JP2003134709A - Yoke structure of thin fan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yoke structure of a fan motor of an inner rotor reduced in thickness having low noise that facilitates coil mounting work and dispenses with a particular coil winder. SOLUTION: A lower flange is formed at the internal peripheral end of an external peripheral ring toward the center thereof. A support is formed at the internal peripheral end of the external peripheral ring toward an upper part, and an upper flange is formed at the upper end of the support toward the center of the external peripheral ring. A stator is formed such that a coil is fitted to the outside of the support so that a winding face is orthogonal to an axis. A magnetic circuit is formed between the three of the N and S poles of a permanent magnet of a rotor arranged at the center of the stator, the upper and lower flanges of a yoke, and the external peripheral ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yoke structure for an inner rotor type thin fan motor.

[0002]

2. Description of the Related Art FIG. 6 is a view showing an example of a yoke structure of a conventional inner rotor type fan motor. York 25
Has a ring-shaped portion 25a and four coil winding portions 25b protruding inward from the ring-shaped portion 25a. A coil 26 is wound around each coil winding portion. A magnet 27 is attached to the shaft 28 at the center of the yoke 25.
The rotor 29 to which is attached is arranged. A magnetic circuit is formed between the ring-shaped portion 25a of the yoke 25, the coil winding portion 25b, and the N and S poles of the magnet, and the rotor 29 rotates.

[0003]

The yoke of the conventional inner rotor type motor has a coil winding portion 25b.
Is formed so as to extend from the inner peripheral end of the outer peripheral ring portion 25a to the center, and the coil is wound in the axial direction. Therefore, winding the coil around the yoke is not easy and requires a dedicated winding machine. Further, since the coil is wound around the yoke, an insulating process must be performed between the coil and the yoke winding portion, which is a labor-intensive structure.
Further, when the polarity of the motor is changed, a new winding machine that winds in conformity with the polarity must be created.

The present invention solves the above problems, and an object thereof is a thin, low-noise inner rotor type fan in which the work for mounting a coil is simple and a special coil winding machine is not required. It is to provide a yoke structure of a motor.

[0005]

In order to achieve the above object, a yoke structure of a thin fan motor according to the present invention has a coil mounted on an outer peripheral frame having a brim portion, and a permanent magnet is attached to a central portion of the yoke. In a yoke structure of a thin fan motor in which a rotor is arranged, a lower brim portion is formed from the inner peripheral end of the outer peripheral ring portion toward the center, and is supported upward from the inner peripheral end of the outer peripheral ring portion. And a coil having an upper brim portion formed from an upper end of the support portion toward the center of the outer peripheral ring portion, and a coil, and the winding surface is provided outside the support portion in a direction perpendicular to the axis. A stator is constructed by fitting the coils so that the N pole and the S pole of the permanent magnet of the rotor arranged in the central portion of the stator.
A magnetic circuit is formed between the pole, the upper brim portion, the lower brim portion of the yoke, and the outer peripheral ring portion. According to the present invention, in the above structure, the stators are vertically stacked, and the energizing directions of the upper coil and the lower coil are adjusted so that the stacked yoke portions have the same pole. Further, according to the present invention, in the above structure, a rising portion is provided at an outer peripheral end of the outer peripheral ring portion.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of a yoke structure of a thin fan motor according to the present invention. On the inner peripheral end surface of the outer peripheral ring portion 1a of the yoke 1,
Two lower brim portions 1b facing each other with the central portion sandwiched therebetween are formed. On the other hand, two arcuate support portions 1c are formed upward on the inner peripheral end surface of the outer peripheral ring portion 1a of the yoke 1, and the upper brim portions 1d facing each other with the central portion sandwiched are formed at the respective tip portions. ing. The coil 2 can be assembled from above the yoke 1.

FIG. 2 is an assembled sectional view of the yoke and coil of FIG. The coil 2 can be manufactured by an ordinary winding machine, and is fitted on the outer side of the support portion 1c.

FIG. 3 is a view for explaining the direction of magnetic flux of the magnetic circuit formed by the assembly of FIG. When the coil 1 is energized in the direction to come out of the paper as shown in FIG. 3A, the upper brim portion of the yoke 1 becomes the S pole and the lower brim portion becomes the N pole.
Excited by the poles. When the energization direction is reversed as shown in FIG. 3 (b), it is excited in the opposite direction. The number of poles can be increased within the range where the yoke can be manufactured, and is not restricted by the coil.

FIG. 4 is a sectional view showing a second embodiment of the present invention, in which two yokes are vertically stacked to form a stator. Upper coil 5 on upper yoke 5
By fitting the lower coil 11 to the lower yoke 6, the upper and lower stators are formed. By arranging the bottom surface side of the lower yoke 6 against the upper yoke 5 and disposing the rotor including the shaft 7, the magnet 9 and the like in the center, the motor torque can be easily increased. By determining the energization directions of the upper coil 10 and the lower coil 11, the central yoke (overlapped portion) is adjusted to have the same pole.

FIG. 5 is a sectional view showing a third embodiment of the present invention, in which a rising portion is provided on the outer circumference of the yoke. By providing the rising portion 13e on the outer circumference of the yoke 13, the leakage flux of the coil can be reduced and the efficiency can be improved.

[0011]

As described above, according to the present invention, a single yoke is used, and a coil manufactured by a normal winding machine can be assembled on the yoke from above, which simplifies the structure. Significant cost reduction has become possible. In addition, it was possible to easily realize a small size and thin shape. Further, by using the inner rotor type, the efficiency of the magnetic circuit is improved, and even if the magnet is made smaller, a sufficient rotating torque can be obtained. Further, it was easy to increase the number of poles, and the operating current could be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a yoke structure of a thin fan motor according to the present invention.

FIG. 2 is an assembled sectional view of the yoke and the coil of FIG.

FIG. 3 is a diagram for explaining directions of magnetic flux.

FIG. 4 is a cross-sectional view showing a second embodiment of the present invention, 2
It is constructed by stacking two yokes on top of each other.

FIG. 5 is a sectional view showing a third embodiment of the present invention, in which a rising portion is provided on the outer circumference of the yoke.

FIG. 6 is a diagram showing an example of a yoke structure of a conventional inner rotor type fan motor.

[Explanation of symbols]

1,13,25 York 2,26 coils 5 Upper yoke 6 Lower yoke 7, 16, 28 axes 8,17 Receiver 9,14,27 magnet 10 upper coil 11 Lower coil

Claims (3)

[Claims] 1. In a yoke structure of a thin fan motor of a type in which a coil is mounted on an outer peripheral frame having a flange, and a rotor having a permanent magnet is arranged in the center of the yoke, an inner periphery of an outer peripheral ring portion is provided. A lower brim portion is formed from the end toward the central portion, a support portion is formed from the inner peripheral end of the outer peripheral ring portion upward, and an upper brim is formed from the upper end of the support portion toward the central portion of the outer peripheral ring portion. A yoke having a portion formed therein, and a coil, and a stator is configured by fitting the coil on the outside of the supporting portion so that the winding surface is in a direction perpendicular to the axis. A thin fan characterized in that a magnetic circuit is formed between the N and S poles of the permanent magnets of the arranged rotor, the upper brim portion, the lower brim portion of the yoke, and the outer peripheral ring portion. Motor yoke structure. 2. The thin fan motor according to claim 1, wherein the stators are vertically stacked, and the energizing directions of the upper coil and the lower coil are adjusted so that the yoke portions of the stators have the same pole. York structure. 3. The yoke structure for a thin fan motor according to claim 1, wherein a rising portion is provided at an outer peripheral end of the outer peripheral ring portion.