JPH06215477A - Disk type storage medium driving device - Google Patents

Abstract

PURPOSE:To reduce a thrust load and a radial load on a bearing and to enhance rotating accuracy by combining a hub and the bearing in a position higher than a hub flange. CONSTITUTION:An outer race of the bearing 19 is combined with the hub 14 in a part upper than the hub flange 18 by a combining part 30. Consequently, even when a lower end of a hub body 17 or joint of the hub flange 18 to the hub body 17 is deformed, the bearing 19 is not influenced by this deformation through the combining part 30. Thus, even when the thickness of the hub flange is reduced, the thrust load and the radial load are not increased on the bearing 19, and a radial gap between outer and inner races of the bearing 19 maintains its initial value, and moreover, the outer race of the bearing 19 is not deformed, so that the hub 14 is rotate without vibration and deflection, and hence the rotating accuracy of disks 10-13 is not deteriorated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a disk type storage medium, and more particularly to a drive device suitable for rotating a disk type magnetic storage medium of a magnetic disk storage device.

[0002]

2. Description of the Related Art In a magnetic disk storage device, for example, a drive device for rotating a disk as a storage medium generally has a shaft, a hub having a flange for supporting the disk-shaped storage medium, a shaft located near the hub flange and It consists of a bearing, which is arranged between the hubs and rotatably attaches the hub to the shaft, and a clamp which is fixed to the hub and crimps the disk-shaped storage medium to the hub flange. The disc is fixed to the hub by fitting the clamp onto the hub from above and pressing the disc against the hub by the clamp to apply pressure.

FIG. 3 shows an example of a specific structure of such a disk drive device. This drive device includes a shaft a, a hub b, and a clamp c. The hub b has a flange d at one end and is held by bearings e and f attached to the shaft a. The disks g to i as the magnetic storage medium are alternately arranged with the hubs b and the spacers j and k.
And is supported by the hub flange d.
The clamp c is fixed to the hub b by a bolt or the like, and the protrusions on the outer periphery press the disks g to i and the spacers j and k in the stacking direction so that they rotate together with the shaft a, the hub b and the clamp c. I am letting you.
The rotation is arranged in the space between the shaft a and the hub b,
Stator coil m and hub b fixed to shaft a
It is made by a rotor magnet n fixed to.

[0004]

A storage device using a disk type storage medium is required to be downsized, and in particular, a magnetic disk storage device is often required not only to be downsized but also to have an increased storage capacity. It is necessary not only to increase the recording density on the disk but also to increase the recording resolution by reducing the distance between the disk supporting the head and the slider or by reducing the flying height, while making the components of the device thinner.

In the disk drive device of the magnetic disk storage device described with reference to FIG. 3, the thinning is performed by reducing the thickness of the flange d on the hub b, but if the thickness of the hub flange d is reduced, Clamp c
Even if the pressing force is uniform, the load F from the clamp c is applied to the hub flange d as shown in FIG. 4, the root of the hub flange d is deformed, and the radial load and the thrust load are applied to the hub b and the bearing. The outer ring of the bearing e is applied to the outer ring of the bearing e through the connecting portion p with the e, the radial clearance between the inner ring and the outer ring of the bearing e is changed, and the outer ring of the bearing e is deformed, so that the hub b vibrates or the hub b swings. Since the disks g to i cannot be rotated with high precision because they rotate, the flying height of the head cannot be reduced, and the storage capacity cannot be increased even if the head is downsized.

It is an object of the present invention to prevent the rotation accuracy of the disk storage medium from deteriorating due to miniaturization, and an object of the present invention is to provide an improved disk storage medium drive device. is there.

[0007]

To achieve the above object, the present invention is directed to a shaft, a hub having a flange for supporting a disk-shaped storage medium, and a shaft located near the hub flange between the shaft and the hub. And a hub for rotatably mounting the hub to the shaft and a clamp fixed to the hub for crimping the disk storage medium to the hub flange. It is characterized by being connected to the bearing at a higher position.

[0008]

The disk type storage medium is mounted by fitting the disk type storage medium to the hub and fixing the clamp to the hub. When the clamp is installed, the disk-shaped storage medium is prevented from coming out by the clamp and the flange, and is pressed onto the hub flange by the clamp. At this time, even if the hub flange is deformed by the pressing force of the clamp, the connection between the hub and the bearing is made at a position higher than the hub flange, that is, the hub and the bearing are not connected to each other at a portion of the hub that is not deformed or a portion that is not deformed. Since the combination of
The thrust load and radial load on the bearing are reduced through this connecting part, and the radial clearance between the inner ring and the outer ring of the bearing does not change and the bearing outer ring does not deform, so even if the thickness of the hub flange is reduced. , The disc does not vibrate or rotate while swinging.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk type storage medium drive device according to the present invention will be described below with reference to FIGS.

The disk-type storage medium drive device is a spindle motor that supports and rotates a disk as a storage medium in a magnetic disk storage device.

This spindle motor is of the in-hub type and, as shown in FIG. 1, includes disks 10 to 13 as magnetic storage media, a hub 14 for holding the disk, a clamp 15 for fixing the disk to the hub, and a hub. A holding shaft 16 is provided.

The hub 14 includes a hub body 17 and a flange 18.
It has and. The hub body 17 has the shape of a hollow cylinder whose one end is open. The hub flange 18 is arranged around the open end of the hub body 17 and is integrally formed with the hub body 17. The hub 14 has a hub body 17 attached to a shaft 16 with bearings 19 and 20 interposed therebetween.

Further, in the internal space of the hub body 17,
A rotor 21 and a stator 22 that form a motor are incorporated. The rotor 21 consists of a permanent magnet,
Located in the inner space of the hub body 17 and the hub body 1
It is fixed at 7. The stator 22 has a motor coil, is arranged to face the rotor 21, and is fixed to the shaft 16. The hub 14 can rotate on the bearings 19, 20 together with the rotor 21 by passing an electric current through the coil 22.

A bracket 23 is provided at the bottom of the hub 14.
Is arranged, and a rotor hub 14 a is arranged above the hub 14. The bracket 23 is formed integrally with the shaft 16, and a magnetic fluid is incorporated in a gap between the bracket 23 and the outer ring of the bearing 19. Rotor hub 14a
Is fitted and fixed to the bearing 19 and the hub body 17 through the shaft 16, and the shaft 1
A magnetic fluid is incorporated in the clearance between the magnetic field and the magnetic field.
Bearings 19, 20, rotor 21 and stator 22
Are sealed by these magnetic fluids.

The disks 10 to 13 are spacers 24 to 26.
It is incorporated into the hub 14 together with. Of these disks 10 to 13, the disk 10 is in direct contact with the hub flange 18, and the disk 11 has a spacer 24 with the disk 10, the disk 12 has a spacer 25 with the disk 11, and the disk 13 has a spacer 25. Spacers 26 are respectively interposed between the disk 12 and the disk 12 and are fitted to the hub body 17.

The clamp 15 has a protrusion 27 on its periphery, is fitted to the rotor hub 14a, and is fixed to the hub body 17 by a bolt 28, so that the disk 1
0 to 13 and spacers 24 to 26 are prevented from slipping out, and this laminate is attached to the hub flange 1
It is crimping toward 8.

In this disk-type magnetic storage medium driving device, the bearings 19 and 20 are, for example, known angular contact bearings, and the inner races of the bearings 19 and 20 are engaged and fixed to the shaft 16. Bearing 1
9, a connecting portion 30 extending in the direction orthogonal to the central axis of rotation is integrally formed with the outer ring, and a hub 14 has a hub body 17 engaged with the outer ring of the bearing 19 and the connecting portion 30 of the bearing 18. However, the joint portion 30 is provided on the outer ring of the bearing 19 so that the whole or part of the joint portion 30 is located higher than the hub flange 18. For example, as shown in the drawing, the coupling portion 30 includes a base portion extending from the upper end of the outer ring toward the hub 14 and a step 31 formed at the base end, and the step 31 contacts the disk 10 at the hub flange 18. It is configured to be higher than the surface.

In this disk type magnetic storage medium driving apparatus, the disks 10 to 13 are mounted in the disks 10 to 13.
13 and the spacers 24 to 26 are alternately inserted into the hub body 17, the stack 15 is covered with the clamp 15, and the clamp 15 is bolted to the rotor hub 14a. However, the outer ring of the bearing 19 is connected to the hub 14 above the hub flange 18 by the connecting portion 30 as described above, that is, is connected to the hub 14 at a less deformable portion of the hub 14, and thus the hub body is 17 bottom edge or hub body 1
Even if the base of the hub flange 18 with respect to 7 is deformed, the bearing 19 is not affected by this deformation through the joint portion 30. Therefore, even if the hub flange 18 is thinned, the thrust load and the radial load do not increase in the bearing 19, the radial clearances of the inner and outer rings of the bearing 19 maintain the initial values, and the outer ring of the bearing 19 is deformed. Without rotating, the hub 14 does not rotate while vibrating or swinging, so that the rotation accuracy of the disks 10 to 13 does not decrease. Since stress concentrates on the root portion of the flange 18 with respect to the hub body 17 of the hub 14, it is preferable that the coupling portion 30 between the bearing 19 and the hub 14 is disposed as high as possible.

This spindle motor is used to construct a magnetic disk storage device as shown in FIG. 2, for example.

The housing 40 is composed of two parts which are fastened together by bolts or the like. A spindle motor according to the present invention is designated by the reference numeral 41 and is a disk 1
0 to 13 and spacers 24 to 26 are housed in the inner space of the housing 40 and fixed to the housing. A head assembly is located between the disks 10-13. The head of each head assembly is fixed to a slider 42, and the slider 42 is attached to a guide arm 43 with a gimbal interposed.
The guide arm 43 is supported by the positioning mechanism. The positioning mechanism includes a carriage and a linear actuator. Carriage 44 has rollers 45 on it
Rolls on a rail 46 fixed to the housing 40 to move a slider 42 having a head in the radial direction of the disks 10 to 13. The coil 47 and the magnet 48, which form a linear actuator, are attached to the carriage 44 and the housing 48, respectively, and the carriage 44 is linearly moved by the electromagnetic action of the coil 47 and the magnet 48.

In this magnetic disk storage device, the spindle motor 41 has the radial gap between the inner and outer rings of the bearing 19 even if the thickness of the flange 18 on the hub 14 supporting the disks 10 to 13 is reduced as described above. Disk 10 due to changes and deformation of outer ring of bearing 19
Since the rotation accuracy of each of the disks 10 to 13 is not deteriorated, the flying height of the slider 42 is reduced and each of the disks 10 to 13 is reduced.
The density record of can be increased. Since the thickness of the hub flange 18 and the distance between the disks 10 to 13 can be reduced, the device thickness H can also be made small. Therefore, in combination with the high recording density of the disks 10 to 13, a compact and large storage capacity can be obtained. It can be used as a magnetic disk storage device.

[0022]

According to the present invention, even if the hub is made thin, the rotational accuracy of the disk storage medium does not deteriorate due to changes in the radial clearance between the bearing inner and outer rings and deformation of the bearing outer ring. It is possible to obtain high-precision writing and / or reading to and from a disk-type storage medium, and to obtain a compact disk-type storage medium drive device, and to reduce the size and increase the storage capacity of a magnetic disk storage device that is demanded. Can be achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a disk-type storage medium drive device of the present invention.

FIG. 2 is a cross-sectional view of a magnetic disk storage device incorporating the drive device of FIG.

FIG. 3 is a cross-sectional view showing an example of a conventional disk-type storage medium drive device.

FIG. 4 is an explanatory view showing a deformed state of the hub.

[Explanation of symbols]

10 to 13 ... Disk type storage medium, 14 ... Hub, 15 ...
Clamp, 16 ... Shaft, 18 ... Hub flange, 1
9, 20 ... Bearings, 30 ... Joining portion between hub and bearing.

Claims (3)

[Claims] 1. A hub having a shaft, a flange for supporting a disk-shaped storage medium, a bearing located near the hub flange, disposed between the shaft and the hub, for rotatably mounting the hub to the shaft, and the hub. A drive for a disk-shaped storage medium, which is fixed to the hub and includes a clamp for crimping the disk-shaped storage medium to the hub flange, wherein the hub is coupled to the bearing at a position higher than the hub flange. Storage medium drive device. 2. A shaft, a shaft-engaged hub having a flange at one end, a first bearing located proximate the hub flange, disposed between the shaft and the hub, and coupled to the hub. A second bearing located near the opposite end of the hub between the shaft and the hub and coupled to the hub; a clamp fixed to the hub by forming a space between the hub flange and the hub flange; And the plurality of disk-shaped magnetic storage media sandwiched by the clamp and the hub flange, and the stator coil arranged in the space between the shaft and the hub and fixed to the shaft. And a rotor magnet fixed to the hub, the outer ring of the first bearing is a hub flag. A drive device for a disk-shaped storage medium, characterized in that the drive device is connected to the hub at a position higher than the contact surface of the disk with the disk. 3. The outer ring of the first bearing is provided with a connecting portion between the outer ring of the first bearing and the hub.
The device according to.