JP2000228079A - Disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease vibrations at high-speed rotation by disposing a static wall having a comb tooth part between the outer peripheral end of a disk and a carriage assembly. SOLUTION: A base 1 which supports a spindle motor assembly, the carriage assembly 2, etc., is formed nearly to a box shape and is provided with a shroud 3 obtained by forming part on the inner side of its side wall to a surface along the outer periphery of the disk. The disk device is provided with the cantilver- like comb-toothed shroud 4 having such a surface as to be continuous with the surface along the outer periphery of the disk so as to shield the air stream toward the outside of the disk generated by the air, friction and centrifugal force accompanying disk rotation. The air stream in the rotating direction generated by accompanying the disk rotation when the disk rotates is eventually made to flow along the circumference of the disk by the shroud 3 disposed at the base 1 side and the freshly disposed comb-toothed shroud 4 and the disturbance which occurs near the carriage may be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus having a head for recording information on or reading information from an information recording medium such as a magnetic disk or a magneto-optical disk, and more particularly to a recording apparatus using a swing type positioning mechanism. Related to the disk device.

[0002]

2. Description of the Related Art To increase the recording density of a magnetic disk drive,
It is effective to reduce the positioning error of the write / read head on the disk and store the information in a narrower area. As a factor for increasing the positioning error, there is vibration of the disk or the positioning mechanism system caused by the air flow accompanying the rotation of the disk. This becomes a serious problem as the disk rotation speed is increased in order to improve the transfer speed. At the same time, there is also a problem that the scattering of the lubricant on the disk surface increases due to such high-speed fluid movement.

The prior art is disclosed in Japanese Patent Application Laid-Open No. 59-7268.
No. 0 discloses that a shroud having a predetermined interval is provided on the outer periphery of the disk in order to reduce out-of-plane vibration (hereinafter, referred to as flutter) of the disk during high-speed rotation. Japanese Patent Application Laid-Open No. 9-204767 discloses that the shroud interval is set to 0.1 mm or less to prevent the liquid lubricant coated on the surface of the magnetic disk from scattering.

[0004]

Problems to be Solved by the Invention
In a conventional device such as the device described in Japanese Patent No. 680, a wall for suppressing airflow outward and flowing air in the disk rotation direction at the disk outer periphery, such as a shroud provided on the disk outer periphery, It cannot be provided near the portion where the carriage arm, which is the head positioning mechanism, is inserted on the disk surface. This is an inevitable problem with a positioning mechanism in which the carriage arm swings around a rotation center provided outside the disk.

Therefore, in the vicinity of the carriage arm where the fluid is likely to be disturbed by the carriage arm, there is no wall for blocking the outward air flow, so that the pressure of the fluid fluctuates, thereby positioning the disk or the head support mechanism. It was the excitation source of the mechanism. For this reason,
There is a problem that it is difficult to obtain a further effect in reducing the vibration caused by the fluid by the shroud.

[0006] By the way, in the magnetic disk device, a higher data transfer speed is required as the storage capacity increases. Thus, a mechanism that reduces vibration caused by fluid such as flutter and improves positioning accuracy is essential.

Another problem is that the amount of fluid lubricant scattered by the airflow toward the outside of the disk near the carriage arm where fluid disturbance is large increases.

Further, there is a problem that the air resistance is increased due to the disturbance of the air flow accompanying the rotation of the disk, and the power consumption of the spindle motor rotating the disk cannot be reduced.

It is therefore an object of the present invention to provide a large-capacity, high-speed magnetic disk drive which solves the above-mentioned problems, reduces vibrations caused by airflow during high-speed rotation.

[0010]

In order to achieve the above object, a stationary wall having a comb tooth portion is provided near the carriage in opposition to the outer peripheral end of the disk, and the comb tooth portion is such that the carriage arm has the innermost circumference. , It is arranged so as to be located between the carriage arms. The stationary wall is arranged so as to be located on the upstream side of the carriage arm in the disk rotation direction.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Here, an example in which the present invention is applied to a 3.5-inch magnetic disk drive will be described.

FIG. 1 is an internal top view of a magnetic disk drive according to an embodiment of the present invention with an upper cover opened. FIG. 1 omits a spindle motor assembly in which a plurality of magnetic disks are stacked and assembled on one spindle motor shaft to facilitate understanding of the present invention. The base 1 supporting the spindle motor assembly, the carriage assembly 2, and the like (not shown) has a substantially box shape. By providing the shroud 3 in which a part of the inner side of the side wall is formed on the surface along the outer periphery of the disk, the air accompanying the rotation of the disk and the airflow outward from the disk generated by friction and centrifugal force are applied to a part of the outer periphery of the disk It is designed to block out. A stationary wall (comb-shaped shroud 4) having a cantilever beam-like comb portion having a surface continuous with the surface along the disk outer periphery was provided. The distance between the disk and the shroud 3 and the comb-shaped shroud 4 may be about 0.5 to 1 mm, which is currently commercialized, and may be 0.1 mm or less as described in the conventional example. That is, the distance may be set to 1 mm or less, but is not limited to this value.

A magnetic circuit 5 of a voice coil motor for driving the carriage arm is provided on the side of the carriage assembly 2 opposite to the side facing the disk (the side of the carriage arm 7). Note that in this embodiment. The arm 7 is provided with a hole 11 for weight reduction. Needless to say, the hole 11 does not need to be provided.

With the configuration of this embodiment, when the disk is driven to rotate, the airflow in the rotational direction generated with the rotation of the disk is reduced by the shroud 3 provided on the base 1 side and the newly provided comb teeth. Since the shroud 4 flows along the circumference of the disk, disturbance generated near the carriage can be suppressed.

Next, the detailed configuration of the comb toothed shroud will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 shows a detailed view of the comb-shaped shroud 4. FIG. 3 shows a cross section of the carriage arm 7, the disk 8, and the comb teeth 6 when cut along a cross section parallel to the spindle motor axis at the center of rotation of the disk.

As shown in FIG. 2, the number of the comb teeth 6 in the present embodiment is nine, which is the same as the number of disks mounted on the magnetic disk device of the present embodiment. These comb teeth 6
Are arranged so as to be inserted into the gap of the arm 7.

As shown in FIG. 3, the comb teeth 6 are arranged along the outer circumference of each disk 8. The thickness of the comb teeth 6 is desirably greater than the thickness of the disk 8 within a range that does not come into contact with the arm 7 in the gap between the arms 7, but may be substantially equal to the disk thickness. This is because the greater the comb tooth thickness is greater than the disk thickness, the greater the effect of damping the flow outward of the disk. But arm 7
When a hole 11 as shown in FIG. 1 is provided for weight reduction, a space surrounded by an outer peripheral end of the disk and a surface 10 of the arm 7 and the carriage body 9 facing the disk,
A local flow 12 between adjacent disks may occur through the holes 11 to disturb the flow on the disk surface. Therefore, since this can be prevented, even if the comb tooth thickness is equal to the disk thickness, it is sufficiently effective.

FIG. 4 shows the vicinity of a general carriage assembly.

In this carriage assembly 2, the carriage body 9 is close to the outer periphery of the disk, and the shroud 3 is extended to the vicinity of the carriage to avoid interference with the carriage arm 7 or body 9. I couldn't extend it any further. In addition, depending on the shape of the carriage body, the tip of the shroud 3 is provided to avoid interference with a part of the body 9 when the carriage assembly 2 swings.
In many cases, it is difficult to approach the carriage assembly 2 as in FIG. Therefore, the portion of the disk outer periphery facing the carriage assembly 2 is only blocked by the carriage body surface 10. However, the carriage assembly 2
In order to avoid the interference caused by the swing of the carriage, the shape of the carriage body surface 10 cannot be formed along the outer periphery of the disk, and a gap is generated before and after that.

On the other hand, in the case where the comb-shaped shroud 4 of the present invention is provided as shown in FIG. 5, the surface along the outer periphery of the disk extends to between the outer periphery of the carriage assembly 2 and the outer periphery of the disk 8. This can block the outward flow of the disk in the vicinity. Further, the positional relationship of the shroud 4 with respect to the disk 8 does not change whether the head 14 is on the inner peripheral side (FIG. 5A) or the outer peripheral side (FIG. 5B). There is no change in the effect of rectifying the airflow above. By providing the comb teeth 6 in this manner, the shroud 4 can be extended to a region inside the arm of the carriage arm 7 from the end face on the upstream side in the disk rotation direction (the end face 16 on the arm upstream side).

The longer the comb teeth 6 are, the longer the length along the outer periphery of the disk is. However, since the comb teeth 6 are cantilevered, if they are extremely long, the error of the comb tooth tip 17 becomes large when machining, and There is a problem such as a decrease in resonance frequency. Therefore, ideally, when the head 14 is at the innermost peripheral position (FIG. 5A), the tip 17 of the comb teeth should be located closer to the inside of the arm than the downstream end face 18 of the arm 7 in the disk rotation direction. good. This depends on the shape of the carriage assembly 2, but an FPC (flexible printed circuit) in which a signal line from the head 14 is connected near the end face 18 on the downstream side of the arm.
This is because when the substrate 19 is arranged, it can be arranged so as to avoid interference. Of course, it can be shorter than this (however, the effect is slightly reduced), and the FPC board 19
It is needless to say that the length can be longer depending on the arrangement.

Comb teeth 6 are attached to carriage body 9 and disc 8
A gap is required between the carriage body surface 10 and the outer peripheral edge of the disc in order to arrange the
Can be secured in two ways.

In the first method, the thickness of the carriage body 9 is reduced so that the body surface 10 is kept away from the outer peripheral edge of the disk. At this time, the same configuration can be made by reducing the diameter of the bearing 20. This also has the effect of reducing the moment of inertia of the carriage assembly 2.

The second method is to move the position of the pivot shaft 13, which is the center of rotation of the carriage, away from the disk. In this case, in order to prevent the angle between the tangential direction of the track on the disk on the disk and the direction of the head 14 (hereinafter referred to as the yaw angle) from changing greatly, the head 14
Of the arm 7 or the head support mechanism 15 becomes longer. This leads to an increase in the moment of inertia about the center of rotation of the carriage assembly 2, and thus seems to be a problem for driving the carriage at high speed. However, in practice, when a modeled control system is constructed by replacing the moment of inertia of the carriage assembly 2 with the equivalent mass converted to the position of the head 14, the equivalent mass is divided by the square of the head turning radius. This is not a problem because the influence of the increase in the moment of inertia is very small.

Next, the comb-shaped shroud 4 will be described with reference to FIG.
Will be described.

The comb-shaped shroud 4 of this embodiment is formed by molding a resin. In particular, in order to make the surface of the comb-shaped shroud 4 facing the outer peripheral end of the disk as close to the outer peripheral end of the disk as possible, it is necessary to improve the mounting accuracy of the comb-shaped shroud 4 to the base 1.

For this purpose, the shroud main body is formed on the cylindrical shaft 21 made of metal such as stainless steel by the outsert molding method. The cylindrical shaft 21 has a female screw portion 22 at a lower portion, and can be fixed with a screw from the back surface of the base 1. Also, a boss 2 provided at the lower part
The rotation of the comb-shaped shroud 4 around the female screw portion 22 is suppressed by fitting the holes 3 provided in the base 1 with the holes 3. The characteristics required for the resin used for the comb toothed shroud 4 are low dust generation and low gas property, and in order to avoid contact with the arm 7 or the disk 8 due to deformation of the comb teeth, a material having a low thermal expansion coefficient is used. Desirably.

Here, the metal cylindrical shaft 21 need not be provided as long as a sufficient clearance for the positional tolerance can be secured. Further, the entire comb toothed shroud 4 can be made of metal such as aluminum. In that case, a method of simultaneously processing the comb tooth portions to suppress the deformation of the comb teeth 6 is necessary. However, the processing is performed by using a multi-layer blade cutter often used for cutting the arm 7. I can do it.

In this embodiment, the female screw portion 22 for mounting the comb-shaped shroud 4 is located at a position to be mounted on the bottom surface of the base 1. It is also possible to use a mounting method in which a shroud 3 as a wall surface formed on the base 1 is fixed with bolts or the like.

The assembling of the comb toothed shroud 4 in the apparatus is performed in the following order. First, the disk spindle assembly is mounted. Next, the comb toothed shroud 4 is fixed to the base 1 by the method described above. Then, the carriage assembly 2
Is fixed to the base 1.

After assembling, the carriage assembly 2 is rotated to load the head 14 onto the disk 8. Therefore, since the comb toothed shroud 4 does not interfere with the arm 7, carriage loading can be performed as in the conventional case.

FIG. 6 is a top view showing the second embodiment.

In this embodiment, the comb teeth 6 are formed as a part of a shroud along the outer peripheral edge of the disk formed on the base 1. In this case, the comb teeth 6 are formed on the shroud integrated with the base 1 by cutting. In this case, depending on the processing method, for example, if the comb teeth 6 are formed from the opening direction (upper surface) of the base 1 with a cutter such as an end mill, a long comb tooth may not be formed in some cases.
On the other hand, being formed on the shroud 3 integrated with the base 1 is not affected by mounting tolerance, unlike a separate component, so that the shroud 3 can be made closer to the outer periphery of the disk.

FIGS. 7 and 8 show a third embodiment. FIG.
Is a perspective view of the carriage assembly, and FIG. 8 is a top view thereof.

Here, an example of the comb-shaped rectifying member 24 mounted on the carriage body 9 is shown. As shown in the figure, a comb-shaped rectifying member 24 is provided in the gap between the arms 7 so as to cover the disk facing surface of the carriage body.

As shown by the dotted line in FIG. 8, a surface close to the outer peripheral end of the disk is provided between the carriage body and the outer peripheral end of the disk, so that the air flow directed outward of the disk is blocked. Since the rectifying member 24 is mounted on the carriage assembly 2, the posture of the carriage assembly 2 (when the head 14 is located at the inner / outer periphery) changes compared to the case of the first embodiment. However, there is a problem that the shape of the surface of the rectifying member 24 facing the outer peripheral end of the disk changes, resulting in a difference in the rectifying effect. However, there is an advantage that it is easy to assemble because it is mounted on the carriage.

In this embodiment, the rectifying member 24 is made of resin, and is formed directly on the carriage body 9 by the outsert molding method. Thereby, the man-hour for mounting the rectifying member 24 can be omitted. In addition, by using a lightweight resin, the mass around the body can be reduced compared to the conventional carriage, and the moment of inertia of the carriage assembly 2 can be reduced.

The surface of the rectifying member 24 that does not face the disk can be smoothed as shown in FIG. 7 and used as a support for mounting the FPC board 19. Another effect of the rectifying member 24 is an effect of reducing the resonance peak gain of the arm 7. This is because the comb teeth 6 are formed so as to fill the gaps at the base of the arm 7, so that a resin having a high damping effect is closely bonded to the base of the arm 7, so that the bending vibration of the arm 7 is reduced. This is because it acts as damping.

As described above, the shroud according to the present invention can rectify the airflow outward of the disk in the vicinity of the carriage assembly 2 and stably flow the airflow in the disk rotation direction. Therefore, the disturbance of the flow near the arm 7 is reduced, the pressure fluctuation is reduced, and the vibration of the disk 8 or the arm 7 or the head support mechanism 15 can be suppressed. Therefore,
High positioning accuracy can be achieved. In addition, by reducing the outward flow component of the disk and stabilizing the flow near the arm 7, the amount of the scattered liquid lubricant on the disk surface can be reduced, and the reliability of the magnetic disk device can be improved.
Further, the disturbance of the air flow near the arm 7 due to the rotation of the disk increases the fluid resistance and leads to an increase in the power consumption of the disk spindle motor. And the power consumption of the magnetic disk drive can be reduced.

As a result, the disk can be rotated at a high speed,
Improvements in performance that are contradictory to conventional technologies, such as low vibration, high reliability, and low power consumption, can be realized at the same time.

Further, by providing the comb-shaped shroud 4 of the present invention to cover the outer peripheral edge of the disk near the carriage body 9, a similar shroud is also provided on the outer peripheral portion of the disk downstream of the carriage arm 7. Lower power consumption can be achieved. In other words, the disk is covered with the shroud over substantially the entire periphery of the outer peripheral end, so that the effect of suppressing the outward air flow and stabilizing the flow is enhanced, and the fluid resistance due to the air disturbance can be reduced.

In the case where the shroud is provided all over the outer periphery of the disk, the following steps are required. Head 14 on disk
And loading the arm 7 to which the head support mechanism 15 is attached, and then attaching a shroud so as to face a vacant portion on the outer periphery of the disk.

Here, the embodiment applied to the 3.5-inch magnetic disk drive has been described. This 3.5-inch type magnetic disk drive is equipped with a smaller diameter 3 inch or 2.5 inch type magnetic disk which is advantageous for speeding up the disk as a matter of course when a 3.5 inch type disk is mounted. The above-described apparatus can be similarly applied. In particular, when a 3.5-inch or 2.5-inch magnetic disk is used in a 3.5-inch magnetic disk drive, the shroud 3
It is easy to provide a wall surface along the outer peripheral edge of the disk as described above. Therefore, the comb toothed shroud of the present invention can be provided also in the vicinity of the carriage where the wall surface along the outer peripheral edge of the disk could not be provided conventionally, and the flow can be stabilized.

Furthermore, if the diameter of the disk is reduced without changing the distance between the center of rotation of the disk and the pivot shaft 13 which is the center of rotation of the carriage assembly 2, the distance between the outer peripheral end of the disk and the surface 10 of the carriage body is inevitable. Due to the spacing,
The space for installing the comb toothed shroud 4 of the present invention is ensured, which is convenient.

On the other hand, the present invention can be similarly applied to a 2.5-inch magnetic disk drive. In the case of a 2.5-inch magnetic disk device having no space, it is difficult to secure a surface along the outer periphery of the disk. Therefore, by providing such a shroud along the outer surface of the disk near the carriage, The proportion that contributes to the effect of flow stabilization increases.

In the above description, the rotation direction of the disk is assumed to rotate counterclockwise in FIGS. 4, 5 and 6, and in these figures, the area on the left side of the arm is
The area on the right side is called the downstream side with the rotation of the disk, and the area on the right side is called the downstream side.

[0047]

According to the present invention, the air flow directed to the outside of the disk can be rectified and flow in the direction of rotation of the disk even on the outer periphery of the disk facing the carriage assembly, thereby suppressing the pressure fluctuation of the fluid. Therefore, vibration of the disk positioning mechanism is not excited. In addition, this can stably obtain a rectifying effect regardless of where the carriage arm is located inside / outside the disk. This makes it possible to realize a disk device capable of high-density recording without lowering the positioning accuracy even when the disk is rotated at a high speed.

Also, by enhancing the rectifying effect of the air flow,
An increase in air resistance due to fluid disturbance can be suppressed, power consumption for driving the spindle motor can be reduced, and a disk device with low power consumption can be provided.

Also, by reducing the airflow outward of the disk, it is possible to prevent the lubricant from scattering on the disk surface.

[Brief description of the drawings]

FIG. 1 is a top view of the inside of a magnetic disk drive according to a first embodiment of the present invention.

FIG. 2 is a detailed side view of the comb toothed shroud of the present invention.

FIG. 3 is a cross-sectional view of the first embodiment of the present invention.

FIG. 4 is a top view of the first embodiment of the present invention.

FIG. 5 is a diagram showing two different posture states according to the first embodiment of the present invention.

FIG. 6 is a top view of the second embodiment of the present invention.

FIG. 7 is a perspective view of a third embodiment of the present invention.

FIG. 8 is a top view of the third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Carriage assembly, 3 ... Shroud,
4 ... shroud with comb teeth 5 ... magnetic circuit 6 ... comb teeth
7 arm, 8 disk, 9 carriage body, 10
... body surface, 11 ... hole, 13 ... pivot shaft, 14 ... head, 15 ... head support mechanism, 16 ... arm upstream end face,
17 ... comb tooth tip, 18 ... arm downstream end face, 19 ...
FPC board, 20: bearing, 21: cylindrical shaft, 22: female thread, 23: boss, 24: rectifying plate.

Claims (6)

[Claims] A spindle motor assembly comprising at least one disk for recording information; a spindle motor for rotating the disk; a head support mechanism for supporting a recording / reproducing head on the disk; A disk drive comprising: a plurality of arms connected to a head support mechanism; a carriage assembly including a carriage that holds and swings the arms; and a base that supports the spindle motor assembly and the carriage assembly. 3. The disk device according to claim 1, further comprising a stationary wall provided with a comb portion between an outer peripheral end of the disk and the carriage assembly. 2. The disk device according to claim 1, wherein said stationary wall is formed by molding resin on a metal mounting member. 3. A spindle motor assembly comprising at least one disk for recording information, a spindle motor for rotating the disk, a head support mechanism for supporting a recording / reproducing head on the disk, A disk drive comprising: a plurality of arms connected to a head support mechanism; a carriage assembly including a carriage that holds and swings the arms; and a base that supports the spindle motor assembly and the carriage assembly. In the above, a stationary wall provided with a comb tooth portion is provided between an outer peripheral end of the disk and a carriage assembly, and the stationary wall is provided in a state where the recording / reproducing head is located at an innermost periphery of the disk. When viewed from a direction parallel to the swing center axis of the arm, the comb teeth are closer than the end face of the arm on the upstream side in the rotation direction of the disk. A disk device characterized in that a tip of a portion is provided on a downstream side. 4. A spindle motor assembly comprising: at least one disk for recording information; a spindle motor for rotating the disk; a head support mechanism for supporting a recording / reproducing head on the disk; A disk drive comprising: a plurality of arms connected to a head support mechanism; a carriage assembly including a carriage that holds and swings the arms; and a base that supports the spindle motor assembly and the carriage assembly. In the above, a stationary wall provided with a comb tooth portion is provided between an outer peripheral end of the disk and a carriage assembly, and a bearing portion for supporting the carriage to swing around its rotation center; A body connected so as to surround the center; and a line connecting the rotation center of the spindle motor and the rotation center of the carriage. The size of the carriage body and the position of the rotation center of the carriage are determined so that the distance between the surface of the body facing the disk and the outer peripheral end of the disk is greater than the width of the comb teeth. A disk device. 5. A spindle motor assembly comprising at least one disk for recording information, a spindle motor for rotating said disk, a head support mechanism for supporting a recording / reproducing head on said disk, A disk drive comprising: a plurality of arms connected to a head support mechanism; a carriage assembly including a carriage that holds and swings the arms; and a base that supports the spindle motor assembly and the carriage assembly. In the above, a side surface of a surface of the body that faces the disk is provided with a bearing portion that supports the carriage to swing around a rotation center, and a body portion that is connected to surround the bearing portion. A rectifying member having a surface opposed to an outer peripheral end of the disk provided on a side thereof so as to be coupled to the carriage; Location. 6. The disk device according to claim 5, wherein the rectifying member is formed by molding a resin on the carriage so as to cover a base of the arm.