JPS6262017A - Ball bearing pre-load mechanism of rotor - Google Patents

Abstract

PURPOSE:To make a rotor thin and improve its performance by providing an annular elastic member in contact with the ball be ring of a shaft placed in a housing and a member retaining said elastic member. CONSTITUTION:A shaft 4 is rotatably supported on a bearing housing 26 by means of a collar 5 and the ball bearings 10, 10. In this case, an annular elastic member, for example O ring 32 is inserted in the lower part of the outer race of the ball bearing 10 positioned under the shaft 4 through a spacer 31. And the O ring 32 is held by an adjusting screw 34 screwing with a motor case 8 from the lower side to generate uniform pressing force acting on the outer periphery of the ball bearing 10. Then a rotor constituted by the shaft 4 and the like can be made thinner and uniform pressing force can be generated on the periphery of the ball bearing 10, and performance of the rotor can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The invention of this application relates to a rotating body ball bearing preload mechanism. More specifically, the present invention relates to a ball bearing preload mechanism for a rotating body used in a polygon scanner or the like.

Conventional technology Balls are installed in the bearing housing to enable the shaft of a rotor used in conventional polygon scanners to move downward in the thrust direction, and to generate and manage preload. A polygon mirror is attached to one end of the shaft so that it can rotate freely in the bearing, a coil spring is provided in contact with the other end of the shaft, and a preload adjustment screw provided below is tightened or loosened to create a ball bearing. It was designed to generate preload. The configuration of the polygon scanner motor will now be described with reference to the accompanying drawings FIGS. 2 and 3. The vertical shaft 4 with the polygon mirror 2 attached to its end is a bearing housing 26 provided approximately in the center of the motor case 8 constituting the motor stator 6, and is mounted on a collar 5 fitted to the shaft 4.
Ball bearing group 1 arranged so as to be in contact with the lower end
0 and is rotatably supported. Inside the motor case 6 is a magnet 2 attached to the inside of the rotor yoke 18, which will be described later.
A stator coil 14 is provided so as to face 0.

The rotating body 12 of the motor consists of the aforementioned vertical shaft 4, a rotor yoke 18 connected to a flange 16 provided on the lower surface of the polygon mirror 2, and magnets 20 and 20 disposed inside the rotor yoke so as to face the stator coil 14. configured. A spacer 2 is attached to the other end of the shaft 4 which has polygon mirror 2 at one end and the outer ring of the ball bearing lO.
A coil spring 28 or a wave-shaped washer (not shown) is disposed so as to be in contact with the coil spring 28 via the coil spring 7, and a threaded portion 30 that is threadedly engaged with the bearing housing 26 or the inner wall of the motor case is provided below the coil spring 28 or a wave washer (not shown).

C1 Problems to be Solved by the Invention In the above-described configuration in which a wave washer or a coil spring is inserted into the extended end of the ball bearing housing to apply preload, for example, when a coil spring is used,
It is difficult to make the rotating body thin, and if the outer periphery of the ball bearing is to be pressed with uniform force, the end treatment of the coil spring is technically complicated. On the other hand, when corrugated washers are used, there are problems such as it is difficult to apply a uniform pressing force to the outer periphery of the ball bearing because the heights of the washers are different.

21 Means and Function for Solving Problems Therefore, in the present invention, an annular elastic member such as an O-ring is fitted and inserted in contact with the ball bearing, without using the coil spring or wave washer used in the conventional example. After that, a configuration is provided in which a preload adjustment device, such as a screw, is tightened from below.

This configuration makes it possible to make the entire rotor thinner and to generate a uniform pressing force on the circumference of the ball bearing.
・You can obtain a single-function rotating body.

E. Embodiment FIG. 1 shows an embodiment of a preload mechanism for a rotating body bearing according to the present invention. Since the same reference numerals used in the description of the conventional example indicate the same members, a description thereof will be omitted. Collar 5 and ball bearing 1 in bearing housing 26
An annular elastic member, such as an O-ring 32, is inserted below the outer ring of the ball bearing 10 (as viewed in FIG. 1) via a spacer 31, which is located below the shaft 4 which is rotatably supported by 0.10 mm. This O-ring 32 is held down by an adjustment screw 34 screwed into the motor case 8 from below, and a uniform pressing force can be generated on the outer periphery of the ball bearing 10.

1. Effects of the Invention According to the present invention, it is easy to make the rotating body thinner, and a uniform pressing force can be generated all around the ball bearing, so that the -) of the rotating body can be kept clean. It can be measured.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a preload mechanism for a rotating body bearing according to the present invention, and FIGS. 2 and 3 are cross-sectional views showing a conventional mechanism. 4...Shaft 6...Motor stator 8.
・・Motor case 10・Ball bearing 12・
...Rotating body 26...Bearing housing 32...
・0 ring Figure 1 Figure 2

Claims (1)

[Claims] 1. An annular elastic member provided in contact with a ball bearing disposed in a housing that holds a ball bearing of a shaft rotatably supported in a motor case, and a member that holds the same. A ball bearing preload mechanism for a rotating body. 2. A ball bearing preload mechanism for a rotating body according to claim 1, wherein an adjustment screw for holding the annular elastic member is screwed onto the inner wall of the motor case. 3. Claim 1 in which the annular elastic member is an O-ring
The ball bearing preload mechanism for the rotating body described in .