KR20050077432A - Spindle motor for driving disk - Google Patents

Abstract

Disc drive spindle motor is disclosed. The disclosed spindle motor includes a noise reduction member mounted on an outer circumferential surface of the rotor yoke to reduce noise due to resonance by changing the resonant frequency band in the axial direction and the radial direction during rotation of the rotor yoke to avoid resonance.

Description

Spindle motor for driving disk

The present invention relates to a disk drive spindle motor, and more particularly, to a disk drive spindle motor that can reduce noise.

In general, a disk drive is a device for reproducing or recording information recorded on a disk while rotating the disk, which is an information storage recording medium. The disk drive includes a spindle motor for seating a disk and rotating the seated disk.

1 is a cross-sectional view showing the structure of a conventional spindle motor. Referring to FIG. 1, the spindle motor 10 includes a stator 20 and a rotor 40.

The stator 20 is a fixed part that is not rotated and is installed on the outer circumference of the bearing housing 22 and the bearing housing 22 surrounding the bearing 21, and the coil 24 and the coil 24 wound around the coil 24. 23 is provided with a printed circuit board 25 for applying a current from the outside or for sending a control signal.

The rotor 40 is a part which is connected to the rotating shaft 30 which is rotatably supported by the bearing 21 and is rotated. The magnet 40 is provided with a magnet, and the core 24 and the magnet 41 The rotor yoke 42 which rotates interactively and the turntable 43 on which the disk is mounted are provided.

Reference numeral 44 is an automatic eccentric adjustment device that automatically maintains a balance of the rotating shaft 30 to reduce vibration and noise generated due to the weight eccentricity of the disk seated on the turntable 43, and the plurality of ball bearings rotate at high speed. The balance moves automatically in the direction of equilibrium with centrifugal force.

The operation of the disk drive spindle motor having the above configuration will be described with reference to the drawings.

When a control signal and a current are alternately applied to the coil 23 through the printed circuit board 25 from the outside, the rotor yoke 42 is rotated by the interaction of the coil 23 and the magnet 41. When the rotor yoke 42 is rotated, the rotation shaft 30 also rotates together with the rotor yoke 42.

When the rotating shaft 30 is rotated, the turntable 43 fixed to the rotating shaft 30 is also rotated, and the disk (not shown) seated on the turntable 43 is also rotated.

By the way, the spindle motor 10 as described above is rotated in interaction with the coil 23 and the magnet 41 is generated vibration and noise. These vibrations and noises are generated by the electromagnetic imbalance force acting inside the spindle motor 10, and noises corresponding to frequency bands of harmonic components corresponding to multiples of the switching frequency are generated. Such noise is noise in a frequency band that is detrimental to human hearing characteristics, that is, noise corresponding to a 3.5 to 5 kHz band.

Therefore, a noise reduction method that can reduce noise in a frequency band that is detrimental to such human hearing characteristics should be devised.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a disk drive spindle motor capable of reducing noise by avoiding resonance by installing a noise reduction member on the outer circumferential surface of the rotor yoke to change the resonance frequency band of the rotor yoke has its purpose. have.

In the disk drive spindle motor of the present invention to achieve the above object is a disk drive spindle motor including a rotary shaft having a turntable is mounted, and a rotor yoke mounted on the rotary shaft and magnetized magnet,

It is provided on the outer circumferential surface of the rotor yoke is provided with a noise reduction member for reducing the noise caused by the resonance by changing the resonant frequency band in the axial direction and the radial direction when the rotor yoke is rotated.

According to the present invention, the noise reduction member is formed of an annular ring and is fitted to the outer circumferential surface of the rotor yoke.

According to the present invention, the noise reduction member is formed of a conical ring and is fitted to the outer circumferential surface of the rotor yoke.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a perspective view showing a disk drive spindle motor to which the noise reduction member is applied according to the present invention, Figure 3 is a cross-sectional view showing a disk drive spindle motor shown in Figure 2, Figure 4 is another embodiment of the present invention A perspective view illustrating a disk drive spindle motor to which a noise reduction member according to an example is applied.

2 to 4, the disk drive spindle motor 100 according to the present invention includes a stator 200 and a rotor 400.

The stator 200 is a fixed part that is not rotated and is installed on a bearing housing 220 surrounding the bearing 210 and an outer circumferential surface of the bearing housing 220, in which a coil 230 is wound around the core 240. And a printed circuit board 250 for applying a current or transmitting a control signal to the coil 230 from the outside.

The rotor 400 is connected to the rotating shaft 300 which is rotatably supported by the bearing 210 to be rotated. The magnet 400 is provided with a magnet, and the core 240 and the magnet are provided. The rotor yoke 420 rotates by the interaction of 410 and a turntable 430 on which a disk (not shown) is mounted.

The turntable 430 has an automatic eccentric adjustment device for automatically maintaining the balance of the rotating shaft 300 in order to reduce vibration and noise caused by the weight eccentricity of the disk (not shown) mounted on the turntable 430 ( 440 is installed. The automatic eccentric adjustment device 440 automatically maintains a balance by moving a plurality of ball bearings in a direction in equilibrium with the centrifugal force at high speed rotation.

By adding a predetermined mass to the rotor yoke 420 on the outer circumferential surface of the rotor yoke 420, a frequency band in which resonance occurs when the rotor yoke 420 rotates is avoided, thereby avoiding resonance and reducing noise generated by resonance. The noise reduction member 500 is installed.

The noise reduction member 500 is fitted to the outer circumferential surface of the rotor yoke 420, the shape is preferably an annular ring shown in Figure 2 or a conical ring shown in FIG. The shape is not necessarily limited to the above shape, and any shape may be applied as long as it can add mass uniformly along the outer circumferential surface of the rotor yoke 420.

The operation of the disk drive spindle motor configured as described above and the operation of the noise reduction member according to the present invention will be described with reference to the drawings.

2 and 3, when a control signal and a current are alternately applied to the coil 230 through the printed circuit board 250 from the outside, the coil 230 and the magnet 410 may interact with each other. The rotor yoke 420 is rotated. When the rotor yoke 420 is rotated, the rotating shaft 300 also rotates with the rotor yoke 420.

When the rotating shaft 300 is rotated, the turntable 430 fixed to the rotating shaft 300 is also rotated together, and a disk (not shown) mounted on the turntable 430 is also rotated together.

The noise reduction member 500 is rotated together with the rotor yoke 420 to add mass to the rotor yoke 420. Then, the mass is added to the rotor yoke 420, the axial direction (rotation axis direction) resonant frequency of the rotor yoke 420 is changed to a low frequency by the mass of the noise reduction member 500. Therefore, the axial resonance frequency of the spindle motor 100 is lowered to avoid the frequency band in which resonance occurs.

As a result of the experiment, when only the rotor yoke 420 was rotated, the resonant frequency in the axial direction was 3.4 는데. Lowered to

In addition, the noise reduction member 500 serves as a reinforcing part to increase the rigidity of the rotor yoke 420 by restraining the radial displacement of the rotor yoke 420 so that the radial resonant frequency is changed to a high frequency. Therefore, the radial resonance frequency of the spindle motor 100 is increased to avoid a frequency band in which resonance occurs.

As a result of the experiment, when only the rotor yoke 420 was rotated, the radial resonant frequency was 5.1 Hz. As a result of the rotation after the noise yoke member 500 was inserted into the rotor yoke 420, the radial resonant frequency was 6.3. Raised to ㎑.

On the other hand, the noise reduction member 500 is not only made of the same material as the rotor yoke 420, but also using a different material, that is, a material having a high density and elastic modulus can obtain a greater mass effect and stiffness effect As a result, resonance can be avoided by changing the resonant frequency band in the radial or axial direction.

As described above, the disk drive spindle motor according to the present invention can avoid the resonance by changing the resonance frequency band of the rotor yoke by installing a noise reduction member in the rotor yoke can reduce the noise generated by the resonance It works.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those of ordinary skill in the art that various modifications and variations can be made therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a cross-sectional view showing the structure of a conventional spindle motor,

Figure 2 is a perspective view showing a disk drive spindle motor to which the noise reduction member according to the present invention is applied,

3 is a cross-sectional view showing a disk drive spindle motor to which another noise reduction member is applied to the present invention;

Figure 4 is a perspective view showing a disk drive spindle motor to which the noise reduction member is applied according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

210 ... Bearing 220 ... Bearing Housing

230 ... coil 240 ... core

250 ... printed circuit board 300 ... rotation shaft

410 magnet 420 rotor yoke

430 ... Turntable 440 ... Automatic center adjustment

500 ... Noise reduction member

Claims (3)

A disk drive spindle motor comprising a rotating shaft having a turntable mounted thereon and a rotor yoke mounted on the rotating shaft and magnetized magnets. And a noise reduction member mounted on an outer circumferential surface of the rotor yoke to reduce noise caused by resonance by changing resonance frequency bands in the axial direction and the radial direction when the rotor yoke rotates, thereby avoiding resonance. Spindle motor. The method of claim 1, The noise reduction member is composed of an annular ring, the disk drive spindle motor, characterized in that installed on the outer peripheral surface of the rotor yoke. The method of claim 1, The noise reduction member is composed of a conical ring, the disk drive spindle motor, characterized in that is installed fitted to the outer peripheral surface of the rotor yoke.