JP2000050604A - Axial gap type brushless axial-flow fan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an axial gap type DC axial-flow fan motor which can reduce attractive force in the thrust direction, reduce axial load and reduce vibration, noise and a current value. SOLUTION: A field magnet 5 which has P (P is an integer of one or larger) pairs of N and S-poles is provided in a rotary fan 6, which has an impeller 9 blowing in an axial direction. A magnetically levitating single-pole permanent magnet 10, which is magnetized so as to have its N or S-pole oriented in the stator side direction, is provided on the inner circumference of the field magnet 5. A coreless stator armature 11, composed of (n) ((n) is an integer of one or larger) coreless armature coils 2 which are arranged on an armature coil mounting surface 3 facing the field magnet 5, is provided. Magnetically levitating permanent magnets 12 and 12' are provided on the stator side position where the coreless armature stator 11 is provided to have their polarities identical to the polarity of the magnetically levitating permanent magnet 10 which faces the magnetic levitation permanent magnet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial air gap type DC axial fan motor capable of reducing a suction force in a thrust direction, reducing an axial load, and reducing vibration, noise and current values. It is suitable for cooling computers and switching power supplies.

[0002]

2. Description of the Related Art In recent years, a small personal computer such as a laptop or a palm top personal computer has often used a small axial gap type DC brushless axial fan motor.

[0003] In this type of small personal computer, vibration, noise and current values are required to be reduced more than ever.

A small axial gap type D which has been widely used in the past
The C brushless axial fan motor 1 'has the structure shown in FIGS. 5 and 6 manufactured and sold by the present applicant. This structure will be described later in the present invention.

[0005]

2. Description of the Prior Art The DC brushless axial fan motor 1 'is very useful because it has a very simple structure and can be mass-produced at low cost. In particular, this structure has a small outer shape, that is, a size of 25 mm × 25 mm, 30 mm × 30 mm, 40 mm ×
This is useful for extremely small and lightweight sizes of 40 mm and thicknesses of 6 mm and 10 mm.

However, although the DC brushless axial fan motor 1 'has a very simple structure, recent demands have been made on vibration, noise and current values more than ever, especially for small personal computers. It is becoming increasingly demanded to reduce this. Here, in the DC brushless axial fan motor 1 ', the armature coils 2-1 and 2-2 are used for the purpose of reducing the current value and closing the magnetic circuit to improve the efficiency.
-2, a status yoke 4 is provided on the lower surface. For this reason, the rotating fan 6 ′ is attracted in the direction of the stator yoke 4 by the weight load of the rotating fan 6 ′ and the magnetic attraction between the field magnet 5 and the stator yoke 4. The rotating shaft 7 attached to 6 'is sucked in the thrust direction. As a result, since the sliding bearing 8 such as the DC brushless axial fan motor 1 'shown in FIGS. 5 and 6 is used, the lower end of the rotating shaft 7 receives the rotating fan 6 with a thrust receiver to thereby reduce the shaft loss. And noise and vibration are increased by the shaft loss. In addition, despite the use of the status yoke 4 to increase the efficiency of the magnetic circuit and reduce the current value, the current value does not decrease and the electromotive current increases.

The rotating fan 6 'in this case is exactly the same as the rotating fan 6 to be described later with the magnetic levitation permanent magnet 10 removed, and reference numeral 3 denotes a printed circuit board. An electric component forming a drive circuit of the DC brushless axial fan motor 1 'is provided, electrically connected to a conductive printed wiring pattern (not shown), and both the armature coils 2-1 and 2-2 are electrically connected. Lead wire 14 electrically connected to printed circuit board 3
Through the armature coils 2-1 and 2-2 and the drive circuit. Other parts common to the present invention will be described later.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce vibration, noise and current in an axial gap type DC brushless axial fan motor.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
A rotating fan 6 having an impeller 9 for blowing wind in the axial direction is provided with a field magnet 5 having P (P is an integer of 1 or more) magnetic poles of N and S poles, and a fixed magnet on its inner periphery. N in direction
A single-pole magnetic levitation permanent magnet 10 magnetized so that one of the magnetic poles of the pole and the south pole faces is provided, and n (n) is provided on the surface of the armature coil mounting substrate 3 facing the field magnet 5.
Is an integer of 1 or more). A coreless stator armature 11 formed by arranging the coreless armature coils 2 is provided, and the permanent magnet for magnetic levitation is provided at a fixed position having the coreless stator armature 11. This can be achieved by providing permanent magnets 12 and 12 ′ for magnetic levitation with the same polarity facing 10.

[0010] Further, the magnetic levitation permanent magnet 12
The armature coil mounting board 3 of the inner peripheral portion of the armature coils 2-1 and 2-2 group facing the magnetic levitation permanent magnet 10
It can be easily realized by arranging it at the surface position.

Alternatively, the magnetic levitation permanent magnet 12 '
Can be easily achieved by arranging at the upper surface position of the inner peripheral portion of the armature coils 2-1 and 2-2 group facing the magnetic levitation permanent magnet 10.

Furthermore, in the above, the purpose can be achieved more easily and cheaply by not providing a stator yoke on the lower surface of the coreless stator armature 11.

[0013]

The permanent magnet for magnetic levitation 10 and the permanent magnet for magnetic levitation 12 or 12 'repel each other, so that the load in the thrust direction by the rotary fan 6 is reduced, so that there is no shaft loss, and vibration and noise are reduced. And the electromotive current is also reduced by more than 10% from the conventional one. In a state where the rotating shaft 7 is horizontal with respect to the drawing, the force of the rotating shaft 7 of the rotating fan 6 sucked in the thrust direction is cancelled, and the shaft loss is reduced. Therefore, it is very advantageous for a portable type personal computer using a power supply battery.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is an exploded perspective view of an axial gap type DC brushless axial fan motor 1-1 showing a first embodiment of the present invention, and FIG. 2 is a fan motor 1 of FIG. 1 is a vertical sectional view of an axial gap type DC brushless axial fan fan according to a first embodiment of the present invention with reference to FIGS.
The data 1-1 will be described.

A square axial gap type D having a small axial thickness
The C-brushless axial fan motor 1-1 is a coreless air gap type DC single-phase brushless axial fan motor having a coreless structure having a venturi case 16 serving as a stator and a rotating fan 6 serving as a rotor. . In this embodiment, the DC single-phase brushless axial fan motor 1-1 has a horizontal size of 20, 30, 40, 50, 60, and 80 in the vertical and horizontal sizes.
Or 90mm × 20, 30, 40, 50, 60, 8
0 or 90mm, axial thickness 6mm, 10m
It has a very thin, small and lightweight flat structure of m or 20 mm.

The fan motor 1-1 is formed by a resin and connected to a stay 17 which extends radially inward on the inner periphery of a venturi case 16 having a concave portion therein and is integrally formed. The setting part 18 is formed integrally with the central part. As a result, a flow passage hole 19 through which the air blown by the impeller (rotating blade) 9 of the rotary fan 6 is passed axially downwardly on the outer periphery of the motor arrangement portion 18 at the bottom of the reventure case 16. Is formed between the stays 17.

The annular rotor yoke 20 of the rotary fan 6
The field magnet 5 provided through the magnetic poles alternately connects the N pole and the S pole with a mechanical angle of 90 so that adjacent magnetic poles are different in polarity.
It has a four-pole flat annular shape having a degree of magnetization width.

An axially extending bearing house 21 is formed integrally with the motor disposing portion 18 (Venturi case 16) at the center of the motor disposing portion 18 by resin.
1 is provided with a sliding bearing 22 (in this case, a ball bearing may be provided at the upper end and a sliding bearing 8 may be provided at the lower end), and the rotating fan 6 is provided.
The rotation fan 7 is rotatably supported on the rotation shaft 7 so that the rotation fan 6 can rotate. The rotating fan 6 is integrally formed of resin except for the field magnet 5, the rotating shaft 7 and the rotor yoke 20, and the field magnet 5, the rotating shaft 7 and the rotor yoke 20 are formed of resin. It is integrated.

A single pole magnetized on the inner periphery of the field magnet 5 so that the N pole (or one of the S poles) faces the surface of the printed circuit board 3 used as the armature coil mounting board. The magnetic levitation permanent magnet 10 is provided. That is, the permanent magnet for magnetic levitation 10 is an annular magnet with the upper surface magnetized to the S pole and the lower surface magnetized to the N pole, and has a thickness smaller than that of the field magnet 5.

The motor arranging portion 18 has two 180-degree symmetrical members.
A stator armature support column 23 extending upward in the axial direction at a location is integrally formed of resin. As will be described later, a function as a reluctance torque generating member for escaping the fulcrum position for enabling the self-starting of the coreless stator armature 11 of the single-phase energization arrangement on the stator armature support column 23. It is positioned and arranged and fixed by a magnetic screw that also serves as a magnetic head.

In the coreless stator armature 11 in the single-phase energization arrangement in this embodiment, two air-core type coreless armature coils 2-1 and 2-2 are formed on the printed circuit board 3 so as to have the same phase. They are formed in a single-phase arrangement so that in-phase conduction can be achieved.

The coreless armature coils 2-1 and 2-2 are
Efficient DC axial gap type brushless axial fan motor
In order to form the motor 8, the opening angle between the effective conductors 2a and 2b that contribute to the generated torque extending in the radial direction is equal to the opening width of one magnetic pole of the field magnet 5, that is, π (π
Is an electrical angle of 180 degrees. Field magnet 5
Are four poles, so the mechanical angle in this case is 90 degrees). Armature coil 2
-1 and 2-2 are adhered to the surface of the annular printed circuit board 3 having the same phase symmetrical with each other by 180 degrees with a double-sided adhesive tape or the like in order to form the coreless stator armature 11 having a single-phase energization arrangement. are doing. The conductors 2c and 2d in the circumferential direction of the armature coils 2-1 and 2-2 are conductors that hardly contribute to the generated torque.

The above-mentioned annular printed (wiring) board 21 is adhered. Although not shown, an electric component 13 for a drive circuit (energization control circuit) is disposed on the lower surface of the printed circuit board 3 in the same manner as shown in FIG. It is electrically connected to the lead wire 14 by attaching.

A not-shown magnetoelectric conversion element such as a ball element or a ball IC used as the only position detection element is disposed at an appropriate position on the printed circuit board 3.

2 forming coreless stator armature 11
A magnetic pole that opposes the magnetic levitation permanent magnet 10 and repels the magnetic levitation permanent magnet 10 on the printed circuit board 3 surface of the inner circumference of the two armature coils 2-1 and 2-2 groups;
That is, an annular magnetic levitation permanent magnet 12 having an N pole magnetized on its upper surface is provided, and the same poles of the magnetic levitation permanent magnet 10 and the magnetic levitation permanent magnet 12 are repelled so that the thrust direction of the rotating fan 6 is changed. To reduce the load.

[0026]

FIG. 3 is an exploded perspective view of an axial gap type DC brushless axial fan motor 1-2 showing a second embodiment of the present invention, and FIG. 4 is a fan motor 1 of FIG. 2 is a vertical sectional view of an axial gap type DC brushless axial fan fan according to a second embodiment of the present invention with reference to FIGS.
Data 1-2 will be described. However, description of parts common to the first embodiment will be omitted.

The axial air gap type DC brushless axial fan motor 1-2 of the second embodiment is different from 1-1 in that the magnetic levitation is provided on the inner peripheral portions of the armature coils 2-1 and 2-2. When there is no room for disposing the permanent magnet 12 for
Armature coil 2 facing permanent magnet 10 for magnetic levitation
A magnetic levitation permanent magnet 12 ′ magnetized in the same manner as the magnetic levitation permanent magnet 12 is disposed on the inner peripheral upper surface of the first, second and second groups, and the magnetic levitation permanent magnet 10 and the magnetic levitation permanent magnet 12 ′ are arranged. The permanent magnet 12 'is repelled.

[0028]

[Others] In the above embodiment, a preferred example in which a starter yoke is not used for cost reduction is shown. However, the strength of the magnetic force of the magnetic levitation permanent magnets 10 and 12 or 12 'is selected. By doing so, a status yoke may be used. In this case, when used for the purpose of generating a reluctance torque for self-starting by a state yoke, or when an axial gap DC brushless axial fan motor is built and used at right angles to the drawing. In order to generate a magnetic attraction between the field magnet 5 and the stator yoke, for example, to prevent the rotation fan 6 from shifting, it is preferable to use it over a small area.

[0029]

According to the axial gap type DC brushless axial fan motor of the present invention, the shaft loss is remarkably reduced, so that noise and vibration can be largely suppressed, and the electromotive current can be reduced. The wear can be measured, and the starter yoke can be omitted, so that the above-described effects and the cost of parts can be further reduced. Even in a state where the rotating shaft is horizontal, the force of suction of the rotating shaft of the rotating fan in the thrust direction is canceled out and the shaft loss is reduced.

[Brief description of the drawings]

FIG. 1 shows an axial gap type DC showing a first embodiment of the present invention.
FIG. 3 is an exploded perspective view of a brushless axial fan motor.

FIG. 2 is a vertical sectional view of the fan motor.

FIG. 3 shows an axial gap type DC showing a second embodiment of the present invention.
FIG. 3 is an exploded perspective view of a brushless axial fan motor.

FIG. 4 is a vertical sectional view of the fan motor.

FIG. 5 is an exploded perspective view of a conventional axial gap type DC brushless axial fan motor.

FIG. 6 is a longitudinal sectional view of the fan motor.

[Explanation of symbols]

1-1, 1-2, 1 'Axial air gap type DC brushless axial fan motor 2-1, 2-2 Armature coil 2a, 2b Effective conductor portion 2c, 2d contributing to generated torque Not contributing to generated torque Conductor 3 Printed circuit board 4 Starter yoke 5 Field magnet 6, 6 'Rotating fan 7 Rotating shaft 8 Sliding bearing 9 Impeller 10 Permanent magnet for magnetic levitation 11 Coreless stator armature 12, 12' Permanent magnet for magnetic levitation DESCRIPTION OF SYMBOLS 13 Electric component 14 Lead wire 15 Thrust receiver 16 Venturi case 17 Stay 18 Motor installation part 19 Flow air passage hole 20 Rotor yoke 21 Bearing house 22 Cut washer 23 Stator armature support column 24 Magnetic screw

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) JK19 PP05

Claims (4)

[Claims] 1. A rotating fan having an impeller for blowing wind in an axial direction, wherein N and S magnetic poles are set to P (P is an integer of 1 or more).
A single-pole rotor-side magnetic levitation provided with a pair of field magnets and magnetized so that either the N-pole or the S-pole faces the fixed side on the inner periphery of the field magnet. A coreless stator armature formed by providing a permanent magnet for use and arranging n (n is an integer of 1 or more) non-core type armature coils on the armature coil mounting board surface facing the field magnet. An axial gap DC brushless shaft, wherein a fixed side magnetic levitation permanent magnet having the same polarity as the rotor side magnetic levitation permanent magnet is provided at a fixed side position having the coreless stator armature. Flow fan motor. 2. The fixed-side magnetic levitation permanent magnet is disposed at an inner peripheral portion of an armature coil group facing the rotor-side magnetic levitation permanent magnet at a position on an armature coil mounting board surface. The axial gap type DC brushless axial fan motor according to claim 1. 3. The permanent magnet for stationary magnetic levitation according to claim 1, wherein the permanent magnet for magnetic levitation is disposed at an upper surface of an inner peripheral portion of an armature coil group opposed to the permanent magnet for magnetic levitation on the rotor side. Axial gap type DC brushless axial fan motor
Ta. 4. An axial gap type DC axial fan motor according to claim 1, wherein a stator yoke is not provided on a lower surface of the coreless stator armature.