KR100591804B1 - Vibroisolating structure in spindle motor - Google Patents

Abstract

The present invention provides a hard disk drive having a base having a motor mounting surface, the spindle motor mounted on the motor mounting surface comprising: a flange having a protrusion formed on a lower end surface of the shaft hole; The spindle motor, comprising a dustproof plate made of a dustproof alloy material and forming a hole in the center to attach the adhesive to the bottom surface of the flange to absorb vibration and noise generated from the spindle motor. Provide an anti-vibration structure.

Spindle motor, flange, dustproof alloy, base

Description

VIBROISOLATING STRUCTURE IN SPINDLE MOTOR}             

1 is an exploded perspective view illustrating a spindle motor and a base of a hard disk drive according to an embodiment of the general technology;

2 is a schematic view showing a flange portion of a spindle motor having a vibration preventing structure according to a first embodiment of the present invention;

3 is a schematic view showing a flange portion of a spindle motor having a vibration preventing structure according to a second embodiment of the present invention;

4 is a schematic view showing a flange portion of a spindle motor having a vibration preventing structure according to a third embodiment of the present invention;

5 is a cross-sectional view of a spindle motor having a vibration preventing structure according to a preferred embodiment of the present invention.

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

10: base 12: motor mounting surface

20: spindle motor 22: flange

24: head mounting groove 26: screw mounting hole

30: dustproof plate 40: adhesive

50: dustproof flange

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor of a hard disk drive, and more particularly, to a vibration preventing structure of a spindle motor having a dustproof plate attached to a flange bottom of the spindle motor.

A hard disk drive is an external storage device in which a magnetic disk is installed in a hub of a spindle motor that rotates at a high speed, and a magnetic head at an arm end pivoting accesses the magnetic disk to record and reproduce data. .

A typical hard disk drive has a spindle motor, a magnetic disk, a voice coil motor, an arm, a magnetic head and a printed circuit board in a sealed housing consisting of a base and a cover.

1 is an exploded perspective view illustrating a spindle motor and a base of a hard disk drive according to an embodiment of the general technology.

As shown in FIG. 1, a circular motor mounting groove 12 is formed on an upper surface of the base 10, and a plurality of screw holes 14 are formed in the motor mounting groove 12 on a concentric circle. The motor mounting groove 12 is equipped with a spindle motor 20 for rotating the magnetic disk disc on which data is recorded at a constant speed.

The spindle motor 20 is a kind of brushless DC motor composed of a flange 22, a hub 28, a spindle shaft, a bearing, a stator and a rotor (above, located in the hub), and the like. Like a motor, it is driven by Fleming's left hand law. The spindle motor 20 is coupled to the motor mounting groove 12 of the base 10 by fastening a plurality of screws to the screw hole 26 of the head seating groove 24 formed at equal intervals on the flange 22. It is fixed.

Although not shown in Figure 1, the bearing is inserted into the outer peripheral surface of the spindle shaft, the hub is mounted on the outer peripheral surface of the bearing. The hub rotates at high speed by magnetic action between a rotor attached to the inside and a stator provided on the spindle shaft. As the hub rotates, self vibration caused by a harmonic component is generated, and noise caused by friction between the bearing and the counterpart is also generated. (The internal structure of a typical spindle motor is shown in FIG. 5 to be described later.)

When the vibration of the spindle motor 20 is transmitted to the base 10 as it is, a relative displacement occurs between the magnetic head and the magnetic disk, thereby causing on-track degradation and data signal error. In addition, when the bearing friction noise in the spindle motor 20 is transmitted to the base 10, a severe discomfort is given to a user who uses the hard disk drive.

 SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a vibration preventing structure of a spindle motor for preventing self vibration or friction noise generated in the spindle motor from being transmitted to the base.

In order to achieve the above object, the present invention provides a hard disk drive having a base having a motor mounting surface, the spindle motor mounted on the motor mounting surface, the flange having a protrusion formed on the lower surface of the shaft hole; The spindle motor, comprising a dustproof plate made of a dustproof alloy material and forming a hole in the center to attach the adhesive to the bottom surface of the flange to absorb vibration and noise generated from the spindle motor. Provide an anti-vibration structure.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

An anti-vibration structure of a spindle motor according to a feature of the present invention includes a first embodiment in which a dustproof plate is attached to the entire bottom of a flange except for a lower end of a shaft hole, and a second embodiment in which a notch is formed at an outer circumferential end of the flange. There is a third embodiment in which the entire flange is formed of an anti-vibration alloy material, and there may be an application example in which a detailed change is made based on such an embodiment.

The vibration damping plates of the first and second embodiments and the flanges of the third embodiment are made of a dustproof alloy material. The anti-vibration alloy is an alloy that absorbs vibration by converting vibration energy into thermal energy by ε martensite or lamination defects when an external force is applied, and is composed of manganese-copper `Sonostone` and manganese-copper-aluminum-based` Incramut '. `, Iron-copper-aluminum-based 'Sirentaloy` and the like, and there are other iron-manganese-chromium, iron-chromium-aluminum and iron-manganese-silicon-based alloys.

Since the anti-vibration alloy has a dustproof property, a mechanical property, and a unit price according to the alloy component, a dustproof alloy having a specific component may be selected and used according to the model of the hard disk drive and the characteristics of the component parts. For reference, the types and characteristics of anti-vibration alloys are published in July 1998 by the Ministry of Science and Technology, A Study on the Development of High Damping Alloys. In detail).

2 is a schematic view showing a flange portion of a spindle motor having a vibration preventing structure according to a first embodiment of the present invention, Figure 3 is a flange of a spindle motor having a vibration preventing structure according to a second embodiment of the present invention 4 is a schematic view showing a flange portion of a spindle motor having an anti-vibration structure according to a third embodiment of the present invention, in which screw holes are omitted to emphasize the features of the present invention.

As shown in FIG. 2, the flange 22 according to the first embodiment of the present invention is formed of an aluminum alloy, and extends and protrudes downwardly to the bottom surface of the shaft hole 25. The anti-vibration plate 30 made of the anti-vibration alloy forms a hole having an outer diameter of the protruding portion 27 in the center so that the anti-vibration plate 30 may be attached to the lower surface of the flange 22 on which the protruding portion 27 is formed. 40).

The protrusions 27 (the same material as the flanges) protruding from the bottom of the shaft hole 25 on the bottom of the flange 22 prevent the natural frequency of the spindle motor from lowering to 500 MHz or less (depending on the specification of the HDD). Do it.

In order to attach the dustproof plate 30 to the flange 22, first, a curable adhesive 40 is applied to the bottom surface of the flange 22 and the top surface of the dustproof plate 30. Subsequently, the flange 22 and the dustproof plate 30 bonded to each other by the adhesive 40 are baked at a high temperature. At this time, the adhesive 40 not only enables the coupling between the dustproof plate 30 and the flange 22, but also minimizes the deformation of the dustproof plate 30 made of a dustproof alloy by heat.

As shown in FIG. 3, the flange 22 according to the second embodiment of the present invention is made of an aluminum alloy like the first embodiment, and has a protrusion 27 projecting downward on the bottom surface of the shaft hole 25. Form an extension. The anti-vibration plate 30 made of an anti-vibration alloy forms a hole having an outer diameter of the protruding portion 27 at the center thereof so that the anti-vibration plate 30 may be attached to the bottom of the flange 22 forming the protruding portion 27. 40).

In particular, the outer circumferential end of the flange 22 is bent downward to form a notch part 32, thereby outgassing between the outer circumferential end of the flange 22 and the base when the spindle motor is mounted on the base. to prevent the outgassing, and the protrusions 27 (the same material as the flanges) protruding from the bottom of the shaft hole 25 at the bottom of the flange 22 have a natural frequency of 500 MHz or less as in the first embodiment. This prevents the drop from (depending on the characteristics of the HDD). Attaching the antivibration plate 30 to the flange 22 also proceeds to the same process as in the first embodiment.

As shown in FIG. 4, the anti-vibration flange 50 according to the third embodiment of the present invention is formed of an anti-vibration alloy material. That is, as in the first and second embodiments, instead of attaching a dustproof plate made of a dustproof alloy material to the flange separately, the flange itself is made of the dustproof alloy, so that vibration and noise generated from the spindle motor are transmitted to the base. This can be prevented as much as possible. The dustproof flange 50 has a shaft hole 25 so that the spindle shaft can be mounted at the center thereof.

5 is a cross-sectional view of a spindle motor having a vibration preventing structure according to a preferred embodiment of the present invention, showing a specific embodiment of the second embodiment schematically shown in FIG.

As shown in FIG. 5, a protrusion (27 of part B) protruding downward is formed at the center of the bottom surface of the flange 22. The protrusion 27 has a circular cross section in a direction perpendicular to the axis, and the protrusion 27 has a shaft hole open at the center thereof. In addition, the flange 22 has a plurality of head seating grooves 24 and screw holes 26 or tab holes.

In particular, the non-adhesive region (see section A) without the adhesive 40 is disposed near the screw hole 26 to prevent outgassing, and the protrusion of the bottom surface of the flange 22 is provided. Reference numeral 27 prevents the natural frequency of the spindle motor 20 from lowering below 500 MHz (different depending on the specification of the HDD).

Subsequently, with reference to FIG. 5, a process in which the anti-vibration plate made of the anti-vibration alloy material exhibits vibration prevention and noise shielding functions of the spindle motor generated during operation of the hard disk drive will be described.

Vibration and resulting noise of the spindle motor 20 is the only noise source in idle mode, the operating state of the hard disk drive. The vibration and noise of the spindle motor are caused by the electromagnetic force acting on the spindle motor 20 and the defect of the ball bearing 29.

The electromagnetic force of the spindle motor 20 is generated by the interaction between the stator and the rotor installed therein, and is affected by the number of poles and slots, and the electromagnetic force acts on the hub so that the hard disk Vibration and noise are generated on the cover and base of the drive.

In addition, the defect of the ball bearing 29 causes friction between the ball bearing 29 and the spindle shaft 21 and the inner surface of the ball bearing 29 and the hub 28, so that the cover and base of the hard disk drive Generate vibration in the

Vibration and noise caused by the electromagnetic force inside the spindle motor 20 and defects of the ball bearing 29 are transmitted to the base and the cover through the hub 28 and the flange 22 of the spindle motor 20. The spindle motor 20 is provided with a dustproof plate 30 on the bottom surface of the flange 22 so that the dustproof plate 30 absorbs a considerable amount of vibration and noise.

 That is, since the anti-vibration plate 30 is made of an anti-vibration alloy material, when vibration is transmitted from the flange 22, a potential due to a stacking defect is generated in the anti-vibration plate 30, and the grain boundary of the grain boundary is formed. Slip causes some of the vibrational energy to be converted into thermal energy. (The anti-vibration characteristic mechanism of the anti-vibration alloy material is described in detail in the above-mentioned reference 'Research on the development of the anti-vibration alloy'.) Therefore, the vibration and noise passing through the anti-vibration plate 30 are greatly reduced in the base and It is delivered to the cover, which leaves only a small amount of vibration and noise in the base and cover.

After all, the spindle motor having a vibration damping plate according to the characteristics of the present invention, even if vibration and noise from the hub and the flange, the transmission loss by the vibration damping plate made of a dust-proof alloy material (vibration reduction phenomenon occurring while passing through a specific portion) This occurs and the amount of vibration and noise transmitted to the base and cover is drastically reduced.

As described above, the anti-vibration structure of the spindle motor according to the embodiment of the present invention absorbs the vibration generated by the self-vibration and the ball bearings generated in the spindle motor to the base, thereby preventing vibrations during the recording and reproducing process of the hard disk drive. In addition to reducing the error rate caused by the operation, it is effective in preventing unpleasant operating noises from leaking out of the device.

Claims (2)

In a hard disk drive having a base having a motor mounting surface, The spindle motor mounted on the motor mounting surface includes: a flange having a protrusion formed on a lower end surface of the shaft hole; The spindle motor, comprising a dustproof plate made of a dustproof alloy material and forming a hole in the center to attach the adhesive to the bottom surface of the flange to absorb vibration and noise generated from the spindle motor. Anti-vibration structure. The vibration preventing structure of the spindle motor according to claim 1, wherein a notch portion is formed at an outer circumferential end of the flange to surround the outer circumferential end of the vibration isolation plate.

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