JPS6260458A - Bearing mechanism of rotary body - Google Patents

Abstract

PURPOSE:To facilitate assembly and adjustment by internally accommodating a bearing housing to motor case and disposing a bearing to the bearing housing. CONSTITUTION:A bearing housing 26 for holding bearings 10 is mounted at the central section of a motor case 8, the bearings 10 are arranged to the upper and lower end sections of a collar 5 fitted to a shaft 4 in the housing 26, and the shaft 4 is supported rotatably. A coil spring 28 is wound on the end section of the shaft 4 at a position opposite to a polygonal mirror 2, and brought into contact with an outer ring for the bearing 10. The case 8 side organizes a stator 6 together with a stator coil 14, and a body of revolution 12 with a magnet 20 is fitted to the shaft 4, thus constituting a motor. Accordingly, a screw section 30 screwing to the inside of the bearing housing 26 while being brought into contact with the spring 28 is operated, thus generating pre-load in the bearings 10, then easily adjusting a bearing mechanism at a stage when the bearings 10 are incorporated.

Description

[Detailed description of the invention] (b) Industrial application fields The invention of this application relates to a bearing mechanism for a rotating body.

More specifically, the present invention relates to a bearing mechanism employed in a polygon scanner driving motor.

(b) Prior Art The structure of a conventionally used polygon scanner driving motor will be described with reference to FIG. 2 of the accompanying drawings.

A vertical shaft 4 having a polygon mirror 2 attached to its end is rotatably supported by a bearing group 10 fitted in a motor case 8 constituting a stator 6 of the motor. A stator coil 14 is provided inside the motor case 6 so as to face a magnet 20 attached to the inside of the rotor yoke 18 described above. The rotating body 12 of the motor is connected to the above-mentioned vertical shaft 4.
, a rotor yoke 18 connected to a flange 16 provided on the lower surface of the polygon mirror 2, and a magnet 2 disposed inside the rotor yoke 18 so as to face the stator coil 14.
0.20. The thrust direction of the shaft 4 is adjusted by an adjustment screw 22 provided at the end opposite to the polygon mirror 2 via a coil spring 24.

(c) Problems to be Solved by the Invention In the above-described configuration, the bearing lO is directly fitted into the motor case 8 so that the motor case 8 can be used as a housing for the bearing 10. The motor case 8 used as a housing has a complicated structure, and it is difficult to maintain high machining accuracy, and it takes time to assemble and adjust related parts such as the shaft 4 supported by the bearing lO. In addition, since the motor case is usually made of aluminum die-casting, etc., while the shaft member is made of steel, the coefficients of linear expansion of both parts are different, so it is difficult to generate and maintain preload. There were also problems such as not being easy to manage.

(d) Means and action for solving the problem Therefore, in the present invention, instead of directly mounting the bearing on the motor case, a bearing housing for holding the bearing is provided inside the motor case, and the bearing is mounted inside the bearing housing. By providing a configuration in which this is arranged, assembly and adjustment are facilitated, and it is possible to maintain high-precision rotation and manage preload.

(E) Embodiment In FIG. 1, the bearing 1 is located approximately in the center of the motor case
A bearing housing 26 for holding the shaft 4 is provided, and the collar 5 fitted on the shaft 4 is mounted on the bearing housing 26.
A shaft and a receiver 10.10 are arranged at the lower end to rotatably support the shaft 4. A coil spring 28 is wound around the end of the shaft 4 opposite to the polygon mirror 2 and comes into contact with the outer ring of the bearing 10. The opening of the bearing housing 26 is closed by operating a threaded portion 30 screwed into the inside of the bearing housing 26 while in contact with the coil spring, thereby generating a preload on the bearing 10.

(f) Effects of the invention In the present invention, it is possible to easily adjust the bearing to maintain high precision rotation at the stage of assembling the bearing to the bearing housing, and the material of the member used for the bearing housing also takes into consideration the coefficient of linear expansion with respect to the shaft. Since the preload can be selected as appropriate, there are advantages such as easy preload management.

FIG. 1 is a cross-sectional view of a bearing mechanism for a rotating body according to the present invention;
FIG. 2 is a cross-sectional view of a conventional bearing mechanism for a rotating body.

Claims (1)

[Claims] A bearing mechanism for a rotating body comprising a shaft rotatably supported by a motor case, characterized in that a bearing housing for holding the bearing is provided at the center of the motor case.