JP3579571B2 - Axial air fan motor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an axial gap type fan motor used for information equipment or power supply devices.
[0002]
[Prior art]
FIG. 4 shows a configuration of a conventional fan motor.
FIG. 4 is a sectional view of an essential part of the axial gap type fan motor. In FIG. 4, a synthetic resin frame also serving as a bearing holder via two ball bearings 22 arranged in the axial direction with respect to the shaft 21. An air-cored coil 25 is mounted on the frame 23 and forms a stator S.
[0003]
The disk-shaped rotor yoke 26 is provided with a burring process at the center thereof to hold one end 21a of the shaft 21, and the inner surface of the rotor yoke 26 is provided with a predetermined gap with the air-core coil 25. The field magnet 27 is attached, and constitutes the rotor R. Further, in the rotor R, a plurality of impellers 28 are provided on the outer periphery of the yoke 26 at equal intervals.
[0004]
In order to efficiently form a magnetic circuit by the field magnet 27, a yoke 29 is mounted between the frame 23 and the air-core coil 25 together with a circuit board. Reference numeral 30 denotes an electronic component mounted on the circuit board, and the frame 23 is resin-molded so as to cover the outer periphery of the turning space of the impeller 28.
[0005]
[Problems to be solved by the invention]
However, in the above-described configuration, since the frame 23 also serving as the bearing holder is made of synthetic resin, the yoke 29 is required to make the magnetic circuit using the field magnet efficient. Therefore, when the frame is made of a synthetic resin, the thickness of the frame and the yoke made of the synthetic resin is required in the thickness direction. For example, in the conventional configuration, the thickness of this portion is about 1 mm. In fact, fan motors having a total thickness of 7 mm, which have become widespread these days, actually account for about 15% of the fan motors.
[0006]
If an attempt is made to reduce the thickness of the motor, the thickness of the air core coil 25, the field magnet 27, and the like must be sacrificed. In such a case, performance is adversely affected. Will be. The same can be said for a fixed shaft type fan motor.
[0007]
Accordingly, an object of the present invention is to provide a fan motor that solves the above-described problem and that can easily realize a thin motor while maintaining various motor characteristics in a favorable state.
[0008]
[Means for Solving the Problems]
The present invention solves the above-mentioned problems by forming a frame as a stator by pressing a metal plate, and using a part of the frame as a yoke. There is no need to provide a yoke in this area, and the thickness of this part is limited to the frame thickness only, which makes it possible to substantially reduce the thickness of the entire motor, making it easy to reduce the thickness of the motor without sacrificing motor characteristics. Can be realized.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
An axial gap type fan motor according to the present invention includes a rotor having a plurality of impellers and an NS-magnetized field magnet, and a stator having an armature coil mounted on a frame through a predetermined gap in the rotor. The stator includes a bearing for rotatably holding the rotor, a yoke for receiving the magnetic field of the field magnet, a cover for covering the outer periphery of the rotating space of the impeller, and a device for mounting on the device side. In the axial direction gap type fan motor including the mounting portion, the stator forms the frame by pressing a metal plate, and a part of the frame also serves as the yoke.
[0010]
Further, it is effective that the stator is formed by integrally forming the bearing portion, the cover portion, and the mounting portion by pressing a metal plate.
It is optimal that the stator is integrally formed with lead wire fixing means.
[0011]
【Example】
FIG. 1 is a longitudinal sectional view of a main part of an axial gap type fan motor according to an embodiment of the present invention, and FIG. 2 is a transverse sectional view of a main part of the axial gap type fan motor in FIG. FIG. 3 is a diagram showing a frame formed by press working in the present invention. That is, in FIGS. 1 and 2, a frame 3 made of a metal plate also serving as a bearing holder is disposed via two ball bearings 2 disposed in the axial direction with respect to the shaft 1. The coil 5 is mounted, and constitutes the stator S.
[0012]
The disk-shaped rotor yoke 6 is provided with a burring process at its center in order to hold one end 1a of the shaft 1, and the inner surface of the rotor yoke 6 is provided with a predetermined gap with the air-core coil 5 through the air gap. A field magnet 7 that is magnetized alternately with NS is attached to form a rotor R. Further, the rotor R is provided with a plurality of impellers 8 at equal intervals on the outer periphery of the yoke 6. Reference numeral 9 denotes a circuit board, on which various electronic components 10 are mounted, and terminals of the air-core coil 5 are connected to a circuit pattern formed on the circuit board 9.
[0013]
In the present embodiment, the rotor yoke 6 is formed in a disk shape by punching an iron plate or the like made of a magnetic material. And an impeller 8 integrated with the yoke.
[0014]
As shown in FIG. 3, the frame 3 is also formed by pressing a metal plate, in this case, a magnetic plate, and then drawing a flat plate made of a magnetic material to form a bearing on the inner peripheral surface. If the cover 3c that covers the outer periphery of the turning space of the impeller 8 and the portion 3a is formed, and then punching is performed, the yoke 3b and the mounting portion 3d for mounting to the device and the like can be formed. Reference numeral 3e denotes four stay portions which are formed by connecting the yoke portion 3b and the cover portion 3c to be integrated. The stay portion 3e has a protrusion 33e formed at one of the stay portions. As shown in (1), the lead wire 11 can be fixed to the stay 3e by passing the lead wire 11 through this portion and then bending the protrusion 33e inward.
[0015]
Reference numeral 3f denotes a rising portion formed by cutting out a part of the yoke and raising this portion. The rising portion 3f is formed at two locations on the circumference, and the rotor R is formed by the rising portion 3f. The stop position of the rotor R is intentionally restricted by shifting the stop position in the rotation direction by about 10 ° with respect to a reference position (dead point) with the armature coil 5. By doing so, the dead point of the rotor R can be eliminated, and the rotor R can always be started.
[0016]
Further, as shown in the figure, the stator R has two air-core coils having an opening angle of 60 ° arranged at intervals of 120 ° so as to be deviated on the circumference. Then, similarly to the above embodiment, the thickness of the motor can be reduced by placing the circuit component 10 in the space formed on the opposite side of the stator R. In this case, if the field magnet 7 arranged on the rotor R is magnetized with six poles at a magnetization opening angle of 60 °, the output of the Hall element switches every 60 ° rotation, and the single-phase operation is performed. Full-wave driving becomes possible.
[0017]
It should be noted that the present invention is not limited to the above embodiment, and can be implemented with appropriate modifications without departing from the gist of the present invention. For example, in the above embodiment, the circuit board is mounted on the yoke portion and the air-core coil and the electronic component are mounted on the circuit board in detail. However, the present invention is not limited to this, and the circuit board may be an iron board with printed wiring. With this configuration, the circuit board can also be used as the yoke, and further reduction in thickness can be expected. In the above embodiment, the shaft rotary type has been described in detail.
[0018]
【The invention's effect】
As described above, according to the present invention, as the stator, a frame is formed by pressing a metal plate, and a part of this frame is also used as a yoke. Therefore, it is necessary to provide a yoke on the frame. In other words, the thickness of this portion is limited only to the frame thickness, so that the thickness of the entire motor can be substantially reduced, and the motor can be easily made thinner without sacrificing the characteristics of the motor.
[0019]
In addition, by providing a protrusion on the stay portion integrally formed with the above configuration, the lead wire disposed on the stay portion can be fixed so as not to come off, so that disconnection of the lead wire is prevented. can do.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a main part of an axial gap type fan motor according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part of the axial gap type fan motor in FIG. 1;
FIG. 3 is a view showing a frame formed by press working in the present invention.
FIG. 4 is a sectional view of a main part of a conventional fan motor.
[Explanation of symbols]
1, 21 ‥‥ shaft 3, 23 ‥‥ frame 3a ‥‥ bearing 3b, 29 ‥‥ yoke 3c ‥‥ cover 3d ‥‥ mounting part 3e ‥‥ stay part 33e ‥‥ projection 3f ‥‥ rising part R ‥‥ Rotor S ‥‥ Stator

Claims (2)

A rotor having a plurality of impellers and a NS-magnetized field magnet, and a stator having an armature coil mounted on a frame through a predetermined gap in the rotor, the stator comprising the field magnet In the axial direction air gap type fan motor including a yoke for receiving the magnetic field, the frame includes a bearing portion provided with a shaft for rotatably supporting the rotor, the yoke and the rotor formed on the yoke and holding the rotor in a predetermined position. The position restricting means for stopping at the position, the cover for covering the outer circumference of the impeller and the stator for connecting the cover to the yoke are formed by pressing the same magnetic plate, and the stator has lead wire fixing means. An axial gap type fan motor formed integrally with the magnetic plate. An axial gap type fan motor, wherein a mounting portion for mounting the fan motor is formed integrally with the frame.

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