JP2000050605A - 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: An axial gap type brushless motor 1B or 1C has a rotary fan 6, a stator armature 11, and a case 16 provided in this order. The rotary fan 6 has a magnet 5 which has one or more pairs of N and S-poles on its surface facing the stator armature 11, an impeller 9 and a rotary shaft 7. The stator armature 11 has coils 2A and 2B and a coil mounting board 3. The case 16 has a bearing 22 which supports the rotary shaft 7. The rotary fan 6 has a 1st rotor side magnet 10, which has a single magnetic pole on its surface which faces the stator armature 11. The stator armature 11 has a 1st stator side magnet 12, whose polarity is the same as the polarity of the facing surface of the 1st rotor side magnet 10, at a position facing the 1st rotor side 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 gap type fan motor, and is used for cooling, for example, a computer and a switching power supply.

[0002]

2. Description of the Related Art In recent years, small axial gap type brushless fan motors have been frequently used in small personal computers such as laptops and palm top personal computers.

[0003] A conventional small axial gap type brushless fan motor 101 has a structure shown in Figs. The axial gap type brushless fan motor 101 will be described with reference to FIGS. Rotating fan 6
, A case 16 and a coreless stator armature 111 in this order. The rotating fan 6 includes a rotating shaft 7, a magnet 5, a magnet yoke 20, and an impeller 9. The magnet 5 directs the magnetic poles of the N pole and the S pole to the coreless stator armature 111. The rotating shaft 7 has a starting end fixed to the center of the rotating fan 6, and has a cut washer 27 at the leading end for preventing the shaft from coming off.

[0004] The case 16 includes a bearing 8 and the rotating shaft 7.
A thrust receiver 15 and a motor disposing portion 18 for receiving the motor in the thrust direction are provided. The coreless stator armature 1
11 has two coreless coils (102A, 102B)
, Coil yoke 3 and printed circuit board 3 forming drive circuit
And the electric component 13. A lead wire 14 for supplying power to the drive circuit is connected to the printed board 3.

[0005]

In the brushless fan motor 101, rotation is caused by the heavy load of the rotating fan 6 and the magnetic attraction between the magnet 5, the magnetic members provided in the stator armature 111 and the case 16, and the like. Since the fan 6 is sucked in the direction of the stator armature 111, the rotating shaft 7 attached to the rotating fan 6 is sucked in the thrust direction. Since the slide bearing 8 is used as in the brushless fan motor 101, the lower end of the rotating shaft 7 is received by the thrust receiver 15. For this reason, a shaft loss occurs on the sliding surface between the rotary shaft 7 and the thrust receiver 15, and noise and vibration increase due to the shaft loss. In addition, energy loss occurs due to friction of the sliding surface, and extra current is consumed.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an axial gap type brushless fan motor which suppresses noise and vibration and reduces current consumption.

[0007]

According to a first aspect of the present invention, a rotating fan and a stator armature are housed in a case, and the rotating fan includes an impeller, A rotating shaft, and a magnet having at least one magnetic pole pair of an N pole and an S pole on a surface facing the stator armature, wherein the stator armature has a coil and a coil mounting board; In an axial gap type brushless fan motor having a bearing that supports the rotating shaft,
The rotating fan includes a first rotor-side magnet having a single magnetic pole on a surface facing a stator armature, and the stator armature includes a rotor-side magnet at a position facing the first rotor-side magnet. A first stator-side magnet having the same magnetic pole as the opposing surface is provided.

According to the first aspect of the present invention, the weight load of the rotary fan and the magnetic attraction of the magnet cause
Since the rotating fan is attracted in the direction of the stator armature 11, the rotating shaft 7 attached to the rotating fan 6 is attracted in the thrust direction, but the opposing surface of the first rotor-side magnet 10 and the first stator-side magnet 12. Are magnetic poles of the same polarity, a repulsive force occurs. The repulsive force prevents the rotary shaft 7 from being sucked in the thrust direction. As a result,
The noise and vibration generated by the shaft loss at the tip of the rotating shaft 7 can be eliminated, and the current value required for rotating the rotating fan 6 can be reduced.

In order to achieve the object of the present invention, according to a second aspect of the present invention, in the first aspect of the present invention, the first stator-side magnet is more than the coil on the surface of the coil mounting board. It is provided at a position on the rotation shaft side.

According to the second aspect of the present invention, the first aspect is provided.
In the invention, by providing the first stator-side magnet at a position closer to the rotation axis than the coil on the surface of the coil mounting board, a gap between the magnet and the coil can be reduced, so that There is an advantage that the magnetic field of the magnet can be strengthened and the thickness of the axial gap type brushless fan motor can be reduced.

In order to achieve the object of the present invention, according to a third aspect of the present invention, in the first aspect, the first stator-side magnet is disposed so as to overlap a part of the coil. It is characterized by the following.

[0012] According to the third aspect of the present invention, the first aspect is provided.
In the embodiment of the invention, in the axial gap type brushless fan motor having no space for disposing the first stator side magnet on the surface of the coil mounting machine substrate, the first stator side magnet is disposed so as to overlap a part of the coil. This can be easily achieved.

In order to achieve the object of the present invention, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the rotating shaft penetrates the stator armature. A second rotor-side magnet having a single-pole magnetic pole on the stator armature side surface at the periphery of the tip located at the end. The case is provided with the second rotor-side magnet at a position facing the second rotor-side magnet. A second stator-side magnet having the same magnetic pole as the opposing surface is provided.

According to the fourth aspect of the invention, in the axial gap type brushless fan motor, the rotating fan is attracted in the case direction by the weight load of the rotating fan and the magnetic attraction of the magnet. The rotating shaft attached to the rotating fan is attracted in the thrust direction, but the opposing surfaces of the first rotor-side magnet and the first stator-side magnet and the second rotor-side magnet and the second stator-side magnet have the same magnetic pole. There is repulsion. Due to this repulsive force, the rotary shaft always tries to keep a fixed position with respect to the bearing, thereby suppressing suction in the thrust direction. As a result, noise and vibration generated by the shaft loss at the tip of the rotating shaft can be eliminated, and the current value of the current required to rotate the rotating fan can be reduced.

[0015] In order to achieve the object of the present invention, the invention according to claim 5 encloses a rotating fan and a stator armature in a case, wherein the rotating fan includes an impeller, a rotating shaft, and an N pole. And a magnet having at least one pair of magnetic poles of an S pole and a surface facing the stator armature, the stator armature having a coil and a coil mounting board, and the case supporting the rotating shaft. In the axial gap type brushless fan motor having a bearing, the first rotor-side magnet having a surface facing the stator armature as a single-pole magnetic pole is provided around the magnet, and penetrates through the stator armature of the rotating shaft. A second rotor-side magnet having a single-pole magnetic pole on a surface opposing the stator armature at a peripheral portion of a tip located at a position where the cylindrical magnet is disposed around the outer periphery of the bearing; One end face of the mold magnet faces the first rotor magnet, the other face faces the second rotor magnet, and each end face of the cylindrical magnet has the same polarity as the opposed faces of the first and second rotor magnets. There is a feature.

According to the invention set forth in claim 5, according to claim 4,
In the invention described in (1), the functions of the first stator-side magnet and the second stator-side magnet can be performed by the cylindrical magnet, and the number of components of the axial gap type brushless fan motor can be reduced.

In order to achieve the object of the present invention, the invention according to claim 6 includes a rotating fan and a stator armature housed in a case, wherein the rotating fan includes an impeller and a rotating member made of a magnetic material. A shaft, and a magnet having at least one magnetic pole pair of an N pole and an S pole on a surface facing the stator armature, wherein the stator armature has a coil and a coil mounting board; In an axial gap type brushless fan motor having a bearing for supporting a rotating shaft, a first rotor side magnet having a single magnetic pole on a surface opposed to a stator armature is provided around the magnet, and is provided on an outer periphery of the bearing. A cylindrical magnet is disposed, and one end surface of the cylindrical magnet on the rotating fan side is a magnetic pole having the same polarity as the opposite surface of the first rotor-side magnet and facing the first rotor-side magnet. The other end surface of the tip and the cylindrical magnet positioned through said stator armature rolling axis, characterized in that substantially at the same height position.

According to the invention described in claim 6, the rotating fan is attracted in the direction of the stator armature by the weight load of the rotating fan and the magnetic attraction force of the magnet, so that the rotating fan is attached to the rotating fan. The rotating shaft is attracted in the thrust direction, but a repulsive force is generated at the opposing surface of the first rotor side magnet and the cylindrical magnet. Further, an attractive force is generated between the rotating shaft of the magnetic material and the cylindrical magnet. The repulsive force and the suction force keep the rotary shaft at a constant position with respect to the bearing, thereby suppressing suction in the thrust direction. As a result, noise and vibration generated by the shaft loss at the tip of the rotating shaft can be eliminated, and the current value of the current required to rotate the rotating fan can be reduced.

Further, in order to achieve the object of the present invention, the invention according to claim 7 is characterized in that, in the invention according to claims 1 to 6, the coil is provided with a coil yoke. .

According to the present invention, a magnetic circuit is formed by the magnet, the coil, the coil yoke, and the magnet yoke by providing the coil with the coil yoke. By closing with the yoke, the magnetic flux passing through the magnetic circuit can be increased.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is an exploded perspective view of an axial gap type DC brushless fan motor 1B showing a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the fan motor 1B of FIG.
An axial gap type brushless fan motor 1B according to a first embodiment of the present invention will be described with reference to FIGS.

The brushless fan motor 1B having a small thickness in the axial direction has a rotating fan 6 serving as a rotor, a stator armature 11, and a case 16 serving as a stator.
In this order.

The case 16 has a cylindrical shape, and the case 16 has a motor mounting portion 18 on the inner periphery of the case 16. Case 1
Reference numeral 6 denotes four stays 17 arranged at equal intervals on the inner periphery of the case 16. The stay 17 extends in the inner circumferential direction of the case 16 and is connected to the motor mounting portion 18. The space surrounded by the case 17, the motor disposing portion 18 and the stay 17 is
It is. The flowing air passage hole 19 is a space for passing the wind blown by the rotating fan 6 in the axial direction. The motor disposition portion 18 has a concave portion on one end surface. A bearing house 21 is integrally formed at a central portion on one end surface side of the motor disposition portion 18. The bearing house 21 houses the bearing 8 that supports the rotating shaft 7 of the rotating fan 6. The four corners of the case 16 have corner flanges, and the case 16 looks substantially quadrangular when viewed from the axial direction. The stator armature 11 is attached to one end surface of the case 18. The stator armature 11 is fixed to the case 16 by two magnetic screws 24. The boss of the magnetic screw 24 is formed integrally with one end surface of the motor disposition portion 18. Motor disposition portion 18, the flange, the case 16, and the motor disposition portion 18
The stay 17, the bearing house 21, and the boss are integrally formed of plastic.

The rotary fan 6 has a magnet yoke 20, a magnet 5, a first rotor-side magnet 10, a rotary shaft 7, and an impeller 9 integrally formed. The magnet 5, the magnet yoke 20, and the first rotor-side magnet 10 are formed in an annular shape. The first rotor-side magnet 10 is arranged on the inner periphery of the magnet. Case 1 of magnet 5
The one end face on the side 6 has N-poles and S-poles alternately having a magnetic width of 90 degrees in mechanical angle so that adjacent magnetic poles are different.
Polarized. The first rotor-side magnet 10 has a single-pole magnetic pole whose one end face on the case 16 side is N-pole. One end face of the magnet 5 and one end face of the first rotor-side magnet 10 are on the same plane and face the stator armature 11. A magnet yoke 20 is provided on the other end surface of the magnet 5. The rotating shaft 7 is attached to the center of the rotating fan 6. The rotating shaft 7, the magnet 5, the first rotor-side magnet 10, and the magnet yoke 20 are molded from plastic, and a part of the plastic forms the impeller 9.

The stator armature 11 is mounted on the coil mounting machine panel 3.
, Coreless coils 2A and 2B, first stator-side magnet 12, lead wires, and electronic components (not shown). The coil mounting board 3 has coreless coils 2A and 2B and a first stator-side magnet 12 disposed on one end face opposing the rotating fan 6. Coreless coil 2A, 2
B is attached to the coil mounting board 3 with a double-sided tape. Although not shown on the other end surface of the coil mounting board 3,
A circuit for supplying a single-phase alternating current to the coreless coils 2A and 2B is formed, and electronic components used for this circuit are housed in a concave portion of the motor disposition portion 18. Since the single-phase AC currents flow through the coreless coils 2A and 2B, the coreless coils 2A and 2B are at a mechanical angle of 18
Located at an angle of 0 degrees. The coreless coils 2A and 2B are composed of portions 2a and 2b called arms and portions 2 arranged in the circumferential direction.
c, 2d. 2a and 2b generate a magnetic field that contributes to the generation of the rotational torque of the rotary fan 6. The angle between 2a and 2b is approximately 90 degrees in mechanical angle. Coreless coil 2
A first stator-side magnet is arranged on one end surface of the coil mounting board 3 at a position on the rotation axis side of A and 2B.

The stator armature 11 in the single-phase energizing arrangement has a dead point at which the rotating fan 6 cannot start itself. In order to avoid this dead point, a cogging torque is generated by the magnetic screw 24.

Although not shown, electronic components for a drive circuit (energization control circuit) are arranged on the other end surface of the coil mounting board 3.
A conductive wiring pattern (not shown) formed on the coil mounting board 3 is electrically connected to the lead wire 14 by soldering or the like. Arm portions 2a of the coreless coils 2A, 2B,
The magnetic pole passing through 2b reverses the direction of the current flowing through the coreless coils 2A, 2B by the N pole and the S pole. A Hall element, which is a magnetoelectric conversion element for detecting the magnetic pole, is attached to the coil mounting board 3 near one arm, and forms a part of the power supply control circuit.

The first rotor-side magnet 10 and the first stator-side magnet 12 are located at positions facing each other.
The opposing surfaces of the first rotor-side magnet 10 and the first stator-side magnet 12 are magnetic poles having the same polarity. Due to the weight of the rotating fan 6 and the magnetic attraction of the magnet 5 and the magnetic screw 24, the rotating shaft 7 of the rotating fan 6 is displaced in the thrust direction with respect to the bearing 8. Rotating fan 6 is stator armature 1
When the distance is too close to 1, the opposing surfaces of the first rotor-side magnet 10 and the first stator-side magnet 12 have the same magnetic pole, and a repulsive force is generated. This repulsive force prevents the rotating fan 6 and the stator armature 11 from getting too close to each other. The rotating fan 6 separates from the stator armature 11,
In order to prevent the rotating shaft 7 from coming off the bearing 8, the rotating shaft 7
A cut washer 29 is attached to a single point of the above.

[0029]

Second Embodiment FIG. 3 is an exploded perspective view of an axial gap type brushless fan motor 1C showing a second embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view of the fan motor 1C of FIG.
A description will be given of an axial gap type brushless fan motor 1C according to a second embodiment of the present invention with reference to FIG. However, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, and the sixth embodiment
In the embodiment, description of parts common to the first embodiment will be omitted.

The axial gap type brushless fan motor 1C according to the second embodiment is the same as the axial gap type brushless fan motor 1B, except that the first stator-side magnet 12 is connected to the rotary fan 6 of the coreless coils 2A and 2B. On the side surface. If there is no space for disposing the first stator-side magnet 12 on the side of the rotary fan 6 of the coil mounting board 3, the first stator-side magnet 12
Are arranged to overlap. The gap between the first rotor-side magnet 10 and the first stator-side magnet 12 is set to a distance such that an appropriate amount of repulsive force is generated.

[0031]

Third Embodiment FIG. 5 is an exploded perspective view of an axial gap type brushless fan motor 1D showing a third embodiment of the present invention, and FIG.
5 is a longitudinal sectional view of the fan motor 1D of FIG.
A description will be given of an axial gap type brushless fan motor 1D according to a third embodiment of the present invention with reference to FIG.

An axial gap type brushless fan motor 1D of the third embodiment is different from 1B in that a second rotor-side magnet 25 is provided at a tip end of a rotating shaft 7 which passes through a bearing 8. The second rotor-side magnet 25 is attached to the rotating shaft 7 so as to fit inside the end face of the case 16. The second rotor magnet 25 has a single magnetic pole on the surface on the stator armature side and has a flat annular shape. The disk 2 made of iron serves to fix the second rotor magnet 25 to the rotating shaft 7.
7 Since the disk 27 is made of magnetic iron,
It serves to close the magnetic flux of the rotor-side magnet 25. Also, this disk 27 is the second rotor side magnet 2
5 has substantially the same diameter. A second stator-side magnet 26 having the same polarity is provided at a position facing the second rotor-side gnet 25 of the case 16. The first rotor side magnet 10 and the first
Stator-side magnet 12, second rotor-side magnet 2
5 and the second stator side magnet 26 oppose each other because of the same magnetic pole. The gap between the first rotor-side magnet 10 and the first stator-side magnet 12 and the gap between the second rotor-side magnet 25 and the second stator-side magnet 26 is a distance at which an appropriate repulsive force is generated. No matter what angle the axial gap type brushless fan motor 1D is tilted, the rotating shaft 7 does not slide on the parts other than the bearing 22, and the rotating fan 6 rotates.

[0033]

Fourth Embodiment FIG. 7 is an exploded perspective view of an axial gap type brushless fan motor 1E showing a fourth embodiment of the present invention, and FIG. 8 is a longitudinal sectional view of the fan motor 1E of FIG. Hereinafter, an axial gap type brushless fan motor 1E according to a fourth embodiment of the present invention will be described with reference to FIGS.

The axial gap type brushless fan motor 1E of the fourth embodiment is different from 1C in that a second rotor-side magnet 25 is provided at the tip end of a rotating shaft 7 that passes through a bearing 8. The second rotor-side magnet 25 is attached to the rotating shaft 7 so as to fit inside the end face of the case 16. The second rotor magnet 25 has a single magnetic pole on the surface on the stator armature side and has a flat annular shape. The disk 2 made of iron serves to fix the second rotor magnet 25 to the rotating shaft 7.
7 Since the disk 27 is made of magnetic iron,
It serves to close the magnetic flux of the rotor-side magnet 25. Also, this disk 27 is the second rotor side magnet 2
5 has substantially the same diameter. A second stator-side magnet 26 having the same polarity is provided at a position opposite to the second rotor-side gnet 25 of the case 16. The first rotor side magnet 10 and the first
Stator-side magnet 12, second rotor-side magnet 2
5 and the second stator side magnet 26 oppose each other because of the same magnetic pole. The gap between the first rotor-side magnet 10 and the first stator-side magnet 12 and the gap between the second rotor-side magnet 25 and the second stator-side magnet 26 is a distance at which an appropriate repulsive force is generated. No matter what angle the axial gap type brushless fan motor 1D is tilted, the rotating shaft 7 does not slide on the parts other than the bearing 22, and the rotating fan 6 rotates.

[0035]

Fifth Embodiment FIG. 9 is an exploded perspective view of an axial gap type brushless fan motor 1F showing a fifth embodiment of the present invention, and FIG. 10 is a longitudinal sectional view of the fan motor 1F of FIG. ,
Hereinafter, an axial gap type brushless fan motor 1F according to a fifth embodiment of the present invention will be described with reference to FIGS. However, description of parts common to the first, second, third, and fourth embodiments will be omitted.

An axial gap type brushless fan motor 1F of the fifth embodiment has a bearing 8 for rotatably supporting a rotating shaft 7 in a case 16 and a cylindrical magnet for fixing the bearing 8 to the outer periphery of the bearing 8. 28 are provided. The cylindrical magnet 28 and the bearing 8 are arranged on the same circumference. This cylindrical magnet 28 is magnetized at both end surfaces in a single pole.
A disk-shaped second rotor-side magnet 25 is provided at the tip end of the rotating shaft 6 provided on the rotating fan 6 and penetrating the bearing 22. The end face of the second rotor-side magnet 25 on the side of the stator armature 11 is a single-pole magnetic pole, and has the same polarity as the magnetic pole of one end face of the cylindrical magnet 28 which faces the end face.
The other end face of the cylindrical magnet 28 and the end face of the first rotor-side magnet 10 that face the face-to-face cylindrical magnet 28 have the same polarity.

Both end surfaces of the cylindrical magnet 28 are opposed to the first and second rotor-side magnets 10 and 25, respectively. Repulsive force is generated at the opposed surfaces. And keep the position properly.

[0038]

Sixth Embodiment FIG. 11 is an exploded perspective view of an axial gap type brushless fan motor 1G showing a sixth embodiment of the present invention, and FIG. 12 is a longitudinal sectional view of the fan motor 1G of FIG. Hereinafter, an air gap type brushless fan motor 1-6 according to a sixth embodiment of the present invention will be described with reference to FIGS.
Will be described. However, the first, second, third, fourth and fifth
The description of the parts common to the embodiment is omitted.

The axial gap type brushless fan motor 1G of the sixth embodiment comprises a bearing 8 for rotatably supporting a rotating shaft 7 in a case 16 and a cylindrical magnet 28 for fixing the outer periphery of the bearing 8. Provided. This cylindrical magnet 28
Is formed such that one end surface on the tip side of the rotating shaft 7 is located at substantially the same height position as the tip portion of the rotating shaft 7. This cylindrical magnet 28 is magnetized at both end surfaces in a single pole. The cylindrical magnet 28 is cylindrical and penetrates the entire length of the bearing house 21. The other end surface of the cylindrical magnet 28 is magnetized to the same polarity as the opposing surface of the first rotor-side magnet 10. The opposing surface between the cylindrical magnet 28 and the first rotor-side magnet 10 has the same magnetic pole, so that a repulsive force is generated. The rotating shaft 7 is made of a magnetic material, and a cut washer 29 for preventing the rotating shaft 7 from coming off is attached to the tip of the rotating shaft 7 that has penetrated the bearing 22. The rotating shaft 7 is a magnetic material and generates an attractive force between the rotating shaft 7 and the cylindrical magnet 28. The rotating fan 6 attempts to maintain an appropriate position with respect to the rotating shaft 7 by the repulsive force and the attractive force, and the weight load of the rotating fan 6 and the magnetic attractive force of the field magnet 5 and the stator yoke 4 The rotation fan 6 is prevented from being sucked in the direction of the stage 4.

In the above-described first to sixth embodiments, an example in which a starter yoke is not used has been described.
Alternatively, a coil yoke may be used. In this case, the coil yaw
The magnet 3 is used for the purpose of generating reluctance torque for self-starting by the shaft 3 or for preventing the displacement of the rotating fan 6 when the axial gap type brushless fan motor is used in a direction perpendicular to the drawing. 5 and coil yo
For the purpose of generating a magnetic attraction force with the magnetic disk, it is preferable to use it over a small area.

[0041]

According to the first aspect of the present invention, noise and vibration generated by the shaft loss at the tip of the rotating shaft are eliminated, and the current value of the current required for rotating the rotating fan is reduced. Comes out.

According to the invention described in claim 2, according to claim 1
In the embodiment of the present invention, the gap between the magnet and the coil can be thinned by providing the first stator-side magnet on the rotation axis side of the coil mounting board 3 with respect to the coil, so that the axial gap is reduced. There is an advantage that the thickness of the brushless fan motor 1B can be reduced.

According to the invention described in claim 3, according to claim 1
In the embodiment of the invention, in the axial gap type brushless fan motor having no space for disposing the first stator side magnet on the surface of the coil mounting machine substrate, the first stator side magnet is disposed so as to overlap a part of the coil. This can be easily achieved.

According to the fourth aspect of the present invention, noise and vibration caused by shaft loss at the tip of the rotary shaft 7 are eliminated, and the current value of the current required to rotate the rotary fan 6 is reduced. Comes out.

According to the invention described in claim 5, according to claim 4,
In the invention described in (1), the functions of the first stator-side magnet and the second stator-side magnet can be performed by the cylindrical magnet, and the number of components of the axial gap type brushless fan motor can be reduced.

According to the sixth aspect of the present invention, it is possible to eliminate the noise and vibration generated by the shaft loss at the tip of the rotating shaft and to reduce the current value of the current required for rotating the rotating fan. Wear.

According to the present invention, a magnetic circuit is formed by the magnet, the coil, the coil yoke, and the magnet yoke by providing the coil with the coil yoke. By closing with the yoke, the magnetic flux passing through the magnetic circuit can be increased.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an axial gap type brushless fan motor according to a first embodiment of the present invention.

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

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

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

FIG. 5 is an exploded perspective view of an axial gap type brushless fan motor showing a third embodiment of the present invention.

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

FIG. 7 is an exploded perspective view of an axial gap type brushless fan motor according to a fourth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of the fan motor.

FIG. 9 is an exploded perspective view of an axial gap type brushless fan motor according to a fifth embodiment of the present invention.

FIG. 10 is a longitudinal sectional view of the fan motor.

FIG. 11 is an exploded perspective view of an axial gap type brushless fan motor according to a sixth embodiment of the present invention.

FIG. 12 is a longitudinal sectional view of the fan motor.

FIG. 13 shows a conventional axial gap type brushless fan motor.
FIG.

FIG. 14 is a longitudinal sectional view of the fan motor.

[Explanation of symbols]

101, 1B, 1C, 1D, 1E, 1F, 1G Axial gap type brushless fan motor 2A, 2B Coreless coil 3 Coil mounting board 5 Magnet 6 Rotary fan 7 Rotary shaft 8 Bearing 10 First rotor side magnet 12 First stator Side magnet 25 Second rotor side magnet 26 Second stator side magnet 28 Cylindrical magnet

Claims (7)

[Claims] 1. A rotating fan and a stator armature are housed in a case, and the rotating fan includes an impeller, a rotating shaft,
A magnet having at least one magnetic pole pair of an N pole and an S pole on a surface facing the stator armature, wherein the stator armature has a coil and a coil mounting board, and the case has the rotating shaft. In the axial gap type brushless fan motor having a bearing to be supported, the rotating fan includes a first rotor side magnet having a single magnetic pole on a surface facing a stator armature, and the stator armature includes the first rotor magnet. 1
An axial gap type brushless fan motor, comprising: a first stator-side magnet having a magnetic pole of the same polarity as an opposing surface of the rotor-side magnet at a position facing the rotor-side magnet. 2. The brushless fan motor according to claim 1, wherein the first stator-side magnet is provided at a position closer to the rotation axis than the coil on the surface of the coil mounting board. 3. The magnet according to claim 1, wherein the first stator-side magnet is disposed so as to overlap a part of the coil.
2. An axial gap type brushless fan motor according to item 1. 4. The rotating shaft includes a second rotor-side magnet having a single-pole magnetic pole on a stator armature side surface around a tip located through the stator armature. 4. The magnet according to claim 1, further comprising a second stator-side magnet having a magnetic pole of the same polarity as an opposing surface of the second rotor-side magnet at a position facing the second rotor-side magnet. Axial gap type brushless fan motor. 5. A rotating fan and a stator armature are housed in a case, wherein the rotating fan has an impeller, a rotating shaft,
A magnet having at least one magnetic pole pair of an N pole and an S pole on a surface facing the stator armature, wherein the stator armature has a coil and a coil mounting board, and the case has the rotating shaft. An axial gap type brushless fan motor having a bearing to be supported, comprising: a first rotor-side magnet having a surface facing a stator armature as a single-pole magnetic pole around a periphery of the magnet; A second rotor-side magnet having a single-pole magnetic pole on a surface opposing the stator armature at a peripheral portion of a tip positioned through the cylindrical armature. One end face of the magnet faces the first rotor side magnet, the other face faces the second rotor side magnet, and each end face of the cylindrical magnet has the first and second rotor side magnets. Axial air-gap type brushless fan motor, which is a anti-face the same polarity. 6. A rotating fan and a stator armature are housed in a case. The rotating fan includes an impeller, a rotating shaft made of a magnetic material, and one or more magnetic poles of N pole and S pole. A magnet having a surface facing the armature,
The stator armature has a coil and a coil mounting board, and the case is an axial gap type brushless fan motor having a bearing that supports the rotating shaft, in a surface opposed to the stator armature around the magnet. A first rotor-side magnet having a single magnetic pole; a cylindrical magnet disposed on an outer periphery of the bearing; one end surface of the cylindrical magnet on a rotating fan side facing the first rotor-side magnet; It is a magnetic pole of the same polarity as the opposing surface of the rotor side magnet, and the tip of the rotating shaft penetrating through the stator armature and the other end surface of the cylindrical magnet are substantially at the same height position. Axial gap type brushless fan motor. 7. The axial gap type fan motor according to claim 1, wherein said stator armature is provided with a coil yoke.