JP2003151258A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost magnetic disk device which can effectively collect dust therein and reduces out-of-surface oscillation of a disk and windily disturbed oscillation of a head, which are caused by the fluid exciting force of air accompanied with rotation of the disk, and has the parts cost and the assembling cost reduced. SOLUTION: A recirculation filter 12 for collecting dust in the magnetic disk device is fixedly arranged on a base 10 below an FRC blanket 21 and above a load/unload mechanism 8 on the flow passage of air flowing in a disk chamber.

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, and more specifically, to an out-of-plane surface of a disk which is generated by an air flow generated by improving a dust collecting ability in the magnetic disk device or by rotating the disk. The present invention relates to a technique for reducing vibration (flutter vibration), wind disturbance vibration of a head, and the like.

[0002]

2. Description of the Related Art A minute gap between a rotating magnetic disk and a magnetic head for reading and writing information on the magnetic disk while flying over the magnetic disk with a minute gap (order: 20
(nm or less), there is a big problem that impairs reliability that a read or write error occurs when dust flows in. The types of dust include dust adhering to the surface of each component constituting the magnetic disk device, mist-like dust of lubricating oil generated from a bearing serving as a spindle or a main shaft of a carriage arm. In order to remove these dusts, a recirculation filter has been conventionally mounted in a sealed device.

When a magnetic disk rotates, an air flow is generated around the disk in the direction of disk rotation. The generated airflow passes through the recirculation filter, so that the dust contained in the airflow is collected. This recirculation filter is generally made of non-woven fabric such as polypropylene. There are several known examples of the mounting position of the conventional recirculation filter.

First, FIGS. 6 and 7 show an embodiment of the prior art. FIG. 6 is a plan view showing the structure, and FIG. 7 is a rectifying plate 19 of FIG.
It is an enlarged view of b.

In the example of Japanese Patent Application Laid-Open No. 11-73756 shown in this figure, a rectifying plate 19b is provided at the corner of the shroud 18 to rectify the airflow generated along the outer periphery of the rotating magnetic disk 1 in the rotating direction. In addition, the recirculation filter 5 that captures dust contained in the airflow introduced from the inflow opening is disposed behind the rectifying plate 19b. That is, the recirculation filter is provided in the disc chamber.

With such a structure, rectifying plates 19a and 19b corresponding to shrouds are provided on the outer circumference of the magnetic disk to reduce the flutter vibration. However, in order to obtain the effect of reducing the flutter vibration, The gap between the shroud and the outer circumference of the magnetic disk must be narrowed to a predetermined gap or less. " Further, according to another known example, Japanese Patent Laid-Open No. 11-232866, there is no effect when the gap is 0.6 mm or more, a reduction of about 10% when the gap is 0.4 mm, and 50% when the gap is 0.2 mm.
It is said that the effect of reducing is obtained.

Furthermore, another embodiment of the prior art is shown in FIG. In US Pat. No. 6,208,484 B1, disk 1
The dust flowing in the gap between the shroud 18 and the shroud 18 is collected by the recirculation filter 12 arranged in front of the voice coil motor 7 and having a curvature so as to surround the outer circumference of the stacked disks 1. . The known example is characterized in that the recirculation filter 12 is mounted at a place where the disc chamber 22 enters the actuator chamber 23.

[0008]

[Patent Document 1] Japanese Patent Laid-Open No. 11-7375
In the case of the configuration described in Japanese Patent Publication No. 6, the rectifying plates 19a and 19b are attached to the base 10 so that a narrow gap for reducing the flutter vibration is realized and the dust is sufficiently collected. Can be difficult.

In the invention described in US Pat. No. 6,208,484, the recirculation filter 12 is arranged at the entrance from the disk chamber 22 to the actuator chamber 23, but due to the pressure loss of the recirculation filter 12. Sufficient airflow does not flow into the actuator chamber 23. Therefore, the effect of collecting dust is reduced.

Further, since the effect that the air flow is once discharged to the actuator chamber 23 side on the upstream side of the carriage arm 5 with respect to the rotating direction of the disc 1 becomes low, the recirculation filter 12 is moved from the disc chamber 22 to the actuator chamber 23. The vibration component excited by the fluid exciting force of the carriage arm 5 is 10% compared to the case where it is not placed at the entrance to the
It was confirmed by experiment that the size becomes large.

Further, a hard disk drive (HDD)
The following three functions are necessary to maintain the internal cleanliness. That is, a recirculation filter that collects dust inside the HDD to maintain the cleanliness inside the HDD. A HDD that is not completely sealed has a breather filter (breathing filter) that blocks dust from the outside when air flows in and out due to pressure fluctuations and the like. Furthermore, a humidity control member (desiccant silica gel) that adjusts the internal humidity. There are three.

Japanese Patent Laid-Open No. 11-73756 and US
In the configuration of Japanese Patent No. 6,208,484, the recirculation filter is configured alone, so that the unit price of parts for maintaining the cleanliness inside the HDD becomes high.

An object of the present invention is to solve these problems by devising the arrangement and structure of the recirculation filter in the magnetic disk. That is, a first object of the present invention is to provide a highly reliable magnetic disk device that efficiently filters suspended dust in the disk device with a recirculation filter.

A second object of the present invention is to reduce the out-of-plane vibration of the magnetic disk and the wind turbulence of the head, which are generated by the influence of the fluid excitation force generated by the rotation of the disk, and It is to improve the follow-up characteristic to the head positioning signal written in (1) and the reliability of the read / write operation.

Further, a third object of the present invention is to realize an inexpensive structure by integrally forming the recirculation filter, the humidity control member and the breathing filter.

[0016]

In order to achieve the above object, a magnetic disk device of the present invention includes a magnetic disk for recording information, a spindle motor for rotating the magnetic disk, and information for the magnetic disk. A magnetic head for reading and writing, an arm for supporting this magnetic head, a voice coil motor for moving this arm, and one of which is fixed to the arm to transmit information to be read and written by the magnetic head.
A PC, a bracket for fixing the other of the FPC to the device, a load / unload mechanism for retracting the arm at an outer peripheral position of the magnetic disk, and an air inside the device arranged between the bracket and the load / unload mechanism are cleaned. A filter, a shroud that constitutes an outer wall of the device, and a cover that shields the internal structure of the device from the outside are provided.

Preferably, an elastic body is fitted in the gap between the filter and the cover or the filter and the shroud bottom surface (base).

Further, the humidity control member for adjusting the humidity inside the apparatus and the breathing filter for blocking the dust from the outside of the apparatus are integrated with the filter.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The authors of the present invention first conducted a flow visualization evaluation in order to investigate the path of suspended dust (a portion having a high dust concentration). Specifically, a 3.5-inch standard x disk diameter φ84 mm x 10,000 RPM magnetic disk device, with a transparent cover mounted so that the flow path of floating dust can be clearly defined, and also simulating floating dust. The HDA
As a result of being thrown in, it was confirmed that it would pass through the route as shown in FIG. That is, it was confirmed that the dust flows along the outermost wall of the base and that the flow velocity of the outermost wall is the fastest. By the way, although the outermost wall was constructed by the base in the experiment, even if it is constructed by the cover, there is no functional difference. In the above disc device, the outermost peripheral velocity of the disc is about 44 m / sec.
Is.

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view showing the configuration of a magnetic disk device according to the first embodiment of the present invention. The small drawing on the right side is a cross-sectional view of the recirculation filter 12 viewed from the arrow side.

In this magnetic disk device, a magnetic disk 1 which is a medium for recording information is a spindle motor 2
To rotate. A head 3 for reading / writing information from / to the magnetic disk 1 is at the tip of the suspension 4. The suspension 4 is supported by a carriage arm 5. The carriage arm 5 is rotatable by a pivot bearing 6. Then, the voice coil motor 7 rotates the carriage arm 5.

The direction of rotation of the disk 1 is from the root side of the suspension 4 to the tip side. The connector is connected to an input / output signal wiring (not shown) of the head 3 provided on the suspension 4. The load / unload mechanism 8 of the ramp load system is in a position where the tab 9 rides when the carriage arm 5 is rotationally moved in the outer direction of the disk 1. The shroud 18 is arranged so as to surround the outer circumference of the magnetic disk, and the base 10 and the cover 11 form the outer wall of the magnetic disk device.

A recirculation filter 12 for removing dust is provided upstream of the flow path (dust path) of the air flow in the apparatus with respect to the load / unload mechanism 8. The recirculation filter 12 is bonded and positioned in the XY plane of the base surface and in the Z direction. In addition, the gap between the cover 11 surface is 1.
The labyrinth gap is 5 mm.

The airflow generated by the rotation of the disk 1 passes between the outer circumference of the disk 1 and the shroud 18, flows between the voice coil motor 7 and the shroud 18, and flows in the direction of the flow along the shroud 18. Will change. Substantially the highest flow rate is along the shroud 18. That is, the flow rate of the portion which passes through the air flow paths 13a, 13b, 13c so as to block the recirculation filter 12 and is circulated to the disk 1 through the load / unload mechanism 8 is the maximum.

The FPC 24 for transmitting signals to be read / written by the head 3 and the FPC on the side opposite to the carriage arm 5
The FPC bracket 21 that fixes 24 does not act as a wall that forms a flow path.

FIG. 2 is a sectional view showing the structure of a magnetic disk device according to the second embodiment of the present invention. The small drawing on the right side is a cross-sectional view of the recirculation filter 12 viewed from the arrow side.

Although it is basically the same as the first embodiment shown in FIG. 1, in FIG. 1, the recirculation filter 1 is used.
2 is adhered to the surface of the cover 11 while being adhered to the surface of the cover 11 in FIG.
Although this is fixed via a double-sided tape type adhesive material, it may be fixed using an adhesive or the like.

The XY plane clearance between the recirculation filter 12 and the shroud 18 is structurally required due to variations in dimensional tolerance, but the clearance is 1.5 m.
It has a labyrinth structure of m or less. Further, the gap between the shroud 18 and the base 10 is also a labyrinth gap of 1.5 mm in consideration of variations in component dimensions.

According to the first and second embodiments of the present invention, the recirculation filter 12 is arranged between the outer periphery of the disk 1 and the voice coil motor 7 as disclosed in US Pat. No. 6,208,484B1. Compared to the case, the dust collection capacity was improved twice.

For this, the recirculation filter 12 is arranged upstream of the voice coil motor 7 (A
Not the point) but the upstream side of the load / unload mechanism 8 (B
Since there is nothing that obstructs the flow from the disk chamber to the entrance to the actuator chamber, the air flow into the actuator chamber is sufficient and pressure loss in the recirculation filter does not occur. HD
It is considered that the circulation efficiency of the air flow in A as a whole does not decrease and the effect of collecting dust is improved.

The flow of air is controlled by the voice coil motor 7
Since it smoothly flows to, the influence on the carriage arm of the fluid excitation force generated with the rotation of the disk 1 is reduced,
The flutter amplitude of disk 1 could be reduced by 10%. Along with this, the head 3 for the servo information on the disk 1
The positioning accuracy of was also reduced by 10%.

Further, in the case of the second embodiment, by attaching the recirculation filter 12 to the cover 11, a space for assembling other components inside the magnetic disk device (the carriage 5, the voice coil motor 7, etc.) is provided. Since it increases, the assembling work becomes easy, the risk of contact with the head 3 and the disk 1 is reduced, and the assembling work reliability is improved.
It is possible to reduce the defective rate and the cost by reducing the number of man-hours.

It was found in the course of experiments by the inventors that the position of the filter in the disk device is related to the vibration of the head arm in addition to the ability to collect dust.

In a comparative example in which the recirculation filter 12 is provided in the flow path from the disk chamber 22 to the actuator chamber 23 as shown in FIG. When the vibration characteristics in the modes were evaluated, both the flutter vibration (2 kHz or less), which is the out-of-plane vibration of the disk 1, and the vibration of the carriage arm 5 were found to be better in the configurations of FIGS. , The vibration amplitude became smaller.

Compared to the case where the recirculation filter 12 is provided in the flow path from the disk chamber 22 to the actuator chamber 23, the recirculation is made in the flow path from the disk chamber 22 to the actuator chamber 23. If the aeration filter 12 is not provided, once the air dragged by the disk 1 due to the viscosity of the air enters the actuator chamber 23 on the upstream side of the carriage arm 5, the pressure of the air hitting the carriage arm 5 itself is correspondingly increased. It can be interpreted that the excitation force is reduced due to the decrease.

By the way, the inventors conducted experiments on 3.5
In the case of mold standard × disk diameter φ84 mm × 10,000 RPM, the peripheral speed of the outermost circumference of the disk 1 is about 44 m / se.
c. In the future, the peripheral speed of the outermost circumference of Disk 1 will be 44 m / s
When it becomes ec or more, the pressure of the air that hits the carriage arm 5 itself increases, so the effect of reducing the pressure that hits the carriage arm 5 according to the configuration of the present invention is more enhanced.

Generally, when the carriage arm 5 is inserted into the disk 1, the wind loss is the diameter of the disk 1 and the shroud 1.
Although it depends on the structure of No. 8, it is proportional to the third to fifth power of the rotation speed. Further, the fluid excitation force received by the carriage arm 5 increases according to the windage loss. Therefore, particularly in order to reduce the loss due to the carriage arm 5, it is important not to provide the recirculation filter 12 at a position where the disk chamber 22 enters the actuator chamber 23 upstream of the carriage arm 5.

With this structure, the HDD
Since the vibration amplitude of the device itself is reduced, it is possible to improve the tracking characteristic of the head positioning signal written on the disk 1 by the head 3 and the reliability of the read / write operation.

FIG. 3 is a sectional view showing the structure of a magnetic disk device according to the third embodiment of the present invention. The small drawing on the right side is a cross-sectional view of the recirculation filter 12 viewed from the arrow side.

In this embodiment, in addition to the embodiment shown in FIG. 2, an elastic body 14 such as rubber is provided in the XY plane between the base 10 and the recirculation filter 12 and in the gap in the Z direction.
By fitting the elastic body 14 into the gap between the recirculation filter 12 and the base 10 and closely contacting the recirculation filter 12, the flow of the air flow due to the rotation of the disk 1 near the surface of the base 10 is not leaked and is collected by the recirculation filter 12. Made possible.

Although not shown, the cover 11 and the recirculation filter 12 are added to the embodiment of FIG.
The elastic body 14 such as rubber is provided in the XY plane and in the gap in the Z direction, and the elastic body 14 is connected to the recirculation filter 12
By fitting in the gap between the cover 11 and the cover 11, the air flow due to the rotation of the disk 1 near the surface of the cover 11 does not leak, and the recirculation filter 1
The structure may be such that it can be collected by 2.

In this embodiment, the casing 17 of the recirculation filter 12 and the inserted elastic body 14 such as rubber act like a "stretching rod", so that the support rigidity and damping of the cover 11 are increased. Therefore, the vibration and noise level of the cover can be reduced.

FIG. 4 is a sectional view showing the structure of a magnetic disk device according to the fourth embodiment of the present invention. The small drawing on the right side is a cross-sectional view of the recirculation filter 12 viewed from the arrow side.

In this embodiment, the recirculation filter 12, the humidity control member (desiccant / silica gel) 15 for adjusting the humidity inside the HDD, and the outside air when the air flows in and out of the HDD. Breathing filter (breather filter) 16 for blocking dust is included in the casing 1
It is provided inside 7 to form an integrated structure and is attached to the surface of the cover 11 with an adhesive. The clearance between the casing 17 and the base 10 in the XY directions is 1.
A labyrinth gap structure of 5 mm or less is formed. Also,
Polycarbonate, which has good dimensional accuracy and dimensional stability, is used as the material of the casing 17.

FIG. 5 is a three-dimensional view of the main parts of the embodiment shown in FIG.

In this embodiment, the members for the three functions for maintaining the cleanliness in the HDD are integrally structured, so that the initial investment such as the die cost for molding the parts and the tool cost is reduced. , The unit price of parts is reduced, the number of steps for assembling parts is also reduced, and the transportation, packing, and management costs are also reduced.
It becomes available at a low cost, the work reliability is improved by reducing the number of parts, and the low cost product can be supplied by reducing the work man-hour.

[0047]

According to the present invention, the recirculation filter improves the ability to collect dust in the magnetic disk device, so that a highly reliable magnetic disk device can be provided.

Further, the out-of-plane vibration of the disk and the wind turbulence vibration of the head due to the fluid exciting force generated with the rotation of the disk can be reduced, the tracking characteristic of the head positioning signal written on the disk is improved, and the read / write operation is performed. Is to improve the reliability of.

Further, by integrally forming the recirculation filter, the humidity control member, and the breathing filter, it is possible to procure the members at a low cost and to realize a low-cost magnetic disk device with a low assembly man-hour.

[Brief description of drawings]

FIG. 1 is a diagram showing an implementation of a recirculation filter of the present invention.

FIG. 2 is a diagram showing another implementation of the recirculation filter of the present invention.

FIG. 3 is a diagram showing another implementation of the recirculation filter of the present invention.

FIG. 4 is a diagram showing a mounting form of an integrated structural component of the recirculation filter, the humidity control member, and the breathing filter of the present invention.

FIG. 5 is a diagram showing a mounting mode of an integral structural component of the recirculation filter, the humidity control member, and the breathing filter of the present invention.

FIG. 6 is a diagram showing a configuration of a conventional technique.

7 is an enlarged view of a conventional recirculation filter mounting portion shown in FIG.

FIG. 8 is a diagram showing another configuration of the conventional technique.

FIG. 9 is a schematic view showing a floating dust passage in the magnetic disk device.

FIG. 10 is a diagram showing a configuration of a comparative example.

[Explanation of symbols]

1 ... Magnetic disk, 2 ... Spindle motor, 3 ... Head, 4 ... Suspension, 5 ... Carriage arm, 6 ...
Pivot bearing, 7 ... Voice coil motor, 8 ... Load / unload mechanism, 9 ... Tab, 10 ... Base, 11 ... Cover, 12 ... Recirculation filter, 13a,
13b, 13c ... Air flow path, 14 ... Elastic body, 15 ... Humidity adjusting member, 16 ... Breathing filter, 17 ... Casing, 18 ...
Shroud, 19a19b ... Current plate, 20 ... Land, 2
1 ... FPC bracket, 22 ... disk chamber, 23 ... actuator chamber, 24 ... FPC.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Gentaro Nakamura             2880 Kozu, Odawara City, Kanagawa Stock Association             Company Hitachi Ltd. Storage Division (72) Inventor Isao Kobayashi             2880 Kozu, Odawara City, Kanagawa Stock Association             Company Hitachi Ltd. Storage Division (72) Inventor Kei Kono             2880 Kozu, Odawara City, Kanagawa Stock Association             Company Hitachi Ltd. Storage Division (72) Inventor Noriyo Nishijima             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center

Claims (6)

[Claims] 1. A magnetic disk for recording information, a spindle motor for rotating the magnetic disk, a magnetic head for reading and writing information on the magnetic disk, an arm for supporting the magnetic head, and a moving arm. A voice coil motor, an FPC having one fixed to the arm and transmitting information to be read / written by the magnetic head, a bracket fixing the other of the FPC to the device, and the bracket against the air flow generated by the rotation of the spindle motor. A magnetic disk device comprising a filter disposed on a more downstream side for cleaning air in the device, a shroud forming an outer wall of the device, and a cover for shielding the internal structure of the device from the outside. 2. A magnetic disk for recording information, a spindle motor for rotating the magnetic disk, a magnetic head for reading and writing information from the magnetic disk, an arm for supporting the magnetic head, and a movement of the arm. A voice coil motor, an FPC having one fixed to the arm for transmitting information to be read and written by the magnetic head, a bracket fixing the other of the FPC to the device, and a load unloading means for retracting the arm at a position outside the magnetic disk. A magnet equipped with a load mechanism, a filter arranged between the bracket and the load / unload mechanism for cleaning air in the device, a shroud forming an outer wall of the device, and a cover for blocking the internal structure of the device from the outside. Disk device. 3. The magnetic disk drive according to claim 1, wherein the filter is fixed to the bottom surface of the shroud or the cover, and the gap between the bottom surface of the shroud and the cover is 1.5 mm or less. 4. The magnetic disk drive according to claim 3, wherein an elastic body is fitted in the gap. 5. The clearance between the filter and the side surface of the shroud is 1.5 mm or less.
The magnetic disk drive according to the item. 6. A humidity control member for adjusting the humidity inside the device, and a respiratory filter for blocking dust from the outside of the device,
6. The magnetic disk device according to claim 1, wherein the filter, the humidity control member, and the breathing filter are integrally structured.