JPH08249873A - Magnetic disk device - Google Patents

Abstract

PURPOSE: To prevent the grease sealed in bearings from being splashed into a device by high-speed rotation of a carriage according to a seek instruction. CONSTITUTION: The bearing parts within an arm assembly which supports an arm assembly 7 mounted with a magnetic head 6 at a revolving shaft 8 via plural pieces of bearings are internally provided with vent holes 12. These vent holes penetrate down to the position on the downstream side of in the rotating direction of a magnetic disk from the inner spaces 14 of plural pieces of the bearings facing each other in this arm assembly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device for reading required data from a magnetic disk surface rotated by a magnetic head and writing the data on the magnetic disk surface. The present invention relates to an improvement for preventing adhesion to a magnetic head or a magnetic disk surface.

[0002]

2. Description of the Related Art In many magnetic disk drives, a magnetic head is mounted on a rotary type carriage, and the magnetic head floats on a magnetic disk surface with a small gap by air pressure generated along with a magnetic disk rotating at a high speed.
Reading and writing magnetic recording.

In this carriage, a positioning pattern written on a magnetic disk is read by a servo head and a servo loop is formed for positioning.
As a result, the carriage can be positioned at a predetermined position at high speed, and at present, a product whose speed, that is, seek time, is already under 10 ms is realized.

The magnetic head floats above the magnetic disk when in use and contacts the magnetic disk when stopped, so-called contact start stop (CS).
A magnetic disk device adopting the S) method is general.

[0005]

At this time, the abrupt positioning operation of the carriage causes the bearing to rotate at high speed, causing grease sealed in the bearing to scatter and adhere to the magnetic head or the magnetic disk surface. is there. As a result, the flying characteristics of the magnetic head may be degraded, making it impossible to read or write to the magnetic head, or the magnetic head may stick to the magnetic disk drive when the device is stopped, possibly causing a serious failure such as a head crash. There is.

Conventionally, in a magnetic disk drive of this type, as shown in FIG.
a, a shield plate 11 having a labyrinth effect on itself 9b
Is inset. This shield plate 11 has a bearing 9a,
A small gap between the inner ring 9b and the inner ring has a mechanical sealing effect, and this labyrinth shape shuts off the space in the grease-filled portion from the outside air. As a result, scattering prevention is more effective as the clearance of the labyrinth part is smaller,
Generally, the clearance is 0.1 to 0 due to the problems of assembling and cost.
It is applied at about 2 mm.

However, due to the recent increase in the speed of magnetic disk devices, the access speed of the carriage is 10 on average.
ms, and recently some products have realized 7ms. Thereby, when the carriage moves at high speed, the bearings used in the carriage also correspondingly rotate at high speed. Conventionally, since the access speed is low, there is no problem even with the technique shown in FIG. However, with the recent increase in the access speed of the carriage, the rotational speed of the bearing reaches 300 to 400 rpm, and the harshness of the operating environment of the apparatus is added. Has become.

As a countermeasure, for example, it is conceivable to prevent grease from scattering with a magnetic fluid called a magnetic fluid seal employed in a bearing of a spindle motor on which a magnetic disk is mounted. However, since the magnetic fluid seal has a large viscous resistance, it is not suitable for a carriage requiring intermittent high-speed operation. In addition to the above-mentioned shield plate of the bearing itself, it is conceivable to add a new mechanical labyrinth seal to the grease scattered flow path. An increase occurs. The effect of preventing grease scattering from the labyrinth structure is very good when the spindle rotates like a spindle and has a constant pressure distribution. Is not enough because it changes each time it rotates. Therefore,
The grease scattering described above cannot be prevented well.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and comprises a magnetic head facing a magnetic disk;
A magnetic disk device comprising: an arm assembly for supporting the magnetic head; a rotating shaft for supporting the arm assembly via a plurality of bearings; a magnetic disk, the magnetic head, and a substrate containing the arm assembly. Vent holes are provided in the arm assembly from the inner spaces of the plurality of opposed bearings to positions downstream in the magnetic disk rotation direction, and a filter is arranged at the vent hole outlet.

[0010]

Next, the present invention will be described with reference to the drawings. As shown in FIG. 1, both ends of the spindle shaft 2 are fixed to a base 4 with covers (not shown) and a base 4. Magnetic disk assembly 5 supported by spindle shaft 2
Mounts the magnetic disk 1 and is rotated at high speed by the DC motor 15.

On the other hand, a magnetic head 6 corresponding to the magnetic disk 1 is supported at one end of an arm assembly 7. The arm assembly 7 has a plurality of bearings 9 a, 9 around the rotating shaft 8 by a torque generated by the voice coil motor 16.
A high-speed swinging operation is performed via b.

Although not specifically shown in FIG. 1, grease 10 is sealed inside the bearings 9a and 9b as in the prior art shown in FIG.
One is inset. In order to further prevent the grease 10 from scattering and to prevent dust and the like from entering the inside of the bearing from outside, the gap between the inner rings of the bearings 9a and 9b and the shield plate 11 is usually minute. Also, in this embodiment, FIG.
As shown in FIG. 3, the arm assembly 7 includes a plurality of bearings 9.
A ventilation hole 12 penetrating from the space 14 between the holes a and 9b to a position downstream in the rotation direction of the magnetic disk 1 is provided, and a filter 13 is attached to the outlet as shown in FIG.

When the arm assembly 7 carrying the magnetic head 1 is rotated by a seek command, the grease 10 enclosed in the bearings 9a, 9b tends to be scattered outside the bearings 9a, 9b, but both sides of the grease 10 are scattered. Since the shield plate 11 is provided in the, the scattering can be prevented to some extent. However, if the rotation speed of the arm assembly is high, it will pass through the shield plate 11. In particular, the equipment environment is harsh and the bearings 9a, 9b
Especially when the ambient temperature is high, the amount of grease 10 scattered exponentially increases.

On the other hand, the space 14 surrounded by the bearings 9a and 9b
A ventilation hole 12 penetrating through the arm assembly 7 is provided further toward the downstream side of the magnetic disk 1, and the space 14 and the outlet of the ventilation hole 12 on the downstream side are formed by the effect of the negative pressure generated in the downstream portion. Due to the pressure difference, the grease 10 is easily scattered to the above-mentioned space 14 side and further flows out into the apparatus through the vent hole 12. In particular, a filter 13 is attached to the outlet of the vent hole 12 in FIG. So grease 10 is
There is no scattering in the device.

Therefore, since there is no sticking to the magnetic disk 1 and the magnetic head 6, there is no change in the floating attitude of the magnetic head 6 due to the attached grease 10, suction, and head crash.

[0016]

As described above, according to the present invention, a magnetic head facing a magnetic disk, an arm assembly for supporting the magnetic head, and a rotary for supporting the arm assembly via a plurality of bearings. In a magnetic disk drive having a shaft and a substrate enclosing the magnetic disk, the magnetic head, and the arm assembly, the arm set extends from an inner space of the plurality of opposed bearings to a position on the downstream side in the magnetic disk rotation direction. By providing a three-dimensional ventilation hole and arranging a filter at the ventilation hole outlet, grease generated at the time of seeking passes through the space between the opposed bearings and the ventilation hole into the apparatus. However, since the filter is arranged at the inlet of the vent hole, the scattered grease is blocked.

As a result, even if the carriage performs a seek operation at a high speed, the grease scattered from the bearing is almost captured by the filter of the ventilation hole, and therefore does not adhere to the magnetic disk or the magnetic head. Changes in the flying attitude of the head, adsorption to the magnetic disk,
Then, head crash does not occur, and the reliability of the magnetic disk device is greatly improved.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention, wherein (a) is a plan view and (b) is a front sectional view.

FIG. 2 is a front sectional view showing an arm bearing portion of another embodiment of the present invention.

FIG. 3 is a front sectional view showing an arm bearing portion of a conventional magnetic disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic disk 2 Spindle shaft 3 Cover 4 Base 5 Magnetic disk assembly 6 Magnetic head 7 Arm assembly 8 Rotating shaft 9a, 9b Bearing 10 Grease 11 Shield plate 12 Vent hole 13 Filter 14 Space 15 DC motor 16 Voice coil motor

Claims (2)

[Claims] A magnetic head facing a magnetic disk;
A magnetic disk device comprising: an arm assembly for supporting the magnetic head; a rotating shaft for supporting the arm assembly via a plurality of bearings; a magnetic disk, the magnetic head, and a substrate containing the arm assembly. A magnetic disk device characterized in that a ventilation hole is provided in the arm assembly from an inner space of the plurality of opposed bearings to a position on a downstream side in a magnetic disk rotation direction. 2. The magnetic disk drive according to claim 1, wherein a filter is attached to the ventilation hole.