KR20060045356A - Rotor of motor - Google Patents

Abstract

While reducing the amount of plastic magnets, the magnets provide a rotor that does not rotate about the rotor core.

The magnet magnets 16 of the S pole and the N pole are arranged on the outer circumferential side of the rotor 10, and the cross-sectional shape of the inner circumferential side of the plastic magnet 16 of each pole is almost semicircular, and the plastic magnet of each pole 16 is connected in a ring shape, and the recessed part 14 corresponding to the plastic magnet 16 of each pole is formed in the outer peripheral part of the rotor iron core 12. As shown in FIG.

Description

Rotor of Motor

1 illustrates a planar shape of a rotor according to one embodiment of the present invention;

2 is a cross-sectional view taken along the line A-A in FIG.

<Explanation of symbols for the main parts of the drawings>

10: rotor 12: rotor iron core

14 concave portion 16 plastic magnet

18: shaft

The present invention relates to a rotor of a motor such as a brushless DC motor and a single phase synchronous motor.

In a rotor in a motor such as a brushless DC motor, a magnet is arranged so that the S pole and the N pole alternate with each other to obtain a magnetic force (see Patent Document 1, for example).

In such a rotor, there is a SPM type (SURFACE PERMANENT MAGNET type) rotor which arranges a magnet on the surface of the rotor iron core.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-48827

The magnets used in the above-described SPM-type rotors have a large number of ferrite plastic magnets, and have a concentric ring shape having an inner and outer diameter, and are integrally formed or fitted to the rotor iron core. And the magnetic field orientation of polar anisotropy is added for every predetermined angle.

In such a ring-shaped magnet, although the orientation force is weak at the boundary between the S-pole and the N-pole, the same amount of magnet as the center of each magnet, i.e., the center of the pole, is used.

As such, when the same amount of magnets as the pole center are used, the amount of plastic magnets increases, resulting in a cost increase.

In addition, because of the ring-shaped magnet, when the fitting defect is weak with respect to the rotor iron core, there is a problem that only the rotor iron core rotates or only the ring-shaped magnet rotates.

Thus, in view of the above problems, the present invention can reduce the amount of plastic magnets and at the same time provide a rotor of a motor in which the magnet does not rotate with respect to the rotor iron core.

The invention according to claim 1 is a plastic magnet in which the outer circumferential side of the rotor is magnetized to the S pole and the inner circumferential side is magnetized to the N pole, and the outer circumferential side of the rotor is magnetized to the N pole and the inner circumferential side is the S pole. The magnets of the magnets are alternately rotated on the outer circumferential surface of the iron core of the rotor for each pole, and the cross-sectional shape of the inner circumferential side of the plastic magnets of each pole bulges the center and becomes thinner toward the end. And the plastic magnets of the poles are connected in a ring shape, and a recess corresponding to the plastic magnets of the poles is formed in the outer circumference of the rotor iron core.

The invention according to claim 2 is a rotor of the motor according to claim 1, wherein the cross-sectional shape on the inner circumferential side of the plastic magnet of each pole is substantially semicircular.

The invention according to claim 3 is a rotor of the motor according to claim 1, wherein the plastic magnet of each pole and the rotor iron core are integrally molded.

The invention according to claim 4 is a concave globoidal in which the rotor iron core is concave and has a curved recess in the axial direction of the outer circumferential portion of the motor according to claim 1. It is a rotor.

The invention according to claim 5 is a rotor of the motor according to claim 1, wherein the motor is a brushless DC motor.

The invention according to claim 6 is a rotor of the motor according to claim 1, wherein the motor is a single-phase synchronous motor.

Embodiment

Hereinafter, the rotor 10 which is one Embodiment of this invention is demonstrated based on FIG.

The rotor 10 of this embodiment is a rotor of a brushless DC motor, which is disposed on the inner circumferential side of the ring-shaped stator.

(1) structure of the rotor (10)

The structure of the rotor 10 is demonstrated in order together with the manufacturing method.

First, the rotor iron core 12 of the rotor 10 is manufactured.

As shown in FIG. 1, the planar shape of the rotor core 12 is manufactured by laminating and caulking the star-shaped steel plate in which eight semicircular recesses 14 were formed in the circular outer peripheral part. In this case, as shown in FIG. 2, the shape of the rotor core 12 in the axial direction is a shape which becomes recessed in the center part of an axial direction, and the whole shape becomes a concave spherical shape.

Subsequently, the rotor iron core 12 manufactured as described above is accommodated in the mold, and the ferrite plastic magnet 16 of each pole is integrally molded on the outer peripheral portion of the rotor iron core 12. Moreover, the shaft 18 which is a rotating shaft is made to penetrate the center of the rotor iron core 12. As shown in FIG. In this case, as shown in FIG. 1, the plastic magnet 16 of each pole is ring-shaped connected by the edge part, The inner peripheral side is bulging in the center part in accordance with the shape of the recessed part 14, and becomes thinner toward the edge part. The loser is curved, ie almost semicircular. The cross-sectional shape of the outer peripheral side of the plastic magnet 16 of each pole becomes concentric shape centering on the shaft 18. As shown in FIG.

In addition, a magnet or a permanent magnet is arranged in the inner circumference of the mold, and the magnets 16 of each pole are alternately magnetized in an S-pole and an N-pole.

The rotor 10 integrally formed as described above is taken out of the mold.

(2) effect of the rotor (10)

The rotor 10 has the following effects.

As a 1st effect, compared with the case where the conventional ring-shaped plastic magnet is used, the usage-amount of the plastic magnet 16 is reduced for each pole, and cost can be reduced. That is, as shown in FIG. 1, according to the conventional concentric ring-shaped plastic magnet, it was necessary to use the plastic magnet to the position indicated by the dotted line 20. In this embodiment, the plastic magnet 16 is recessed ( Since it is provided in a curved shape in accordance with 14), the amount of plastic magnet 16 used can be reduced as compared with the conventional one by the amount of triangle used in FIG.

In the second effect, since the concave portion 14 is formed in the outer circumference of the rotor iron core 12 and the plastic magnet 16 is fitted thereto, the concave portion 14 has a ring shape with respect to the rotor iron core 12. The connected plastic magnets 16 do not rotate. In other words, the recess 14 serves as a rotation stop.

In the third effect, since the rotor iron core 12 is a concave spherical shape, the plastic magnet 16 can be prevented from falling off in the axial direction in FIG. 2.

As a fourth effect, since the shape of the inner circumferential side in the plastic magnet 16 of each pole is semicircular, the magnetization waveform due to the magnetic flux becomes close to the sine wave, and the characteristics of the motor are improved.

(Change example)

The present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit thereof.

(1) Modification Example 1

In the above embodiment, the rotor iron core 12 and the plastic magnet 16 are integrally formed. However, the rotor iron core 12 and the plastic magnet 16 are molded in the first place, and only the plastic magnet 16 is molded first, and then the rotor iron core 12 is formed in the cavity of the center thereof. The manufacturing process to insert may be sufficient.

(2) Modification Example 2

In the above embodiment, a brushless DC motor is used as the motor, but the present invention can be applied as long as it uses a permanent magnet for the rotor, and can be used for the rotor of a single-phase synchronous motor, for example.

The rotor of the motor of the present invention is suitable for rotors such as brushless DC motors, single-phase synchronous motors, and the like.

In the rotor of the motor of the invention according to claim 1, the plastic magnet is a ring, but the cross-sectional shape of the inner circumferential side in the plastic magnet of each pole is a curved shape that bulges the center portion and becomes thinner toward the end. Compared with the conventional ring-shaped plastic magnet, the amount of use is smaller, and the magnetization waveform due to the magnetic flux is closer to the sine wave, so that the motor characteristics are improved and the rotor core is not rotated.

According to the rotor of the motor of the invention according to claim 2, since the cross-sectional shape of the plastic magnet of each pole is almost semicircular, the magnetization waveform due to the magnetic flux is closer to the sine wave, and the characteristics of the motor are improved.

According to the rotor of the motor of the invention according to claim 3, the plastic magnet of each pole and the rotor iron core are integrally molded, so that the manufacture is easy, and the plastic magnet and the rotor iron core are more reliably fitted.

According to the rotor of the motor of the invention according to claim 4, since the rotor iron core is concave spherical, the plastic magnet of each pole does not fall off in the axial direction with respect to the stator iron core.

According to the rotor of the motor of the invention according to claim 5, since the motor is a brushless DC motor, the motor characteristics can be improved.

According to the rotor of the motor of the invention according to claim 6, the motor characteristics can be improved because the motor is a single-phase synchronous motor.

Claims (6)

The plastic magnet in which the outer circumference of the rotor is magnetized to the S pole and the inner circumference of the rotor is magnetized to the N pole, and the plastic magnet of the outer circumference of the rotor is magnetized to the N pole and the inner circumference of the rotor As a rotor of a motor installed on the outer circumferential surface of the rotor iron core alternately one pole The cross-sectional shape of the inner circumferential side in the plastic magnet of each of the poles is a curved shape that bulges the center portion and becomes thinner toward the end, The plastic magnet of each pole is connected in a ring shape, And a concave portion corresponding to the plastic magnets of the respective poles is formed in an outer circumferential portion of the rotor iron core. The method of claim 1, A rotor of a motor, characterized in that the cross-sectional shape of the inner circumferential side of the plastic magnet of each pole is approximately semicircular. The method of claim 1, The rotor of the motor, characterized in that the plastic magnet of each pole and the rotor iron core are integrally molded. The method of claim 1, The rotor of the motor, characterized in that the rotor iron core is concave globoidal, and that there is a curved recess in the axial direction of its outer circumference. The method of claim 1, The rotor of the motor, characterized in that the motor is a brushless DC motor. The method of claim 1, The rotor of the motor, characterized in that the motor is a single-phase synchronous motor.

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