JPH0361272B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a sealed magnetic disk device in which a rotating shaft on which a magnetic disk is mounted and a positioning device on which a magnetic head is mounted are sealed with a cover and a substrate, and in particular, The present invention relates to a completely sealed magnetic disk device having a both-end supported rotary shaft with both ends supported by bearings and having magnetic fluid seals inside both bearings.

[Conventional technology]

In recent years, as the recording density of magnetic disk devices has increased, bearings are installed at both ends of the rotating shaft on which the magnetic disk is mounted, in order to minimize positional errors in writing and reading due to whirling vibrations when the magnetic disk rotates. Increasingly, devices having a structure in which the rotating shaft is supported at both ends are being adopted.

Further, since the amount of dust must be minimized due to the reduction in the flying height of the magnetic head, the amount of dust mixed in from the outside must be reduced to zero. For this reason, magnetic fluid seals that are completely insulated from the external environment have come to be used on the rotating shaft.

Furthermore, as the density increases, magnetic disks begin to use thin film media, so humidity control is also required, and therefore a device with a completely sealed structure using the magnetic fluid seal is required.

Conventional sealed magnetic disk devices are shown in Figure 2 A and B.
As shown in FIG. 1, the rotating shaft 6 has a cantilevered structure supported by a bearing 10 attached to one side of a spindle hub 22 of the substrate 2. As shown in FIG. A magnetic fluid seal 18 is mounted above the bearing 10. Further, the magnetic disk 12, magnetic head 16, positioning device 14, etc. fitted to the spindle hub 22 are housed inside the cover 4 joined to the substrate 2, and are kept completely hermetically sealed by the magnetic fluid seal 18.

Therefore, in order to make such a structure even higher-density device, it is necessary to adopt a structure shown in FIGS. 3A and 3B in order to provide a support structure at both ends. That is, the cover 4 and spindle hub 22 shown in FIG. 2 are modified like the cover 30 and spindle hub 32 shown in FIG. 3, and the other bearing 34 and magnetic fluid seal 36 are retained.

[Problems to be solved]

However, with the structure shown in FIGS. 3A and 3B, after assembling the magnetic disk device, (1) servo track writing work (hereinafter referred to as STW) for writing positioning information to the servo surface, and (2) When installing the positioning device 14, there are the following problems. That is, cover 3
0 cannot be used, the above work is performed using a temporary cover for assembly (hereinafter referred to as a dummy cover) that has a bearing to support the upper end of the rotating shaft 6 and the space required for the above work is left open. After that, the dummy cover is replaced with the cover 30 to complete the assembly. Therefore, conventional magnetic disk devices have a problem in that assembly work is troublesome.

[Means for solving problems]

The present invention solves the above problems,
A rotating shaft having a spindle hub on which a plurality of magnetic disks are stacked and mounted, and a first bearing having a first magnetic fluid seal near one end of the rotating shaft and holding the rotating shaft. a first substrate; a second substrate having a second magnetic fluid seal near the other end of the rotating shaft and a second bearing for holding the rotating shaft; A positioning device including a magnetic head for writing and reading information to and from a magnetic disk between the substrates and a voice coil motor for driving the magnetic head, and openings provided on the sides of the first and second substrates, A cover is attached to the open portion to seal the entirety.

〔Example〕

Next, the embodiment will be described with reference to FIGS. 1A and 1B.

1A and 1B are a sectional view taken along line IA-IA in FIG. 1B and a sectional view taken along line IB-IB in FIG. 1A, respectively, of an embodiment of the sealed magnetic disk device according to the present invention. .

In the figure, the rotating shaft 56 has a magnetic fluid seal 62 near its upper end, and is supported by a bearing 58 attached to the substrate 52. On the other hand, the rotating shaft 5
6 has a magnetic fluid seal 64 below, and is supported by a bearing 60 attached to the substrate 50, forming a both-end support structure. The magnetic disks 66 are stacked and assembled on a spindle hub 78 that is integrated with the rotating shaft 56, and these disks are rotated integrally with the rotating shaft 56 by a drive motor 80.

On the other hand, a positioning device 68 equipped with a magnetic head 70 for writing and reading information on the magnetic disk 66 is attached to the substrate 50, and these rotating shafts 56 (including the magnetic disk 66) and the positioning device 68 Cover 54 (Fig. 1B
) and the substrates 50, 52.

When assembling the magnetic disk device configured as described above, first, the magnetic disks 66 are stacked on the spindle hub 78, and the rotating shaft 56 is connected to the bearing 58,
60 to be rotatably supported on the substrates 50, 52, and the substrates 50, 52 are fixed with bolts 72, 74, 76. As a result, without the cover 54, one side becomes a completely free space.

After the positioning device 68 is mounted and fixed at a predetermined position on the board 50 in the above state, it is mounted on a servo track writing device in order to perform servo track writing work for writing positioning information on the servo surface. (STW device), write operation is performed, and finally, the magnetic disk positioning device is sealed with a cover 54 to complete the assembly.

〔effect〕

As explained above, the present invention includes a first substrate that has a magnetic fluid seal and holds one end of a rotating shaft integral with a spindle hub on which a magnetic disk is mounted;
The second substrate that holds the other end of the rotating shaft with a magnetic fluid seal is assembled with the side opening part, and then the cover is assembled on the side opening part, so that the cover There are advantages in that servo track writing for writing positioning information onto the servo surface from the side open portion can be easily performed before installation, and the positioning device can be easily assembled, simplifying assembly work.

[Brief explanation of drawings]

1A and 1B are a sectional view taken along line IA-IA in FIG. 1B, and a sectional view taken along IB-IB in FIG.
FIGS. 2A and 2B are a plan view of a conventional sealed magnetic disk device, and a sectional view taken along line B-B in FIG. , and B-B in A of the same figure.
It is a sectional view along a line. 2, 50, 52... board, 4, 30, 54...
Cover, 6, 56... Rotating shaft, 8, 10, 34,
58,60...Bearing, 12,66...Magnetic disk, 14,68...Positioning device, 16,70...
...Magnetic head, 18, 36, 62, 64...Magnetic fluid seal, 20,80...CD motor, 22,
32,78...Spindle hub.

Claims (1)

[Claims] 1 A rotating shaft having a spindle valve on which a plurality of magnetic disks are stacked and mounted, and a first bearing having a first magnetic fluid seal near one end of the rotating shaft and holding the rotating shaft. 1st to have
a second substrate having a second magnetic fluid seal near the other end of the rotating shaft and holding the rotating shaft;
a second substrate having a bearing of the first and second bearings;
a positioning device including a magnetic head for writing and reading information to and from a magnetic disk between the two substrates and a voice coil motor for driving the magnetic head, and openings provided on the sides of the first and second substrates. A sealed magnetic disk device, characterized in that a cover is attached to the open portion to seal the entirety.