JPH0380461A - Spindle mechanism of magnetic disk device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and particularly to a spindle mechanism suitable for high precision and low vibration.

[Conventional technology]

In general, in magnetic disk drives, reducing the vibration of the drive is an important technical issue in order to achieve highly accurate positioning of the magnetic head.

The causes of vibration include, first of all, vibrations generated from within the bearings of the spindle mechanism that holds and rotates the magnetic disk, and rotationally synchronous vibrations caused by mass imbalance of the rotating body portion.

Second, there is vibration due to the reaction of the access operation of the actuator when the magnetic head accesses a specified position on the magnetic disk.

When such vibrations occur, it is difficult to accurately position the magnetic head, and various vibration damping structures have been proposed. For example, in Japanese Patent Application Laid-Open No. 57-94961, a vibration damper is provided on a base member that supports the components of a magnetic disk drive, and both the vibration of the spindle assembly and the reaction during access operation of the actuator are reduced. A technology that attempts to attenuate both is shown.

[Problem to be solved by the invention]

In the above-mentioned prior art, a vibration damper is provided at the base of the device, and such a structure can prevent vibrations generated from, for example, the spindle assembly from being transmitted to the actuator, and vice versa. It is also possible to prevent the recoil upon access of the actuator from being transmitted to the spindle assembly6, that is, to provide damping in the middle of the vibration transmission path. However, in this method, the effect of damping the self-oscillation of the rotating part of the spindle assembly, which is the source of vibration, is small, and although the transmission of vibration from the spindle assembly to others can be prevented.

The self-oscillation of the rotating body remains as it is, and ultimately has a negative effect on the positioning of the magnetic head.

An object of the present invention is to solve the above problems and provide a spindle mechanism for a magnetic disk device that has low vibration and high accuracy.

[Means to solve the problem]

To achieve the above object, the present invention provides a rotating part of a spindle assembly with a damping mass that acts as a vibration damper.

[Effect]

In order to effectively damp the vibrations of a magnetic disk drive, it is first important to reduce the vibrations of the rotating part of the spindle assembly itself, which is the vibration source, and then to cut off the vibration transmission path. That's good.

In the present invention, directly to the rotating part of the spindle assembly.

It is equipped with a damping mass. This makes it possible to reduce vibrations such as vibrations of the ball bearing caused by rotation of the spindle and unbalanced vibrations caused by unbalance of the rotating parts.

〔Example〕

FIG. 1 is a side view of a magnetic disk device according to one embodiment.

In FIG. 1, the magnetic disk drive includes a base 1 and a cover 3 that forms a sealed space 2 and is detachably attached to the base 1.

A part of the base l has a rotating shaft 4 passing through the base 1.
The rotating shaft 4 is rotatably supported by a plurality of bearings 5 and 6 arranged at positions sandwiching the large-diameter central portion of the rotating shaft 4 .

A pulley 7 is attached to the outer end of the rotating shaft 4 so that one end of the pulley 7 contacts the inner ring 6a of the bearing 6.

It is fixed to the rotating shaft 4 via a fixing screw 8a and a locking piece 8b that are screwed into the outer end surface of the rotating shaft 4 in the axial direction.

A belt 9 is stretched between a pulley 7 fixed to the rotating shaft 4 and a motor (not shown), and the rotating shaft 4 is driven at a desired rotational speed by the motor.

Between the outside @6b of the bearing 6 attached to the end side of the rotating shaft 4 and the base, there is a coil-shaped coil coaxially provided on the rotating shaft 4 so as to bias the rotating shaft 4 in the axial direction. A thrust spring 10 is interposed, and the play in the axial direction of the bearings 5 and 6 interposed between the base 1 and the spindle assembly S consisting of the rotating shaft 4, the bearings 5 and 6, the pulley 7, the belt 9, etc. has been removed.

Further, a radial spring 11 is provided between the outer ring 6b of the bearing 6 and the base t, and biases the bearing 6 in a direction perpendicular to the axial direction of the rotating shaft 4. The radial play due to the fit tolerance between the supporting bearings 5 and 6 and the base 1 is eliminated.

In this case, on the inner end side of the rotating shaft 4 of the spindle assembly S protruding into the sealed space 2, a hub 12 (holding means) accommodated in the sealed space 2 is placed in contact with the inner ring 5a of the bearing 5. A fixing screw 13 is mounted coaxially by a clearance fit so that the fixing screw 13 is screwed in the axial direction on the end face of the rotating shaft 4.
It is removably fixed using an engaging means 13 consisting of a locking piece 13b interposed between the fixing screw 13a and the end surface of the hub 2.

Further, a plurality of magnetic disks 15 are held on the outer periphery of the hub 12 so as to be parallel to each other at predetermined intervals in the axial direction by sandwiching a plurality of spacers 14, and are screwed onto the end surface of the hub 12. It is removably fixed by a fixing screw 16a and a locking piece 16b.

As a result, the plurality of magnetic disks 15 held on the hub 12 are rotated as desired by the rotational force transmitted from an external motor (not shown) through the rotating shaft 4, pulley 7, etc. that constitute the spindle assembly S. It is something that is rotated at a high speed.

A plurality of magnetic disks 1 are held by a hub 12 inside a sealed space 2 consisting of a base l and a cover 3.
Near the rail 16, a carriage 18 is supported by a bearing 17 that rolls on the rail 16 and is capable of reciprocating in the radial direction of a plurality of magnetic disk drives 5 held by the hub 12. An actuator assembly A consisting of a voice coil motor 19 and the like that applies thrust to the carriage 18 to open the carriage 18 is arranged.

In this actuator assembly A, the end face of the carriage 18 facing the plurality of magnetic disks 15 is arranged in the arrangement direction of the plurality of magnetic disks 15, and a tip end is inserted into each gap between adjacent magnetic disks 15. The proximal ends of the plurality of helad arms 20 are fixed.

A plurality of magnetic heads 21 are supported on each of the distal ends of the plurality of helad arms 20, and are arranged to face each of the opposing recording surfaces 15a of the adjacent magnetic disks 15. is carriage 1
One of the plurality of recording surfaces 15a is simultaneously recorded at any position in the radial direction of the magnetic disk 15 by the reciprocating movement of the magnetic head 8. One of the plurality of recording surfaces 15a is a servo surface 15b on which servo information indicating the radial position of the magnetic head 21 with respect to the magnetic disk 15 is recorded. The magnetic head 21 facing the servo surface 15b is configured to function as a servo head 2a.

Then, the servo head 21a causes the servo surface 15 to
By controlling the displacement of the carriage 8 through feedback control of the voice coil motor 19 by the positioning control system X, which will be described later, based on the servo information read from the The positioning operation of the magnetic head 21 of the section is performed with respect to an arbitrary position in the radial direction of the rotating magnetic disk 15.

The hub 12 is provided with a ring-shaped groove 24 coaxial with the rotating shaft 4, and a donut-shaped damping mass 22 made of a material with high specific gravity, such as a button, is placed inside. The ring-shaped groove 24 containing the damping mass 22 is sealed by a sealing member 23, and the damping mass 22 is in contact with the sealing member 23. When the spindle assembly S rotates,
Rotational vibration occurs inside the bearings 5 and 6, and the rotating parts including the rotating shaft 4 vibrate. Also, the rotating shaft 4. Hub 12. If the center of mass of the rotating part constituted by the magnetic disk 15 or the like is shifted from the center of rotation of the rotating shaft 4, unbalanced vibrations synchronized with the rotation will occur, which will also cause the rotating part to vibrate.

In the present invention, even if such vibration occurs in the rotating part of the spindle assembly S, the hub 1, which is a part of the rotating part,
Damping mass 2 for damping vibration inside 2
2, vibrations are attenuated by the contact friction between the damping mass 22 and the sealing member 23, and the vibrations of the rotating part itself can be damped and also prevented from being transmitted to other parts.

Also, the damping mass 22 is connected to the hub 12 by the sealing member 23.
Since the inside of the magnetic head 21 and the magnetic disk 15 are sealed, there is a risk that abrasion powder generated by friction between the damping mass 22 and the sealing member 23 will scatter inside the device and be caught in the opposing portion of the magnetic head 21 and the magnetic disk 15, damaging both. Failures can also be prevented.

〔Effect of the invention〕

According to the present invention, it is possible to directly prevent the vibration of the spindle rotating part, which is a source of vibration, and also to reduce transmission to other parts. Therefore, highly accurate positioning of the magnetic head becomes easy.

[Brief explanation of drawings]

FIG. 1 is a side view showing a spindle mechanism of a magnetic disk device according to an embodiment of the present invention. 1... Base, 3... Cover, 4... Rotating shaft, 5
... bearing, 15 ... magnetic disk, 19 ... voice coil motor, 22 ... damping mass, 24 ...
·groove.

Claims (1)

[Claims] 1. A spindle mechanism for a magnetic disk device having a spindle assembly for rotationally supporting a magnetic disk, wherein a damping mass for damping vibrations is provided in a rotating body portion of the spindle assembly.