JPS6230207Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a disk rotating device that particularly requires a stable rotational state.

For example, in a disk rotating device used as an information signal recording/reproducing device such as a magnetic disk,
In particular, stable rotational conditions are required.

The configuration of a conventional disk rotating device of this type is shown in FIG. Reference numeral 1 denotes a disk plate, such as a magnetic disk, for recording or reproducing information signals, and this disk plate 1 is detachably fixed to the upper end of a rotating shaft 2. The rotating shaft 2 has rolling bearings 3, 3 at the upper and lower ends of the housing 6.
It is rotatably supported by. A motor stator 5 is provided within the housing 6, and a corresponding motor rotor 4 is provided on the rotating shaft 2. Therefore, the rotating magnetic field between the motor stator 5 and the motor rotor 4 causes the rotating shaft 2 to rotate, and the disk plate 1 to rotate as well.

By the way, in this case, the disk plate 1 is
It is fixed to the upper end of the rotating shaft 2, and is of a so-called overhang type.

However, such an overhang type rotating shaft is subject to the rotating body's gyro motion, unbalanced vibration, and critical speed, which are determined by the mass and moment of inertia of the disk and the mechanical properties of the rotating shaft, such as stiffness against deflection and stiffness against bending. It has the disadvantage of easily generating unique movements.

In addition, vibrations specific to rolling bearings, such as the accuracy of the fit between the outer ring of the rolling bearing and the housing,
Accuracy of fit between inner ring of rolling bearing and rotating shaft, 2
Nonlinear vibrations such as subharmonic vibrations, subharmonic vibrations, and harmonic vibrations are likely to occur due to concentric errors between two bearings, uneven ball diameters of rolling bearings, etc.

When the various types of vibrations described above occur, track pitch irregularities and wow and flutter (jitter) occur when recording or reproducing information signals on a disk.

This idea was made to eliminate these drawbacks, and by replacing the rolling bearing with a hydrostatic fluid bearing and making the disk and motor rotor equivalent, it prevented the vibrations that are typical of rolling bearings. The object of the present invention is to provide a disk rotation device.

Hereinafter, one embodiment of this invention will be described in detail with reference to FIG.

In Fig. 2, 1 is a disk plate;
As in the conventional case, it is removably fixed to the upper end of the rotating shaft 2. On the other hand, a motor rotor 11 having a mass and moment of inertia equivalent to that of the disk plate 1 is fixed to the lower end of the rotating shaft 2.

The rotating shaft 2 is supported in the radial direction at two upper and lower locations by journal hydrostatic bearings 7, 7, and its load is supported by a thrust hydrostatic bearing 8 below the motor rotor 11. Each bearing 7 has a fluid supply port (fluid discharge part) 9.
b is formed, and behind it is an upper housing 14.
An upper fluid pocket 13 formed by is in communication. And this upper fluid pocket 13
is provided with a fluid inlet 9a.

Therefore, a fluid such as air is introduced into the fluid pocket 13 from the fluid inlet 9a, and this fluid is discharged from the fluid supply port 9b toward the rotating shaft 2 as shown by the arrow, and eventually from the fluid outlet 10a. It will be discharged.

On the other hand, 12 is a motor stator, which is installed at a position corresponding to the motor rotor 11 and supports the housing 14.

Further, a fluid supply port 9b is formed in the lower thrust hydrostatic fluid bearing 8 so as to face the lower surface of the motor rotor 11 that constitutes a part of the bearing 8, and a fluid pocket 13 is formed in the lower part of the fluid supply port 9b. . This fluid pocket 13 is communicated with a fluid inlet 9a. The bearing 8 is supported within the cylindrical housing 6. 10b is the housing 6
A fluid outlet formed in the Therefore,...
The fluid introduced from the inflow port 9a is transferred from the fluid pocket 13 to the motor rotor 1 via the fluid supply port 9b.
It is discharged onto the bottom surface of 1. Then, the fluid is discharged from the fluid discharge port 10b. Note that each of the fluid pockets 13 serves to temporarily store the fluid supplied from the fluid inlet 9a.

As described above, according to this invention, instead of the conventional rolling bearing, it is composed of a thrust hydrostatic fluid bearing that supports the rotating shaft by discharging fluid to the rotating shaft, and a journal hydrostatic fluid bearing. Since it is equivalent to a disk plate, there is no vibration that occurs in conventional rolling bearings.
A disk rotating device in a stable rotating state can be obtained. In particular, by molding the journal hydrostatic bearing into an integral type or a two-part type, the concentricity of two or more bearing parts can be made extremely accurate.

In the above embodiments, an information signal recording or reproducing device such as a magnetic disk was explained as an example.
The object of application of this invention is not limited thereto, but can be applied to all disk rotation devices that generally require a stable rotation state.

[Brief explanation of the drawing]

FIG. 1 is a central vertical sectional view showing the configuration of a conventional disk rotating device, and FIG. 2 is a central vertical sectional view showing the configuration of a disk rotating device according to an embodiment of the invention. 1... Disc plate, 2... Rotating shaft, 7...
...Journal hydrostatic fluid bearing, 8...Thrust hydrostatic fluid bearing, 9a...Fluid inlet, 9b...Fluid supply port, 10a, 10b...Fluid outlet, 11...
Equivalent motor rotor, 12...Motor stator, 1
3...Fluid spot.

Claims (1)

[Scope of utility model registration request] A rotating shaft, a disk portion fixed to the upper end of the rotating shaft, and a fluid discharge portion fixed to the lower end of the rotating shaft and discharging fluid from below to a motor rotor having a mass and moment of inertia equivalent to the disk portion. a thrust hydrostatic fluid bearing for supporting the rotating shaft; and a journal hydrostatic fluid bearing that is provided between the disk portion and the motor rotor and supports the rotating shaft by discharging fluid from a fluid discharge portion to the rotating shaft. A disk rotation device equipped with.