JP2003289645A - Low-vibration type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-vibration type motor capable of reducing the vibration of the motor by obtaining stable thrust torque and applying lateral pressure, and attaining easy setting of a cogging position. <P>SOLUTION: An attaching part 3a of a cylindrical magnet 3 is fixed to a center hole 2a, in a rotor 2 having a plurality of fans 8. A shaft 1 is crimped against a hole 3b of the cylindrical magnet 3. At the outer periphery of the cylindrical magnet 3, stators constituted of coils 9 and yokes 4 are arranged so as to face each other. The stators are fixed to a housing 5. A cylindrical attaching part 5a, for pressing a sliding bearing 6 into the center of the housing 5, stands at the center of the housing 5. A magnetic body ring 7 having a slit 7a shown in FIG. (b) is crimped against the outer periphery of the cylindrical attaching part 5a. The lateral torque can be adjusted by changing the width of the slit 7a. A stable load in the thrust direction can be obtained by fitting the magnetic ring 7, dislocated in the thrust direction from the cylindrical magnet 3. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and thin fan motor, and more particularly to a motor structure in consideration of vibration reduction.

[0002]

2. Description of the Related Art Conventionally, in an outer rotor type fan motor, when a sliding bearing is used, it is difficult to apply a lateral pressure to the shaft, and when the bearing is rotating, clearance of the shaft is generated due to clearance, which causes the bearing to strike It became a sound and was a cause of vibration.

6A and 6B are views showing an example of a conventional motor structure. FIG. 6A is a front sectional view and FIG. 6B is a view for explaining a force in a thrust direction. A magnet 31 is attached to the inner peripheral surface of the rotor 22. The coil 27 and the yoke 28 are provided at positions facing the magnet 31 from the inside.
A stator 25 made of is arranged. Stator 25
Is fixed to the housing 26, and the slide bearing 30 is press-fitted into the cylindrical portion of the housing 26. The shaft 23 fixed to the rotor 22 is inserted into the slide bearing 30, and the washer 29 is locked near the tip of the shaft 23 to prevent the shaft 23 from coming off. The tip of the shaft 23 is received by the thrust receiver 24, and movement in the thrust direction is regulated.

[0004]

In the above conventional example, the thrust torque is generated by shifting the positional relationship between the yoke and the magnet as shown in (b), but it is difficult to obtain a stable thrust torque. Is.
When the stator and magnet are displaced and thrust is applied, the magnetic balance is lost and a magnetic balance force acts when the coil is energized. Therefore, it was a cause of thrust vibration. Further, it is difficult to measure the shaft pressure on the bearing.

Further, since the coking torque is conventionally obtained by the gap on the stator yoke side, it is not easy to set the coking angle position. The purpose of the present invention is to
An object of the present invention is to provide a low-vibration motor structure capable of reducing the vibration of the motor by obtaining a stable thrust torque and applying a lateral pressure, and easily setting the coking position.

[0006]

In order to achieve the above object, a low vibration type motor according to the present invention is an inner rotor type motor in which a cylindrical magnet is attached to a rotor and a stator is arranged facing the outer peripheral side of the cylindrical magnet. In the motor, a magnetic ring is provided on the outer peripheral portion of the bearing, and the magnetic ring is arranged so as to be displaced in the thrust direction with respect to the cylindrical magnet to generate an arbitrary thrust load. In addition, the magnetic ring in the present invention has a slit, the slit position is set to be a coking angle position, and by selecting the slit width, a coking torque and a lateral pressure of arbitrary magnitudes are generated. It is configured. Further, according to the present invention, in the above structure, a neodymium magnet is used as the cylindrical magnet, and the magnetic force inside the cylindrical magnet can be adjusted by a magnetizing method. Further, according to the present invention, in the above structure, a portion for supporting the bearing is eccentrically formed by a mold, and the magnetic body ring is press-fitted to the outer periphery of the molded portion, so that magnetic attraction between the cylindrical magnet and the magnetic body ring is obtained. It is configured to eccentric force. Further, the magnetic ring press-fitted into the mold portion in the present invention may be formed in a pipe shape, a cylindrical curling shape, or a coil spring.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B are views showing an embodiment of a low vibration type motor according to the present invention. FIG. 1A is a front sectional view and FIG. 1B is a perspective view of a cylindrical magnetic body ring. Central hole 2 of rotor 2 having a plurality of fans 8
The mounting portion 3a of the cylindrical magnet 3 is fixed to a.
The shaft 1 is crimped to the hole 3b of the cylindrical magnet 3. A stator composed of a coil 9 and a yoke 4 is arranged outside the cylindrical magnet 3 so as to face each other. The stator is fixed to the housing 5.

At the center of the housing 5, a cylindrical mounting portion 5a for press-fitting the slide bearing 6 is provided upright. A magnetic ring 7 having a slit 7a shown in (b) is pressure-bonded to the outer periphery of the cylindrical mounting portion 5a. The lateral pressure torque can be adjusted by changing the width of the slit 7a.
Further, by disposing the magnetic ring 7 in the thrust direction with respect to the cylindrical magnet 3 and installing the magnetic ring 7, a stable load in the thrust direction can be obtained. The rotor 2 is assembled to the bearing 6 by inserting the shaft 1 into the bearing 6 and locking the washer 1a in an annular groove near the tip of the shaft. The tip of the shaft 1 hits the thrust receiver 10 and its movement in the thrust direction is restricted.
The positions of the stator and the yoke are arranged so as to coincide with the center position of the cylindrical magnet 3.

2A and 2B are views for explaining the setting of the coking angle. FIG. 2A is a perspective view of the vicinity of the magnetic ring and FIG. 2B is a plan view. FIG. 2A shows the shape of the slit of the magnetic ring 7 by breaking the vicinity of the front part of the cylindrical magnet 3. Using the intermediate position between the upper yoke 4a and the lower yoke 4b as a reference, the slit 7a is aligned with the desired coking angle position and the magnetic ring 7 is fixed. Since it suffices to align the slit at a position that matches the desired cogging angle, it is easy to set the cogging torque.

FIG. 3 is a partial front sectional view showing another embodiment of the present invention. A neodymium magnet is used as the cylindrical magnet 3, and the magnetic force can be easily adjusted by the magnetizing method. The cylindrical magnet 3 is attached to the attachment portion 12 on the lower surface of the rotor 11. The cylindrical magnet can be made by integrally molding the plastic magnet. Moreover, separation can be easily performed.

FIG. 4 is a view showing the structure of a magnetic ring which is installed with its center position displaced in the radial direction. The bearing mounting portion 16 is manufactured by a molding die, and the molding itself is eccentric. A cylindrical magnetic ring 17 is pressure-bonded to the outer periphery of the bearing mounting portion 16. Since the cylindrical magnet is installed eccentrically, the attraction force on one of the left and right sides becomes strong, and lateral pressure can be applied.

FIG. 5 is a diagram showing each embodiment of the magnetic ring. Magnetic ring is a pipe-shaped magnetic ring 1
9, the cylindrical curling magnetic ring 20, and the coil spring magnetic ring 21 can be attached by press fitting.

[0013]

As described above, the present invention is an inner rotor type motor in which a cylindrical magnet is attached to a rotor, and a stator is arranged so as to face the outer peripheral side of the cylindrical magnet. A magnetic ring is provided, and the magnetic ring is arranged so as to be displaced in the thrust direction with respect to the cylindrical magnet, and a vibration load of the motor can be reduced by generating a thrust load. Further, a slit is provided in the magnetic ring, the slit position is set to be the coking angle position, and the slit width is selected, so that the coking torque and the lateral pressure of arbitrary magnitude can be easily generated. The thrust load can be easily adjusted by changing the vertical position of the magnetic ring installation, and the fluctuation of the thrust load during rotation can be reduced. Since the outer circumference of the magnet of the rotating torque generating portion can be made small, the peripheral speed can be made small, and vibration during rotation can be easily made small. As a result, downsizing of the motor can be realized.

[Brief description of drawings]

1A and 1B are views showing an embodiment of a low-vibration motor according to the present invention, in which FIG. 1A is a front sectional view and FIG. 1B is a perspective view of a magnetic ring.

FIG. 2 is a diagram for explaining setting of a coking angle,
(A) is a perspective view near the magnetic ring, and (b) is a plan view.

FIG. 3 is a partial front sectional view showing another embodiment of the present invention.

FIG. 4 is a diagram showing a structure of a magnetic ring in which a center position is displaced in a radial direction.

FIG. 5 is a diagram showing each embodiment of a magnetic ring.

6A and 6B are views showing an example of a conventional motor structure, FIG. 6A is a front sectional view, and FIG. 6B is a diagram for explaining a force in a thrust direction.

[Explanation of symbols]

1,14 shaft 2,11 rotor 3 Cylindrical magnet 4 Stator yoke 4a Upper yoke 4b Lower yoke 5 housing 5a Cylindrical mounting part 6,15 bearing 7,17 Magnetic ring 7a slit 8 fans 9 coils 13 neo di magnet 16 Bearing mounting part (mold part) 19 Pipe-shaped magnetic ring

Claims (5)

[Claims] 1. An inner rotor type motor in which a cylindrical magnet is attached to a rotor, and a stator is arranged facing the outer peripheral side of the cylindrical magnet, wherein a magnetic ring is provided on an outer peripheral portion of a bearing, and the magnetic ring. Is a low-vibration motor that generates an arbitrary thrust load by arranging the cylindrical magnet so as to be displaced in the thrust direction with respect to the cylindrical magnet. 2. The magnetic ring has a slit, the slit position is set to be a coking angle position, and a coking torque and a lateral pressure of arbitrary sizes are generated by selecting the slit width. Characteristic low vibration type motor. 3. The low vibration type motor according to claim 1, wherein a neodymium magnet is used as the cylindrical magnet, and the magnetic force inside the cylindrical magnet can be adjusted by a magnetizing method. 4. The magnetic attraction force between the cylindrical magnet and the magnetic ring is eccentric by forming the portion supporting the bearing eccentrically with a mold and press-fitting the magnetic ring on the outer periphery of the mold portion. The low-vibration motor according to claim 1, wherein 5. The low-vibration motor according to claim 4, wherein the magnetic ring press-fitted into the mold portion is formed in a pipe shape, a cylindrical curling shape, or a coil spring.