JPH089583A - Rotary shaft vibration preventive device for motor - Google Patents

Abstract

PURPOSE:To provide a vibration preventive device which prevents the vibration of the rotary shaft constituting a motor by simple constitution, CONSTITUTION:This device consists of a projection 8, which is made on the topside of the first bearing 3 supporting a rotary shaft 7, and a washer 9, which is set freely on the rotary shaft 7 in such condition that it contacts with the rotary shaft through a viscous member and besides rotates by receiving the torque of the rotary shaft 7 and abuts on the projection 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor used in a disc player or the like configured to read a signal recorded on a disc by an optical pickup, and more particularly to a vibration preventing device for a rotating shaft.

[0002]

2. Description of the Related Art Disc players, which perform an operation of reading a signal recorded on a disc using an optical pickup, are widely used. However, in such a disc player, in order to accurately perform a signal reading operation, It is necessary to suppress the vibration of the disc. As a method of suppressing the vibration of the disc, there is a method of utilizing the attractive force of a magnet as a clamping means for clamping the disc on the turntable. Since it was necessary to provide it, it was not suitable for making the disc player thinner.

As a technique for improving such a point, Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent No. 151675, a ball bearing has been developed. According to such a technique, since the disc player can be made thin, it is often adopted in portable disc players.

[0004]

DISCLOSURE OF THE INVENTION Disc players constructed to hold a disc by using a ball bearing do not include a clamp member for pressing the upper surface of the disc, so that it is easy to prevent the disc from vibrating. I can't do it.

Therefore, in order to suppress the vibration of the disc, such a disc player is configured to accurately perform the rotational driving operation of the turntable on which the disc is mounted. The turntable is rotationally driven. There is a problem that minute vibrations caused by the gap between the rotating shaft of the electric motor and the bearing have a large adverse effect on the rotation of the disk.

The present invention is intended to provide a rotating shaft vibration preventing device for an electric motor, which solves the above problems.

[0007]

A rotary shaft vibration preventing device of the present invention is an electric motor having a rotary shaft rotatably supported by first and second bearings provided above and below, respectively.
The convex portion formed on the upper end surface of the first bearing is loosely fitted to the rotary shaft so as to be in contact with the rotary shaft via a viscous material, and the convex portion is formed by the rotational force of the rotary shaft. It is composed of a washer that abuts against.

[0008]

According to the present invention, vibration of the rotary shaft is prevented by displacing the rotary shaft in a direction perpendicular to the axial direction by the reaction force received from the convex portion of the washer.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing an essential part of a rotational vibration preventing device of the present invention, and FIG. 2 is a sectional view taken along line AB in FIG.

Reference numerals 1 and 2 denote an upper housing and a lower housing which constitute an electric motor, and 3 denotes a first bearing 5 which is press-fitted and fixed in a central hole 4 formed in a central portion of the upper housing 1. A second bearing 7 is press-fitted and fixed in a recess 6 formed in the center of the lower housing 2, and 7 is a rotating shaft of an electric motor, which is rotatably supported by the first bearing 3 and the second bearing 5. Has been done.

Reference numeral 8 denotes a cylindrical projection formed on the upper end surface 3a of the first bearing 3, and reference numeral 9 denotes a play on the rotary shaft 7 so as to be in contact with the rotary shaft 7 via a viscous material. The washer is fitted and is configured to come into contact with the convex portion 8 by the rotational displacement force received through the viscous material during rotation of the rotary shaft 7. The washer 9 has a shape in which a circular part is cut out in a half-moon shape as shown in FIG. 1, for example, and a linear part 9 a of the cutout part is configured to abut the convex part 8. There is.

In such a structure, when the rotary shaft 7 rotates clockwise, the rotational force is transmitted to the washer 9 through the viscous material, so that the washer 9 also rotates clockwise. When the washer 9 rotates in the clockwise direction, the linear portion 9a of the cutout portion formed on the washer 9 comes into contact with the convex portion 8 as shown in FIG.

The rotary shaft 7 rotates in this state, but the washer 9 is held in the state shown in FIG. 1 by contact with the convex portion 8. In such a state, the washer 9 receives the rotational displacement force by the reaction force received from the convex portion 8, and the rotational displacement force acts on the rotary shaft 7.
Since the displacement force acts in a direction perpendicular to the axial direction of the rotary shaft 7, the rotary shaft 7 rotates while being pressed against the side wall of the rotation center hole formed in the first bearing 3. Will be done. Therefore, the rotating shaft 7 of the electric motor and the first bearing 3
The rotating shaft 7 does not vibrate even if there is a gap between the rotating shaft 7 and the rotating shaft 7.

If a highly viscous oil is used as a viscous material that is interposed between the washer 9 and the rotary shaft 7 and applies the rotational force of the rotary shaft 7 to the washer 9, the assembly can be easily performed. I can. Further, when the washer 9 is made of synthetic resin, the friction between the washer 9 and the rotary shaft 7 can be reduced, so that even if the displacement force of the washer 9 acts on the rotary shaft 7, the rotary shaft 7 is rotated. No load is applied to the rotating operation of 7, and the rotating operation can be smoothly performed.

[0015]

According to the present invention, in a motor having a rotating shaft rotatably supported by first and second bearings provided above and below, a convex portion formed on the upper end surface of the first bearing is provided. A washer that is loosely fitted to the rotary shaft so as to be in contact with the rotary shaft via a viscous material, and that abuts against the convex part by the rotational force of the rotary shaft. Since the rotating shaft is pressed and displaced in the direction perpendicular to the axial direction by the reaction force received, the rotating shaft rotates while being pressed by the side wall of the rotation center hole formed in the first bearing. As a result, even if there is a gap between the rotary shaft of the electric motor and the first bearing, the vibration of the rotary shaft can be prevented. Therefore, the present invention provides
This is very effective when applied to an electric motor that requires accurate rotation operation, such as an electric motor that rotationally drives a disk of a disk player.

Further, since oil is used as the viscous material, the assembling operation of the device can be performed easily and the washer is made of synthetic resin, so that the friction with the rotating shaft can be reduced. As a result, the present invention has the effect that the rotation characteristics can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part of a rotary shaft vibration prevention device of the present invention.

2 is a sectional view taken along the line AB in FIG.

[Explanation of symbols]

 3 1st bearing 5 2nd bearing 7 Rotating shaft 8 Convex part 9 Washer

Claims (3)

[Claims] 1. An electric motor comprising a rotating shaft rotatably supported by first and second bearings provided above and below, and a convex portion formed on an upper end surface of the first bearing, and the rotating shaft. A washer that is loosely fitted to the rotary shaft so as to be in contact with the rotary shaft via a viscous material, and that rotates by receiving the rotational force of the rotary shaft and contacts the convex portion. A rotation shaft vibration preventing device for an electric motor, wherein the rotation shaft is pressed and displaced in a direction perpendicular to the axial direction by a reaction force received from the portion. 2. The vibration preventing device for a rotating shaft according to claim 1, wherein oil is used as the viscous material. 3. The rotation shaft vibration preventing device according to claim 1, wherein a washer made of synthetic resin is used.