JPH05166327A - Magnetic disk unit - Google Patents

Abstract

PURPOSE:To reduce the disk distortion due to screw driving stress and to improve the flatness of the recording surface of a magnetic disk by defining a non-circular disk inner diameter and a non-circular spindle outer shape and fixing the disk to a spindle with a metallic holder and a screw. CONSTITUTION:The force generated in the revolving direction of a spindle is fixed to a magnetic disk 3. For this purpose, the section of a spindle 1 has a non-circular shape and the inner diameter of a hole of the disk 3 also has a non-circular shape similar to the section of the spindle 1. Then a spacer 2 and the disk 3 are put into the spindle 1 and supported there, and the up-down stress is fixed with a metallic holder 4 and a fixing screw 5. Thus the number of screws can be decreased and the screw driving torque can also be reduced. Then the screw driving distortion is reduced and the deformation and the warp of the disk 3 can be prevented when the disk 3 is fixed. As a result, the recording surface of the disk 3 can keep a satisfactory shape and the satisfactory reliability.

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 which supports a magnetic disk by a spindle used in a recording device of information equipment and rotates and performs recording / reproducing.

[0002]

2. Description of the Related Art A contact start stop (CSS) method is generally adopted in a magnetic disk device which is a peripheral device such as an electronic computer, and a magnetic head and a surface of a magnetic disk are in contact with each other during recording and reproduction. The movement is repeated. Further, in terms of recording characteristics, it is required that the space between the magnetic film and the magnetic head be uniform. Further, in recent years, particularly, this space has become small, and the requirement of 0.1 micron or less is increasing. That is, in the magnetic disk device, the surface shape and the flatness of the magnetic disk are strictly required in order to reduce the impact at the time of contact start / stop and to maintain the stable flying of the magnetic head from the recording / reproducing characteristics.

FIGS. 5A and 5B show the structure of a conventional magnetic disk, and FIGS. 6A and 6B show the structure of a magnetic recording device in which the conventional magnetic disk is incorporated in a spindle.

As shown in FIGS. 5A and 5B, in a conventional magnetic disk, for example, a 3.5 inch magnetic disk,
The outer diameter is 95 mm, the inner diameter is 25 mm, and the shape is circular. The plate thickness is 0.8 to 1.27 mm, which is a very thin structure.

Further, in a conventional magnetic disk device incorporating a plurality of the above magnetic disks, a spacer 8 and a magnetic disk 9 are inserted into a spindle 7 as shown in FIGS. Spacer 8 is placed on
This operation is repeated when a plurality of magnetic disks are required. Finally, the magnetic disk 9 and the spacer 8 are fixed to the spindle 7 with a plurality of fixing screws 5 via the metal retainer 10. With the above configuration, the spindle 7 normally rotates at a high speed of about 3600 rotations per minute. When rotating, magnetic disk 9
Tries to move in the two directions of the rotation direction of the spindle 7 and the direction perpendicular to the spindle 7, that is, the vertical direction. In order to suppress this movement, a metal retainer 10 is placed, and the magnetic disk 9 is fixed by tightening with a screw 5. Normally, the screw tightening torque was 2 kg-cm or more per screw, and several screws were required to completely suppress the vibration of the magnetic disk.

[0006]

However, in the above-described conventional fixed screw tightening work, the screw tightening force is unevenly applied to the disk, the magnetic disk 9 is distorted, the disk is deformed, and the flatness is deteriorated. .. As a result, a phenomenon such as a large impact from the magnetic head at the time of contact start / stop or a contact between the magnetic disk and the magnetic head even during normal rotation occurs, leading to a serious trouble of the magnetic head crash. In recent years, the thickness of magnetic disks has tended to become thinner as the capacity of magnetic recording devices has increased, and deformation of magnetic disks due to screw tightening is more likely to occur.

The present invention solves such a problem, and has a magnetic disk supporting structure that does not deteriorate the flatness of the recording surface due to the distortion of the magnetic disk due to the stress due to the screw tightening, and the high speed rotation of the disk. It is an object of the present invention to provide a small-sized and high recording density magnetic disk device that can withstand even the above.

[0008]

In order to solve this problem, the present invention relates to a magnetic disk having a magnetic recording layer formed on the surface of a non-magnetic disc-shaped substrate and having a hole at the center, and a unidirectional disk. And a spindle rotating at a constant speed, wherein one or a plurality of the magnetic disks are fixed to the spindle via a spacer, the spindle has a non-circular cross-sectional shape, and the magnetic disk has a hole. Is a non-circular shape similar to the cross-sectional shape of the spindle, and the magnetic disk is inserted into and supported by the spindle.

Further, the spindle has a circular sectional shape having a convex portion or a concave portion, and a magnetic disk having a hole having a shape similar to the sectional shape of the spindle provided at the center is inserted into and supported by the spindle. is there.

[0010]

According to this structure, the spindle and the magnetic disk are connected by the non-circular hole, and the stress in the rotational direction is supported by the spindle. Therefore, it is possible to reduce the number of screws tightened when installing the magnetic disk in the magnetic recording device, and also to reduce the screw tightening torque, maintain a good shape without causing distortion on the magnetic disk, and flatten the recording surface. It is possible to provide a magnetic disk having excellent contact start / stop characteristics and flying characteristics without any loss.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic disk device according to an embodiment of the present invention will be described below. 1 (a) and 1 (b) show the structure of the magnetic disk of this embodiment, and FIGS.
1 shows a configuration of a magnetic disk device incorporating the magnetic disks of (a) and (b).

As shown in FIGS. 2 (a) and 2 (b), the magnetic disk 3 of this embodiment is mounted on the spindle 1 of the magnetic disk device.
Attach to. This embedding method can be the same as the conventional method. However, in this embodiment, the spindle 1 and the spacer 2 are shaped according to the inner diameter of the magnetic disk.
Has been applied to. In addition, the spindle 1 magnetic disk 3
And when inserting the spacer 2, a fitting is required. In the magnetic disk device having such a structure, the force in the rotational direction is received by the shape 6 of the inner diameter of the magnetic disk 3, and only the vertical vibration is fixed by the metal retainer 4 and the fixing screw 5. Therefore, the screw tightening torque can be made much smaller than in the past. Therefore, it is possible to fix with one screw 5, the stress applied to the magnetic disk 3 is reduced, and the deformation of the magnetic disk is reduced.

According to the structure of the present embodiment, the surface of the magnetic disk is kept extremely flat when it is incorporated in the magnetic disk device, and the impact from the head at the time of contact start / stop and the magnetic field during high-speed rotation. No serious problems such as crashes due to contact between the disk and magnetic head occur.

FIGS. 3A to 3C show some examples of the inner diameter shape of the magnetic disk of this embodiment. 3A shows a polyhedral shape of the inner diameter, FIG. 3B shows a circular shape having a convex portion, and FIG. 3C shows a circular inner diameter shape having a concave portion. Considering the high-speed rotation of the spindle, the shape shown in FIG. 3 (a) is preferable because the rotation can be easily balanced. However, the shape of the inner diameter shown in FIG. 3 (b) and FIG.

FIG. 4 shows the manufacturing process of the magnetic disk used in this embodiment. The shape of the inner diameter is determined in the first step, which is a punching step of the thin plate. That is, the shape of the completed magnetic disk can be easily determined by the shape of the die when punching.

[0016]

As is apparent from the above description of the embodiments, according to the present invention, in order to fix the force in the spindle rotation direction of the magnetic disk recording device to the magnetic disk, the inner diameter of the magnetic disk is made non-circular. Further, the magnetic disk is fixed to the spindle by fixing the vertical stress with the metal retainer and one screw. According to this configuration, it is possible to reduce distortion when tightening the screw applied to the magnetic disk. Therefore, the deformation and warpage of the magnetic disk that occurs when the magnetic disk is fixed can be eliminated, and screw tightening can be done at one location, so there is no need for delicate adjustment work when using multiple screws. Thus, the number of steps for fixing the magnetic disk is significantly reduced, and it is possible to provide a magnetic disk device having a high recording density and excellent reliability.

[Brief description of drawings]

FIG. 1A is a plan view of a magnetic disk according to an embodiment of the present invention, and FIG. 1B is a side view of the magnetic disk.

FIG. 2A is a plan view showing the configuration of the magnetic disk device, and FIG. 2B is a side view showing the configuration of the magnetic disk device.

3A is a plan view showing a polygonal inner diameter shape of the magnetic disk, FIG. 3B is a plan view showing a circular inner diameter shape having a convex portion of the magnetic disk, and FIG. 3C is a concave portion of the magnetic disk. Plan view showing a circular inner diameter shape having a

FIG. 4 is a manufacturing process diagram of the magnetic disk.

FIG. 5A is a plan view showing the configuration of a conventional magnetic disk, and FIG. 5B is a side view showing the configuration of the same magnetic disk.

FIG. 6A is a plan view showing the configuration of the magnetic disk device, and FIG. 6B is a side view showing the configuration of the magnetic disk device.

[Explanation of symbols]

 1 Spindle 2 Spacer 3 Magnetic disk 4 Metal retainer 5 Fixing screw 6 Magnetic disk inner diameter and spindle outer diameter

Claims (2)

[Claims] 1. A magnetic disk having a magnetic recording layer formed on the surface of a non-magnetic disk-shaped substrate and having a hole at the center thereof, and a spindle rotating at a constant speed in one direction. A structure in which a plurality of the magnetic disks are fixed to the spindle via a spacer, wherein the spindle has a non-circular cross-sectional shape, and the holes of the magnetic disk have a non-circular shape similar to the cross-sectional shape of the spindle; A magnetic disk device in which the magnetic disk is inserted and supported in. 2. The magnetic disk according to claim 1, wherein the spindle has a circular sectional shape having a convex portion or a concave portion, and a magnetic disk having a hole having a shape similar to the sectional shape of the spindle provided at the center is inserted into and supported by the spindle. Magnetic disk device.