JPH04300416A - Motor for light deflection device - Google Patents

Abstract

PURPOSE:To fit ball bearings smoothly without adding excessive force and alleviate mechanical precision of bearing bracket bearing insertion portion. CONSTITUTION:In a photodeflection device motor in which a rotary shaft 11 integral with a rotor portion is supported by means of ball bearings 13, an elastic body 26 is interveniently installed in an outer ring 23 outer periphery of a ball bearing 11, and the ball bearing 13 is put in a bracket 15.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for an optical deflection device incorporated in a laser beam printer or the like.

0002

2. Description of the Related Art A scanning optical system in a laser beam printer or the like uses an optical deflection device that rotates a polygon mirror at high speed using a DC brushless motor. Therefore, a conventional motor for this type of optical deflection device is shown in FIG. In the figure, reference numeral 10 indicates the housing of the motor, and reference numeral 11 indicates the housing of the motor.
indicates the rotation axis of the motor. A polygon mirror (not shown) is attached to the tip of the rotating shaft 11, and in this case, it is fixed on the flange-shaped mount portion 12a of the support plate 12 coaxially with the rotating shaft 11. The rotating shaft 11 has two upper and lower ball bearings 13, 1.
3, these bearings 13, 13 are supported by a cylindrical bearing bracket 15 in the bottom center of the housing 10.
are held at intervals vertically on the inner circumferential surface of the A stator core 16 and a stator coil 17 are arranged on the outer peripheral surface of the bearing bracket 15, and an annular rotor magnet 18 is arranged so as to surround the stator core 16 from the outside with a slight interval therebetween. This rotor magnet 18 is supported via a rotor yoke 19 that is integral with the support plate 12 to constitute a rotor portion, and therefore, the rotor magnet 18 and the rotating shaft 11 are configured to rotate together. On the other hand, a pressurization boss 20 is fitted into the lower end of the rotating shaft 11, and this pressurization boss 20 is biased via a compression spring 21, thereby applying pressurization to the ball bearings 13, 13. It looks like this.

0003

Conventionally, in such a motor, the ball bearings 13 are press-fitted into the bearing bracket 15. However, if excessive force is applied during assembly to press fit, the ball bearings 13, which are delicate parts, may become misaligned, which may cause abnormal noise or fluctuations in rotational speed when rotating at high speed. In addition, ball bearing 1
3 and 13 must be attached with high coaxiality, the bearing bracket 15 is required to be machined with high precision, which increases the processing cost.

SUMMARY OF THE INVENTION Therefore, the present invention solves the problems of the prior art, and provides an optical deflection system that allows a ball bearing to be installed smoothly and without difficulty, and that reduces the mechanical precision of the bearing insertion portion of a bearing bracket. The purpose is to provide a motor for equipment.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a motor for an optical deflection device in which a rotating shaft integrated with a rotor is supported by a ball bearing, in which an elastic body is attached to the outer periphery of the outer ring of the ball bearing. The ball bearing is fitted into the bearing bracket.

[0006]

[Operation] According to the present invention, the elastic body acts as a buffer material,
Excessive force and impact are not applied when the bearing is installed, and vibrations during rotation due to errors in bearing concentricity are absorbed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motor for an optical deflection device according to the present invention will be described below with reference to the accompanying drawings. The motor for an optical deflection device in this embodiment is basically the same type of motor as the motor for an optical deflection device in FIG. 4 described above except for the bearing part, and FIG. 1 is a diagram showing the bearing part. . Hereinafter, the same components as those in FIG. 4 will be described with the same reference numerals. As the pair of upper and lower ball bearings 13, 13 that support the rotating shaft 11, ball bearings whose details are shown in FIG. 2 are used. In FIG. 2, reference numeral 22
23 is an inner ring, 23 is an outer ring 23, and 24 is a ball. A circumferential groove 25 is formed on the outer periphery of the outer ring 23, and a ring-shaped elastic body 26 made of an elastic material such as rubber is attached to the circumferential groove 25.

Next, in FIG. 3, the ball bearing 13 is fitted into bearing insertion portions 27 formed on the inner periphery of both ends of the bearing bracket 15 with a clearance fit in this embodiment. A ring-shaped groove 28 is formed in this bearing insertion portion 27, and the elastic body 26 is fitted into this groove 28.

As shown in FIG. 1, the ball bearings 13, 13 have an elastic body 26 interposed between the inner peripheral surface of the bearing bracket 15 and the outer ring 24 at both ends of the bearing bracket 15. It is installed in the condition. This elastic body 2
Since the ball bearing 6 acts as a buffer material, no excessive force or impact is applied when the ball bearing 13 is inserted into the bearing bracket 15. In addition, the upper and lower ball bearings 13,
Even if the precision of the concentricity of 13 is not very high, the vibrations caused by the precision errors are absorbed by the elastic body 26.

0010

[Effects of the Invention] As is clear from the above description, according to the present invention, an elastic body is interposed on the outer periphery of the outer ring of the ball bearing, and this ball bearing is fitted into the bearing bracket, so that during assembly, Ball bearings can be installed easily and smoothly without applying excessive force or impact. In addition, vibrations during rotation due to errors in the concentricity of the ball bearing are absorbed by the elastic body, so even if the mechanical precision of the bearing insertion part of the bearing bracket is relaxed, the circularity and coaxiality can be achieved with high precision. You can get the same effect as you did.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a bearing portion of a motor for an optical deflection device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the ball bearing of the bearing section.

FIG. 3 is a sectional view of a bearing bracket to which the ball bearing is attached.

FIG. 4 is a vertical cross-sectional view showing the overall configuration of a conventional motor for an optical deflection device.

[Explanation of symbols]

10 Motor housing 11 Rotation axis 13 Ball bearing 15 Bearing bracket 18 Rotor magnet 19 Rotor yoke 23 Outer ring 26 Elastic body

Claims (1)

[Claims] Claim 1: In a motor for an optical deflection device in which a rotating shaft integrated with a rotor is supported by a ball bearing, an elastic body is interposed on the outer periphery of the outer ring of the ball bearing, and the ball bearing is fitted into a bearing bracket. A motor for an optical deflection device characterized by: