JPH04195781A - Disk fixing structure - Google Patents

Abstract

PURPOSE:To make it possible to prevent deformation induced by unequal disk fastening force by allowing a soft material to be present between a rigid cramp material and a disk. CONSTITUTION:This is a disk fixing structure which fixes a disk 17 mounted on a rotative hub 12 of a disk device. It fastens a rigid cramp material 20 with the hub 12 by way of a soft material 19 between the cram material and the disk. Therefore, it does not call for a large space in the radial direction, but it is capable of fastening the disk on the disk with equal fastening force in its peripheral direction. This construction makes it possible to minimize undulated deformation in the disk and hence improve the quality of a disk device.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to prevent deformation due to uneven fastening force of the disk with respect to the fixing structure for fixing the disk to the hub in a disk device such as a magnetic disk device. A fixing structure for fixing a disk mounted on a rotatable hub, the clamp member being fastened to the hub via a flexible member between a rigid clamp and the disk.

[Industrial application field]

The present invention provides a disk device such as a magnetic disk device,
This invention relates to a fixing structure for fixing a disk to a hub.

[Conventional technology]

In conventional disk devices such as magnetic disk devices, one or more disks are mounted on a hub, and the top disk has a washer-like clamp that is rigid at the part that contacts the disk and elastically deformable at the part away from the disk (near the screw). The members were brought into contact with each other, and the clamp member was fastened and fixed to the hub using a plurality of screws (often six or three) arranged at equal intervals on the same circumference. In this fixing method, the fastening force is distributed in the circumferential direction of the disk depending on the number of screws, and the tightening force is distributed in the circumferential direction of the disk depending on the number of screws.
Wave-like undulating deformation occurs on the disk on the order of 1000 yen, resulting in unstable flying of the head and reduced reliability of the device. Therefore, when fixing the disk, consideration must be given to ensuring that the fastening force is evenly transmitted over the entire circumference.

FIG. 3 shows a disk fixing structure that takes such considerations into account. In the figure, reference numeral 1 denotes a hub shaft, which is fixed to a casing (not shown). Reference numeral 2 denotes a hub, which is rotatably supported by the hub shaft 1 at the rear 3.3' of the rolling shaft. A yoke 4 and a permanent magnet 5 serving as a rotor are attached to the inside of the hub 2, and together with a stator consisting of a coil 6 provided on the hub shaft 1, constitute a motor that rotationally drives the hub 2. A plurality of discs 7 are stacked and supported on the outer periphery of the hub 2 with spacers 8 in between, and are fixed with clamp members 9 and tightening screws 10. This clamp member 9 has a flexible structure with a thinner wall thickness at the tightening part.
A uniform fastening force is applied to the disc 7. There are also examples of making the material even softer by making many holes in the thinner part. (Publication number 1986-136943)
Problems to be Solved by the Invention: The hub fixing structure shown in FIG. 3 is not effective unless the distance β between the disk pressing point of the clamp member 9 and the tightening screw 10 is sufficiently large.

Therefore, it is difficult to realize the effect in a small device of 5 inches or less.

In view of the above conventional problems, an object of the present invention is to provide a disk fixing structure that can prevent deformation due to uneven fastening force of the disk.

[Means to solve the problem]

In order to achieve the above object, the disk fixing structure of the present invention is a disk fixing structure that fixes a disk 17 mounted on a rotatable hub 12 of a disk device, and includes a rigid clamp member 20 and a disk fixing structure. Soft member 1 between
It is characterized in that the clamp member 20 is fastened to the hub 12 via the clamp member 9.

[For production]

Rigid clamping member 20 and disc 17 (top disc 1
By interposing the flexible member 19 between 7a),
The rigid clamp member 20 is fastened to the hub 12 without undulation deformation in the circumferential direction, and the clamp member 20 uniformly presses the flexible member 19, so that the flexible member 19 is applied with uniform force in the circumferential direction. Since the disk 17a is pressed, deformation of the disk 17a is prevented.

〔Example〕

FIG. 1 is a diagram showing a first embodiment of the present invention, (a)
is an assembled sectional view, and (b) is an enlarged view of part B in figure a.

In the figure, 11 is a hub shaft fixed to a housing (not shown), 12 is a hub, and the hub is supported by the hub shaft 11 via rolling bearings 13 and 13' on the upper and lower sides thereof. A yoke 14 and a permanent magnet 15 serving as a rotor are provided inside the hub 12, and together with a stator consisting of a coil 16 provided on the knob shaft, constitute a motor that rotationally drives the hub.

A plurality of disks 17 are stacked and supported on the outer periphery of the hub 12 with a spacer 18 in between, and a ring-shaped disk having approximately the same inner and outer diameters as the spacer 18 and a cross section is placed on the uppermost disk 17a. A substantially U-shaped ring spring (flexible member) 19 having spring properties is placed, and a washer-like rigid clamp member 20 having a stepped portion on the outer periphery is placed on top of the ring spring 19. 20 is tightened and fixed to the hub 12 by a plurality of tightening screws 21. In this case, the clamp member 20 is in close contact with the hub 12, and its stepped portion presses the ring spring 19 to press the disk 17a.

In this embodiment configured in this manner, the clamp member 20 is rigid and tightly attached to the hub 12 and is fastened and fixed by the screws 21, so that there is no deformation. Further, since the ring spring 19 is pressed by the clamp member 20 which is not deformed, it is possible to press the disk 17a with a uniform force in the circumferential direction. As a result, the disk 17a is pressed with a uniform force in the circumferential direction, so that no undulating deformation occurs at the outer periphery.

FIG. 2 is a diagram showing a second embodiment of the present invention, (a)
is an assembled sectional view, and (b) is an enlarged view of figure A. In this figure, the same parts as in FIG. 1 are designated by the same reference numerals.

The difference between this embodiment and the previous embodiment is that the rigid clamp member 20 and the ring spring 19 were separate members in the previous embodiment, whereas in this embodiment, the rigid clamp member 20 and the ring spring 19 were separate members. As shown, grooves 20a and 20b are formed in a rigid clamp member 20, and a flexible portion 20c is formed integrally with the rigid clamp member 20. The clamp member 20 is tightly secured to the hub 12 by a plurality of tightening screws 21.

Is this embodiment configured in this way a clamp member? 0 is rigid and is tightly tightened and fixed to the hub 12, so there is no deformation. Therefore, since the soft portion 20C presses the disk 17a with a uniform force in the circumferential direction, no deformation of the disk 17a occurs.

In the first and second embodiments, the portions of the ring spring 19 and the flexible portion 20C that are in contact with the disk 17a are provided with polycentric curvature so that the center of the suppressing portion is approximately at the center of the width of the spacer 180. is preferred.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to fix the disk on the hub with uniform fastening force in the circumferential direction without taking up space in the radial direction, thereby making it possible to reduce waviness deformation of the disk. This will greatly contribute to improving the quality of disk devices.

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of the invention, FIG. 2 shows a second embodiment of the invention, and FIG. 3 shows a conventional disk fixing structure. In the figure, 11 is a hub shaft, 12 is a hub, 13.13' is a rolling bearing, 14 is a yoke, 15 is a permanent magnet, 16 is a Koinobe 17 is a disk, 18 is a spacer, 19 is a ring spring (flexible member), 20 is a clamp member, and 21 is a tightening screw. Figure 3 shows the conventional disk fixing structure.

Claims (1)

[Claims] 1. A disk fixing structure for fixing a disk (17) mounted on a rotatable hub (12) of a disk device, comprising: a rigid clamp member (20) and the disk (17a); the clamping member (20) with a flexible member (19) in between.
A disk fixing structure characterized in that the disk is fastened to a hub (12). 2. The disk fixing structure according to claim 1, wherein the flexible member (19) is a ring spring having a substantially U-shaped cross section. 3. Disc (17) of the rigid clamping member (20)
Grooves (20a, 20b) are provided near the portions that contact the
2. A disk fixing structure according to claim 1, characterized in that said flexible member (19) is replaced by a flexible member (19).