JPH0515142B2 - - Google Patents

Description

[Detailed Description of the Invention] (A) Technical Field of the Invention The present invention relates to a small motor, particularly a motor for driving a compact disk, etc., in which the perpendicularity between the shaft and the motor mounting surface and the concentricity between the shaft and the bearing part are fixed. In order to obtain a small motor, which is often subject to strict conditions, a plate-shaped spacer formed by cutting is fixed to the end face of the motor case, and the small motor is made to meet the above conditions. It is related to motors.

(B) Technical background and problems Small motors with permanent magnet fields have been widely used as drive motors for audio equipment, optical equipment, office equipment, etc., but in recent years they have also been used for computer-related equipment. It's starting to look like this. Application as a drive motor for so-called compact disks is being considered.

For the drive motor of the compact disk, strict mounting accuracy is required for the motor to the equipment. Strict precision is required, with a deviation of 0.02 mm or less. on the other hand,
For the purpose of mass production and cost reduction, small permanent magnet field motors have traditionally been press-formed by drawing a metal plate.
For this reason, it is difficult to obtain the above-mentioned perpendicularity by only the press working. Furthermore, even in the assembled motor, it is quite difficult to obtain the above-mentioned concentricity due to variations in machining accuracy of bearings, shafts, etc.

For this purpose, the motor case and case lid of the manufactured motor are precisely finished by cutting.
Although it is possible to achieve the above accuracy, it is not practical in terms of mass production and cost.
Therefore, no suitable measures have been found to deal with the above-mentioned severe conditions, and the only way to do so has been to inspect mass-produced motors and select and use motors that meet the above-mentioned conditions.

(C) Object and Structure of the Invention The present invention aims to solve the above problem, and the present invention has the purpose of solving the above-mentioned problem. A plate-shaped spacer machined with high precision by cutting etc. is added, and the above-mentioned motor
The case and the spacer are bonded together to obtain a small motor with the desired accuracy. This will be explained below with reference to the drawings.

(D) Embodiments of the Invention FIG. 1 is a perspective view of a small motor according to an embodiment of the present invention, and FIG. 2 is a partially cutaway side view of the small motor according to the embodiment.

In FIG. 1, 1 is a motor case, 2 is a shaft, 3 is a spacer according to the present invention, and in the case shown, it is a disc-shaped spacer obtained by cutting, and 4 is a hollow cylindrical wall. The hollow part encloses the bearing part provided in the motor case 1 and serves as a reference surface for ensuring the desired concentricity of the outer peripheral surface of the hollow cylinder wall, 5 is a motor mounting hole, and 6 is a reference plane. Reference numeral 7 represents a motor terminal on the outer surface of the spacer and serves as a reference surface for obtaining the desired perpendicularity.

In other words, a disk-shaped spacer 3 is bonded to the end face of a motor case 1 of a motor manufactured by mass production. The spacer 3 is formed by cutting, and the outer surface 6 constitutes a motor mounting surface for a compact disk, etc., and is designed to have a surface that is perpendicular to the shaft 2 shown with high precision. There is. Further, a hollow cylindrical wall 4 is provided, and the outer peripheral surface of the cylindrical wall 4 is machined with high precision to obtain a desired degree of concentricity with the shaft 2.

A partially cutaway side view is shown in FIG. 2, in which numerals 1 to 7 correspond to those in FIG. 1, 8 is a permanent magnet field, 9 is a rotor, 10 is a brush, and 11 is a case lid. , 12 is a commutator, 13 is a bearing part provided in the case lid, 14 is a bearing part provided in the motor case, 15 is a terminal insulating tube, 16 is a motor mounting external device surface, and 17 is a screw. There is. Further, 18 is an adhesive that adheres between the spacer 3 and the motor case 1. That is, even if the outer surface portion 6 of the spacer 3 is processed correctly, there may be some undesirable looseness between the outer surface portion 6 of the spacer 3 and the motor case 1 formed by drawing press processing, or the spacer If the contact condition between 3 and the bottom outer surface of the motor case 1 changes undesirably (that is, due to the tightness of the screw 17 shown in the figure), the above-mentioned correct machining will be completely meaningless. Become. In order to eliminate this problem, spacer 3 and motor case 1
An adhesive 18 is interposed between the outer surface of the bottom of the spacer 3 and the shaft 2 intersects with a plane constituted by the outer surface of the spacer 3 at 90° with high precision.
A spacer 3 is permanently glued to the bottom outer surface of the motor case 1.

The structure shown in FIG. 2 except for the parts related to the spacer 3 and the adhesive 18 is conventionally known, and a detailed explanation will be omitted, but the rotor 9 can be rotated by the bearings 13 and 14. Supported by

In the case of the small motor of the present invention, as described at the beginning of this specification, the outer surface portion 6 of the spacer 3
The perpendicularity between the shaft 2 and the cylindrical portion of the outer peripheral surface of the hollow cylinder wall 4 is maintained within 90°±6', and
The spacer 3 and the motor case 1 are bonded and fixed with an adhesive 18 while maintaining the above-mentioned accuracy so that the concentricity with the motor case 1 is maintained within a deviation of 0.02 mm.

(E) Effects of the Invention As explained above, according to the present invention, a drive motor for a compact disk or the like can be provided at a relatively low cost. Furthermore, it is possible to use the same motor case as a mass-produced product.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a small motor according to an embodiment of the present invention, and FIG. 2 is a partially cutaway side view of the small motor according to the embodiment. In the diagram, 1 is the motor case, 2 is the shaft, and 3
is a spacer, 4 is a hollow cylinder wall, 5 is a motor mounting hole, 6 is an outer surface of the spacer, 8 is a permanent magnet field, 9
14 represents a rotor, 14 represents a bearing portion, and 18 represents an adhesive.

Claims (1)

[Scope of Claims] 1. A motor case formed by drawing press into a cylindrical shape with a bottom, one end of the shaft being supported by a bearing portion provided in the motor case; In a small motor having a rotor that is rotatably supported, a plate-shaped spacer is provided on the bottom outer surface of the bottomed cylindrical motor case with a hollow cylindrical wall surrounding the bearing part, and is machined by cutting. A highly precisely machined plate-shaped spacer is fixed with adhesive, and the shaft is configured such that the plane formed by the outer surface of the spacer intersects with the shaft at an angle of 90° with high precision. A small motor characterized by the ability to