JPH09161436A - Magnetic disc device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a large memory capacity magnetic disc by bringing a clamp into linear contact with an opening part on the surface of a disc the nearest the clamp to prevent the deformation of the magnetic disc. SOLUTION: A clamp 1 is brought into contact with a corner part of the surface of a magnetic disc 2 the nearest the clamp 1 and the disc 2 is fixed on a hub 4 by the clamp 1. By linear contact between the corner part of the disc 2 and the clamp 1, prevents the deformation of the disc 2 is prevented by keeping a moment from working on the disc 2 thereby realizing a large memory capacity with a high recording density. A contact part of the clamp 1 with the disc 2 is built in a tapered structure while the angle B of the taper is preferably smaller than the angle A of chamfering of the disc 2. When the number of the discs 2 is more than one, a spacer 6 is bonded preferably between the discs 2.

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.

[0002]

2. Description of the Related Art In magnetic disk devices, the storage capacity is being increased by increasing the recording density. As a method of increasing the recording density, there is a method of narrowing the track width of recording information and a method of narrowing the track width interval.

In order to narrow the track width, a gap (hereinafter, referred to as a gap) between a head which reads and writes information and a disk which is a medium.
It is important to reduce the flying height). In order to reduce the flying height, it is necessary to eliminate the factors that cause the flying height to fluctuate. One of the factors is the deformation of the disc, and it is necessary to devise the method and shape of the clamp for fixing the disc.

In order to narrow the track width intervals, it is necessary to reduce the positioning error factors that affect the positioning of the head on the tracks. The cause of this error is the eccentricity of the track, which is caused by the displacement of the disk due to impact or the like. In order to prevent the disc from being displaced due to a shock or the like, it is necessary to devise a clamp method and a shape for fixing the disc as in the above. That is, the clamp for fixing the disk is an important technique for increasing the storage capacity. The same applies to the fixing of the arm member for mounting the head as with the disk.

A known technique for preventing the disc from being displaced due to an impact is disclosed in Japanese Patent Laid-Open No. 6-5033. This invention uses a clamp that makes surface contact with the entire circumference of the chamfer on the inner circumference of the disc.
It prevents the gap.

[0006]

However, the known technology has a problem that the disk is deformed.

As shown in FIG. 3, when the clamping force acts on the chamfered portion C on the inner circumference of the disc, a moment acts with the point D as a fulcrum, and the outer circumference of the disc rises. This is a deformation of the disk, which hinders an increase in storage capacity.

[0008]

To achieve the above object, the present invention provides one or more discs having openings.
In a magnetic disk device provided with a hub having a flange portion that supports this and a clamp that is attached to the hub and fixes the position of the disk, a corner of an opening on the disk surface closest to the clamp and the clamp are Characterized by contact.

Preferably, in the magnetic disk device, a spacer is adhered between the disks when the number of the disks is two or more.

Further, preferably, in the magnetic disk device, a contact portion of the clamp with the disk has a taper structure.

More preferably, in the magnetic disk device, the taper angle is smaller than the chamfer angle of the disk.

Further, in the magnetic disk device, preferably, the clamp is made of a resin material.

More preferably, in the magnetic disk device, a groove is provided in the hub, and a clamp is fitted in the groove.

In order to achieve the above object, according to the present invention, one or more discs having an opening, a spacer adhered to the disc, and a hub having a flange portion for supporting the spacer, In a magnetic disk device attached to the hub and provided with a clamp for fixing the position of the disk, an inner diameter of the spacer is made smaller than an inner diameter of the disk, and the clamp is provided in a gap between the spacer and the hub in a disk radial direction. Is installed.

Further, preferably, in the magnetic disk device, when the number of the disks is three or more, two or more of the spacers are provided and adjacent spacers are bonded.

To achieve the above object, the present invention provides a hub having one or more discs having openings, spacers having the openings adhered to the discs, and flanges for supporting the spacers. And a magnetic disk device attached to the hub and provided with a clamp for fixing the position of the disk, wherein the opening of the spacer is smaller than the opening of the disk, and the corner of the opening of the spacer and the Characterized by the contact of the clamps.

Preferably, in the magnetic disk device, a contact portion of the clamp with the spacer has a taper structure.

More preferably, in the magnetic disk device, the taper angle is smaller than the chamfer angle of the spacer.

Further, preferably, in the magnetic disk device, when the number of the disks is three or more, two or more of the spacers are provided and adjacent spacers are bonded.

In order to achieve the above object, according to the present invention, a head for reading and writing information from and to a disk, an arm member for mounting the head, and a voice coil motor for moving the head are provided. A coil or magnet that is a component, a bobbin on which the coil or magnet is mounted, a bearing body having a flange portion that supports the arm member and the bobbin, and a clamp that fixes the arm member and the bobbin to the bearing body. Equipped with
The arm member and the bobbin are fixed by adhesion, welding, press-fitting, etc., and an assembly capable of accommodating the bearing body is provided in the assembly of the arm member and the bobbin. In the inserted magnetic disk device,
The corner of the opening of the assembly may contact the clamp.

Preferably, in the magnetic disk device, a contact portion of the clamp with the assembly has a taper structure.

More preferably, in the magnetic disk device, the taper angle is smaller than the chamfer angle of the assembly.

Further, preferably, in the magnetic disk device, the clamp is made of a resin material.

More preferably, in the magnetic disk device, a groove portion is provided in the bearing body, and a clamp is fitted in the groove portion.

According to the present invention having the above-described structure, the direction of the clamping force is directed to the point D in FIG. 3 by the contact between the corner portion of the disk and the clamp, so that no moment acts on the disk and the disk does not act. Can be prevented from deformation. At the same time, the disc can be fixed in the plane direction of the disc and in the direction perpendicular to the plane direction, so that the disc can be prevented from being displaced due to an impact or the like.

Further, since the clamp is installed between the spacer and the hub, the clamping force does not act directly on the disc, so that the disc can be prevented from being deformed. At the same time, the disc can be fixed in the plane direction of the disc and in the direction perpendicular to the plane direction, so that the disc can be prevented from being displaced due to an impact or the like.

Further, since the opening portion of the spacer is made smaller than the opening portion of the disk and the corner portion of the opening portion of the spacer comes into contact with the clamp, the clamping force does not directly act on the disk, so that the deformation of the disk can be prevented. it can. At the same time, the disc can be fixed in the plane direction of the disc and in the direction perpendicular to the plane direction, so that the disc can be prevented from being displaced due to an impact or the like.

Further, since the clamp comes into contact with the corner of the opening in the surface opposite to the surface of the assembly which comes into contact with the flange of the bearing body, no moment acts on the assembly,
The deformation of the assembly can be prevented. At the same time, the assembly can be fixed in the plane direction of the disc and in the direction perpendicular to the plane direction, so that the displacement of the assembly due to impact or the like can be prevented.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS. The present embodiment is a magnetic disk device in which two disks are mounted.

FIG. 1 is a side sectional view of the magnetic disk device according to this embodiment. A spindle shaft 14 is fixed to the base 13, and a spindle motor 19 that rotates at a predetermined speed is fixed to the spindle shaft 14. A flange portion 3 is formed on a hub 4 which is a component of the spindle motor 19, and the flange portion 3 supports a disk 2 which is a recording medium and has an opening. The hub 4 is inserted into the opening of the disc 2. A spacer 6 is bonded between the two disks 2. The clamp 1 made of a resin material has a ring shape. The ring-shaped clamp 1 is fitted into the groove portion 7 of the hub 4. The clamp 1 that contacts the corners of the disk 2 has a tapered structure. As a result, the disc 2 is fixed to the hub 4 by the clamp 1.

FIG. 2 shows a sectional view of the contact portion between the clamp 1 and the disc 2 shown in FIG. Here, the disk surface closest to the clamp described in claim 1 is the surface shown by the broken line in FIG. The corner of this surface and the tapered surface of the clamp 1 are in contact with each other. This contact is line contact because it covers the entire circumference, but it does not necessarily have to be the entire circumference. The taper angle B of the clamp 1 is smaller than the chamfer angle A of the disk 2 so as to contact only the corners.

The manner in which the clamp 1 is fitted into the groove portion 7 of the hub 4 will be described with reference to FIGS. 4 to 6. FIG. 4 shows the ring-shaped clamp 1 placed on the hub 4. Then, when the force is applied in the direction of the arrow while opening the clamp 1 with the jig, the state shown in FIG. 5 is obtained. The state of FIG. 5 is a state in which the clamp 1 is elastically deformed and its diameter is expanded. When a force is further applied in the direction of the arrow, the state shown in FIG. 6 is obtained. In this state, the clamp 1 fixes the disc 2. At the moment when the clamp 1 contacts the disc 2,
Since the disk 2 may shift from the hub 4,
It is necessary to prevent the disc 2 from being displaced by using a jig or the like.

The clamp 1 can be fixed to the hub 4 by shrink fitting. In this case, the groove portion 7 becomes unnecessary. A metal material is suitable because heat is applied to the clamp 1 to expand it.

A shaft 15 fixed to a base 13 is provided in the lateral direction of the disk 2 so as to be parallel to the spindle shaft 14. A head for reading / writing information from / to the disk 2 is mounted on the slider 8. The slider 8 is fixed to the load arm 9. The load arm 9 functions to press the slider 8 against the disk 2 with a predetermined biasing force. Load arm 9
A spacer 6 having an opening is fixed to. Here, the arm member described in claim 13 means the slider 8
A load arm 9 and a spacer 6. A coil 10, which is a component of a voice coil motor for moving the head, is fixed to a bobbin 11 having an opening.
The yoke 17, which is another component of the voice coil motor, is fixed to the base 13, and the magnet 16 is fixed to the yoke 17. A magnet 16 may be fixed to the bobbin 11 instead of the coil 10. Then, the arm member and the bobbin 11 are fixed by aligning the openings to form an assembly. The fixing method may be various methods such as adhesion, welding, and press fitting, but is not particularly limited. The opening in the assembly
The bearing body 12 supported by the shaft 15 is inserted. The bearing body 12 has a flange portion 3. Assembly is flange 3
Supported by The assembly is fixed to the bearing body 12 by fitting the clamp 1 into the groove portion 7 of the bearing body 12. The structure of the clamp and the fitting state are the same as those for fixing the disc 2. The clamp 1 that contacts the corners of the spacer 6 has a tapered structure. The taper angle of the clamp 1 is smaller than the chamfering angle of the spacer 6 in order to contact only the corners.

The spindle motor 19, the bearing body 12, the voice coil motor and the like are housed in a closed space formed by a cover 18, a base 13 and screws (not shown). A control circuit including a voice coil motor and a drive circuit for the spindle motor 19 is not shown.

According to this embodiment, the moment as shown in FIG. 3 does not act on the disc 2, and the deformation of the disc 2 can be prevented. At the same time, the position of the disk 2 can be fixed to the hub 4 in the two directions, that is, the surface direction of the disk 2 and the direction perpendicular thereto.
It is possible to prevent the deviation. Further, the moment does not act on the arm member, and the deformation of the arm member can be prevented. At the same time, the position of the arm member can be fixed with respect to the bearing body 12 in two directions, that is, the surface direction of the disk 2 and the direction perpendicular thereto, so that the displacement of the arm member due to impact or the like can be prevented. Further, in this embodiment, since the clamp 1 does not need a screw, there is an effect of reducing the thickness of the screw head and reducing the cost by reducing the number of parts.

A second embodiment of the present invention will be described with reference to FIGS. The present embodiment is a modification of the disk fixing portion of the magnetic disk device of the first embodiment.

In FIG. 7, this embodiment is different from the first embodiment in that the shape of the clamp 1 and the screw 5 are provided. The clamp 1 has a generally disk shape, and the contact portion with the disk 2 has a taper structure. The disk 2 is fixed to the hub 4 by fixing the clamp 1 to the hub 4 with the screw 5. The other structure is the same as that of the disk fixing portion of the first embodiment. As shown in FIG. 8, the spacer 6 is unnecessary when the number of the disks 2 is one.

According to this embodiment, the effect of preventing the deformation and displacement of the disk 2 can be obtained as in the first embodiment. Needless to say, the same effect can be obtained by adding the spacer 6 even when the number of the disks 2 is three or more.

A third embodiment of the present invention will be described with reference to FIG. In this embodiment, as in the second embodiment, the disk fixing portion of the magnetic disk device of the first embodiment is changed.

FIG. 9 is a sectional view of the disk fixing portion according to this embodiment.

In FIG. 9, the present embodiment differs from the second embodiment in that the clamp 1 has a different shape. The clamp 1 of this embodiment has a flat plate shape. The flat plate clamp 1 is fixed to the hub 4 by screws 5. When the flat plate clamp 1 is deformed, the deformed portion is tapered and is in line contact with the corner of the disk 2. The other structure is similar to that of the second embodiment.

According to this embodiment, the same effect as the second embodiment can be obtained.

A fourth embodiment of the present invention is shown in FIGS.
2 will be described. This embodiment is similar to the second embodiment except that the disk fixing portion of the magnetic disk device of the first embodiment is changed.

FIG. 10 shows a sectional view of the disk fixing portion according to this embodiment.

In FIG. 10, this embodiment is different from the second embodiment in that the shape of the clamp 1 and the shape of the spacer 6 are different, and the clamp 1 is installed between the hub 4 and the spacer 6. Is. The other structure is similar to that of the second embodiment.

FIG. 11 shows the shape of the clamp 1 of this embodiment. The clamp 1 is formed by bending a thin plate. In this embodiment, the disc 2 is fixed in the surface direction of the disc 2 by installing the clamp 1 between the hub 4 and the spacer 6. Furthermore, the two bent portions also fix the disk 2 in the direction perpendicular to the surface thereof.

FIG. 12 shows a disc fixing portion having three discs 2 mounted therein. This is adding a spacer 6.
The lower spacer 6 does not touch the middle disk 2 and the two spacers 6 are glued together. Of course, each disk 2 is adhered to the spacer 6. In this embodiment, the clamp 1 is installed at one place on the circumference,
This is an imbalance of weight with respect to the center of rotation.
In order to eliminate this, attach a weight or the like to the hub 4 or spacer 6
It is necessary to attach it to and adjust the imbalance. As another method of eliminating the imbalance, the clamps 1 may be arranged at two or more places and arranged at equal intervals on the circumference, or the clamps 1 may be formed into a cylindrical shape.

According to this embodiment, since the clamp 1 and the flange portion 3 do not come into contact with the disc 2, the clamping force does not act on the disc 2, so that the disc 2 can be prevented from being deformed. At the same time, the position of the disk 2 can be fixed to the hub 4 in two directions, the surface direction of the disk 2 and the direction perpendicular to the surface direction, so that the disk 2 can be prevented from being displaced due to an impact or the like. Further, since the screw head of the screw 5 and the height of the disk 2 can be made approximately the same, there is an effect of thinning.

A fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, as in the second embodiment, the disk fixing portion of the magnetic disk device similar to that of the first embodiment is modified.

FIG. 13 shows a sectional view of the disk fixing portion according to this embodiment.

In FIG. 13, the present embodiment is different from the first embodiment in that the shape of the spacer 6 is different.
In the shape of the spacer 6 of this embodiment, the diameter of the opening is smaller than the diameter of the opening of the disk 2. Clamp 1
Also, the flange portion 3 comes into contact with the spacer 6. The clamp 1 that comes into line contact with the corner of the spacer 6
It has a taper structure. The other structure is the same as that of the disk fixing portion of the first embodiment. In addition, the disk 2 is 3
To mount more than one sheet, the same procedure as in the fourth embodiment may be performed.

According to this embodiment, the same effect as that of the first embodiment can be obtained.

A sixth embodiment of the present invention is shown in FIGS. 14 and 15.
This will be described below. The present embodiment differs from the first to third and fifth embodiments in the chamfered shape of the parts contacting the clamp 1 or the shape of the clamp 1.

An enlarged view of the disk fixing portion according to this embodiment is shown in FIGS. 14 and 15.

In FIG. 14, the present embodiment differs from the first to third and fifth embodiments in that the chamfer is a curved surface. On the other hand, in FIG. 15, the clamp 1
Is not a taper structure. Other structures are the same as those of the first to third and fifth embodiments.

According to this embodiment, it is possible to prevent the disc 2 from being displaced due to an impact or the like.

[0059]

According to the present invention, since the corner portion of the disc and the clamp are in line contact with each other, the moment does not act on the disc and the deformation of the disc can be prevented.

Further, a clamp is installed between the spacer and the hub, or the opening of the spacer is made smaller than the opening of the disk, and the corner of the opening of the spacer comes into line contact with the clamp, so that the clamping force is applied to the disk. Does not act directly, it is possible to prevent the deformation of the disc.

Further, since the clamp makes a line contact with the corner of the opening in the surface opposite to the surface of the assembly that contacts the flange of the bearing body, no moment acts on the assembly and deformation of the assembly is prevented. Can be prevented.

Further, at the same time as the above effects, the disc and the assembly can be fixed in the plane direction of the disc and in the direction perpendicular to the plane direction, so that the disc and the assembly can be prevented from being displaced due to an impact or the like. As a result, the recording density can be increased, and a large storage capacity of the magnetic disk device can be realized.

In addition, in the first embodiment, since the clamp 1 does not need a screw, it has the effect of reducing the thickness of the screw head and reducing the cost by reducing the number of parts.

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnetic disk device according to a first embodiment of the present invention.

2 is a cross-sectional view of the disc and clamp shown in FIG.

FIG. 3 is a cross-sectional view showing a deformation of a disk according to a conventional technique.

FIG. 4 is a cross-sectional view of a state in which the clamp is placed on the hub for explaining how the clamp shown in FIG. 1 is fitted into the groove of the hub.

5 is a cross-sectional view showing a state where the clamp shown in FIG. 1 is fitted into the groove of the hub, with the clamp being pushed into the upper portion of the hub.

FIG. 6 is a cross-sectional view of the clamp shown in FIG. 1 fitted into the groove of the hub for explaining how the clamp fits into the groove of the hub.

FIG. 7 is a sectional view of a disk fixing portion of a magnetic disk device according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of a disk fixing portion when the magnetic disk device according to the second embodiment of the present invention has one disk.

FIG. 9 is a sectional view of a disk fixing portion of a magnetic disk device according to a third embodiment of the present invention.

FIG. 10 is a sectional view of a disk fixing portion of a magnetic disk device according to a fourth embodiment of the present invention.

11 is a perspective view of the clamp shown in FIG.

FIG. 12 is a cross-sectional view of a disk fixing portion when the magnetic disk device according to the fourth embodiment of the present invention has three disks.

FIG. 13 is a sectional view of a disk fixing portion of a magnetic disk device according to a fifth embodiment of the present invention.

FIG. 14 is a sectional view of a disk fixing portion of a magnetic disk device according to a sixth embodiment of the present invention.

FIG. 15 is a sectional view of a clamp having a non-tapered structure in a disk fixing portion of a magnetic disk device according to a sixth embodiment of the present invention.

[Explanation of symbols]

1 ... Clamp, 2 ... Disc, 3 ... Flange part, 4 ... Hub, 5 ... Screw, 6 ... Spacer, 7 ... Groove part, 8 ... Slider, 9 ... Load arm, 10 ... Coil, 11 ... Bobbin,
12 ... Bearing body, 13 ... Base, 14 ... Spindle shaft, 15 ... Shaft, 16 ... Magnet, 17 ... Yoke, 18 ... Cover, 19 ... Spindle motor.

Claims (17)

[Claims] 1. A magnetic disk device comprising: one or more disks having openings; a hub having a flange portion for supporting the disks; and a clamp mounted on the hub for fixing the position of the disks. A magnetic disk drive, wherein an opening on the disk surface closest to the clamp is in line contact with the clamp. 2. The magnetic disk device according to claim 1, wherein a spacer is bonded between the disks when the number of the disks is two or more. 3. The magnetic disk device according to claim 1, wherein a contact portion of the clamp with the disk has a taper structure. 4. The magnetic disk device according to claim 3, wherein the taper angle is smaller than the chamfering angle of the disk. 5. The magnetic disk device according to claim 1, wherein the clamp is a resin material. 6. The magnetic disk drive according to claim 5, wherein the hub is provided with a groove, and the clamp is fitted in the groove. 7. One or more discs having an opening, a spacer bonded to the disc, a hub having a flange portion for supporting the spacer, and a hub attached to the hub to fix the position of the disc. In a magnetic disk device provided with a clamp, an inner diameter of the spacer is made smaller than an inner diameter of the disk, and the clamp is installed in a gap between the spacer and the hub in a disk radial direction. 8. The magnetic disk device according to claim 7, wherein when the number of disks is three or more, two or more spacers are provided and adjacent spacers are bonded. 9. One or more disks having an opening, a spacer having an opening bonded to the disk, a hub having a flange portion for supporting the spacer, and a disk mounted on the hub, A magnetic disk device comprising a clamp for fixing the position, wherein the opening of the spacer is smaller than the opening of the disk, and the opening of the spacer and the clamp make a line contact. 10. The magnetic disk device according to claim 9, wherein a contact portion of the clamp with the spacer has a tapered structure. 11. The magnetic disk drive according to claim 10, wherein the taper angle is smaller than the chamfer angle of the spacer. 12. The magnetic disk device according to claim 9, wherein when the number of disks is three or more, two or more spacers are provided and adjacent spacers are bonded. 13. A head for reading / writing information from / to a disk, an arm member for mounting the head, a coil or a magnet which is a component of a voice coil motor for moving the head, the coil or the coil. A bobbin on which a magnet is mounted, a bearing body having a flange portion that supports the arm member and the bobbin, and a clamp that fixes the arm member and the bobbin to the bearing body, the arm member and the bobbin being bonded, welding,
The assembly of the arm member and the bobbin is fixed by press-fitting or the like, and an opening for accommodating the bearing is provided in the assembly, and the magnetic disk device has the bearing inserted in the opening. The magnetic disk device, wherein the opening of the disk is in line contact with the clamp. 14. The magnetic disk device according to claim 13, wherein a contact portion of the clamp with the assembly has a taper structure. 15. The magnetic disk drive according to claim 14, wherein the taper angle is smaller than the chamfer angle of the assembly. 16. The magnetic disk device according to claim 13, wherein the clamp is a resin material. 17. The magnetic disk drive according to claim 16, wherein a groove portion is provided in the bearing body, and the clamp is fitted in the groove portion.