JP2007282408A - Rotor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor where a rotation axis is formed by reducing a use amount of a metal. <P>SOLUTION: In the rotor 10, a rotor iron core 12 of a brushless DC motor and a plurality of magnets 22 and 24 are put in a mold, and molding is performed by molded resin 28. The rotation axis 26 is also integrally formed by molded resin 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor rotor and a method for manufacturing the same.

  Conventionally, in an inner rotor type motor, a rotating shaft of a rotor is formed of metal (for example, iron) (see, for example, Patent Document 1).

For example, as shown in FIG. 4, as the rotor 100 of the motor, S-pole and N-pole magnets are alternately inserted into a rotor core 102 in which steel plates are laminated, and are integrally formed with a mold resin 106. After that, the rotor 100 is assembled by press-fitting a metal rotating shaft into the integrally formed product.
JP 2004-96905 A

  In the rotor configured as described above, since metal, for example, iron is used for the rotating shaft, it has been difficult to reduce costs.

  Therefore, in view of the above problems, the present invention provides a rotor that can reduce the amount of metal used to form a rotating shaft.

  According to a first aspect of the present invention, in a rotor of a motor in which a rotor core and a plurality of magnets are molded with a mold resin, a rotation shaft of the rotor is integrally formed with the rotor core and the plurality of magnets by the mold resin. It is the rotor characterized by having.

  The invention according to claim 2 is the rotor according to claim 1, wherein a metal cover is put on a portion of the rotating shaft made of mold resin that protrudes from the rotor core.

  The invention according to claim 3 is the rotor according to claim 1, wherein the motor is a brushless DC motor.

  According to a fourth aspect of the present invention, in a method of manufacturing a rotor of a motor in which a rotor core and a plurality of magnets are molded with a mold resin, the rotor shaft is rotated together with the rotor core and the plurality of magnets by the mold resin. It is a manufacturing method of a rotor characterized by carrying out integral molding.

  The invention according to claim 5 is the method for manufacturing a rotor according to claim 4, wherein a metal cover is put on a portion of the rotating shaft made of the mold resin that protrudes from the rotor core.

  According to the present invention, the amount of metal used can be reduced because the rotating shaft is formed of the mold resin, and the cost is reduced.

  Hereinafter, the rotor 10 of the motor of one Embodiment of this invention is demonstrated based on FIGS. 1-3. The rotor 10 of this embodiment is, for example, a rotor of a brushless DC motor.

  The structure of the rotor 10 will be described based on the manufacturing method.

  As shown in FIGS. 2 and 3, the rotor core 12 is formed. The rotor core 12 is laminated while punching a steel plate 18 in which a plurality of isosceles triangular core portions 16 protrude at equal intervals from the outer periphery of the ring-shaped connecting portion 14.

  S pole and N pole magnets 22 and 24 are inserted into the slots 20 of the rotor core 12 in order. In FIG. 3, the shaded portions of the magnets 22 and 24 indicate the S pole.

  The rotor core 12 with the magnets 22 and 24 inserted therein as described above is placed in a mold and covered entirely with mold resin. In this case, the outer peripheral portion of the rotor core 12 is not covered, and the rotating shaft 26 is also integrally formed simultaneously with the mold resin 28 as shown in FIG. In order to increase the strength of the rotary shaft 26, a cover 30, which is an integrally formed product made of iron, is insert-molded into the portion of the rotary shaft 26 that protrudes from the rotor core 12 on both sides.

  By doing so, the rotor 10 having the rotation shaft 26 formed of the mold resin as shown in FIG. 1 is completed. And in order to increase the intensity | strength, the cover 30 is covered on the both ends of the rotating shaft 26. FIG.

  In the manufacturing method of this rotor 10, since a metal rotating shaft is not used unlike the conventional method, the amount of metal used can be reduced and the cost can be reduced.

(Example of change)
The present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof.

  In the above embodiment, the cover 30 is covered on the rotary shaft 26 in order to increase the strength. However, when the strength can be maintained only by the mold resin, it is not necessary to attach the cover 30.

  Moreover, although the said embodiment demonstrated in the rotor of the brushless DC motor, it is not restricted to this, The rotor of another kind of motor may be sufficient.

It is a longitudinal cross-sectional view of the rotor which shows one Embodiment of this invention. It is a front view of a rotor similarly. It is a rear view of a rotor similarly. It is a longitudinal cross-sectional view of the conventional rotor.

Explanation of symbols

10 Rotor 12 Rotor Core 22 Magnet 24 Magnet 26 Rotating Shaft 28 Mold Resin 30 Cover

Claims (5)

In a rotor of a motor in which a rotor core and a plurality of magnets are molded with a mold resin,
A rotor characterized in that a rotating shaft of the rotor is integrally formed with the rotor core and a plurality of magnets by the mold resin. 2. The rotor according to claim 1, wherein a metal cover is placed on a portion of the rotating shaft made of mold resin that protrudes from the rotor core. The rotor according to claim 1, wherein the motor is a brushless DC motor. In a method of manufacturing a rotor of a motor in which a rotor core and a plurality of magnets are molded with a mold resin,
A method for manufacturing a rotor, wherein the rotating shaft of the rotor is integrally formed with the rotor core and a plurality of magnets by the mold resin. The method for manufacturing a rotor according to claim 4, wherein a metal cover is placed on a portion of the rotating shaft made of mold resin that protrudes from the rotor core.

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