JPH04132044A - Rotation supporting structure for disk file device - Google Patents

Abstract

PURPOSE:To reduce thickness in accordance with the miniaturization of a device by utilizing the magnetic attractive force of the rotor magnet and the iron core of the stator of a motor to drive a disk as the pre-loading means in an axial direction of a ball bearing, and using only one bearing, and fixing its inner race, and fixing the holder of the disk to its freely rotatable outer race. CONSTITUTION:Since the magnet 14 for the rotor fixed to the disk holder 5 and a magnetic body 16 fixed to the stationary part of the device and constituting the stator attract magnetically each other, pre-load in the axial direction is given to the outer race of only one ball bearing 1 to which the holder 5 is fixed, and the outer race displaces in regard to the inner race. Thus, play between a ball and the races is absorbed, and smooth rotation is secured, and thin type rotation supporting structure to meet the miniaturization of the disk device can be obtained.

Description

[Detailed Description of the Invention] [Summary] Regarding the rotation support structure in a disk file device such as a magnetic disk device or an optical disk device used in an external storage device of a combiator, a thin rotation support structure is provided in response to the miniaturization of the disk device. In a disc twill device that is rotatably supported by a single radial ball bearing composed of a plurality of steel balls sandwiched between an inner ring and an outer ring, the central shaft fixed to the inner ring is is fixed to a stationary part constituting the device, a disk holding holder is fixed to a rotatable outer ring, a disk is fixed to the holder at approximately the same height as the ball bearing, and the disk is fixed to the holder at approximately the same height as the ball bearing. A rotor magnet of a motor for rotatably supporting the disk together with a holder and for rotationally driving the holder is attached to the holder, while a stator of the motor is attached to a stationary part facing the rotor magnet, An axial preload is applied to the ball bearing by a magnetic attraction force generated between the rotor magnet and the stator.

[Industrial application field]

The present invention relates to a rotation support structure in a disk file device such as a magnetic disk device or an optical disk device used in an external storage device of a computer.

[Conventional technology]

As shown in FIG. 3, the rotation support structure of a conventional disk file device includes upper and lower wheels 2 that are housed in a bearing housing 18 provided on a stationary base 10 with the outer ring fixed to the inner wall. A knob 5 is fixed to a rotating shaft 4 supported by a pair of radial ball bearings 1.2, and three discs 9, for example, stacked vertically are attached to this via a disc clamper 17. . The motor for driving this disk 9 includes a stator consisting of an iron core 7 and a winding 6 installed surrounding the outer wall of the housing 18;
The rotor is composed of a magnet 8 fixed to the inner wall of the hub 5 facing the rotor.

One of the bearings 1 has a fixed position in the height direction with respect to the rotating shaft 4 for both the inner ring and the outer ring, but the position of the other bearing 2
In this case, one of the inner ring and the outer ring is not fixed in its axial position with respect to the rotating shaft 4, and instead, an axial preload spring 3 is provided between both bearings 1.2. This axial preload absorbs the play that inevitably exists between the bearing race and the pawl, allowing the rotating shaft 4 to rotate smoothly together with the inner ring.

Recently, with the miniaturization of disk devices, thin spindles have come into use.For example, as shown in FIG.
A surface-facing DC brushless motor is used as the motor, and the bearing 1 is The structure is such that an axial preload is applied to the bearing to absorb play between the bearing race and the ball.

[Problem to be solved by the invention]

In the rotation support structure shown in Fig. 4, the number of bearings can be halved and the preload spring can be omitted compared to the structure shown in Fig. 3, making it possible to make the structure significantly thinner. Since the shaft 4 rotates together with the inner ring, the disc 9
It is necessary to install the hub 5 that holds the bearing 1 above the bearing 1, and there is still a limit to how thin the hub 5 can be.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and provide a thin rotary support structure that is compatible with the miniaturization of disk devices.

[Means for solving the problem] This purpose is to fix the problem to the inner ring in a disc file device that is supported by a single radial ball bearing that is configured by sandwiching a plurality of steel balls between the inner ring and the outer ring. The central shaft of the device is fixed to a stationary part that constitutes the device, a disk holding holder is fixed to the rotatable outer ring, and the disk is fixed to the holder at approximately the same height as the ball bearing. a stationary part that rotatably supports the disk along with the holder around the holder, and that a rotor magnet of a motor for rotationally driving the holder is attached to the holder, while a stator of the motor faces the rotor magnet; This is achieved by a rotation support structure for a disk file device, characterized in that the ball bearing is attached to the rotor magnet and the stator is attached to the rotor, and an axial preload is applied to the ball bearing by a magnetic attraction force generated between the rotor magnet and the stator.

[Effect]

The rotor magnet fixed to the disk holding holder magnetically attracts the magnetic material constituting the stator fixed to the stationary part of the device, and the holder is fixed to the outer ring of the only ball bearing. An axial preload is applied, and by displacing it with respect to the inner ring, play between the ball and the race is absorbed, ensuring smooth rotation.

Hereinafter, the present invention will be explained in more detail based on preferred embodiments shown in the drawings.

〔Example〕

FIG. 1 is a side sectional view of a first implementation side of the rotation support structure of the disk file device of the present invention.

This rotation support structure is constructed by sandwiching a ball bearing 1 between a base 10 that constitutes a frame of the disk file device and a cover 11 that is parallel to the base 10. In this example, a shaft bearing rig in which the inner ring also serves as the shaft 4'' is used as the ball bearing 1, and the shaft 4' is connected to the base 10 and the cover 1.
It is formed as a shaft 4° with both ends fixed to 1, and the shaft 4°
A hub-shaped holder 5 carrying a disk 9 is fixed to the outer ring 1a, which is rotatable around the outer ring 1a.

In order to rotationally drive this disk 9, a surface facing type (axial flux type) DCC brushless morph is installed, and its rotor magnet 14 is arranged on the lower surface of the hub type holder 5 concentrically with respect to the axis 4°. ing. In this case, the holder 5 may be made of a magnetic material and may also serve as the rotor yoke, but the holder may be made of a non-magnetic material such as aluminum and the rotor yoke may be adhesively fixed thereto.

On the other hand, a stator coil 13 and a stator yoke 16 are fixed to the base 10 so as to face the rotor magnet 14.

With this configuration, the rotor magnet 14 and the stator yoke 16
A magnetic attraction force is generated between the holder 5 and the rotor magnet 14, and the holder 5 to which the rotor magnet 14 is fixed is attracted toward the base 10. Therefore, the outer ring 1' of the ball bearing 1 also receives a downward biasing force in the figure.

Therefore, the outer ring 1'' moves in the axial direction relative to the fixed inner ring 4'', and the play that inevitably exists between the ball and the race is absorbed, and the smooth rotation of the disc 9 is ensured. Guaranteed.

FIG. 2 is a side sectional view of a second implementation side of the present invention.

In this example as well, the rotational support structure is formed by a ball bearing 1 held between the base 10 and cover 11 of the disk file device, with the fixed shaft 4' serving as the inner ring of the ball bearing and the rotatable outer ring 1' A hub-shaped holder 5 that holds a disk 9 is fixed to.

The difference from the first embodiment is that the motor for rotationally driving the disk 9 is not a surface facing type motor in which the rotor and stator face each other in the axial direction, but a radial flux type DC motor in which the rotor and stator face each other in the radial direction. The reason lies in the fact that it uses a brushless motor.

In this case, the rotor magnets 14 are arranged circumferentially on the inner wall of the hub of the holder 5, and the stator consisting of an iron core 7 around which a coil 6 is wound is correspondingly arranged circumferentially on the base 10. It is located. The horizontal central axis A of the rotor magnet 14 and the horizontal central axis B of the iron core 7 are slightly shifted in the vertical direction so that they do not coincide. As a result, a component force perpendicular to the magnetic attraction force acting between the rotor magnet 14 and the iron core 7 is generated, and this acts as an axial preload on the ball bearing, producing the same effect as in the case of the first implementation side. arise.

In these embodiments, it is not necessarily necessary to fasten and fix between the shaft 4° and the cover 11, but in order to increase the rigidity, it is desirable to secure both ends of the shaft.

It is desirable that the disk 9 be mounted at the same height as the ball bearing 1, 1 which allows the entire mechanism to be made even thinner.

Further, although an example has been described in which a shaft bearing in which the inner ring and the shaft are integrated is used as a ball bearing, it is also possible to use a normal system in which the inner ring and the shaft are provided separately.

In the illustrated example, the space between the bearing side and the disk side is sealed by the labyrinth seal 12.
Even better sealing performance can be obtained by using a magnetic fluid.

〔Effect of the invention〕

According to the present invention, the magnetic attractive force between the rotor magnet of the motor that drives the disk and the iron core of the stator is used as a preloading means in the axial direction of the ball bearing, thereby omitting mechanical means such as a spring.
Moreover, by using only one bearing, fixing its inner ring and fixing the disk holder to the freely rotatable outer ring, the thickness of the holder is reduced, making it possible to construct the entire disk file device with a thin structure. At the same time, it is possible to reduce costs by reducing the number of parts and assembly man-hours.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the configuration of the first implementation side of the present invention, FIG. 2 is a side sectional view of the second implementation side, and FIGS. 3 and 4 are the rotation support structure of a conventional disk file device. FIG. 1.2-m-Ball bearing 3-Preload spring 4-Rotating shaft 4°--Fixed shaft 5--Holder 6--Coil 7-Iron core 8--Rotor magnet 9-Disc 10--Base 11 - Cover 12 -- Labyrinth seal 13 -- Stator coil 14 -- Rotor magnet 16 Stator yoke A side sectional view showing the configuration of the first implementation side of the present invention. Side cross section showing the structure of 9th cell 4th side cross section of the conventional rotary support structure 8.14...rotor magnet

Claims (1)

[Claims] 1. In a disk file device that is pivotally supported by a single radial ball bearing (1) configured by sandwiching a plurality of steel balls between an inner ring and an outer ring, Center axis (4')
is fixed to a stationary part (10) constituting the device, a disk holding holder (5) is fixed to a rotatable outer ring (1'),
A disk (9) is fixed to the holder (5), and the disk (9) is moved to the holder (5) centering on the ball bearing (1).
A motor rotor magnet (14) for rotatably supporting the holder (5) and rotationally driving the holder (5) is attached to the holder (5), while the stator (6, 7) of the motor
, 13, 16) are attached to the stationary part (10) facing the rotor magnet (14), and the magnetic attraction force generated between the rotor magnet (14) and the magnetic body (7, 16) on the stator side 1. A rotation support structure for a disk file device, characterized in that an axial preload is applied to the ball bearing. 2. The rotation support structure according to claim 1, wherein the disk (9) is fixed at approximately the same height as the ball bearing (1). 3. The rotation support device according to claim 1, wherein the motor is a surface-facing DC brushless motor. 4. The rotation support device according to claim 1, wherein the motor is a radial flux type DC brushless motor, and the rotor magnet and the stator have different axial height positions.