JPH08186965A - Electric motor rotor manufacturing method - Google Patents

Abstract

(57) [Summary] [Purpose] To manufacture a rotor of an electric motor excellent in electrical characteristics and strength characteristics by a simple method. [Structure] A pipe-shaped member 6 molded from a mixed material of a conductive material and a thermoplastic resin is inserted into a conductor cavity of a rotor core, and a temperature condition equal to or higher than a melting temperature of the thermoplastic resin of the pipe-shaped member The rotor of the electric motor is obtained by press-fitting the conductor bar 10 forming the rotor conductor into the pipe-shaped member while melting the thermoplastic resin. Since the thermoplastic resin of the pipe-shaped member melts and acts as a lubricating film, the conductor bar can be smoothly press-fitted. By using a resin material having excellent electric insulation for the thermoplastic resin, the lubricating film functions as an insulating film after the resin is cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a rotor of an electric motor, which is composed of a rotor core and a rotor conductor.

[0002]

2. Description of the Related Art An electric motor equipped with a rotor having the above structure is
Conventionally, it has been used as a liquid ring type canned electric motor or a roots type canned electric motor. For example, in a liquid-sealed canned electric motor, a stator core formed by laminating silicon steel plates is arranged in a frame, a stator coil is mounted on the stator core, and the rotating core is provided at the center thereof. The child is disposed so as to penetrate the main shaft with a small clearance from the stator core.

The rotor of an electric motor is composed of a rotor core 1 formed by laminating silicon steel plates and a rotor conductor 2 (see FIGS. 2 and 3). A spindle insertion hole 3 for inserting a spindle is formed in the center of the rotor core 1, and a groove 4 for inserting the rotor conductor 2 is provided. A large number of grooves 4 are formed around the spindle insertion hole 3. The rotor conductor 2 inserted in the groove 4 penetrates the rotor core 1 in the axial direction and is in contact with the rotor conductors (end rings) 5 fixed to both ends of the rotor core 1.

[0004]

The rotor conductor of such an electric motor is generally manufactured by casting or die casting of aluminum (Al). During the manufacturing process, gas entrainment and solidification in the conductor are caused. Occurrence of defects such as shrinkage cavities due to shrinkage cannot be avoided, and Al
Of the electric motor, which in turn causes the electric characteristics of the electric motor to deteriorate.

In order to solve this, some of the pressurization of the molten Al is performed in the solidification process, but a two-stage pressurizing mechanism or the like is required, which complicates the manufacturing equipment.

Although copper (Cu), which has excellent electrical characteristics, is also machined and used as a material for the rotor conductor, the conductor insertion groove has an edge of a silicon steel plate forming the rotor core. The end portion of the groove is exposed, and this becomes a press-fitting resistance, so that it takes time and effort to drive the Cu bar into the conductor insertion groove. In addition, since it is inevitable that a slight gap is left between the rotor groove and the Cu bar, the strength is inferior, and noise or damage may occur due to vibration during operation. Further, there is a problem in that the welding for short-circuiting the end rings on both ends and the Cu bar and the post-treatment after the welding are required, which makes the price expensive.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems of the prior art and to manufacture a rotor of an electric motor excellent in electrical characteristics and strength characteristics by a simple method. .

That is, according to the present invention, the rotation of an electric motor comprising a rotor core having a spindle insertion hole and a conductor cavity, and a rotor conductor inserted into the conductor cavity of the rotor core. A method for manufacturing a child, wherein a pipe-shaped member formed of a mixed material of a conductive material and a thermoplastic resin is inserted into the conductor cavity portion of the rotor core, and the thermoplastic resin of the pipe-shaped member is melted. While melting the thermoplastic resin under a temperature condition of temperature or higher,
The conductor bar forming the rotor conductor is press-fitted into the pipe-shaped member.

In order to apply a temperature condition above the melting temperature of the thermoplastic resin of the pipe-shaped member when press-fitting the conductor bar, the conductor bar heated above the melting temperature of the thermoplastic resin is pipe-shaped. The conductor bar is press-fitted into the member, or the rotor core is heated to a temperature equal to or higher than the melting temperature of the thermoplastic resin of the pipe-shaped member to press-fit the conductor bar into the pipe-shaped member.

It is preferable to use a resin material having an electric insulation property as the thermoplastic resin. As a result, the electrically insulating thermoplastic resin melted by press-fitting the conductor bar into the pipe-shaped member is cured after completion of press-fitting of the conductor bar to form an insulating coating film of the electrically insulating thermoplastic resin. . The insulating coating completely insulates the rotor core 1 and the conductor 2 from each other, thereby preventing the leakage of current from adversely affecting the motor characteristics.

As the pipe-shaped member, a mesh member formed by weaving fibers of the conductive material and fibers of the thermoplastic resin into a cylindrical mesh can be used. As a result, when the conductor bar is press-fitted, the mesh member is pressed against the inner wall surface of the conductor cavity while expanding its diameter, and the adhesion strength is improved.

The conductive material of the pipe-shaped member and the material of the conductor bar are pure copper, copper alloy, pure silver, silver alloy or a mixture thereof, or a material in which a third component (iron, stainless steel, etc.) is further mixed. Can be used.

[0013]

After a pipe-shaped member made of a conductive material and a thermoplastic resin is inserted and fixed in the conductor cavity of the rotor core, the temperature is equal to or higher than the melting temperature of the thermoplastic resin forming the pipe-shaped member. Press in the conductor bar that forms the rotor conductor. Since the thermoplastic resin of the pipe-shaped member melts and acts as a lubricating film, the conductor bar can be smoothly press-fitted. The lubricating film functions as an insulating film after the resin is cured.

[0014]

Embodiments of the present invention will be described below with reference to FIG. The overall structure of the electric motor rotor manufactured in this embodiment is the same as that of the conventional technique shown in FIGS. 2 and 3, and therefore, in FIG. ing.

Reference numeral 6 in FIG. 1 denotes a mesh member woven of pure copper fibers and electrically insulating thermoplastic resin (for example, nylon) fibers in a cylindrical mesh shape.
The mesh member 6 has an inner diameter dimension B (B <A) slightly larger than an outer diameter dimension A of a pure copper bar 10 described later, and an outer diameter dimension C slightly smaller than an inner diameter dimension D of the conductor cavity portion 4. (C <D).

The mesh member 6 is inserted into the conductor cavity portion 4 of the rotor core 1. As described above, since the outer diameter dimension C of the mesh member 6 is formed smaller than the inner diameter dimension D of the conductor cavity portion 4, this insertion can be performed very easily.

In order to prevent the mesh member 6 from moving in the axial direction when the pure copper bar 10 to be described later is press-fitted, a flange 7 is formed in advance at one end of the mesh member 6, and the hollow holder 8 is used. While pressing the flange 7,
It is preferable to insert the mesh member 6 into the conductor cavity portion 4 from the other end side until the flange 7 engages with the end surface of the rotor core 1. After the insertion of the mesh member 6 is completed in this manner, the other end of the mesh member 6 is subjected to flanging processing and then cured, so that the mesh member 6 is loosely fitted in the conductor cavity portion 4 and is axially opposed to each other. It can be placed while restricting movement. In addition, as shown in FIG. 1, the pure copper bar 1 is inserted from the side of the flange 7 of the mesh member 6.
When limiting the press-fitting direction so that 0 is press-fitted, it is possible to leave the other end of the mesh member 6 without flange processing.

Thereafter, the pure copper bar 10 heated above the melting temperature of the thermoplastic resin of the mesh member 6 (for example, 250 ° C.) is pressed into the mesh member 6 inserted in the conductor cavity portion 4. Pure copper bar 10 heated in this way
By the press-fitting, the mesh member 6 expands in diameter and the thermoplastic resin in the mesh member melts, so that the lubricating film 9 made of the melted thermoplastic resin is provided between the pure copper bar 10 and the inner wall surface of the conductor cavity portion 4. Formed, smooth press-fitting of the pure copper bar 10.

By the way, instead of heating the pure copper bar 10 above the melting temperature of the thermoplastic resin of the mesh member 6, or together with it, heating the rotor core 1 above the melting temperature of the thermoplastic resin, The thermoplastic resin may be melted when the pure copper bar 10 is press-fitted.

When the press-fitting of the pure copper bar 10 is completed as described above, the rotor conductor 2 made of the pure copper bar 10 is firmly adhered to the conductor cavity portion 4 of the rotor core 1.
The lubricating film 9 becomes an insulating film after the thermoplastic resin is hardened, electrically insulates the rotor core 1 and the conductor 2 completely, and prevents deterioration of motor characteristics due to current leakage.

After that, the end rings 5 are installed at both ends of the rotor conductor 2 by an arbitrary means such as crimping by a press machine, caulking, brazing, etc., and the rotor of the electric motor as shown in FIGS. 2 and 3 is manufactured. To be done. Alternatively, pure copper bar 1
On the side opposite to the press-fitting end of 0, the rotor core 1 and the end ring 5 may be integrated beforehand.

In addition, the end rings 5 are integrated in advance at both ends of the rotor core 1, and the conductor cavity portion 4 is formed.
After inserting the mesh member 6 from the side of the straight end opposite to the end where the flange 7 is formed, the straight end may be flanged on the opposite side of the rotor. By doing so, the rotor core 1 and the end ring 5 are firmly integrated by the flanges formed at both ends of the mesh member 6, and the step of mounting the end ring after press-fitting the pure copper bar becomes unnecessary. In this case, the pure copper bar press-fitted may be left as it is, or if necessary, it may be caulked and brought into close contact with the end ring by brazing or the like.

[0023]

According to the present invention, since the rotor conductor is firmly integrated in the groove of the rotor core, vibration during rotation is suppressed, and problems such as noise and damage due to vibration are solved. You can Therefore, in particular, a rotor that can be suitably used for an electric motor that is driven at a high speed by a power source containing harmonics by an inverter system is provided.

The electrically insulating thermoplastic resin forming the pipe-like member melts to form a lubricating film when the conductor bar is press-fitted,
The conductor bar is smoothly press-fitted, and after the press-fitting is completed, the conductor bar is cured to form an insulating film, which electrically insulates the rotor core and the conductor completely, thereby improving the efficiency of the electric motor.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for manufacturing an electric motor rotor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a general configuration of an electric motor rotor.

FIG. 3 is a sectional view taken along line XX in FIG.

[Explanation of symbols]

 1 rotor core 2 rotor conductor 3 spindle insertion hole 4 groove (conductor cavity) 6 pipe member (mesh member) 7 flange 8 hollow holder 9 lubricating film 10 pure copper bar (conductor bar)

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[Procedure amendment]

[Submission date] April 26, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art An electric motor equipped with a rotor having the above structure has been conventionally used as a general-purpose electric motor or a liquid ring canned electric motor .
It is used as vacuum roots canned type motors or the like. For example, in a liquid-sealed canned electric motor, a stator core formed by laminating silicon steel plates is arranged in a frame, a stator coil is mounted on the stator core, and the rotating core is provided at the center thereof. The child is disposed so as to penetrate the main shaft with a small clearance from the stator core.

Front page continuation (72) Inventor Ichiro Soga 3-1-1 Kyobashi, Chuo-ku, Tokyo Within Jamme Sewing Machinery Co., Ltd. (72) Inventor Minoru Iwata 11-1 Haneda-Asahicho, Ota-ku, Tokyo Ebara Co., Ltd. (72) Inventor Shinnosuke Yamauchi 11-1 Haneda-Asahicho, Ota-ku, Tokyo Ebara Densan Co., Ltd.

Claims (5)

[Claims] 1. A method of manufacturing a rotor of an electric motor, comprising: a rotor core having a spindle insertion hole and a conductor cavity; and a rotor conductor inserted into the conductor cavity of the rotor core. Where a pipe-shaped member molded from a mixed material of a conductive material and a thermoplastic resin is inserted into the conductor cavity portion of the rotor core, and the temperature is equal to or higher than the melting temperature of the thermoplastic resin of the pipe-shaped member. A method of manufacturing a rotor of an electric motor, comprising: pressurizing a conductor bar, which forms the rotor conductor, into the pipe-shaped member while melting the thermoplastic resin under the conditions. 2. The method of manufacturing a rotor for an electric motor according to claim 1, wherein the conductor bar heated to a temperature equal to or higher than a melting temperature of the thermoplastic resin of the pipe-shaped member is press-fitted into the pipe-shaped member. 3. The electric motor according to claim 1, wherein the rotor core is heated to a temperature equal to or higher than a melting temperature of the thermoplastic resin of the pipe-shaped member, and the conductor bar is press-fitted into the pipe-shaped member. Method of manufacturing rotor. 4. The thermoplastic resin has an electric insulation property, and the electrically insulating thermoplastic resin melted by press-fitting the conductor bar into the pipe-shaped member is after completion of press-fitting of the conductor bar. 2. The method for manufacturing a rotor of an electric motor according to claim 1, wherein the rotor core and the rotor conductor are electrically insulated by curing to form an insulating coating film of the electrically insulating thermoplastic resin. 5. The electric motor according to claim 1, wherein a mesh member formed by weaving fibers of the conductive material and fibers of the thermoplastic resin into a cylindrical mesh is used as the pipe-shaped member. Method of manufacturing rotor.