the coating layer generated when the strand 2 is wound. After preheating), a liquid repellent impregnation treatment and an insulating varnish impregnation treatment are performed.

FIG. 2 is a schematic cross-sectional view showing the winding state of the coil 12 formed by the concentrated winding method.
As shown in the figure, the lower layer winding 12a wound on the side closer to the center of the iron core 11 is wound in a layered manner with good alignment, whereas the upper layer winding 12b is somewhat aligned. It has collapsed.
FIG. 3 is a schematic diagram showing the difference between the portion of the upper winding 12b and the portion of the lower winding 12a when the insulating varnish is dropped onto the coil 12 shown in FIG.

The penetration depth of the insulating varnish in the coil 12 is obtained by the following Lucas Washburn equation.
l = (r × γ × cos θ × t / (2 × η)) ^0.5
l: depth of penetration, r: gap between windings, γ: surface tension of insulating varnish, θ: contact angle, t: penetration time, η: viscosity of insulating varnish

FIG. 4A is a schematic diagram showing a state of the insulating varnish 6 that penetrates the coil 12.
As shown in the drawing, the lowermost end portion of the insulating varnish 6 penetrating downward in the coil 12 forms a meniscus 4 one after another with the wire 2.
FIG. 4B is a diagram showing the relationship of the contact angle θ <b> 1 between the insulating varnish 6 penetrating the coil 12 and the wire 2.
Here, the contact angle θ <b> 1 is an angle formed by the tangent of the element wire 2 at the meniscus bottom end 41 of the insulating varnish 6 and the tangent of the bottom end of the meniscus 4 of the insulating varnish 6.

Moreover, although not correctly represented in the drawing, in the upper layer winding 12b with low alignment, the inter-winding gap r is larger than the winding gap r in the lower alignment winding 12a with high alignment.
Accordingly, when the penetration depth l per unit time is compared, l is smaller in the lower layer winding 12a having higher alignment than in the upper layer winding 12b having lower alignment.
That is, there is a relationship of V1> V2 between the penetration speed V1 of the insulating varnish 6 in the upper layer winding 12b and the penetration speed V2 of the insulation varnish 6 in the lower layer winding 12a.

FIG. 5 is a schematic diagram showing a flow of insulation processing of the winding body 1.
In the preheating process, after the liquid repellent 5 is dropped through the liquid repellent dropping nozzle 51 and the liquid repellent 5 is permeated into the upper layer portion of the coil 12 to the winding body 1 heated to 100 ° C. or more, the insulating varnish is dropped. The insulating varnish 6 is dropped through the nozzle 61 and penetrates the entire coil 12.
FIG. 6 is a view showing a permeation range of the liquid repellent 5 after the liquid repellent 5 is dropped.
In FIG. 6, in order to show the upper layer winding 12b to which the liquid repellent 5 is adhered, the strand 2 is shown thin, but the wire diameter does not actually change.
FIG. 7 is a schematic diagram showing the permeation rate of the insulating varnish 6 after the insulating varnish 6 is dropped.
As shown in FIG. 6, in the liquid repellent 5, since the boiling point of the solvent is lower than the temperature of the coil 12 whose temperature has been adjusted in advance, the solvent evaporates immediately before reaching the lower layer winding 12a.
Thereby, the liquid repellent component adheres to the surface of the upper layer winding 12b, and only the surface of the upper layer winding 12b is subjected to the liquid repellent treatment.

FIG. 4C is a diagram showing the contact angle θ2 at the portion of the upper layer winding 12b that has been subjected to the liquid repellent treatment.
In the upper layer winding 12b subjected to the liquid repellent treatment, the contact angle θ in the above-mentioned Lucas Washburn equation increases as the wettability of the insulating varnish 6 decreases to θ2.
Thereby, the penetration depth l per unit time decreases.
As a result, as shown in FIG. 7, the permeation speed V1 ′ of the insulating varnish 6 in the upper layer winding 12b is lower than the permeation speed V1 when the liquid repellent treatment is not performed, and the permeation speed of the insulating varnish 6 in the lower layer winding 12a. The difference from V2 becomes smaller, and a relationship of V1> V1′≈V2 is established among V1, V1 ′, and V2.

Thus, the coil 12 impregnated with the insulating varnish 6 is heated to the curing temperature of the insulating varnish 6 to obtain the coil 12 impregnated with the insulating varnish 6.
Accordingly, the insulating varnish 6 does not overflow from the upper layer winding 12b until the insulating varnish 6 sufficiently penetrates into the lower layer winding 12a, and the insulating varnish 6 penetrates sufficiently into the lower layer winding 12a. It is possible to prevent a gap from remaining between the lower layer windings 12a.
As a result, the insulation performance and heat dissipation of the coil 12 can be improved.

Hereinafter, application example A of this embodiment will be described.
First, a wire 2 having a wire diameter of 1.05 mm is wound around the iron core 1 to form a coil 12 having a space factor of 87%.
Next, the winding body 1 is preheated for 2 hours in a hot air drying oven at 150 ° C. which is equal to or higher than the glass transition temperature of the coating layer of the wire 2, and the silicon-based liquid repellent 5 A is applied to the coil 12 whose temperature is adjusted to 130 ° C. 1 g is dropped per coil (hereinafter referred to as a liquid repellent impregnation step).
Next, after the solvent of the liquid repellent 5A evaporates, 2 g of the insulating varnish 6 is dropped per coil (hereinafter referred to as a varnish impregnation step).
After that, the insulating varnish 6 is cured by heating in a hot air drying furnace at 170 ° C. for 2 hours to obtain the impregnated coil 12.
The used silicon-based liquid repellent 5A has a boiling point of 60 ° C.

Hereinafter, the application example B of the present embodiment will be described focusing on portions different from the application example A.
In the liquid repellent impregnation step, a coil impregnated with the insulating varnish 6 was obtained by performing the same process as in Application Example A except that 1 g of a fluorine-based liquid repellent 5C was dropped as the liquid repellent 5. The fluorine-based liquid repellent C used has a boiling point of 45 ° C.

Hereinafter, a configuration of a comparative example for comparison with application examples A and B of the present embodiment will be described.
A coil 12 in which 2 g of insulating varnish 6 was dropped in the insulating varnish impregnation step was prepared without performing the liquid repellent impregnation step.

Next, the insulation performance and heat dissipation performance of the coil 12 obtained in Application Example A, Application Example B, and Comparative Example were evaluated. Regarding the insulation performance, the value of the dielectric loss tangent between the coil 12 and the iron core 1 was measured as a representative value.
The dielectric loss tangent was measured using a DAC-ASM-7, which is a tan δ measuring machine manufactured by Soken Denki Co., Ltd., with a power supply of AC 2500 V and 60 Hz.

FIG. 8 is a diagram illustrating the configuration of a measurement device for heat dissipation characteristics.
With the heat sink 7 attached to the iron core 11, a voltage of AC 100 V and 60 Hz is applied to the coil 12 from the AC power supply 8, and the resistance of the coil 12 is measured initially and after 1 hour of energization with the resistance meter 9, and the resistance is lower than that of JIS-C4203. The temperature rise of the winding was determined according to the formula.
T = T2-Tα = (R2 / R1-1) × (235 + T1) + (T1-Tα) [° C.]
T: Winding temperature rise value, T1: Winding temperature at the time of initial resistance measurement, T2: Winding temperature after the test Tα: Room temperature after the test, R1: Initial resistance, R2: Resistance after the test Table 1 Summarize the measurement results.

As shown in Table 1, the dielectric loss tangent is as high as 4.8% in the comparative example while the application example A and the application example B are 1.6%.
In Application Example A and Application Example B, the insulating varnish 6 penetrates into the lower layer winding 12a when the insulating varnish 6 is dropped and impregnated, and the insulating varnish 6 is sufficiently filled to the center of the coil 12. In the comparative example, it is shown that the insulating varnish 6 does not sufficiently permeate and a gap remains between the lower layer windings 12a and the leakage current increases between the coil 12 and the iron core 11.

Further, the temperature rise is as large as 58.4 ° C. in the comparative example, while the application example A is 46.2 ° C. and the application example B is 46.8 ° C.
In the application example A and the application example B, the insulating varnish 6 is sufficiently filled up to the center of the coil 12, and Joule heat generated in the coil 12 can be efficiently transferred to the iron core 11. In FIG. 5, there is a gap between the lower layer winding 12a and between the lower layer winding 12a and the iron core 11, indicating that heat transfer from the coil 12 to the iron core 11 is inhibited.

  From the above results, according to the winding body 1 of the electric device and the manufacturing method thereof according to Embodiment 1 of the present invention, only the upper layer winding 12b of the coil 12 is liquid-repellent processed, and the upper layer winding of the coil 12 is processed. By equalizing the permeation speed of the insulating varnish 6 in 12b and the lower layer winding 12a, a sufficient amount of the insulating varnish 6 can be uniformly filled in the coil 12, and the winding of the electrical device having excellent insulation performance and heat dissipation performance The body 1 and its manufacturing method can be provided.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

1 winding body, 11 iron core, 12 coil, 12a lower layer winding, 12b upper layer winding,
V1, V1 ', V2 penetration rate, 2 strands, 4 meniscus,
5,5A, 5C Liquid repellent, 51 Liquid repellent dripping nozzle, 6 Insulating varnish,
61 Insulating varnish dripping nozzle, 7 heat sink, 8 AC power supply, 9 resistance meter,
θ, θ2 Contact angle.

Claims (4)

In a winding body of an electric device including an iron core and a coil wound around the iron core,
The coil has an upper layer part in which the strand is liquid-repellent processed with a liquid repellent and a lower layer part that is not liquid-repellent processed,
A winding body of an electric device in which the entire coil is impregnated with an insulating varnish. The winding body for an electric device according to claim 1, wherein the liquid repellent is a silicon-based or fluorine-based liquid repellent. A coil winding process in which a wire is wound by winding a wire around an iron core;
A preheating step of preheating the winding body around which the coil is wound to a predetermined temperature;
A liquid repellent impregnation step of impregnating the liquid repellent from the surface layer of the coil of the winding body after the preheating step to a predetermined layer;
A method for manufacturing a winding body of an electric device, comprising: an insulating varnish impregnation step of impregnating the entire coil with an insulating varnish after the liquid repellent impregnation step. The preheating temperature in the said preheating process is a manufacturing method of the winding body of the electric equipment of Claim 3 set higher than the boiling point of the solvent of the said liquid repellent used in the said liquid repellent impregnation process.

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