JPH11306655A - Disk drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an automatic aligning mechanism fully demonstrate the performance by bringing a centroid of a drive unit near to a rotational center of a recording medium disk. SOLUTION: This optical disk drive device 1 is constituted in such a manner that the drive unit 3 provided with a spindle motor 6 to rotate a turntable 15 supporting the optical disk on a mechanical chassis 2, an optical pickup 20 moving in the radial direction of the optical disk supported with the turntable to record or reproduce a signal as to the optical disk or to perform both operations, etc., is supported on a base chassis through an elastic material, then the automatic aligning mechanism 16 furnished with a housing room 17 rotating with rotor parts 13, 14 of the spindle motor and balance balls 18 freely movable in the housing room is provided on a rotation driving part including the spindle motor 6, and a counter-weight 19 is disposed on a stator substrate of the spindle motor, thereby a centroid G' of the drive unit is made to coincide with the rotational center of the spindle motor, or to approach thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel disk drive device. More specifically, in a disk drive device in which a rotation drive unit for rotating a recording medium disk is provided with an automatic alignment mechanism for eliminating imbalance in the recording medium disk, the automatic alignment mechanism reliably exerts its function. To be able to technology.

[0002]

2. Description of the Related Art FIGS. 5 and 6 schematically show an example of a conventional disk drive.

The disk drive device a has a mechanical chassis b on which necessary members and components are mounted.

A spindle motor d for rotating the turntable c is provided at one end of the mechanical chassis b, and the optical disk e is supported and rotated on the turntable c. A thread motor f is provided on the mechanical chassis b.
An optical pickup g that is moved in the radial direction of the optical disk e supported by the turntable c is disposed. In this way, the required members and components are arranged on the mechanical chassis b to form the drive unit h, and the drive unit h is attached to the base chassis j via the elastic bodies i, i,. this is,
This is because, when an optical disk having an unbalance, that is, an optical disk whose center of gravity is not located at the center rotates at a high speed, vibration generated thereby is prevented from being transmitted to the outside of the disk drive device a.

The spindle motor d has an automatic alignment mechanism.

[0006] The self-centering mechanism of the spindle motor d is described by Theall's self-balancing device. T
For details on the automatic equilibrium device of Hearl, see “Mechanical Mechanics” published by Rigaku Corporation (March 1982), p.
Please refer to.

The principle and function of the Thearl's automatic balancer k will be briefly described with reference to FIG. The Thearl's automatic balancing device k is composed of a holder 1 having an annular race portion, and a plurality of balls m, m that can move freely on the holder 1. When the unbalanced optical disc e is supported on the turntable c, the drive unit h and the elastic bodies i, i,.
When the optical disk e is rotating at a frequency higher than the resonance frequency of the vibration system composed of
Vibrates with a delay of 0 °. Since the balls m, m automatically move in the direction in which the drive unit h vibrates, the balls m, m move in the opposite phase to the unbalance of the optical disk e, and the operation principle is that the balance is automatically taken. .

For example, when an unbalanced optical disk e is rotated and a vibration occurs in the drive unit h,
In addition to the possibility that the reading and writing of the signal related to the optical disk e may not be sufficiently performed, if the vibration is transmitted to the outside of the disk drive device a, the peripheral device such as the hard disk drive device may be vibrated to malfunction. However, such an adverse effect can be prevented by providing the spindle motor d with the above-described self-aligning mechanism.

[0009]

In the conventional disk drive device a, however, there has been a problem that the operation of the automatic alignment mechanism becomes unstable and its performance cannot be sufficiently exhibited.

The center of gravity G of the drive unit h is determined by the arrangement of the optical pickup g and the sled motor f, the shape of the mechanical chassis b, and the like. And, in the drive unit h, the center of gravity G
As shown in FIG. 6, is deviated from the rotation center of the optical disk e, that is, the center of the rotation axis of the spindle motor d, in the direction in which the optical pickup g and the sled motor f are arranged.

If the center of gravity G of the drive unit h is shifted from the center of rotation of the optical disk e, the optical disk e
The vibration caused by the imbalance of the shaft, that is, the shape of the vibrating shaft is a vibration of a two-degree-of-freedom system of parallel vibration and rotational vibration, which differs in each direction of the drive unit h. Becomes oval.

When the shaft vibrates in an elliptical shape, the operation of the self-aligning mechanism becomes unstable, and its performance cannot be sufficiently exhibited.

Accordingly, an object of the present invention is to make the center of gravity of the drive unit close to the rotation center of the recording medium disk so that the automatic alignment mechanism can sufficiently exhibit its performance.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a disk drive apparatus according to the present invention includes a rotary drive section including a spindle motor for rotating a turntable supporting a recording medium disk, together with a rotor section of the spindle motor. An automatic alignment mechanism having a rotating holder and a balance member movable within the holder is provided, and a counterweight is disposed on a stator portion of the spindle motor, whereby the center of gravity of the drive unit is set at the center of rotation of the spindle motor. Are matched or approached.

Therefore, in the disk drive device of the present invention, since the center of gravity of the drive unit coincides with or approaches the rotation center of the spindle motor, the trajectory of the vibration of the rotation center of the recording medium disk can be approximated to a circular orbit.
The force generated by the vibration of the drive unit is stabilized in any phase direction, and the balance member can quickly move to a position where the imbalance is eliminated, that is, a balance position.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a disk drive device according to an embodiment of the present invention.

In the illustrated embodiment, the present invention is applied to an optical disk drive for recording and / or reproducing data on and from an optical disk.

The optical disk drive 1 is constructed by mounting a drive unit 3 in which required members and components are mounted on a mechanical chassis 2 to a base chassis 5 via elastic bodies (dampers) 4, 4,...

A spindle motor 6 is fixed to one end of the mechanical chassis 2 via a stator substrate 7.

A cylindrical shaft support 8 is provided on the stator substrate 7.
Is fixed, and a spindle shaft 9 is rotatably supported by the shaft support 8 via bearings 10 and 10. The lower end of the spindle shaft 9 is supported by a thrust bearing 11 attached to the shaft support 8. A stator coil 12 is disposed and fixed to the stator substrate 7 so as to surround the shaft support 8.

A rotor yoke 13 formed of a magnetic material and having a deep dish shape is fixed to the spindle shaft 9 so as to surround the outside of the stator coil 12 at its peripheral wall. The rotor magnet 14 is fixed to face the stator coil 12.
Thus, when the stator coil 12 is energized, the rotor yoke 13 rotates, and the spindle shaft 9 to which the rotor yoke 13 is fixed is rotated.

A turntable 15 is fixed to the upper end of the spindle shaft 9.

The rotor yoke 13 and the turntable 1
5, an automatic alignment mechanism 16 is provided. The self-aligning mechanism 16 includes a ring-shaped storage chamber 17 and a plurality of balance balls 18 movably disposed in the storage chamber 17. The storage chamber 17 is formed by a dish-shaped member fixed to the spindle shaft 9, and the upper surface of the storage chamber 17 is closed by the turntable 15.

A counterweight 19 is attached to the stator substrate 7. As the material of the counterweight 19, it is preferable to use a material obtained by stacking steel plates or a material having a high density such as sintered metal and having a large weight compared to the volume.

An optical pickup 20 is provided on a portion of the mechanical chassis 2 behind the portion where the spindle motor 6 is disposed.
Are supported by guides 22 and 23 so as to be movable in the radial direction of the optical disc 21 supported on the turntable 15.

The optical pickup 20 is provided with a rack gear 24. The rack gear 24 is fed by a pinion gear 26 rotated by a thread motor 25 fixed to the mechanical chassis 2, so that the optical pickup 20 is guided by guides 22 and 23. And moves in the radial direction of the optical disk 21 supported on the turntable 15.

The mechanical chassis 2 is provided with other necessary members and components in addition to the components described above to form the drive unit 3.

Thus, the optical disk 21 supported on the turntable 15 is rotated together with the turntable 15 in accordance with the driving of the spindle motor 6, and the optical pickup 20 moves in the radial direction of the optical disk 21 while moving. A signal is recorded and / or reproduced with respect to the optical disk 21.

At this time, when the optical disk 21 supported on the turntable 15 is unbalanced and vibrates, the balance ball 18 of the automatic alignment mechanism 16 is moved to a position where the unbalance is eliminated. And move
The vibration is eliminated or reduced.

As described above, in the optical disk drive 1 according to the present invention, since the counterweight 19 is provided on the stator substrate 7 of the spindle motor 6, the center of gravity G 'of the drive unit 3 is ,
As shown in FIG. 3, since the rotation coincides with or is close to the rotation center of the spindle shaft 9 of the spindle motor 6, the vibration caused by the imbalance becomes close to a circular shape. Promptly and
It is definitely done.

The reason will be described with reference to FIG.

The centrifugal force Fr = mrω ² generated by the rotation of the storage chamber 17 and the force Fe = meω ² generated by the vibration of the drive unit 3 act on the balance ball 18.

Here, m is the mass of the balance ball 18, r is the orbital radius when the balance ball 18 is on the storage room 17,
e is the amplitude of the vibration of the drive unit 3, and ω is the rotation speed of the spindle motor 6.

The balance ball 18 has a spindle motor 6
Only rotates, only the centrifugal force Fr acts, and the balance ball 18 is only pressed against the outer inner peripheral surface of the storage chamber 17. However, the drive unit 3 vibrates and the resultant force F is exerted by operating Fe. Occurs, which results in a declination α, so that the balance sphere 18 moves circumferentially and adjusts the balance.

However, actually, the balance ball 18
And the storage chamber 17 has a rolling friction coefficient μ,
The condition for the balance ball 18 to move is μ
<Tanα.

Here, α = sin ⁻¹ (Fe sin θ /
F) (θ is the angle between Fr and Fe).

Accordingly, as the Fe generated by the vibration of the drive unit 3 increases, the allowable rolling friction coefficient μ increases.
Becomes larger.

Then, if, as in the prior art,
If the center of gravity G of the drive unit h is largely displaced from the rotation center of the optical disk e and the axis vibrates in an elliptical orbit n,
In the major axis direction of the ellipse, Fe increases, the allowable rolling friction coefficient increases, the ball m moves easily, and the automatic balancing device k operates easily. However, in the minor axis direction, Fe decreases, The allowable rolling friction coefficient is small, the ball m is hard to move, and the automatic balancing device k
Becomes difficult to operate.

On the other hand, in the optical disk drive 1, the counterweight 19 is disposed on the stator substrate 7, which is the stator member of the spindle motor 6, so that the center of gravity G 'of the drive unit 3 is That is, since the center of the spindle shaft 9 is coincident with or close to the center, the trajectory of the rotation center of the optical disk 21 can be moved from the elliptical trajectory to the circular trajectory 27, and in any phase direction, Fe is stable and automatic tuning is performed. The core mechanism 16 becomes easy to operate.

In order to obtain the above effects more reliably,
It is preferable that the arrangement position of the counterweight 19 is opposite to the position where the optical pickup 20 and the thread motor 25 are arranged with the spindle shaft 9 interposed therebetween.

The number of counterweights is not limited to one, and a plurality of counterweights may be provided.

In the above embodiment, the self-aligning mechanism 16 includes the ring-shaped storage chamber 17 and the storage chamber 1.
Although a configuration comprising a plurality of balance balls 18 movably disposed in the inside 7 is shown, the form of the automatic alignment mechanism is not limited to this, and is based on the eccentricity of the rotating body. If there is vibration, any configuration may be used as long as it has a balance member that moves in the direction of correcting the eccentricity and balances.

In the above embodiment, the present invention is applied to an optical disk drive for recording and / or reproducing data on an optical disk. However, the scope of the present invention is not limited to this. Instead, the present invention can be widely applied to disk drive devices using other recording medium disks.

[0044]

As is apparent from the above description, the disk drive device of the present invention comprises a spindle motor for rotating a turntable having a recording medium disk supported on a mechanical chassis, and a spindle motor for rotating a recording medium disk supported by the turntable. A disk drive device comprising: a drive unit provided with a pickup or the like that moves in a radial direction to reproduce and / or record a signal on a recording medium disk via an elastic body on a base chassis; An automatic alignment mechanism having a holder that rotates together with the rotor of the spindle motor and a balance member movable in the holder is provided in the rotation drive unit including: a counter weight is provided in the stator of the spindle motor; The center of gravity of the drive unit Wherein the center of rotation of the pin dollar motor-matched or close.

Therefore, in the disk drive device of the present invention, since the center of gravity of the drive unit coincides with or approaches the rotation center of the spindle motor, the locus of vibration of the rotation center of the recording medium disk can be made closer to a circular orbit.
The force generated by the vibration of the drive unit is stabilized in any phase direction, and the balance member can quickly move to a position where the imbalance is eliminated, that is, a balance position. Thereby, the self-centering mechanism can surely exhibit its function.

According to the second aspect of the present invention, the holder of the self-aligning mechanism is a ring-shaped storage chamber, and the plurality of balance members are movably disposed in the storage chamber. Since the balance sphere is used, the automatic alignment mechanism can be easily configured. It should be noted that the shapes and structures of the respective parts shown in the above-described embodiments are merely examples of the specific embodiments performed in carrying out the present invention, and the technical scope of the present invention is limited by these. It must not be interpreted in a confusing way.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a disk drive device of the present invention together with FIGS. 2 to 4, and is a perspective view showing an outline of the disk drive device.

FIG. 2 is an enlarged vertical sectional view of a rotation drive unit.

FIG. 3 is a schematic plan view.

FIG. 4 is a diagram for explaining an effect of a trajectory of vibration on an automatic alignment mechanism.

FIG. 5 shows a conventional disk drive together with FIG. 6, and FIG. 5 is a schematic perspective view.

FIG. 6 is a schematic plan view.

FIG. 7 is a diagram illustrating the principle of the Thearl's automatic balancer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk drive device (disk drive device), 2 ... Mechanical chassis, 3 ... Drive unit, 6 ...
Spindle motor, 15: turntable, 16: automatic alignment mechanism, 17: storage chamber (holder), 18: balance ball (balance member), 19: counterweight, 20:
Optical pickup (pickup), 21 ... optical disk,
G ': Center of gravity of drive unit

Claims (2)

[Claims] 1. A spindle motor for rotating a turntable supporting a recording medium disk on a mechanical chassis, and reproducing or recording a signal on or from a recording medium disk by moving in a radial direction of the recording medium disk supported on the turntable. What is claimed is: 1. A disk drive device comprising a drive unit provided with a pickup and the like that performs both of them, supported on a base chassis via an elastic body, wherein a holder that rotates together with a rotor of a spindle motor in a rotation drive unit including the spindle motor and the holder A self-aligning mechanism having a balance member that is movable in the inside, a counterweight is arranged on the stator portion of the spindle motor, and thereby the center of gravity of the drive unit coincides with or approaches the rotation center of the spindle motor. Disc characterized by the above Drive device. 2. The self-aligning mechanism according to claim 2, wherein the holder is a ring-shaped storage chamber, and the balance member is a plurality of balance balls movably disposed in the storage chamber. 2. The disk drive device according to 1.