KR20020077979A - A spindle motor - Google Patents

Abstract

PURPOSE: A spindle motor is provided to reduce vibration and noise by automatically maintaining balance of rotating shaft even when the CD ROM disk is arranged eccentrically by the centrifugal force of fluid. CONSTITUTION: A spindle motor comprises a support(4) fixed to a CD ROM case(2); a stator core(6) attached in a circumferential direction at the outer surface of the support and wound with a coil; a rotating shaft(8) inserted into the support and connected to a turn table(14); a magnet(10) disposed in a circumferential direction at the outer surface of the stator core; a rotating yoke(12) where the magnet is mounted; a fluid balance(30) mounted at the top of the rotating yoke, and which permits the rotating shaft to automatically maintain a balanced state; and the turn table fixed to the upper portion of the rotating shaft, and which rotates together with the rotating shaft. The fluid balance includes a cylindrical housing(32) mounted at the top of the rotating yoke, and which has a hollow center for penetration of the rotating shaft; and a fluid(34) filling the housing, and which maintains balance of the rotating shaft by the centrifugal force generated during the rotation of the rotating shaft.

Description

A spindle motor

The present invention relates to a spindle motor applied to a CD-ROM drive, and more particularly, to install a fluid balance on a rotating shaft of the motor, even if the CD-ROM disk is eccentrically seated, the spindle can automatically maintain the balance of the rotating shaft to reduce vibration and noise. It's about a motor.

1 is a cross-sectional view showing a spindle motor of a CD-ROM drive according to the prior art, wherein the support 122 is fixed to the CD-ROM case 102 and is fixed in the outer circumferential direction of the support 122 and the coil is wound. A stator core 104, a rotation shaft 106 rotatably inserted into the support body 122, a magnet 120 disposed in an outer circumferential direction of the stator core 104, and a rotation yoke on which the magnet is mounted ( 126, a bearing 108 mounted in an upper circumferential direction of the rotary shaft 106 to rotatably support the rotary shaft 106, and a turntable 110 fixed to an upper end of the rotary shaft 106 and seated with a CD-ROM disk. )

Since the spindle motor rotates at a high speed of about 7500 rpm or more, vibration and noise are generated due to the weight eccentricity of the CD-ROM disk seated on the turn table 110. Therefore, the motor 104 is mainly used a vibration resistant motor having an auto balance function for automatically maintaining the balance of the rotating shaft.

The bearing 108 is composed of six to seven balls for vibration resistance of the motor, and the ball in the upper layer of the motor moves in the direction of equilibrium of centrifugal force and force during high speed rotation to maintain balance automatically.

However, the spindle motor according to the related art as described above has a problem in that noise and vibration are generated because the positions of the balls are moved for the auto-balancing action at high speed.

The present invention was created to solve the above problems, an object of the present invention is to install the fluid balance on the rotation axis of the motor, even if the CD-ROM disc is eccentrically seated by the centrifugal force of the fluid to automatically maintain the balance of the rotation axis vibration and To provide a spindle motor that can reduce noise.

1 is a cross-sectional view showing a spindle motor of a CD-ROM drive according to the prior art,

2 is a cross-sectional view showing a spindle motor of the CD-ROM drive according to the present invention;

3 is a cross-sectional view taken along the line A-A of FIG. 2.

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

2: cd rom case 4: motor

6: rotating shaft 8: motor case

10: turntable 30: fluid balance

32 housing 34 fluid

38: sealing member

Spindle motor according to the present invention for realizing the above object, the stator core is fixed to the CD-ROM case, the stator core is fixed in the outer circumferential direction of the support, the coil is wound, rotatably inserted into the support and connected to the turntable A rotating shaft, a magnet disposed in an outer circumferential direction of the stator core, a rotating yoke on which the magnet is mounted, and a fluid balance mounted on an upper side of the rotating yoke to maintain a balance automatically. do.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a cross-sectional view showing a spindle motor applied to the CD-ROM drive according to the present invention.

The CD-ROM drive according to an embodiment of the present invention includes a support 4 inserted into and fixed to the CD-ROM case 2, a stator core 6 fixed in an outer circumferential direction of the support 4 and wound with a coil, and A rotating shaft 8 rotatably inserted into the support body 4, a magnet 10 disposed in the outer circumferential direction of the stator core 6, a rotating yoke 12 on which the magnet 10 is mounted, A fluid balance 30 mounted on an upper side of the rotating yoke 12 and having a self-aligning function so that the rotating shaft 8 can be automatically maintained in balance, and fixed to the upper side of the rotating shaft 8 to be rotated together and a CD-ROM. And a turn table 14 on which the disk is seated.

The spindle motor is a motor that rotates at a high speed of about 7500 rpm or more, and a lower end thereof is fixed to the CD-ROM case 2 and the rotating shaft 8 is mounted upward.

The fluid balance 30 is mounted on the top surface of the rotating yoke 12 and penetrates through the rotation shaft 8 at the center thereof, and has a cylindrical housing 32 having a predetermined space therein, and the housing 32. It is made of a fluid 34 is filled by a predetermined amount to maintain the balance of the rotary shaft by the centrifugal force generated when the rotary shaft 8 rotates.

Here, the sealing member 38 is interposed between the portion through which the rotating shaft 8 of the housing 32 passes and the rotating shaft 6 to prevent the fluid 34 filled in the housing 32 from leaking. do.

The fluid 34 is formed in a gel type having a certain viscosity, the centrifugal force is applied when the rotating shaft 8 rotates to maintain the balance of the rotating shaft 8.

The operation of the spindle motor drive structure applied to the CD-ROM drive according to the present invention made as described above will be described below.

3 is a state diagram showing the operating state of the spindle motor drive structure of the CD-ROM drive according to the present invention.

When power is applied while the CD-ROM disk is seated on the turn table 14, the rotor core 12, on which the magnet 10 is fixed, is rotated to rotate the rotating shaft 8, and the connected turn table of the rotating shaft 8 ( 14) rotates the CD-ROM disk. At this time, when the center of gravity of the CD-ROM disk is eccentric, when the rotating shaft 8 is rotated, the rotating shaft 8 is eccentrically rotated, and at this time, the axis center of the rotating shaft 8 by the centrifugal force of the fluid 34 filled in the fluid balance. The balance of the rotating shaft 8 is maintained while moving to the center.

As such, even when the CD-ROM disk eccentrically seated on the turntable 14 is rotated and rotated, the centrifugal force of the fluid 34 filled in the fluid balance 30 acts on the rotating shaft 8 to automatically maintain the balance, thereby causing vibration and noise. Reduce the occurrence.

Therefore, the spindle motor of the CD-ROM drive according to the present invention constructed and operated as described above has an axis of the rotating shaft caused by the centrifugal force of the fluid filled in the fluid balance even when the CD-ROM disc in an eccentric state is seated and rotated on the turntable of the high-speed CD-ROM drive. By automatically adjusting the eccentricity of the rotating shaft while the center is moved to the center, vibration and noise can be reduced, and there is an advantage of reducing the reading error of data recorded on the disk.

Claims (3)

A stator core fixed to the CD-ROM case, a stator core fixed in an outer circumferential direction of the support and wound with a coil, a rotation shaft rotatably inserted in the support and connected to a turntable, and disposed in an outer circumferential direction of the stator core And a magnet, a rotating yoke on which the magnet is mounted, and a fluid balance mounted on an upper side of the rotating yoke to automatically maintain a balance of the rotating shaft. The method of claim 1, The fluid balance is mounted on the upper surface of the motor case and penetrates through the rotating shaft at the center thereof, and has a cylindrical shape with a predetermined space therein, and a centrifugal force generated when the rotating shaft is filled by filling the case by a predetermined amount. Spindle motor, characterized in that consisting of a fluid to maintain the balance of the axis of rotation. The method of claim 2, The fluid is a spindle motor, characterized in that formed in a gel type having a certain viscosity to which the centrifugal force is applied during the rotation of the rotary shaft.