JPH07312066A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent deformation of a magnetic disk medium and to miniaturize the magnetic disk device by providing the magnetic disk medium directly on a flat surface of a spindle part. CONSTITUTION:A magnetic recording layer 6 constituting the magnetic disk medium is provided in a film state on the flat surface 3a of a disk part 3B of the spindle part 3 equipped with a spindle 3A in the central part. By this constitution, screw setting work at the time of assembling the magnetic disk medium is not required, and hence distortion of the magnetic disk medium can completely be eliminated. Consequently, even when the device is miniaturized, disorder of the floating posture of a magnetic head is not generated, and hence the magnetic disk device having good read/write characteristics and capable of effectively suppressing occurrence of a head crush can be obtained. It is desirable that a protective layer 7 and a lubricative layer 8 are layered in turn on the external surface of the magnetic recording layer 6, and also the flat surface 3a of the disk part 3B of the spindle part 3 is provided in advance with fine ruggedness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device which is an external storage device of a computer.

[0002]

2. Description of the Related Art In a conventional magnetic disk device, as shown in FIG. 3, a disk-shaped magnetic disk medium 51 is screwed to a spindle 52A forming a part of a rotary drive motor 52 with a screw 53A. In FIG. 3, reference numeral 50
Indicates a body case of the magnetic disk device, and reference numeral 54 indicates an arm assembly for supporting the magnetic head 54a. Also,
Reference numeral 55 indicates a disk medium pressing plate.

[0003]

In this conventional magnetic disk apparatus, the tightening of the screw 53A causes deformation such as distortion of the magnetic disk medium 51. This tendency tends to increase with the miniaturization of magnetic disk devices. That is, as the magnetic disk medium 51 becomes lighter and smaller in diameter along with the miniaturization of the magnetic disk device, the magnetic disk medium 51 becomes thinner, so that the deformation due to the screw tightening becomes more significant.

Therefore, as the size of the magnetic disk device becomes smaller, the flying attitude of the magnetic head is disturbed and the read / write characteristics are deteriorated, resulting in a head crash.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a miniaturized magnetic disk device which improves the disadvantages of the prior art, particularly has good read / write characteristics and can effectively suppress the occurrence of head crash. To aim.

[0006]

DISCLOSURE OF THE INVENTION In the present invention, a magnetic head assembly mounted corresponding to a magnetic disk medium, and a cross section T having a spindle shaft at the center and a disk-shaped flat surface at one end It is provided with a character-shaped spindle portion, a motor base that rotatably supports the spindle shaft, and a drive motor portion that is mounted on the motor base and that rotationally drives the spindle portion. Then, a magnetic recording layer forming a magnetic disk medium is provided on a flat surface at one end of the spindle portion. This aims to achieve the above-mentioned object.

[0007]

[Operation] In the present invention, the flat surface 3a of the spindle portion 3 on which the recording layer 6 is formed is measured before and after assembly.
It has been confirmed that the flatness is maintained at 2 [μm] or less. In this respect, in the conventional example, the diameter is 48 [m
m], and a flatness of 0.381 [mm] in a magnetic disk medium, even when the flatness is 2 [μm] or less when not clamped, the flatness is 10 [μm] when fixed to the spindle unit 3 by screwing.
Whereas the above is normal, the flatness is greatly improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 indicates a motor base. The motor base 1 is fixed to the case main body 2 in a state where the motor base 1 is opened upward in FIG. At the center of the motor base 1, there is provided a cylindrical support 1A that extends upward from the center of the motor base 1.

Reference numeral 3 indicates a spindle portion. The spindle portion 3 has a disc portion 3B having a spindle shaft 3A directed downward in FIG. 1 in the central portion and a flat surface 3a at one end surface.
Is formed in a T-shape in cross section. This spindle part has a cylindrical shaft part 1 whose spindle shaft 3A is described above.
A bearing 4 is provided in the cylindrical column 1A.
It is rotatably supported via A and 4B.

A drive motor unit 5 is provided in the motor base 1 described above around the cylindrical column 1A.
The drive motor unit 5 is provided with a drive coil unit 5A fixed to the motor base 1 and a disk unit 3B of the spindle unit 3 corresponding to the drive coil unit 5A, and is suspended downward from the periphery of the disk unit 3B in FIG. And a magnet portion 5B.

The flat surface 3a of the disk portion 3B of the spindle portion 3
Is provided with a magnetic recording layer 6 forming a magnetic disk medium in the form of a film. A protective layer 7 and a lubricating layer 8 are sequentially laminated on the outer surface (upper end surface in FIG. 1) of this magnetic recording layer 6 in FIG. Further, fine irregularities are provided in advance on the flat surface 3a at one end of the spindle portion 3, so that the magnetic recording layer 6 can be firmly adhered to the flat surface 3a of the disc portion 3B (upper end portion in FIG. 1) of the spindle portion 3. It is fixed (attached).

More specifically, in FIG. 1, the disk portion 3B of the spindle portion 3 has a diameter set to 48 [mm]. Further, the magnet portion 5B covers the outside of the drive coil portion 5A fixed to the motor base 1 so that ACC4.0 [m / S ² ] or less (at 3600 [rpm]).
It is equipped so that it can rotate at 5400 [rpm] without being greatly shaken.

Further, the disk portion 3 of the spindle portion 3 described above.
The flat surface 3a, which is the outer surface of B, is polished to have a flatness of 2 [μm] or less, and thereafter, the center line average roughness “Ra = 5 to 6” having a directivity in the circumferential direction on the entire surface is obtained. [N
m] ”, fine grooves (texture) having a uniform roughness are formed by polishing by the free abrasive grain method. On top of that, recording layer 6 made of magnetic material and having a thickness of 30 nm, the thickness of carbon
A protective layer 7 having a thickness of 20 [nm] and a lubricating layer 8 having a thickness of 3 [nm] are sequentially formed in a film shape.
0 is formed. Reference numeral 54 indicates an arm assembly that supports the magnetic head 54a, and reference numeral 2A indicates a main body cover. Other configurations are the same as those of the conventional example described above.

In this embodiment, the flat surface 3a of the spindle portion 3 on which the recording layer 6 is formed has a flatness of 2 in the final measurement.
It has been confirmed that the thickness is kept below [μm]. In this respect, the conventional example has a diameter of 48 [mm] and a plate thickness of 0.381.
Even if the unclamped flatness of the magnetic disk medium of [mm] is 2 [μm] or less, the flatness usually becomes 10 [μm] or more when fixed to the spindle portion 3 by screwing. However, the flatness is greatly improved.

As described above, in the above-described embodiment, since the magnetic disk medium 10 is directly provided on the flat surface 3a of the spindle portion 3, the magnetic disk medium 10 is prevented from being deformed and distorted, and the magnetic disk medium 10 is prevented. There is an advantage that the labor for attaching to a rotary drive motor or the like can be saved, and therefore the efficiency of the assembling work at the time of production can be remarkably improved.

In this case, the rotary drive motor may be an ultrasonic motor for converting the high frequency elastic vibration generated by the voltage element into a mechanical output by using a frictional force. This has the advantage of reducing driving noise and electromagnetic induction noise.

[0018]

Since the present invention is constructed and functions as described above, according to this, since the recording layer is attached to the disk portion of the spindle portion forming a part of the drive motor, the magnetic layer which has been conventionally required. The screwing work that was done when assembling the disk medium is no longer necessary, and therefore the distortion of the magnetic disk medium that has been conventionally caused by screwing can be almost completely eliminated. It is possible to almost completely eliminate the inconvenience that the read / write characteristics are disturbed and the head crash is likely to occur, and it is not necessary to set the area for screwing. Therefore, the storage area is increased accordingly. In that respect, it is possible to expand the storage capacity,
As described above, the screwing work is not required, so that the productivity can be remarkably improved, and in this respect, it is possible to provide an excellent magnetic disk device which has not been available in the past and can reduce the cost.

[Brief description of drawings]

FIG. 1 is a partially omitted sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a state where the embodiment of FIG. 1 is assembled.

FIG. 3 is a schematic exploded perspective view showing a conventional magnetic disk device.

[Explanation of symbols]

 1 Motor Base 3 Spindle Part 3A Spindle Shaft 3a Flat Surface 5 Drive Motor Part 6 Magnetic Recording Layer 7 Protective Layer 8 Lubrication Layer 54a Magnetic Head

Claims (3)

[Claims] 1. A magnetic head mounted corresponding to a magnetic disk medium, a spindle section having a T-shaped cross section having a spindle shaft at a central portion and a disc portion having a flat surface at one end surface thereof, A motor base that rotatably supports the spindle shaft and a drive motor unit that is mounted on the motor base and rotationally drives the spindle unit are provided, and a magnetic recording layer is attached to a flat surface of one end of the spindle unit. A magnetic disk device characterized by the above. 2. The magnetic disk device according to claim 1, wherein a protective layer and a lubricating layer are sequentially laminated on the outer surface of the magnetic recording layer. 3. The magnetic disk device according to claim 1, wherein fine protrusions and depressions are provided in advance on a flat surface of one end of the spindle portion.