JPS6079586A - Magnetic disc apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic disk drive, and more particularly to an air inflow mechanism for a magnetic disk drive.

[Background of the invention]

A conventional magnetic disk device is shown in FIGS. 1 and 2. 1st
The figure is a plan view and a side view of the magnetic disk device, and FIG. 2 is a side view and cross-sectional view taken along the line X--X in FIG.

A plurality of magnetic disks I and spacers 2 are alternately stacked and fixed on a spindle hub 3.

This spindle hub 3 is rotatably mounted on a base 5 via a bearing 4. And magnetic disk 1
Magnetic spatulas 1-6 (
There are two types of data, a data head 8 and a servo head 9 for positioning reference signals.The head 8 is for data and the servo head 9 is for positioning reference signals.

In this way, when a plurality of magnetic disks 1 are stacked on one spindle hub 3, the windage loss that occurs between the magnetic disk 1 and the air in its vicinity when the magnetic disk 1 rotates,
The so-called frictional heat is large enough to have a negative effect on the equipment. Some ideas have been made to reduce this windage loss by sealing helium etc.
7-113472), in the case of general air, the windage loss is almost determined by the size and rotational speed of the magnetic disk l. For example, a 14-inch magnetic disk lO
When a sheet is rotated at 360 ORPM, its windage loss is approximately 20
It even reaches 0W.

Therefore, as shown in FIGS. 1 and 2, an air guide 7 is provided to forcibly feed cooling air from the outside as shown by arrow A to reduce the temperature. However, as the capacity and recording density of magnetic disk devices increase and the track pitch becomes smaller, the track position of the magnetic head 6 may shift due to thermal deformation of the magnetic head 6, magnetic disk 1, etc. This significantly reduces the margin for width and even causes reading errors.

By the way, the magnetic disk 1 on which the positioning reference signal is written is usually located in the second-most layer (or the bottom layer),
The servo hens 1 to 9 for reading this signal are also correspondingly placed in the uppermost layer (or the lowermost layer), and the magnetic disk 1 for data and the corresponding data hens 1 to 8 are located in other layers. Furthermore, since the servo head 9 and the data head 8 are also made of the same material, they will exhibit the same amount of thermal deformation for the same amount of heat, and no rack position displacement will occur. However, in an actual apparatus, a problem arises in that the 1-rack positional deviation varies from head to head as described above.

[Purpose of the invention]

The purpose of the present invention is to reduce the 1-rack misalignment of the magnetic head in order to improve the drawbacks of the prior art as described above.
The object of the present invention is to provide a magnetic disk device capable of large-capacity, high-density recording.

[Summary of the invention]

In order to achieve the above object, the present invention provides a head for a magnetic disk device that includes a plurality of magnetic disks, a spindle that stacks and supports the magnetic disks via spacers, a magnetic head positioning mechanism, and a cover that covers them. - In the disk assembly, by providing a blowing means configured to blow more air into the central layer than the upper and lower edge layer portions of the magnetic disk, the temperature distribution between each magnetic disk is made uniform and the magnetic The feature is that the amount of head track position deviation is reduced.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described based on the drawings. First, the principle thereof will be explained.

As a result of considering the causes of 1-rack positional deviation for each head, the inventors found that even when magnetic disks are mounted on the same spindle, the temperature distribution differs depending on the mounting position, resulting in a difference in thermal expansion. I discovered that. This is due to the phenomenon that, as shown in Figure 3, the magnetic disks 1a and lc in the top and bottom layers have almost the same temperature distribution, but the temperature near the magnetic disk lb in the center is high. It is something to do. The reason for the high temperature near the magnetic disk l'b in the center layer is that the heat generated from the magnetic disk 1a and IC in the upper and lower layers is transferred to the cover 10.
It seems that the heat generated from the magnetic disk 1b in the center layer is difficult to radiate, whereas the heat is radiated from the base 5.

Now, FIG. 4 is a plan view showing a magnetic disk device according to an embodiment of the present invention, and FIG. 5 is a sectional view taken along the line X--X in FIG. 4.

Magnetic disks 1 and spacers 2 are alternately stacked and fixed on a spindle hub 3. The spindle hub 3 is rotatably attached to the base 5 via a bearing 4. A magnetic head 6 (general term for data head 8 and servo head 9) is provided corresponding to each magnetic disk 1, and a magnetic disk positioning mechanism (not shown) is provided for positioning each magnetic head 6 on a desired track on the magnetic disk 1. (omitted) is provided. Each of these components is protected from external dust by a cover 10.

To read and write data on the magnetic disk 1, the servo head 9 reads a positioning reference signal written on the lowermost magnetic disk 1, controls the magnetic disk positioning mechanism using the read reference signal, and controls the data head 8. This is done by positioning on the desired track.

As shown by arrow A, an air guide 7a for blowing cooling air between each layer of the magnetic disk l is arranged just outside the outer circumference of the magnetic disk l.

The air guide 7a functions to reduce the temperature rise within the cover 10 caused by the high speed rotation (usually 360 ORPM) of the magnetic disk 1 when the device is driven, and to equalize the temperature distribution between the layers of the magnetic disk 1.

The shape of this air guide 7a is shown in FIG. As shown in the figure, the opening 1] of the air guide 7a is connected to the magnetic disk l.
The structure is such that it narrows down towards the central layer.

Therefore, the cooling air blown out from the opening 11 is
The largest amount of inflow flows into the central layer of the magnetic disk I, and the amount of inflow decreases toward the upper and lower end layer portions. The effect of reducing the temperature rise by cooling air is proportional to the amount of cooling air. Therefore, as shown in FIG. 3, even if the temperature increase due to windage is highest in the central layer of the magnetic disk 1 and decreases toward both ends of the magnetic disk 1, the air guide 7a By controlling the amount of cooling air so that it is greatest in the central layer and decreases toward both ends, the temperature A can be reduced while making the temperature distribution uniform. As a result, the thermal deformation of the servo head 9 and the data head 8 is reduced, and the amount of thermal deformation is also the same for both, so the amount of track position deviation is reduced, and large capacity and
High-density recording becomes possible.

As the cooling air, it is possible to take in external air by passing it through a filter, or it is also possible to use the clean air inside the cover 10 by first drawing it out to the outside with a Doug 1- or the like and cooling it. be.

FIG. 7 is a perspective view of an air guide 7b according to a second embodiment of the invention. As shown in the figure, the openings 12 of the air guide 7b according to this embodiment are divided so as to face the layers of each magnetic disk 1, and the size of each opening 12 varies from the center to both ends. Therefore, it is configured to be small.

Therefore, more cooling air flows into the central layer of the magnetic disk 1, and the magnetic disk 1 as shown in FIG.
Uneven temperature distribution between each eyebrow can be corrected.

In order to prevent vibration of the magnetic disk 1 due to air turbulence, there is also a magnetic disk transport system in which the magnetic disk 1 is surrounded by a shroud so that a steady flow of air circulating along the inner wall of the shroud is generated. In this case, the shroud, the opening 11 of the air guy 1<7a, and the opening 12 of the air guide 7b must be configured so that cooling air can be blown into the shroud 1.

〔Effect of the invention〕

As explained above, according to the magnetic disk device of the present invention, the air blowing means is configured such that the amount of air blown is larger in the center layer than in the upper and lower end layer portions of the stacked magnetic disk group. As a result, the temperature distribution between each magnetic disk is made uniform, the amount of track position deviation of the magnetic head due to temperature difference is reduced, and large-capacity, high-density recording becomes possible.
・

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a conventional magnetic disk device, FIG. 2 is a sectional view taken along the line X-X in FIG. 1, FIG. 3 is a diagram showing the temperature distribution between magnetic disks, and FIG. A plan view showing a magnetic disk device according to an embodiment, FIG. 5 is taken along line XX in FIG.
6 is a perspective view showing an air guide according to one embodiment of the present invention, and FIG. 7 is a perspective view showing an air guide according to another embodiment of the present invention. ■=Magnetic disk, 6:Magnetic・＼ノ1-27a, 7b:
Air guide, 8: Data head, 9: Zubo head, +
1, 12: Open 1'' part of air guy 1-. Figure 1] O Figure 2 Figure 3 Temperature difference (°C) Figure 4 Figure 0 Figure 5 Only Figure 6

Claims (3)

[Claims] (1) In a head disk assembly of a magnetic disk device that includes a plurality of magnetic disks, a spindle that stacks and supports the magnetic disks via spacers, a magnetic head positioning mechanism, and a cover that covers them,
A magnetic disk drive characterized in that a blowing means is provided that is configured to send a larger amount of air to the center layer than to the upper and lower end layer portions of the magnetic disk. (2) The blowing means has an air guide for introducing air between each layer of the magnetic disk, and the air guide is configured to be narrowed toward the central layer of the magnetic disk. A magnetic disk device according to claim 1. (3) The air blowing means has an air guide for introducing air between each layer of the magnetic disk, and the opening of the air guide is divided, and the area of each divided opening is from the center. 2. The magnetic disk device according to claim 1, wherein the magnetic disk device is configured to become smaller toward both ends.