JPH1139784A - Disk driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a disk driving device low in cost and high in performance by forming an annular space part around a driving shaft on the under surface of a turntable and arraging an annular ring for adjusting slidably in the redial direction of the space in the inner part of the space. SOLUTION: An annular recessed part 1a around a driving shaft 8 is formed on the under surface of a turntable 1. The recessed part 1a forms an annular space closed with the back yoke 13 made of magnetic plate. In the annular space part, an annular ring 12 made of a magnetic material is arranged slidably on the back yoke 13 in the radial direction of the space part. Then, when an imbalance due to weight is present in a disk 5 at the time of rotatingly driving the disk 5, however an eccentric center of gravity with respect to a driving shaft 8 is generated to generate a vibration, the ring for adjustment 12 slides on the back yoke 13 to reduce the eccentric center of gravity and also to eliminate it. That is, when the deviation of a radius (r) with respect to a rotational center is generated in the weight (b) of the ring for adjustment 12, it is made possible to generate an eccentric center of gravity adjusting effect of br.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive for rotating a disk-shaped recording medium (disc), and more particularly to a vibration reducing means (international means) for suppressing self-vibration due to imbalance of the disk during rotation. Patent classification G11B 33/08).

[0002]

2. Description of the Related Art As a conventional vibration reducing device, there is a vibration damping means incorporated in a disk clamper for pressing and fixing a disk to a turntable. According to this method, an annular space centered on the center of rotation is formed in a disk clamper, and a plurality of hard balls are slidably inserted into the space.

[0003]

However, although a thin type disk drive requires the same performance, a disk clamp mechanism is built in the motor due to the characteristics of the product, so that a conventional type of vibration reduction is required. The means could not be adopted.

[0004]

In order to solve the above-mentioned problems, a disk drive according to the present invention comprises an annular space centered on the drive shaft below a turntable driven by a drive shaft of a motor. And an annular adjusting ring is arranged in the annular space so as to be slidable in the radial direction. According to this configuration, since the vibration reducing means is disposed on the turntable side, the vibration reducing means can be applied to a thin type disk drive device. The ring can move the center of gravity with a shorter moving distance, and can quickly and stably rotate.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a cylinder according to an embodiment of the present invention; FIG. The drive shaft 8 of the motor is rotatably supported in the holder 10 by a bearing 11 and a thrust bearing 9.

A plurality of stator coils 3 are annularly arranged on the outer periphery of the holder 10, a turntable 1 is fixed to a tip of a drive shaft 8 of the motor, and an outer peripheral portion of the turntable 1 is provided. An annular rotor magnet 2 having a plurality of polarizations having a back yoke 4 fixed to the outer periphery is arranged so as to have a predetermined gap between the stator coil 3 and the stator coil 3. Constitutes a motor.

On the lower surface of the turntable 1, there is formed an annular concave portion 1a centered on the drive shaft 8.
The recess 1a is closed by a back yoke 13 made of a magnetic plate to form an annular space. In this annular space, an annular adjusting ring 12 made of a magnetic material is slidably disposed on the back yoke 13 in the diameter direction.

In FIG. 1, reference numeral 5 denotes a disk mounted on the turntable 1, and reference numeral 6 denotes a clamper for fixing the disk 5 to the turntable 1.

In the above configuration, when the disk 5 is rotationally driven, if the disk 5 has a weight imbalance, an eccentricity with respect to the drive shaft 8 is generated and vibration occurs. To reduce and remove the eccentricity. The diagram shown in FIG. 2 shows a state in which the adjustment ring 12 is shifted by 180 degrees in phase with respect to the minute displacement x caused by the eccentricity of the mounted disk and the eccentricity adjustment is effective. It is a thing. According to this, the mass of the adjusting ring 12 is located at the center of gravity point b, and a deviation of the radius r with respect to the center of rotation occurs.
The effect of adjusting the eccentricity of the adjustment ring weight b (mg) * radius r (cm) can be generated.

[0010]

As described above, according to the magnetic disk drive of the present invention, in addition to the components required at least as a motor, a great effect can be obtained simply by adding an eccentricity adjusting ring with a simple configuration. Thus, an inexpensive and high-performance disk drive can be provided.

Further, as compared with the conventional ball balancer system using a plurality of hard balls, the annular adjusting ring can move the center of gravity with a shorter moving distance and can promptly and stably rotate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a magnetic disk drive according to an embodiment of the present invention;

FIG. 2 is a plan view showing a main part of the magnetic disk drive.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Turntable 1a Depression 2 Rotor magnet 3 Stator core 4 Back yoke 5 Disk 7 Substrate 8 Drive shaft 10 Holder 11 Bearing 12 Adjustment ring 13 Back yoke

Claims (1)

[Claims] An annular space centered on the drive shaft is formed below a turntable connected to a drive shaft of a motor and driven to rotate by the drive shaft, and an annular adjustment portion is formed in the annular space. A disk drive device wherein a ring for use is slidably movable in the radial direction.