JPS5922273A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To provide a magnetic disc device having completely closed structure by applying a magnetic fluid seal to a part close to a separator of a spindle shaft extruded from a closed room in which a magnetic disc is stored. CONSTITUTION:A magnetic fluid housing 23 is adhered to the separator 1 arranged close to the spindle shaft 2. The housing 23 is magnetized in the direction of an arrow (a) by a magnetic substance, so that a magnetic loop is formed between the housing 23 and magnetic substance 24, the magnetic fluid 25 is adsorbed to the surface of the magnetic loop to fill the gap between the magnetic fluid housing 23 and external periphery of the shaft 2 with the magnetic fluid 25 and the inside and outside of the fixed disc is completely sealed. Therefore, even if the shaft is turned at a high speed, the magnetic fluid 25 acts as a lubricating agent, preventing the generation of a gap or scattering of the fluid. The magnetic fluid seal 22 consists of the magnetic fluid housing 23, the magnetic substance 24, or the magnetic substance 24 and the magnetic fluid 25, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a sealed structure that separates a fixed disk side and a blower fan side of a magnetic disk device.

(Technical Background of the Invention) Generally, a fixed disk attached to a spindle shaft is placed in a sealed chamber, and in a structure in which the spindle shaft protrudes from this sealed pot, conventionally, as shown in FIG. A separator 1 that separates the magnetic disk side from the outside (the blower fan side) is arranged close to the spindle shaft 2.The spindle shaft 2 and the separator 1
By setting the gap 3 with the reed as small as possible and keeping the pressure on the sealed chamber side (upper side in the figure) more positive than the outside air, the outside air can be prevented from entering the sealed chamber side during steady rotation of the spindle shaft. It was.

(Key Points of the Invention Technique) However, when the spindle shaft 2 is at rest, or when its rotation is rising or falling, there is a risk of outside air entering the sealed chamber.

[Purpose of the invention]

An object of the present invention is to provide a magnetic disk device having a completely sealed structure.

[Summary of the invention]

The present invention achieves the above object by applying a magnetic fluid seal to a portion of a spindle shaft protruding from a closed chamber housing a magnetic disk near a separator.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings, using the same reference numerals for the same parts as in the conventional example.

FIG. 2 is a sectional view showing an embodiment of the magnetic disk device of the present invention. A hub 4 is fixed to the upper part of the spindle shaft 2, and a replaceable disk 5 is held on the outer periphery of the hub 4. A head 6 that contacts the replaceable disk 5 to read and write data on the disk is supported by a carriage 7. This carriage 7 is mounted on a main base 8. A shroud 9 for sealing the replaceable disk 5 is mounted on the main base 8, and a case 10 for covering the replaceable disk 5 is housed within the shroud 9. A flange 12 for holding a fixed disk 11 is fixed to the lower part of the spindle shaft 2. A head 13 for reading, writing, and writing data on the disk is in contact with the fixed disk IJ, and the head 13 is supported by a carriage 4. A separator 1 is disposed adjacent to the underside of the flange 12 of the spindle shaft 2.

Further below the separator 1, a spindle shaft 2 is provided with a blower fan 1 for blowing Tallinn air into both the disks 5 and the fixed disk 11.
There are 5 and 1 installation. Further, the fixed disk 11, flange 12, carriage 14, blower noah/15, etc. are housed in a casing (compartment) 6 for guiding the air sucked in by the blower blower/15. This casing 16 is provided with a filter 7 and a filter 18 for removing dust contained in the sucked air. A pulley 19 for driving the spindle shaft is fixed to the lower end of the spindle shaft 2.
A belt 20 for transmitting torque from a motor (not shown) is suspended on J19. Incidentally, reference numeral 21 is a ball bearing section inside the spindle, and a magnetic fluid seal is used for sealing this section. Also,
A magnetic fluid seal 22 is attached to the joint between the spindle shaft 2 and the separator 1. This magnetic fluid seal 22 closes the gap between the separators that separate the inside of the fixed disk 5 from the blower fan 15 side.

The pulley 1 is connected to the belt 20 by a motor (not shown).
Power is transmitted to 9, and the spindle shaft 2 rotates. Then, the blower fan J5 blows air from below to the casing 16.
Inhale it inside. The sucked air is guided by the casing 6 and passes through a filter 17 to remove dust from the air, and then one side is supplied into a replaceable disk 5, and the other side is further passed through a filter 18 to remove dust. is fed into the removed bundle fixing disk 5. The inside of the fixed disk 5 must be filled with clean air and must be completely sealed from the outside air. Therefore, except for the vicinity of the spindle shaft 2 and the separator 1, the joints between the other parts are completely sealed with a sealing material.

FIG. 3 is an enlarged sectional view of section A in FIG. 2. A magnetic fluid housing 23 is glued to the separator 1, which is located close to the spindle axis 2. This magnetic fluid housing 23 is magnetized by a magnetic body 24 in the direction of arrow a in the figure, and therefore forms a magnetic loop with the spindle shaft 2 as shown by arrow C, and the magnetic magnetic fluid 25 It is attracted onto the loop, filling the gap formed between the magnetic fluid housing 23 and the outer peripheral surface of the spindle shaft 2, and completely sealing the inside and outside of the fixed disk. Even if the spindle shaft 2 rotates at high speed, the magnetic fluid 25 acts as a lubricant and will not form gaps or scatter. Therefore, the inside of the fixed disk 1 can be completely sealed regardless of whether it is in operation or not. The magnetic fluid seal 22 includes a magnetic fluid housing 23, a magnetic body 24, a magnetic fluid 25, and the like.

According to this embodiment, by providing the magnetic fluid seal 22 in the gap between the spindle shaft 2 and the separator 1, the fixed disk 11 side and the blower fan 15 side are completely shielded, and the spindle shaft inside the fixed disk 11 is completely shielded. 2, it can be completely sealed regardless of whether it is in operation or not. Therefore, it is possible to completely eliminate the risk of outside air entering the fixed disk 11 when the spindle shaft 2 is not operating or when the rotation starts or stops, which is the case in the conventional example.

The above describes a magnetic disk device with a structure in which a convertible magnetic disk and a fixed disk are coaxially supported on the spindle shaft, and a blower fan is also coaxially attached to the spindle shaft. The present invention can be applied to any structure having a protruding structure.

〔Effect of the invention〕

As described above, according to the present invention, by applying a magnetic fluid seal to the gap between the spindle shaft and the separator, it is possible to provide a magnetic disk drive having a completely sealed structure.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional spindle shaft and a separator adjacent to each other, FIG. 2 is a sectional view showing an embodiment of the magnetic disk device of the present invention, and FIG. 3 is a section A of FIG. 2. It is a detailed sectional view. 1... Separator 2... Spindle shaft 11.
・Fixed disk 15 ・Prower fan 16 ・・
Casing 22...6U Sexual fluid seal agent
Patent Attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] In a magnetic disk device in which a spindle shaft that supports and rotates the magnetic disk protrudes from a sealed compartment housing a magnetic disk, the magnetic disk is disposed close to the spindle shaft that protrudes from inside the magnetic disk; A magnetic disk drive characterized in that a magnetic fluid seal is provided in a gap between a separator that shields the inside of the magnetic disk from outside air and the spindle shaft.