JP2000023431A - Manufacture of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve coil cooling capacity of a motor by eliminating gaps between the coil and the internal surface of a coil slot. SOLUTION: A resin layer 30 having the thickness necessary for securing a dielectric breakdown voltage is formed on the outer periphery of a single rectangular cassette coil formed by concentratedly winding a coil 40 composed of a flat enameled wire by molding the cassette coil with a resin and, when the cassette coil is molded with the resin, communicating grooves 32 which have a prescribed depth and can communicate with each other in the axial direction and radial direction of a coil stator are formed into the resin layer 30 which is in contact with the internal surface of the stator ((a) and (b)). Then the cassette coil carrying the resin layer 30 having the grooves 32 is inserted into a coil slot (c) and the gap 7 formed between the cassette coil and internal surface of the coil slot and the grooves 32 are impregnated with an insulating filler 52 by dripping if from a nozzle 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing an electric motor,
In particular, the present invention relates to a method of manufacturing a motor for improving cooling performance of a coil in a coil slot of a stator of the motor.

[0002]

2. Description of the Related Art Conventionally, an insulation structure of an electric winding in which a winding coil (hereinafter referred to as "coil") is accommodated in a coil slot of a generally used stator is, for example, a sectional view shown in FIG. It has a structure as shown in FIG. That is,
In the coil slot 1, for example, a U-shaped slot insulator 11 using a polyester film or the like is mounted. Inside the slot insulator 11, a coil 5 using a synthetic resin enamel wire such as a polyester wire is stored. After enclosing the slot insulator 11, a wedge 9 made of a polyester film or the like formed into a half U shape is driven into the coil 5 to fix it. Further, the assembled coil 5 is immersed and impregnated,
Alternatively, the thermosetting resin 4 is impregnated in the coil slot 1 and the coil end portion by a dropping impregnation process or the like, and is heated and cured to integrally form the coil 5.

In the conventional coil insulation structure described above, the withstand voltage between the coils is maintained by the insulation strength of the enameled wire, and the ground voltage is maintained by the slot insulator 11. Also,
The insulating resin impregnating the inside of the coil slot 1 and the coil end part plays a role of mechanically and strongly improving the moisture resistance insulation of the coil in addition to reinforcing the dielectric strength.

However, in the above-described insulating structure, when the coil 5 is housed in the slot insulator 11, the slot insulator in the cross-sectional area in the coil slot 1 is taken into consideration in consideration of workability and damage to the enamel wire coating. 11, coil 5,
The ratio of the wedges 9, that is, the space factor in the coil slot 1, is usually 55 to 60%. Therefore, nearly the other half of the slot cross section of the remaining 40 to 45% remains as an air layer. The air layer also exists between the slot insulator 11 and the coil 5 and between the electromagnetic steel plate 2 on the inner wall of the coil slot 1 and the slot insulator 11.

On the other hand, the insulating paper 20 generally used as the slot insulator 11 cannot transmit the thermosetting resin 4 by the immersion impregnation method or the drop impregnation method. For this reason, even after performing the immersion impregnation process or the drop impregnation process, the gap 7 remains between the electromagnetic steel sheet 2 and the insulating paper 20 and between the insulating paper 20 and the coil 5 as shown in FIG. . The gap 7 is provided between the coils 5a, 5
Since the thermal conductivity from b to the iron core is significantly reduced, the development of a small and high-output motor has been hindered.

In view of the above circumstances, Japanese Patent Application Laid-Open No. 54-159607 proposes a rotary electric winding in which an air layer generated between the inner wall of the coil slot 1 and the slot insulator 11 is removed. ing. Here, the slot insulator 1
As shown in FIG. 6, a fine powder piece or nonwoven fabric 1 made of a polyester fiber or the like excellent in resin impregnation on at least one surface thereof is provided on a base material 15 such as a polyester film as shown in FIG.
6 is composed of the laminated composite insulation.

Therefore, as shown in FIG. 7, the slot insulator 11 made of the composite insulation is inserted into the coil slot 1 in a U-shape, and then the coil insulator is inserted into the slot insulator 11 as shown in FIG. 5, a semi-U-shaped wedge 9 is driven in, the thermosetting resin 4 or the like is impregnated with a synthetic resin by a vacuum impregnation or drop impregnation method, and slot insulation is performed via a resin impregnation layer such as a nonwoven fabric 16. Synthetic resin such as thermosetting resin 4 smoothly impregnates between the object 11 and the inner wall of the coil slot 1 and solidifies. Thereby, the slot insulator 11
The air layer between the coil and the inner wall of the coil slot 1 can be removed.

[0008]

However, since the slot insulator 11 disclosed in the above publication is made of composite insulation as described above, its thickness becomes large. For example,
The thickness of normal insulating paper is 0.3 mm,
When insulating paper is used, the thickness becomes 0.3 mm or more. On the other hand, there is a problem that as the thickness of the slot insulator 11 increases, the thermal conductivity from inside the slot decreases.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to reduce the distance between the inner wall of the coil slot and the coil to a minimum distance sufficient for dielectric strength, and to connect the inner wall of the coil slot to the coil. It is an object of the present invention to provide a method for manufacturing a motor in which an air layer is eliminated between the coils to improve coil cooling capacity.

[0010]

Means for Solving the Problems In order to solve the above problems, a method for manufacturing a motor according to the present invention has the following features.

(1) In a manufacturing method of manufacturing an electric motor by inserting a concentratedly wound cassette coil into one or more coil slots provided in a stator, a predetermined thickness is formed on the outer periphery of the concentratedly wound cassette coil. A resin layer having a predetermined depth on a surface of the resin layer facing the inner wall of the coil slot, and an axial direction of the stator,
Forming a communication groove capable of communicating with each other in the radial direction of the stator, inserting a cassette coil formed with a resin layer having the communication groove into the coil slot, and then between the cassette coil and a coil slot inner wall. This is a method for manufacturing an electric motor in which an insulating filler is impregnated in formed voids.

By forming communication grooves which can communicate with each other in the axial direction of the stator and in the radial direction of the stator in the resin layer formed on the outer periphery of the cassette coil, the insulating filler material to be impregnated or dipped and impregnated has communication grooves. , The entire space formed between the cassette coil and the inner wall surface of the coil slot is filled. Therefore, there is no possibility that an air layer remains between the cassette coil and the inner wall of the coil slot. Furthermore, since the resin layer on the outer periphery of the cassette coil and the filler filled in the gap between the inner wall of the coil slot and the cassette coil function as an insulating layer, the thickness of the insulating layer should be as close as possible to the thickness required for insulation. Can be. Therefore, the coil cooling capacity can be improved by eliminating the air layer and reducing the thickness of the insulating layer.

(2) In the method of manufacturing a motor according to the above (1), after the insulating filler is impregnated between the inner wall of the coil slot and the cassette coil, the stator is rotated to fill the cassette. This is a method for manufacturing an electric motor that facilitates filling of materials.

By rotating the stator after the dropping impregnation process or the immersion impregnation process of the filler material, a uniform and void is not formed in the entire coil slot by centrifugal force.
An insulating filler can be filled. Therefore, there is no possibility that an air layer remains between the inner wall of the coil slot and the cassette coil. Therefore, the coil cooling capacity can be further improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described.

A method of manufacturing the electric motor according to the present embodiment will be described with reference to FIGS.

As shown in FIG. 1, what is inserted into the coil slot 18 of the stator 14 in the electric motor according to the present embodiment is a concentratedly wound cassette coil, unlike the random winding described in the prior art.

A manufacturing method will be described using a rectangular cassette coil used in the manufacturing method of the present embodiment. In the present embodiment, a coil made of a flat enameled wire covered with a synthetic resin such as a polyester wire is used as the rectangular cassette coil.

First, FIG. 2, FIG. 3 and FIG.
As shown in (b), a coil 4 made of a flat enameled wire
The cassette coil 10 having a resin layer 30 of a predetermined thickness formed on the outer periphery is obtained by resin molding into a single cassette coil in which 0 is concentratedly wound. Here, the predetermined thickness is preferably equal to or more than a thickness required for withstand voltage between the cassette coil and the inner wall of the coil slot 18, for example, 0.02 to 0.05 mm. In particular, on the surface of the inner wall of the coil slot 18 which faces the electromagnetic steel plate surface and the surface which comes into contact with the other cassette coil 12 to be combined, a resin layer 30 having a thickness necessary for the dielectric strength is formed. Perform molding. In addition, the contact surface between the cassette coil 10 and the cassette coil 12 only needs to have a resin layer 30 having a thickness required for the above-mentioned withstand voltage on at least one of the contact surfaces of the cassette coil.

Further, at the time of this resin molding, a communication groove 32 having a predetermined depth and capable of communicating with each other in the axial direction of the stator 14 and in the radial direction of the stator 14 is formed in the resin layer 30 which comes into contact with the inner wall of the coil slot 18. To form The communication groove 32 may have any shape as long as it allows the insulating filler for the impregnation treatment described later to circulate through the groove.

The resin layer 30 having such communication grooves 32
As a resin molding method, a plurality of protrusions having a height corresponding to a predetermined thickness of the resin layer 30 and capable of forming the above-described communication groove 32 are formed on a mold die surface, for example. There is a method in which a cassette coil wound in a concentrated manner is put in the mold, and the mold is filled with a mold resin while supporting the coil wire with the protrusions.

Similarly, a resin layer 30 similar to the cassette coil 10 is formed on the outer periphery of the other cassette coil 12, and a predetermined surface of the resin layer 30 in contact with the inner wall of the coil slot 18 is provided. A communication groove 32 having a depth in the axial direction of the stator 14 and a radial direction of the stator 14 is formed. Since the resin molding method at this time is the same as the molding method of the cassette coil 10, the description thereof is omitted here.

Next, the cassette coil 10 and the cassette coil 12 having the resin layer 30 having the communication groove 32 formed thereon are formed.
Is inserted into the coil slot 18 as shown in FIG. As described above, since the coil slot 18 has a wide structure in the slot radial direction, the cassette coil 12 is first inserted, and then the cassette coil 10 is inserted and fixed.

Generally, the surface of the steel plate of the stator 14 constituting the inner wall of the coil slot 18 is uneven. Then, between the cassette coil in a state where each cassette coil is inserted and the inner wall of the coil slot 18, FIG.
As shown in (c), there are many voids 7.

Then, after inserting the cassette coil, FIG.
As shown in (d), the gap 7 and the communication groove 32 formed between the cassette coil and the inner wall of the coil slot are impregnated with the insulating filler 52 from the nozzle 50 by dropping. Before the dripping and impregnation of the insulating filler 52, it is preferable to preheat the stator 14 with the cassette coil inserted therein to a temperature at which the insulating filler can flow. In the present embodiment, the drop impregnation process is performed. However, the present invention is not limited to this, and an immersion impregnation process may be performed.

Here, the insulating filler 52 may have a fluidity due to a decrease in viscosity at a certain temperature, but may gel at other temperatures, for example, a varnish. When using a varnish, the preheating temperature is preferably around 100 ° C.

As described above, according to the manufacturing method of this embodiment, the communication grooves which can communicate with each other in the axial direction of the stator and in the radial direction of the stator are formed in the resin layer formed on the outer periphery of the cassette coil. Therefore, the insulating filler to be impregnated or dipped and impregnated can fill the entire gap formed between the cassette coil and the inner wall surface of the coil slot via the communication groove. Therefore, there is no possibility that an air layer remains between the cassette coil and the inner wall of the coil slot, and the resin material on the outer periphery of the cassette coil and the filler filled in the gap between the inner wall of the coil slot and the cassette coil serve as an insulating layer. To function, the thickness of this insulating layer can be as close as possible to the thickness required for insulation. Therefore, the coil cooling capacity can be improved by eliminating the air layer and reducing the thickness of the insulating layer.

In this embodiment, the stator 14 may be rotated after the impregnation with the insulating filler. Thereby, the insulating filler 52 can be filled without forming a uniform gap in the entire coil slot 18 by centrifugal force. Therefore, there is no possibility that an air layer remains between the inner wall of the coil slot 18 and the cassette coil, so that the coil cooling capacity can be further improved.

The rotation speed of the stator 14 is preferably such that the impregnated filler is not scattered, for example, about once per second to six times per second.

In this embodiment, the dripping impregnation method has mainly been described, but the present invention is not limited to this, and an immersion impregnation method or a vacuum impregnation method may be used.

In the example of the electric motor manufactured by the manufacturing method of the present embodiment, the evaluation result of the MGI (generator) for the electric HV unit shows that the motor is operated until the maximum coil temperature reaches 150.degree. The extra time is 2 for 2.5 minutes of the insulation paper type motor.
It improved to 5 minutes. Therefore, further miniaturization of the motor,
High output can be achieved.

[0032]

As described above, according to the method of manufacturing an electric motor according to the present invention, the resin layer in which the communication groove which can communicate with each other in the axial direction of the stator and the radial direction of the stator is formed on the outer periphery of the cassette coil. Therefore, the insulating filler to be impregnated or dipped and impregnated is filled in the entire gap formed between the cassette coil and the inner wall surface of the coil slot via the communication groove. Thus, there is no possibility that an air layer remains between the cassette coil and the inner wall of the coil slot. Furthermore, since the resin layer on the outer periphery of the cassette coil and the filler filled in the gap between the inner wall of the coil slot and the cassette coil function as an insulating layer, the thickness of the insulating layer should be as close as possible to the thickness required for insulation. Can be. Therefore, the coil cooling capacity can be improved by eliminating the air layer and reducing the thickness of the insulating layer.

Further, by rotating the stator after the dripping impregnation treatment or the immersion impregnation treatment of the filler, the insulating filler can be filled uniformly without forming voids in the entire coil slot by centrifugal force. it can. Therefore, there is no possibility that an air layer remains between the inner wall of the coil slot and the cassette coil, and the coil cooling capacity can be further improved.

[Brief description of the drawings]

FIG. 1 is a partially omitted view illustrating a configuration of a stator manufactured by a method of manufacturing an electric motor according to the present invention.

FIG. 2 is a perspective view of a resin-molded rectangular cassette coil used in the electric motor manufacturing method of the present invention.

FIG. 3 is an enlarged sectional view of a portion taken along line AA ′ of FIG. 2;

FIG. 4 is a diagram illustrating a method for manufacturing a motor according to the present invention.

FIG. 5 is a slot longitudinal sectional view showing a conventional method of insulating a winding slot of a rotating electrical machine.

FIG. 6 is a view showing the structure of a slot insulator disclosed in Japanese Patent Application Laid-Open No. 54-159607.

FIG. 7 is a longitudinal sectional view showing a slot insulating method disclosed in Japanese Patent Application Laid-Open No. 54-159607.

FIG. 8 is an end perspective view in which an insulator of a slot disclosed in Japanese Patent Application Laid-Open No. 54-159607 is mounted in a slit.

FIG. 9 is an enlarged sectional view of a portion D in FIG. 8;

[Explanation of symbols]

10, 12 cassette coil, 14 stator, 18
Coil slot, 30 resin layer 32 communication groove.

Claims (2)

[Claims] 1. A manufacturing method for manufacturing an electric motor by inserting a concentratedly wound cassette coil into at least one or more coil slots provided in a stator, wherein the concentratedly wound cassette coil has a predetermined thickness on an outer periphery thereof. Along with forming the resin layer, having a predetermined depth on the surface of the resin layer facing the inner wall of the coil slot and forming a communication groove capable of communicating with each other in the axial direction of the stator and the radial direction of the stator, Inserting the cassette coil in which the resin layer having the communication groove is formed into the coil slot, and then impregnating the gap formed between the cassette coil and the coil slot inner wall with an insulating filler. Manufacturing method of electric motor. 2. The method according to claim 1, wherein the insulating filler is impregnated between an inner wall of the coil slot and a cassette coil, and then the stator is rotated to remove the filler. A method for manufacturing an electric motor, characterized by promoting filling.