JP2000149396A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk driving device reduced in vibration of a base and noise of the device caused by a driving reaction force of a carriage. SOLUTION: As a coupling means of a base 1 and VCM, a VCM yoke 2 is inserted between visco-elastic rubber bushes 7 so that a reaction force is not transmitted to the base 1 even if such a driving reaction force occurs as brings about a resonance of a base side member of an actuator. And, the vibrations transmitted to the base 1 are attenuated by adopting such a structure as compresses the rubber bushes 7 by a stud bolt 10 and couples the VCM to the base 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to a technique effective for improving positioning accuracy, reducing seek noise, and improving product reliability.

[0002]

2. Description of the Related Art Generally, as a magnetic disk drive having an oscillating actuator, for example, Japanese Patent Laid-Open No. 05-22 / 2005
No. 5,769.

In this device, a VCM is directly fixed to a base by a screw.

[0004] Fig. 8 shows an example of a VCM fastening means in a general conventional 2.5 "magnetic disk device.
It is directly fixed to the base by screws 10. 2.
Since the 5 ″ base is thin, vibration generated when the actuator is driven is transmitted from the VCM to the base 1, and noise during driving is increased.

Further, when the VCM is fastened to the base 1, each part has a dimensional tolerance, and the base is deformed and twisted. Furthermore, the yoke of a VCM is usually made of iron, while the base 1 is made of aluminum,
When the dissimilar metal is rigidly fixed with the screw 10 in this manner,
When the temperature changes, thermal stress occurs. Therefore, the base 1 is deformed by this thermal stress, causing a change in the attitude of the pivot bearing fixed to the base 1, causing a variation in the flying height of the magnetic head supported by the carriage, and deteriorating the positioning accuracy.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a conventional 2.5 "magnetic disk drive which reduces the vibration of the base and the noise of the drive due to the reaction force of the carriage.
Furthermore, since the base of the 2.5 "magnetic disk device is made thin, deformation of the base by fastening the VCM causes
It is an object of the present invention to provide a disk drive device having a VCM support structure that prevents deterioration of positioning accuracy and is suitable for downsizing a small disk device.

[0007]

In order to achieve the above object, a base on which a spindle motor for high-speed rotation is mounted, one or more disks fixed to the spindle motor, and a disk rotating in a radial direction of the disks. An actuator movably fixed to the base, a suspension arm provided with an elastic member, and an actuator having a coil holder that holds a coil that generates a rotational power when an electric current is applied,
A VCM having a head and a slider incorporated at the tip of the suspension arm for writing or reading data to or from the surface of a disk, and a magnet incorporated to sandwich the coil and generating a magnetic field for generating a rotating force in a coil through which current flows. And a 2.5 "disk drive device, which is disposed outside the outer periphery of the disk and comprises a VCM yoke sandwiched between viscoelastic rubber bushes as fastening means for the base and the VCM, and a stud-attached screw. And compress the rubber bush with V
The structure is such that the CM is fastened.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention; FIG.

FIG. 1 is a schematic plan view of a magnetic disk drive on which the VCM fastening means of the present invention is mounted.
2 and 3 are sectional views of the VCM fastening means.
FIG. 4 is a plan view showing a cutout of a fastening portion of the VCM yoke, and FIG.
5 is a detailed view of a VCM rubber bush mounting portion cutout, FIG. 6 is a detailed view of a VCM rubber bush mounting portion aperture, and FIG. 7 is a diagram showing a seek noise reduction effect of the VCM fastening means of the present invention. .

The VCM fastening means will be described with reference to FIGS.

Inside the base 1, a disk, a drive mechanism for supporting and rotating the disk, a head assembly including a head for writing information on the disk, a carriage for supporting the head assembly, and moving the head over the disk to the head. A mechanism for guiding the cartridge so as to perform the operation is accommodated.

The means for fastening the VCM will be described.
The (magnetic circuit) yoke is a rubber bush 7 having viscoelasticity.
The VCM is attached to the base 1 by compressing the rubber bush 7 with the screws 10 with studs. V
Since the CM is fastened to the base 1 via the rubber bush 7, when the vibration at the time of driving the actuator is continued from the VCM to the base 1, the vibration is attenuated by the rubber bush 7. Variations in the flying height of the magnetic head supported by the carriage due to the change in the attitude of the pivot bearing fixed to the base 1 due to the force can be reduced, which is effective in preventing the positioning accuracy from deteriorating.

Further, since the vibration transmitted to the base 1 is attenuated, it is also effective in reducing noise during a seek operation.

FIGS. 4 to 6 show specific means for attaching the VCM yoke 2 and the rubber bush 7. The VCM yoke 2 is provided with a notch hole 30 at a fastening portion with the base 1, and the portion of the notch hole 30 is formed by a VC
The VCM yoke has a structure 32 narrowed down from the upper surface of the M yoke 2. The rubber bush 7 can be easily inserted from the cutout portion of the yoke, and has a structure that is hard to come off.

Further, in this VCM, in order to attenuate the vibration transmitted from the VCM to the base 1, the eigenvalue of the mounting rigidity between the VCM and the base 1 is set to 1 KHz to 3 KHz.
It has a structure that avoids resonance with the eigenvalue with the base 1.

The calculation formula of the support rigidity is shown below.

[0017]

Fvcm = 1 / 2π√Kvcm / Mvcm Fvcm: Support frequency (Hz) Kvcm: Support rigidity (N / m) Mvcm: VCM mass (Kg) (Equation 1) Referring to FIG. The effect of device noise when the actuator of the means is driven will be described. When the VCM and the base 1 are directly fastened and when the VCM yoke is sandwiched between the rubber bushes 7 and fastened, the O.V. A. The value has a reduction effect of about 3 dBA. In terms of frequency, the effect of reduction in the range of 5 KHz to 10 KHz is large.

Further, the rubber bush 7 has the following functions.

One function is to absorb the dimensional tolerance of the mounting portion. Since the distance between the base 1 and the VCM has a dimensional tolerance, if there is no elastic member, either of them is deformed and attached. When the base 1 is deformed,
This causes a change in the attitude of the pivot bearing 21 fixed thereto, which leads to a deterioration in positioning accuracy. Further, when the VCM is deformed, a gap between the coil 4 and the magnet 3 is changed, and there is a possibility that interference between components occurs.

On the other hand, by using the structure having the rubber bush 7, the dimensional tolerance is absorbed by the rubber bush 7, the deformation of the base 1 and the VCM is reduced, and the deterioration of the positioning accuracy can be suppressed.

Another function of the rubber bush 7 is to reduce thermal stress when the temperature changes.

The VCM is made of a magnetic material in order to form a magnetic circuit, and is mainly made of iron, while the base 1 on which the VCM is mounted is made of aluminum. Since iron and aluminum have different coefficients of thermal expansion, thermal stress occurs when the temperature changes. When the base 1 and the VCM are deformed by this stress, the positioning accuracy is deteriorated in the same manner as described above. By using the structure having the elastic member 7, the thermal stress is relaxed at this portion, and the deterioration of the positioning accuracy is suppressed.

[0023]

As described above in detail, according to the magnetic disk drive of the present invention, when seeking the head, the vibration caused by the driving reaction force can be attenuated with a simple structure that is space-saving and low-cost, and the positioning is achieved. It is also possible to improve the accuracy and reliability, and reduce the noise during seeking.

[Brief description of the drawings]

FIG. 1 shows a VCM of a disk device according to an embodiment of the present invention.
And FIG.

FIG. 2 is a detailed sectional view of a sectional view of a VCM fastening portion of FIG.

FIG. 3 is a cross-sectional view of the VCM fastening portion of FIG.

FIG. 4 is a detailed plan view of a cutout of a rubber bush attachment portion of the VCM of FIG. 1;

FIG. 5 is a perspective view showing details of a rubber bush attachment portion aperture of the VCM of FIG. 1;

FIG. 6 is a detailed sectional view of a mounting structure of a rubber bush of the VCM of FIG. 1;

FIG. 7 is a characteristic diagram showing a reduction effect at the time of seeking in FIG. 1;

FIG. 8 is a cross-sectional view of a general VCM fastening structure.

[Explanation of symbols]

1. Base, 2. VCM yoke, 3. Magnet, 4.
Coil, 5: Carriage, 7: Rubber bush, 10: Screw with stud, 21: Pivot bearing, 22: Head suspension, 24: Spindle, 30: VCM
Notch hole at the joint, 32 ... VCM at the joint of VCM.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsugu Kamifune 2880 Kozu, Kozuhara-shi, Kanagawa Prefecture Storage Systems Division, Hitachi, Ltd. (72) Takako Hayakawa 2880 Kozu, Kozu, Odawara-shi, Kanagawa Hitachi, Ltd. F-term in the Storage System Division of Manufacturing (reference) 5D109 CA02 CA04 CA10

Claims (3)

[Claims] 1. A base on which a spindle motor for high-speed rotation is mounted, one or more disks fixed to the spindle motor, and an elastic member fixed to the base so as to be rotatable in a radial direction of the disk. An actuator having a suspension arm provided in the above, a coil holder for holding a coil for generating a rotational force by passing an electric current, and writing or reading data on the surface of the disk incorporated in the tip of the suspension arm A magnetic disk drive comprising a head and a slider for performing the above, and a VCM having a magnet which is incorporated in a manner sandwiching the coil and which generates a magnetic field for generating a rotating force in the coil through which a current flows, as a fastening means between the base and the VCM VCM yoke is sandwiched between rubber bushes having viscoelasticity. Defining a write height, shoulder screw, or via a spacer, a magnetic disk device characterized by fastening the VCM based compressing the rubber bushing by a screw. 2. The magnetic disk drive according to claim 1, wherein the fastening portion of the VCM yoke has a notch. 3. The magnetic disk drive according to claim 1, wherein the characteristic value of the mounting rigidity of the VCM and the base is from 1 KHz to 3 KHz.