JPH048873B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a filter structure for cleaning air in a magnetic disk device using a self-circulation system, and particularly to a filter structure for a disk device suitable for reducing the size of the device.

[Background of the invention]

In general, in order to improve the reliability of magnetic disk devices, dust prevention measures are very important. Therefore,
As a dust-proof measure, the disk and its peripheral equipment are usually covered with a cover. In addition, the disk and its peripheral equipment inside the cover are washed and cleaned in advance, and various techniques are used to clean them, such as performing the assembly work in a clean room or clean bench. A filter is provided inside the cover to ensure even more safety.

A conventional filter structure will be explained with reference to FIGS. 1 to 3. Before that, the overall structure of a head disk assembly (hereinafter abbreviated as HDA) will be explained with reference to FIG.

3 is a disk for storing information, and a plurality of disks 3 are loaded on the spindle motor hub 2. Reference numeral 4 denotes a head that transfers information to and from the disk 3, and is supported by a carriage 6 via an arm 5. This carriage 6 positions the head 4 at a predetermined position on the surface of the disk 3. These HDA components are placed on the base 1, but in order to isolate the HDA from outside dirty air, the entire HDA is covered with a cover 7.
It is sealed with 8 seals and 1 base. In addition, in order to purify the air inside the cover 7, a partition plate 9 is provided on the top of the disk 3, and this partition plate 9 and the cover 7
A filter 10 is provided between the two.

Next, the air purifying effect inside the cover 7 will be explained. Air has viscosity, and the disk 3 exists in this viscous air. Therefore, when the disk 3 rotates in conjunction with the rotation of the spindle motor hub 2, air in the vicinity of the disk 3 flows from the center to the outer periphery of the disk 3 due to the centrifugal force accompanying the rotation. Therefore, as shown in FIG. 4, the air pressure inside the cover 7 increases as it moves away from the center of the disk 3. Then,
Air moves from high pressure to low pressure, so
Air at the outer periphery flows toward the center. The air that has flowed to the center flows out again to the outer periphery due to centrifugal force, and then returns to the center due to the pressure difference. In this way, the cover 7 has a self-circulating air flow 1
1 occurs. Therefore, if a filter 10 is provided in the flow path of this air flow 11, the air inside the cover 7 will be purified by the dust removal action of the filter 10.

By the way, recently, due to technological advances, the recording density of disks has further improved, and along with this, the disk size has been reduced from 14 inches in diameter to 8 inches and then to 5 inches. Therefore, it is possible to downsize the device and reduce disk rotational energy.
Demand for disk devices is increasing. However, there is an inversely proportional relationship between the miniaturization of the device and the cleaning effect of the filter by the self-circulation method. That is,
The self-circulation system utilizes the pressure difference between the air at the center and the outer periphery, and this pressure difference is proportional to the distance between the center and the periphery, so if the device is downsized, there will be a sufficient pressure difference. Since the amount of air passing through the filter decreases, the cleaning effect of the filter becomes weaker.

Therefore, in order to compensate for the decrease in the amount of air passing through the filter due to the decrease in pressure difference, a conventional method has been adopted in which the filter 10 is folded in to increase its area as shown in FIG. However, this method has the drawback that the filter dimension 19 in the height direction becomes large, and although it is possible to reduce the width and depth of the device by reducing the disk size, it is not possible to reduce the height dimension.

In order to reduce the height dimension, as shown in Fig. 2, there is a method in which a folded filter 10a is not provided on the top of the disk 3 but on the side, and an air flow 11a is created using a partition plate 9a. . However, this method is difficult to adopt because the width and depth of the apparatus must be increased in order to prevent the mounting position of the filter 10a from overlapping the mounting position of the carriage 6, etc. of the head drive section.

As an alternative, as shown in FIG.
A method of expanding b between the upper part of the disk 3 and the cover 7 is also conceivable. However, a pressure difference is required for the airflow 11b to pass through the filter 10b;
Since the pressure difference between the outer peripheral parts 12 and 13 is small, air does not pass through the filter 10b here, and only the central part 14 is effectively effective as a filter, reducing the effective area for the air flow 11b to pass through. I can't get it.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a filter structure for a disk device that can eliminate the drawbacks of the prior art as described above and make the device more compact.

[Summary of the invention]

In order to achieve the above object, the filter structure of the magnetic disk according to the present invention rotates the disk in a sealed box, and uses a self-circulating path that utilizes the pressure difference between the center of the disk and the outer circumference caused by the rotation of the disk. In the filter structure of a magnetic disk device disposed inside, there is a disc-shaped filter support portion with a plurality of windows to which filters are attached, a hole in the center having a diameter smaller than the disk inner diameter, and an outer periphery of the filter support portion. A partition plate having a ring-shaped convex portion attached to the filter support portion, and a skirt portion extending downward from near the center of the filter support portion and extending horizontally longer than the edge of the disk while remaining close to the disk surface. It is distinctive in that it is placed directly above the disk inside the box.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 5 is a sectional view of an HDA of a disk device to which an embodiment of the present invention is applied.

The HDA other than the filter structure is the same as that shown in FIG. That is, 1 is a base, 2 is a spindle motor hub, 3 is a disk, 4 is a head, 5 is an arm, 6 is a carriage, 7 is a cover, and 8 is a packing, which have the same functions as conventional ones.

This embodiment is characterized by its filter structure, and particularly by the shape of its partition plate 9c. FIG. 6 is a perspective view of the partition plate 9c, and FIG. 7 is a perspective view of the partition plate 9c, and FIG.
FIG. The shape of the partition plate 9c will be explained below with reference to FIGS. 6 and 7.

The partition plate 9c includes a ring-shaped convex portion 15, a donut-shaped flat disk filter support plate 16, and a skirt portion 1.
Consists of 8. The filter support plate 16 is provided with a plurality of windows 17 for setting the filter 10c, and a ring-shaped protrusion 15 is fixed to the outer periphery. Further, a skirt portion 18 extends downward from near the center of the filter support plate 16, and a hem portion of the skirt portion 18 widens in the horizontal direction.

The filter 10c without folding is attached to the window 17 of the filter support plate 16, and the ring-shaped protrusion 15
FIG. 5 shows the state in which the cover 7 is fixed to the ceiling part.

With such a filter structure, the air flow 11
c becomes as shown in FIG. That is, disk 3
Due to the rotation of , the air pressure at the outer periphery is higher than that at the center.Furthermore, since the hem of the skirt 18 blocks the air flow generated by centrifugal force, the upper surface of the hem of the skirt 18 has air pressure from the center to the outer periphery. There is no air flow due to the centrifugal force toward the. Therefore,
Air flowing toward the outer periphery due to centrifugal force passes between the upper surface of the hem of the skirt portion 18 and the filter support plate 16, and heads toward the center. However, since the direction toward the center is blocked by the skirt portion 18 and the filter 10c is provided on the filter support plate 16, the air passes through the filter 10c. Thereafter, it enters the hole in the center of the filter support plate 16, and flows again to the outer periphery due to centrifugal force.

Note that, as the total area of the plurality of windows 17 increases, the total area of the filter 10c also increases.
Of course, since the amount of air passing through increases, the air purifying effect is improved. Moreover, the shape of the window 17 is arbitrary.

Furthermore, the outer diameter of the hem of the skirt portion 18 needs to be equal to or larger than the outer diameter of the disk 3. This is to sufficiently block airflow toward the outer periphery due to centrifugal force and to obtain a smooth airflow toward the center. Further, it is preferable that the hole in the center of the filter support plate 16 be made equal to or smaller than the inner diameter of the disk 3. This is to increase the total area of the filter 10c, increase the amount of air passing through the filter, and enhance the dust removal effect of the filter 10c.

Since the ratio of the outer diameter to the inner diameter of the disk 3 is 2:1, in the filter structure shown in FIG. 3, the effective area of the filter is only about 25% of the area of the disk 3. In the example, approximately 75% or more can be used. Furthermore, while the filter height 19 in the filter structure shown in FIG. 1 is approximately 20 mm, the filter height 19c in this embodiment is approximately 8 mm, allowing the height dimension to be reduced. Furthermore, since the filter 10c does not need to be folded in, it is inexpensive.

〔Effect of the invention〕

As explained above, according to the filter structure of the disk device according to the present invention, the device can be made smaller by devising the shape of the partition plate so that a large amount of air passes through the filter without folding. can.

[Brief explanation of drawings]

1 to 3 are diagrams for explaining the filter structure of a conventional disk device, FIG. 4 is a diagram showing the air pressure distribution in the disk device, FIG. 5 is a diagram showing an embodiment of the present invention, and FIG. 6 is a perspective view of the partition plate in FIG. 5, and FIG. 7 is a sectional view taken along the line X--X in FIG. 6. 10c: Filter without folding, 15: Ring-shaped protrusion, 16: Filter support plate, 17: Window, 18:
Skirt part.

Claims (1)

[Claims] 1. In a filter structure of a magnetic disk device arranged in a self-circulating path that rotates a disk in a sealed box and utilizes the pressure difference between the disk center and the outer periphery caused by the rotation of the disk,
a disc-shaped filter support portion having a plurality of windows to which filters are attached and a hole having a diameter smaller than the inner diameter of the disk in the center; a ring-shaped convex portion attached to the outer periphery of the filter support portion; A partition plate that extends downward from near the center of the filter support part and has a skirt part that extends horizontally longer than the edge of the disk while remaining close to the disk surface is provided in the box directly above the disk. A filter structure for a magnetic disk device characterized by: