JPS63276774A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To excellently secure the weight balance of a disk rotation system by fitting rotation drive motors of identical characteristic to both end parts of a spindle when both end parts of the spindle supporting a magnetic disk are supported by bearings provided on the bases that face to each other. CONSTITUTION:Magnetic disks through which the spindle 2 is penetrated and fixed are stored in a chamber 7 constituted of the pair of bases 4, 4' facing each other, and both end parts of the spindle 2 are supported by the bearings provided on the respective bases 4, 4'. The spindle is protruded from the bearings 5 at its both ends, and the rotors 3a, 3a' of the respective rotation drive motors 3, 3' are fitted with said protrusion parts. The stators 3b, 3b' of the motors 3, 3' are so disposed as facing to the rotors 3a, 3a'. With such a constitution, heat generating parts are disposed symmetrically, hence the occurrences of off-tracking due to vibration or thermal distortion can be made less, and the recording density can be larger.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a magnetic disk device designed to reduce off-track caused by vibration and thermal distortion.

<Conventional technology and problems> In the disk rotation system of conventional magnetic disk devices,
There was one motor that rotated the spindle on which the magnetic disk was attached, and there were two types of structures:

The first one, as shown in FIG. 2, is equipped with a rotary drive motor 3 at one end of a spindle 2 to which a magnetic disk 1 is attached, a rotor 3a of the second motor 3 is attached to the spindle 2, and a stator 3b is attached to the spindle 2. It is installed on 4. In the figure, 5 is a bearing that rotatably supports the spindle 2 at both ends thereof, 6 is a cover that defines a space for accommodating the magnetic disk 1 together with the base 4, and 7 is a device for recording and reproducing information on the magnetic disk 1. This is a head housing equipped with a magnetic head (not shown) that performs the following operations. However, in a magnetic disk drive having such a structure, since the rotational drive motor 3 is attached to one end of the spindle 2, the weight balance in the axial direction of the spindle 2 is lost.
When this head disk assembly is vibrated by the head body 7 or the like during rotation, the spindle 2 vibrates in a complicated vibration mode, and there is a problem in that off-track occurs due to this vibration. Furthermore, since the coil of the stator 3b of the motor, which is a heat source, is omnipresent on one side of the head disk assembly, thermal distortion of the structure occurs due to temperature imbalance of the head disk assembly, and this thermal distortion causes off-track. There was a problem that occurred.

There has been a problem in that the recording density cannot be increased due to the occurrence of off-track due to such vibrations and thermal distortion.

The second type, as shown in FIG. 3, is of an inside hub motor type, in which a rotational drive motor 3 is mounted inside a hub 8 at the center of the spindle 2. In this structure, the rotor 3a of the rotary drive motor 3 is rotatably supported by the fixed spindle 2 via the bearing 5.
The stator 3b is attached to the fixed spindle 2.

However, in a magnetic disk drive having such a structure, the coil of the stator 3b, which is a heat source, is connected to the base 4.
Since the head disk assembly is located inside the head disk assembly surrounded by the cover 6 and the head disk assembly, there is a problem in that the temperature of the head disk assembly increases significantly and off-track due to thermal distortion increases. In addition, the hub 8
A magnetic seal 9 made of an iron-based magnetic material must be provided on the disc, which poses a problem in that the rotational load on the disk rotation system increases.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a magnetic disk device that reduces off-track caused by vibration and thermal distortion and achieves higher recording density.

Means for Solving the Problems> A magnetic disk device of the present invention includes a spindle on which a magnetic disk is attached, which is rotatably supported via bearings at both ends thereof. It is characterized by being equipped with a drive motor.

By placing rotary drive motors at both ends of the spindle, the weight of the disk rotation system is balanced and the heat generation sources are arranged symmetrically, reducing off-track caused by spindle vibration and thermal distortion of the head disk assembly. Reduce off-track.

Embodiments The magnetic disk device of the present invention will be specifically described based on embodiments.

FIG. 1 is a sectional view of a magnetic disk device according to an embodiment of the present invention. Incidentally, the same parts as in the conventional example described above are given the same reference numerals, and redundant explanation will be omitted.

As shown in the figure, in this embodiment, a pair of symmetrical bases 4, 4
By joining ', a space for accommodating the magnetic disk 1 is defined. A spindle 2 with a magnetic disk 1 attached thereto is connected to bases 4, 4 through bearings 5 at both ends thereof.
Rotational drive motors 3 and 3' are respectively mounted at both ends of the spindle 2, which is rotatably supported by the spindle 2 and protrudes outside the space defined by the bases 4 and 4'.

The rotary drive motors 3.3' are the same motors, the rotors 3m and 3a' are respectively attached to the spindle 2, and the stators 3b and 3b' are attached to the bases 4 and 4', respectively.
installed on. Note that the head positioner 7 is fixed to the bases 4, 4'.

According to the magnetic disk device having the above configuration, the spindle 2
Since the rotary drive motors 3 and 3' are mounted on both ends of the head disk assembly, the weight balance in the axial direction of the spindle 2 is maintained, and the rotary drive motors 3 and 3', which are heat generating parts, are mounted outside the head disk assembly. Moreover, they will be located at symmetrical positions. As a result, vibration modes are prevented from becoming complicated, thermal distortion of the structure due to temperature imbalance is reduced, and off-track due to vibration and thermal distortion is reduced.

In the above embodiment, a base 4' was used in place of the conventional cover 6 to mount the rotary drive motor 3' and to make the structure symmetrical. The cover 6 may be used instead of the base 4' as long as it satisfies the above requirements.

<Effects of the Invention> According to the magnetic disk device of the present invention, since the structure and the arrangement of the heat generating parts are configured symmetrically, off-track due to vibration and off-track due to thermal distortion can be reduced, and the recording density can be improved. can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a head disk assembly of a magnetic disk device according to an embodiment of the present invention, and FIGS. 2 and 3 are sectional views of a head disk assembly of a conventional magnetic disk device. In the drawing, 1 is a magnetic disk, 2 is a spindle, 3.3' is a rotary drive motor, and 5 is a bearing. Swimming −

Claims (1)

[Claims] What is claimed is: 1. A magnetic disk device comprising a spindle on which a magnetic disk is attached, which is rotatably supported via bearings at both ends of the spindle, characterized in that rotational drive motors are disposed at both ends of the spindle.