JPH0322668B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a spindle assembly for rotating a magnetic disk used in a magnetic disk device.

[Background of the invention]

As the storage capacity of magnetic disk devices increases,
Particularly high precision rotational performance is required of spindles for rotating magnetic disks. Spindle holding methods are divided into two types, a cantilever method and a double support method, depending on the bearing arrangement. The cantilever type is a type in which a bearing is mounted within a single housing and a disk fixing hub is fixed to the shaft end. In this method, the hub is fixed to the shaft end, so the rotational performance is generally worse than the dual support method, but since the housing is single, it is easy to process and assemble, and the magnetic fluid seal is used to prevent bearing grease from scattering. This method is often used in small magnetic disk devices that do not have any problems even if the rotational performance is relatively poor because of its high productivity, such as requiring only one part.

On the other hand, in the double-support system, the housing that supports the bearing is separated left and right or top and bottom, and the hub that fixes the disk can be placed in a well-balanced position between both bearings, so its rotational accuracy can be maintained using bearings of the same size. Compared to the cantilever method, it is possible to obtain more than 10 times better results. Such a double-support type magnetic disk is described, for example, in Japanese Patent Laid-Open No. 130468/1983.

Therefore, dual-support type spindles have become mainstream in large magnetic disk drives with large storage capacities. The features and problems of the conventional dual-support type spindle will be explained in detail below with reference to FIG.

FIG. 2 is a sectional view showing the structure of a conventional double-support type spindle used in a magnetic disk device. The assembly procedure for this spindle will be explained below. The hub 26 is fixed to the shaft 21 in advance by shrink fitting or the like. Next, the shaft 21 is inserted from above the lower housing 15, and the magnetic sealing liquid, preload spring 27, lower bearing 28, collar 29, motor rotor 32, and washer 30 are tightened from below using the built-in screws 31 in this order. The magnetic fluid seal portion 43 for sealing the lower bearing 28 is fixed in advance to the upper end portion of the lower housing 15 by adhesive or other means.

Further, the motor stator coil 34 is inserted into the lower housing 15 at the illustrated position and sealed with the cover 33. Next, the magnetic disk 3 and spacer 25 are sequentially inserted into the hub 26 and fixed with screws 20 and disk clamps 24. Next, the cover base 16 is fixed to the lower housing 15 with screws 22. Further, the magnetic fluid seal portion 1 is fixed to the lower end of the upper housing 38 by adhesive or other means, and the upper housing 38 is fixed to the cover base 16 with screws 37. Finally, upper housing 3
The magnetic sealing liquid, upper bearing 19 and washer 18 are inserted into the upper end of the shaft 21 from above 8, and the screw 17 is tightened to complete the process.

In magnetic disk devices, defective disks are often replaced, and this trend is becoming more and more common as magnetic recording density increases. When attempting to replace a disk in a disk device employing a dual-support type spindle, it is necessary to attach and detach the upper housing 38 and the cover base 16, as is clear from the above explanation of the assembly procedure. Therefore, by removing the upper housing 38, the magnetic fluid sealing portion 1 is disassembled, and the magnetic sealing liquid 42 is left at the upper end of the shaft 21, as shown in FIG. Remaining magnetic sealing liquid 42
is usually cleaned to control the amount of liquid, but due to the characteristics of the magnetic sealing liquid, it is highly adhesive and this cleaning process takes a lot of time. Furthermore, if the magnetic sealing liquid inadvertently adheres to the surface of the disk 3, there is a risk of serious accidents such as data loss. Therefore, there is a need for a double-supported spindle structure that does not require cleaning or reinjecting the magnetic sealing liquid when replacing the disk.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk device in which a magnetic disk can be replaced without disassembling a magnetic fluid seal.

[Summary of the invention]

The present invention provides a magnetic disk device having a shaft that supports a magnetic disk, a cover base forming a storage body for storing the magnetic disk, and a motor, and the present invention provides a magnetic disk drive having a shaft that supports a magnetic disk, a cover base that forms a storage body for storing the magnetic disk, and a motor. A magnetic circuit is formed between the bearing to which the inner peripheral part is fixed, the housing member that holds the outer peripheral part of the bearing and is attached to the cover base, and the housing member and the collar member through a magnetic fluid. The present invention is characterized in that the collar member, the bearing, the housing member, and the magnetic fluid seal portion can be integrally removed from the cover base and the shaft.

[Embodiments of the invention]

An embodiment of the present invention will be described below. 1st
The figure shows one embodiment of a magnetic disk device using the spindle of the present invention. A spindle for rotating the magnetic disk 3 is mounted in a pair of housings 15 and 16 and is driven by the motor 2. an actuator is attached to the opening of the housing;
This actuator includes a carriage on which a magnetic head is mounted, two rails 5 that allow the carriage to move linearly, a coil 6 that is the movable part of a linear motor,
Actuator base 4 that further fixes the rail
Information is transmitted to higher-level equipment via lead wires 7 and connectors 8. Further, in the opening, the magnetic circuit section 11 (magnet) of the linear motor is connected to a pair of magnet supports 9, 10.
When combined with the coil 6, a so-called voice coil motor is formed.
Position or move a carriage at high speed. Further, an air filter 12 for purifying the air inside the device, and a cover 14 to which the connector 8 is connected and provided with a connection terminal 13 for connecting to the outside are attached to the housing opening to seal the inside of the device.

FIG. 4 is a sectional view showing the spindle portion of this embodiment. Further, FIG. 5 is a detailed sectional view showing the upper part of the spindle of this embodiment. The structure and operation will be explained below in accordance with the assembly procedure of each component with reference to FIGS. 3 and 4. The hub 26 is fixed to the shaft 21 in advance by shrink fitting or the like. Next, insert the shaft 21 from above the lower housing 15, and tighten the magnetic sealing liquid, preload spring 27, lower bearing 28, collar 29, motor rotor 32, and washer 30 from below with the set screws 31 in this order. The magnetic fluid seal part 43 for sealing the lower bearing 28 is fixed in advance to the upper end of the housing 15 by adhesive or other means.) Furthermore, the stator coil 34 for the motor is inserted into the illustrated position of the lower housing 15, and the cover 33 is inserted.
Seal it tightly. Next, the magnetic disk 3 and spacer 25 are sequentially inserted into the hub 26 and fixed with screws 20 and disk clamps 24. Next, cover base 16
is fixed to the lower housing 15 with screws 22. Further, the magnetic fluid seal portion 1 is fixed to the lower end of the upper housing 38 by adhesive or other means, and the upper housing 38 is fixed to the cover base 16 with screws 37. Finally, the sealing O-ring 41, collar 40, magnetic sealing liquid, upper bearing 19, and washer 18 are inserted in this order from above the upper housing 38, and the screw 17 is tightened to complete the spindle. The spindle is stator coil 34
and a motor rotor 32.

Next, the spindle upper structure, which is a feature of this embodiment, will be explained with reference to FIGS. 5 and 6. The spindle upper housing 38 is pre-assembled as shown in FIG. That is, the bearing outer ring 46 is connected to the upper housing 38 and the bearing inner ring 46 is connected to the collar 4.
Furthermore, a magnet 47 of the magnetic fluid sealing portion is also fixed to the upper housing 38 at the position shown in FIG. 6 by means of adhesive or the like. It forms a magnetic circuit and can hold the magnetic sealing liquid 42, exhibiting a sealing effect. Therefore, when replacing the disk, if you remove the screw 17, the sixth
Since the subassembly structure shown in the figure can be removed all at once, the disk can be replaced without any modification to the magnetic fluid seal section. In addition, it is possible to inspect the quality of the magnetic fluid seal part in the state shown in FIG. 6, which contributes to improving the reliability of the device.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to replace the disk without disassembling the magnetic fluid sealing part, so it is possible to prevent a decrease in device reliability due to adhesion of magnetic fluid sealing liquid, etc., and to simplify assembly and disassembly work. This can be facilitated.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a magnetic disk device using a spindle according to the present invention, FIGS. 2 and 3 are sectional views showing the structure of a conventional double-support type spindle, and FIG. FIG. 5 is a detailed sectional view showing the spindle upper housing portion of this embodiment, and FIG. 6 is a sectional view showing a sub-assembled state of the spindle of this embodiment. 1...Magnetic fluid seal section, 2...Motor, 3...
...magnetic disk, 4...actuator base,
5...Rail, 6...Coil, 7...Lead wire,
8... Connector, 9, 10... Magnetic support, 11... Magnetic circuit section, 12... Air filter, 13... Connection terminal, 14... Cover, 15...
...Lower housing, 16...Cover base, 17
... Screw, 18 ... Washer, 19 ... Upper bearing, 20 ... Screw, 21 ... Shaft, 22 ... Screw,
23...Pin, 24...Disc clamp, 25
... Spacer, 26 ... Hub, 27 ... Preload spring, 28 ... Lower bearing, 29 ... Collar,
30... Washer, 31... Screw, 32... Rotor, 33... Cover, 34... Stator coil,
40... Collar, 41... O ring, 42... Magnetic sealing liquid, 43... Magnetic fluid sealing part, 44...
...Bearing outer ring, 45...Ball, 46...Bearing inner ring, 47...Magnet.

Claims (1)

[Scope of Claims] 1. A magnetic disk device having a shaft supporting a magnetic disk, a motor rotating the shaft, and a cover base forming a storage body for storing the magnetic disk, wherein one end of the shaft a collar member that is fitted into the outer periphery; a bearing that rotatably holds the shaft and whose inner periphery is fixed to the outer periphery of the collar member; and a bearing that holds the outer periphery of the bearing. a housing member attached to the cover base; and a magnetic fluid seal portion forming a magnetic circuit via a magnetic fluid between the housing member and the collar member, the collar member, the bearing, the housing member and A magnetic disk device characterized in that a magnetic fluid seal portion can be integrally removed from the cover base and the shaft.