WO2008130058A1

WO2008130058A1 - Stator, its manufacturing method, and motor

Info

Publication number: WO2008130058A1
Application number: PCT/JP2008/058001
Authority: WO
Inventors: Shigeto Takeuchi; Tomotsugu Taira
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2007-04-18
Filing date: 2008-04-18
Publication date: 2008-10-30
Also published as: JP2008271661A

Abstract

It is possible to provide a stator which can effectively eliminate generation of an air gap between a coil and a stator core without lowering a volume ratio occupied by the coil. A method for manufacturing the stator and a motor are also disclosed. Between the coil (3) and teeth is arranged a slot insulating paper sheet (10) having a self-fusing layer (2) at least on one of its surfaces with the self-fusing layer (2) facing the coil side. The self-fusing layer (2) is fused onto the coil (3) so as to constitute a stator. When the stator is a distributed winding stator, an inter-phase insulating paper sheet (20) having the self-fusing layer (2, 2) on its both surfaces is arranged between coils of different phases and the self-fusing layers (2, 2) are fused onto the coils.

Description

Description Stator, manufacturing method thereof and motor

The present invention relates to a stator, a manufacturing method thereof, and a motor, and more particularly, to a stator capable of preventing electric field concentration due to an air gap between insulating paper and a coil and preventing insulation from being deteriorated, and a manufacturing method thereof. The present invention relates to a motor including the stator. Background art

A stator constituting a motor (electric motor) is formed by laminating a steel plate including an annular yoke, a plurality of teeth projecting radially inward from the yoke, and a slot formed between adjacent teeth. A stator is formed from a stator core, and a stator is manufactured by fitting between teeth while a coil is inserted into the slot. Here, there are concentrated winding method and distributed winding method in coil winding form. Concentrated winding method is a form in which a coil is mounted for each tooth, and distributed winding method spans multiple teeth. The coil is wound.

According to the centralized winding method, since the coil is installed for each tooth, the protruding length of the coil end from the end of the stator core can be relatively shortened, and therefore the motor can be downsized. There is an advantage that it is easy to plan. In addition, the space factor, which is the ratio of the coil cross section to the slot cross section, can be easily increased, and the production efficiency is also high. On the other hand, according to the distributed method, the reluctance torque is relatively large, and furthermore, the amount of heat generated when the rotor is driven is small, so that the output performance of the motor (rotor performance and torque performance of the rotor) increases. .

In either method, slot insulation paper is interposed between the slot wall surface and the coil from the viewpoint of ensuring insulation between the slot wall surface and the coil end. Interphase insulation paper is provided for insulation between different phase coils. After the insulation paper and coil are formed, coil the varnish from the coil end. „

WO 2008/130058 It is impregnated in the coil, and the insulation between the stator core and the coil and between the different phase coils is ensured by curing the varnish. The impregnation of the varnish has not only the sealing of the coil but also the purpose of ensuring insulation and promoting the heat radiation from the coil by filling the gap between the coils with the varnish.

By the way, as the winding density is increased in order to increase the coil space factor, the varnish becomes difficult to impregnate between the slot wall surface and the coil between the coil-phase different coils, and as the coil space factor increases. Such impregnation difficulty is further increased. This will be described with reference to FIGS. Fig. 10 shows the air gap A between the U-phase coil Q 1 and the V-phase coil Q 2 and the interphase insulating paper P 1 interposed between them at the coil end of the distributed stator. Explains the situation that is occurring. Here, while each coil is impregnated with varnish W, each coil Q l, Q 2 and interphase insulating paper P 1 are not impregnated with varnish W, resulting in an air gap A. Become.

On the other hand, Fig. 11 is common to both concentrated and distributed stators, and the air gap between slot insulation paper P2 and coil Q installed in slot R Explains the situation where A occurs. Even in slot R, varnish W is impregnated between the coils, but varnish becomes difficult to impregnate between the slot wall surface and coil Q as the coil space factor increases. It tends to occur.

If the varnish is not sufficiently impregnated, it will not be possible to sufficiently obtain the effects of ensuring insulation and promoting heat dissipation as described above, and electric field concentration will occur in the air gap where the varnish is not impregnated. The part where insulation is severe will occur. Furthermore, the heat release performance of the air gap is significantly reduced as compared with the varnish-impregnated portion.

By the way, Patent Document 1 discloses a technique related to an electric wire for a coil of an electric motor. Specifically, an insulating coating made of polyester is formed on the surface of a conductor, and further, an inorganic filler is contained on the outside thereof. A fused film is formed. With this fusion coating, the heat dissipation of the electric wire can be improved.

Patent Literature 1

JP 2 0 0 3-1 5 7 7 2 8 Disclosure of the invention

It is possible to suppress the occurrence of an air gap by using the electric wire of Patent Document 1 for the coil of the motor and fusing the electric wires together with this fusion coating, but the electric wire takes a configuration. As a result, the cross section of the conductor occupying the electric wire is reduced, and the space factor of the coil is greatly reduced. In addition, it is inevitable that the manufacturing cost will increase because multiple wires are manufactured in such a configuration, eliminating the air gap between the coil and the stator core, or the air gap between the different phases of the coin end. It is not realistic as a way to do it.

The present invention has been made in view of the above-described problems, and it is possible to effectively generate an air gap between the coil and the stator core without lowering the coil space factor at an inexpensive manufacturing cost. It is an object of the present invention to provide a stator that can be eliminated, a method of manufacturing the stator, and a motor including the stator.

To achieve the above object, a stator according to the present invention includes an annular yoke, a plurality of teeth projecting radially inward from the yoke, and a slot formed between adjacent teeth. A stator insulating paper having a self-bonding layer on at least one side surface between the coil and the teeth. The self-bonding layer is welded to the coil.

In the stator of the present invention, slot insulating paper is disposed in the slot, and this slot insulating paper is of a concentrated type that ensures insulation between the coil made of the conductor and the slot wall surface of the stator core. Intended for the stator.

Here, the slot insulating paper used is, for example, a high heat-resistant resin material on at least one side surface of a polymer paper sheet having insulating performance such as polyethylene telenaphthalate (PET) or polyethylene naphthalate (PEN). An insulating paper having a self-bonding layer made of is used.

The self-bonding layer can be formed from a polyamide resin such as nylon 6, nylon 6-6, nylon 6 or 10, for example. In the stator of the present invention, the varnish is impregnated in the coil after the coil is formed, but the self-bonding layer is heated and melted to be generated between the coil conductor and the slot insulating paper. The self-bonding layer melted in the air gearup portion where the varnish is not impregnated is impregnated by the surface tension, and the air gap portion is filled. Finally, by cooling the stator, the fused layer is solidified, and a stator without an air gap can be manufactured between the coil and the insulating paper. In addition, the configuration in which the self-bonding layer is provided on the insulating paper does not reduce the coil space factor, and moreover, the manufacturing cost compared to the case where the self-bonding layer is formed on the conductive wire. Will be much cheaper.

In another embodiment of the stator according to the present invention, the coil is a distributed multiphase coil, and between the U phase coil and the V phase coil and between the V phase coil and the w phase coil in the coil end. Is characterized in that interphase insulating papers each having a self-bonding layer on both sides are interposed, and the self-bonding layer is bonded to the coil.

The stator of the present invention is intended for a distributed type stator having a U-phase coil, a V-phase coil, and a W-phase coil. In the case of this distributed type stator, in addition to the slot insulating paper, Interphase insulating paper is installed to insulate between the different phase coils at the coil end.

Therefore, as the interphase insulating paper interposed between the U-phase coil and the V-phase coil and between the V-phase coil and the W-phase coil, the interphase insulating paper provided with self-bonding layers on both sides of the above-mentioned polymer material is used. use. The self-bonding layer of the interphase insulating paper can also be formed from the above-mentioned high heat-resistant resin material, and the air gap generated between each phase coil and the interphase insulating paper is filled with the self-bonding layer by heat treatment. be able to.

By manufacturing a motor (electric motor) having the above-described concentrated-winding type stator or distributed-winding type stator, a motor having high heat dissipation and high insulation safety can be obtained. This insulation safety means that the occurrence of electric field concentration can be eliminated to prevent the occurrence of severely insulating parts, resulting in a low probability of motor dielectric breakdown. In addition, since there is no electric field concentration site, it becomes possible to apply a higher electric field to the coil, and it is possible to increase the insulation while ensuring insulation. Realization of motor output can be achieved. Such high-performance motors have a wide range of applications, including not only application to next-generation SR motors for hybrid vehicles, but also motors used in various home appliances and model playground equipment.

The stator manufacturing method according to the present invention is a stator manufacturing method in which a coil is concentratedly wound, and includes a step of preparing slot insulating paper having a self-bonding layer on at least one side surface, and a stator core. A step of manufacturing, a step of disposing the slot insulating paper in the spout in a posture in which the self-bonding layer is directed to the side opposite to the wall surface of the spout, and a coil around each tooth. And a step of heat-treating the stator core on which the coil is formed to fuse the slot insulating paper to the coil.

In the above manufacturing method, the varnish is impregnated from the coil end after the coil is formed, and then the heat treatment is performed. However, even if the heat treatment is performed prior to the varnish impregnation, the self-bonding layer is melted. Alternatively, a method of melting the self-bonding layer in the heat treatment step after varnish impregnation may be used. Note that this heat treatment may be any method of current heating and furnace heating, and is preferably performed in a temperature atmosphere that is higher than the melting point of the self-bonding layer and does not cause thermal deterioration of the stator core.

Furthermore, a stator manufacturing method according to the present invention is a stator manufacturing method in which coils are distributedly wound, and includes slot insulating paper having a self-bonding layer on at least one side surface, and a self-bonding layer on both sides. A step of preparing an interphase insulating paper provided on the surface, a step of manufacturing a stator core, and the slot insulating paper with its self-bonding layer facing away from the slot wall surface in the slot. A step of arranging, distributing the U-phase coil and arranging the interphase insulating paper on the coil end, then distributing the V-phase coil and arranging the separate interphase insulating paper on the coil end, Next, it includes at least a step of distributedly winding the W-phase coil, and a step of heat-treating the stator core on which the coil is formed to fuse the slot insulating paper and the interphase insulating paper to the coil.

In the case of a distributed coil, the coil end is laced and then varnish-impregnated, and the heating process is performed prior to this lacing to melt the self-bonding layer. Or heat treatment after varnish impregnation treatment A method of melting the self-bonding layer in stages may be used.

As can be understood from the above description, according to the stator of the present invention and the motor including the stator, the air gap between the coil and the insulating paper can be reduced at low cost without reducing the coil space factor. It is possible to eliminate the occurrence, and to obtain a stator and a motor excellent in heat dissipation and insulation. Brief Description of Drawings

FIG. 1 is a perspective view of an embodiment of the slot insulating paper of the present invention.

FIG. 2 is a perspective view of an embodiment of the interphase insulating paper of the present invention.

In Fig. 3, (a) is a cross-sectional view showing the situation before the self-bonding layer of the slot insulation paper is melted, and (b) is the situation where the self-fusion layer of the slot insulation paper is melting. FIG.

FIG. 4 is a perspective view of the distributed winding stator of the present invention.

FIG. 5 is an enlarged view of a portion V in FIG.

6 is a cross-sectional view of the inside of the coil end of FIG.

FIG. 7 is an enlarged view of a part VII in FIG.

FIG. 8 is a sectional view of the inside of the slot of FIG.

Figure 9 is a schematic diagram of a simulation analysis result image regarding the presence or absence of electric field concentration. (A) is the result for a case using conventional insulating paper, and (b) is the result of using the insulating paper of the present invention. It is the result regarding the case.

FIG. 10 is a cross-sectional view showing a U-phase coil and a V-phase coil in a conventional coiled end of a distributed stator and interphase insulating paper interposed therebetween.

FIG. 11 is a cross-sectional view showing a slot wall surface and slot insulating paper in a conventional spout of a stator. In the drawing, 1 is a piece of paper, 2 is a self-bonding layer, 3, 3 A, 3 B are conductors, 3 1 is a conductor, 3 2 is an enamel coating, 4 is a stator core, 4 1 is a tooth, 4 2 is a slot, 4 3 is coiled, 5 is varnish, 10 is slot insulating paper, 20 is interphase insulating paper, and 1 0 0 is distributed stator. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an embodiment of the slot insulating paper of the present invention, and FIG. 2 is a perspective view of an embodiment of the interphase insulating paper of the present invention. Fig. 3a is a cross-sectional view showing the situation before the self-bonding layer of the slot insulating paper is melted, and Fig. 3b is a cross-section showing the state of the self-bonding layer of the slot insulating paper being melted. FIG. 4 is a perspective view of a distributed-spreading stator according to the present invention, FIG. 5 is an enlarged view of a portion V in FIG. 4, and FIG. 6 is a cross-sectional view inside the coil end of FIG. 7 is an enlarged view of the VII portion of FIG. 4, and FIG. 8 is a cross-sectional view of the inside of the slot of FIG. Fig. 9 is a diagram simulating the simulation analysis result image regarding the presence or absence of electric field concentration, Fig. 9 a is the result for the case using conventional insulating paper, and Fig. 9 b is the case using the insulating paper of the present invention. Is the result. Of course, the shape of the insulating paper is not limited to the embodiment shown in the drawing, and any insulating paper having a self-bonding layer on at least one side and both sides of the paper may be used. The shape is arbitrary.

FIG. 1 shows an embodiment of slot insulation paper. This slot insulating paper 10 is made of a paper piece 1 of a polymer material having an insulating performance such as polyethylene naphthalate (PET) or polyethylene naphthalate (PEN), and on one side, nylon 6, nylon A self-bonding layer 2 made of a highly heat-resistant resin material such as polyamide resin such as 6-6 and nylon 6-10 is fixed and formed.

The slot insulating paper 10 is arranged in a posture in which the self-bonding layer 2 is directed to the side opposite to the slot wall surface (coil side) in a stator slot (not shown).

On the other hand, FIG. 2 shows an embodiment of interphase insulating paper. This interphase insulating paper 20 is a paper piece 1 made of the same material as the slot insulating paper 10 and self-bonding layers 2 and 2 of the above material fixed to both sides thereof. It is inserted between the phase coil and the V-phase coil and between the V-phase coil and the W-phase coil.

Fig. 3 shows that when slot insulating paper 10 is placed in a high-temperature atmosphere, its self-bonding layer 2 melts and coil 3 (consists of copper conductor 3 1 and enamel coating 3 2 on its periphery). ) And slot insulating paper 10 are simulated. Fig. 3a shows the situation before melting of the self-bonding layer 2, and Fig. 3b shows the self-bonding layer. 2 shows a melting state (the self-bonding layer 2 melts in the direction of the arrow in Fig. 3b). The self-bonding layer 2 that has melted and the viscosity has been reduced penetrates between the paper piece 1 and the coil with surface tension, and the slot insulating paper 10 is disposed across the height of the stator core. Therefore, the possibility of unimpregnated parts of the melted self-bonding layer 2 is extremely low. The melting of the self-bonding layer 2, that is, the heat treatment step may be performed before or after the varnish impregnation treatment step.

Fig. 4 shows that the slot insulating paper 10 is placed in the slot, and the interphase insulating paper 20 is between the U-phase coil and V-phase coil of coil end 4 3 and between the V-phase coil and W-phase coil. A distributed stator 100 is shown in which each self-bonding layer 2 is bonded to the coil through heat treatment.

FIG. 5 is an enlarged view of the coil end, and FIG. 6 is an enlarged sectional view of the inside. When FIG. 6 is compared with FIG. 10, the air gap A generated in FIG. 10 is impregnated with the melted self-bonding layer 2 of the interphase insulating paper 20, so that the U-phase coil 3 A and There is no air gap between V-phase coil 3 B and paper piece 1. In addition, varnish 5 is impregnated between the conducting wires 3 A,..., 3 B,. Therefore, there is no air gap between the coils and between the coil and the insulating paper, and a stator with high interphase insulation is formed.

On the other hand, FIG. 7 is an enlarged view of the inside of the slot, and FIG. 8 is an enlarged sectional view of the inside thereof. When FIG. 8 is compared with FIG. 11, the air gap A generated in FIG. 11 is impregnated with the melted self-bonding layer 2 of the slot insulating paper 10, and as shown in FIG. There is no air gap between and the piece of paper 1. Also, the varnish 5 is impregnated between the conductors 3 and 3 in the same manner as the coil end, so that high insulation between the stator core and the coil is ensured.

When using slot insulation paper 10 or interphase insulation paper 20 that forms a self-fusion layer on one or both sides of the insulation paper, compared to the case where a self-fusion layer is formed on the outer periphery of the conductor. The coil space factor does not decrease. Also, when the air gap that can occur between the insulation paper and the coil is eliminated, the amount that satisfies the assumed air gap cross section P

By forming the self-bonding layer of WO 2008/130058 on the side surface of the insulating paper, such an air gap can be more reliably eliminated. Therefore, by producing a stator to which the sputt insulation paper and interphase insulation paper of the present invention is applied, a stator having excellent insulation performance and heat dissipation performance can be obtained without reducing the coil space factor. Can be obtained.

[Simulation analysis results regarding the presence or absence of electric field concentration]

The present inventors simulated whether or not there is electric field concentration between the case where the insulating paper (the paper piece) and the coil conductor are fused using the insulating paper of the present invention and the case where the conventional insulating paper is used. Analyzed. An image showing the analysis results is simulated in Fig. 9, where Fig. 9a shows the case of using conventional insulating paper, and Fig. 9b shows the case of using the insulating paper of the present invention having a self-bonding layer. Shows the case.

In Fig. 9a, Ml is a conventional insulating paper model without a self-bonding layer, and coil models M2 and M3 are arranged on both sides of the insulating paper model M1 with a gap (air gap). As input conditions for the analysis, the potential difference is 650 V, the conductor diameter is 0.85 mm, the enamel width is 0.035 mm, the insulating paper thickness is 0.125 mm, and the relative permittivity is self-bonding layer. 3 for air, 1 for coil, 0 for coil, and 4 for enamel and insulating paper.

As a result of the analysis, the electric field distribution is 7 to 9.5 X 10 ⁶ (V / m) in the air gap region (V l, V2 region). As the distance from the V3 region, V 4 region and the air gap increases. The voltage goes down. In other words, it can be identified that electric field concentration occurs in this air gap.

On the other hand, when the coil and the insulating paper are fused through the self-bonding layer (here, the insulating paper model with the self-bonding layer is Ml,) As shown in b, the electric field distribution in the region where the air gap occurred in Fig. 9a (V 3 region in Fig. 9 b) is 5 X 10 ⁶ (V / m), and the outer V 4 region The electric field level is about the same as the electric field distribution (3 X 10 ⁶ (V / m)). From this analysis result, it is possible to specify that the electric field concentration does not occur when the paper piece and the coil are fused in the self-bonding layer and there is no air gap. Note that the electric field levels in the 3 and V4 regions in Fig. 9 & are the same as those in Fig. 9b.

From the above analysis results, the insulating paper piece and coil are fused through the self-bonding layer, and the air It was found that the elimination of the gap can effectively prevent the occurrence of electric field concentration.

Although not shown, the motor having the stator 100 is particularly suitable for a drive motor for a hybrid vehicle or an electric vehicle that requires high durability and high output performance.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like within the scope not departing from the gist of the present invention. However, they are included in the present invention.

Claims

The scope of the claims

1. a stator core provided with an annular yoke, a plurality of teeth projecting radially inward from the yoke, slots formed between adjacent teeth, and a coil formed around the teeth; In the stator consisting of

A slot insulating paper provided with a self-bonding layer on at least one side surface is interposed between the coil and the teeth with the self-bonding layer facing the coil side, and the self-bonding layer is A stator characterized by being fused to a coil.

2. The coil is a distributed multiphase coil;

Between the U-phase coil and the V-phase coil in the coil end, between the V-phase coil and the w-phase coil, interphase insulating papers with self-bonding layers on both sides are interposed, respectively.

The status according to claim 1, wherein the self-bonding layer is bonded to the coil.

3. A motor comprising at least the stator according to claim 1 or 2 and a rotor rotating inside the stator.

4. A stator manufacturing method comprising concentrated winding of coils,

Preparing a slot insulating paper having a self-bonding layer on at least one side; manufacturing a stator core;

The slot insulating paper is disposed in the slot in such a manner that its self-bonding layer is directed to the opposite side of the slot wall surface;

Forming a coil around each tooth;

A process of heat-treating the stator core on which the coil is formed, and fusing the slot insulating paper to the coil.

5. A stator manufacturing method in which coils are distributed,

Providing a slot insulating paper having a self-bonding layer on at least one side and a phase insulating paper having a self-bonding layer on both sides;

Manufacturing a stator core; and

The slot insulating paper with its self-bonding layer facing away from the slot wall surface A step of being arranged in the slot in a force;

Distribute the u-phase coil and dispose the interphase insulating paper on the coil end, then distribute the V-phase coil and dispose another interphase insulating paper on the coil end, and then distribute the w-phase coil. The process of

And a step of heat-treating the stator core on which the coil is formed to fuse the slot insulating paper and the interphase insulating paper to the coil.