JPH08289523A - Small brushless motor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a small brushless motor that is composed of inexpensive parts using metal stamping and has a simpler structure, and that the force generated during assembly does not affect the mounting surface. The purpose is to improve the squareness of the shaft. [Structure] By providing at least two or more through holes 11 on the top surface of the frame 2 of the rotor, the stator can be supported through the through holes, so that the force generated during assembly is not applied to the mounting base. The structure is such that the printed circuit board 7 is adhered and fixed to the plane portion of the bracket 4 with a double-sided tape. In this mechanism, a retainer (metal ring) 8 formed by metal pressing is press-fitted and fixed to the other end of the rotor shaft 1 to prevent the rotor from coming off. A structure in which a bottom plate (steel plate) 9 formed by metal pressing to support the load in the thrust direction of the rotor is press-fitted and fixed to the burring inlet of the bracket 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact brushless motor used for transmitting rotation of a disc such as a CD or a CD-ROM.

[0002]

2. Description of the Related Art In recent years, devices such as CDs and CD-ROMs are increasingly demanded for low cost and high reliability, and a small brushless motor using an inexpensive oil-impregnated metal for a bearing is being adopted as a motor used for the device. .

An example of a conventional small brushless motor mechanism will be described below with reference to the drawings.

FIG. 3 is a sectional view of a small brushless motor used in a conventional CD-ROM. In FIG. 3, 101 is a shaft that transmits rotation,
A boss 102 formed by cutting metal such as brass is press-fitted and fixed. A ring-shaped magnet 103 magnetized in multiple poles in the circumferential direction is adhered or press-fitted and fixed to a frame 104 formed by metal pressing. The inner diameter side of the frame 104 is fixed to the boss 102 by caulking to form a rotor. Reference numeral 105 denotes a bearing housing formed by cutting a metal such as brass, in which a first oil-impregnated metal 106 and a second oil-impregnated metal 107 that support the shaft 101 of the rotor are press-fitted and fixed. Reference numeral 108 denotes a metal printed board on which a motor drive circuit and the like are mounted, and the inner diameter hole is fixed to the bearing housing 105 by caulking. Reference numeral 109 denotes an armature in which a copper wire is wound around an iron core via resin insulation, and is fixed to the bearing housing 105 by press fitting or crimping, and the end of the copper wire is soldered to the metal printed board to fix the stator. Are configured. Reference numeral 110 denotes a retainer that prevents the rotor from coming off in the thrust direction.
A groove is formed in and inserted into. Reference numeral 111 denotes a bottom plate that supports the load of the rotor in the thrust direction, and is fixed to the bearing housing 105 by caulking via a wear-resistant resin plate 112.

[0005]

However, in the above-mentioned conventional structure, the mechanism is complicated, the number of cutting parts is high, and the cost is high, and the mechanical mounting surface, that is, the metal printed board and the bearing housing are formed by caulking. Therefore, the outer peripheral portion of the metal printed circuit board must be supported when the bottom plate is crimped, and the force causes the metal printed circuit board to be deformed and the perpendicularity of the shaft to be difficult to be obtained. Therefore, it is difficult to read the disc signal of the CD-ROM, which may cause a READ error.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a simple structure of a small brushless motor and to improve the perpendicularity between the mounting surface and the shaft.

[0007]

In order to achieve this object, a small brushless motor of the present invention has a bearing housing and a mounting base formed of a steel plate as a bracket by a metal press burring process, and an oil-impregnated metal is formed inside the burring portion. The bearing and the armature are press-fitted and fixed to the outside.
In addition, the printed circuit board is attached and fixed with double-sided tape. Burring is applied to the center of the rotor frame and the shaft is fixed by direct press fitting. By providing a plurality of through holes on the top surface of the rotor frame, the armature surface can be received through the through holes, and the assembly can be assembled so that the force generated when press-fitting and fixing the thrust receiver is not applied to the mounting base. Has become. The retaining ring is formed by press fitting a ring punched by metal pressing. The thrust receiver is formed by metal press working and fixed to the bracket by press fitting.

[0008]

This mechanism is composed of inexpensive parts made by metal press working, and has a simple structure so that the assembling process can be simplified. Then, the stator can be supported through the hole on the top surface of the frame, and a small brushless motor can be realized in which the force generated during assembly does not adversely affect the mounting surface and the squareness of the shaft can be maintained with high accuracy.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a small brushless motor according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a shaft for transmitting rotation, and 2 is a frame of a rotor, in which a ring-shaped magnet 3 magnetized in multiple poles in the circumferential direction is press-fitted or adhered. A burring process is applied to the central portion and the shaft 1 is directly press-fitted to form a rotor. Reference numeral 4 denotes a bracket in which a baring process is applied to a substantially central portion of a steel plate to form a bearing housing and which is integrated with a mounting base. An oil-impregnated metal 5 that rotatably supports the shaft is press-fitted and fixed to the inside of the burring process of the bracket, and an armature 6 in which a copper wire is wound around an iron core via a resin insulator is press-fitted and fixed to the outside. Further, a printed board 7 on which at least a part of a circuit for driving and controlling a motor is mounted is adhesively fixed to a flat surface of a bracket with a double-sided tape, and a winding end of a copper wire of the armature is placed on the printed board. Wiring and configuring the stator. Reference numeral 8 denotes a retainer that prevents the rotor from coming off in the thrust direction, and is formed by metal pressing. And it is press-fitted into the other end of the shaft. 9
Is a bottom plate that supports the load in the thrust direction of the rotor,
It is press-fitted and fixed to the burring inlet of the bracket through a wear-resistant resin plate (thrust plate) 10.

FIG. 2 is a plan view of the small brushless motor according to the embodiment of the present invention as seen from above. In FIG. 2, there are a plurality of through holes 11 on the top surface of the frame of the rotor, and when the bottom plate is press-fitted into the bracket, the P surface of the armature can be supported through the through holes, and the force at the time of press-fitting the bracket It is possible to assemble without adding to the mounting base.

[0012]

As described above, according to the present invention, it is possible to realize a small brushless motor which has a simple structure and is inexpensive, and it is possible to easily improve the accuracy of the squareness of the mounting surface and the shaft.

[Brief description of drawings]

FIG. 1 is a sectional view of the structure of a small brushless motor according to an embodiment of the present invention.

FIG. 2 is a plan view of the small brushless motor according to the embodiment of the present invention viewed from above.

FIG. 3 is a sectional view of the structure of a conventional small brushless motor.

[Explanation of symbols]

 1,101 Shaft 2 Rotor Frame 3,103 Magnet 4 Bracket 5 Oil-impregnated Metal 6,109 Armature 7 Printed Circuit Board 8,110 Detachment Prevention 9,111 Bottom Plate 10 Resin Plate (Thrust Plate) 11 Through Hole 102 Rotor Boss 104 Frame 105 Bearing housing 106 First oil-impregnated metal 107 Second oil-impregnated metal 108 Metal printed circuit board 112 Resin plate

Claims (4)

[Claims] 1. A bracket in which a barring is applied to a substantially central portion of a steel plate and which is used as a bearing housing to be integrated with a mounting base, and an oil impregnating member which rotatably supports a shaft of a rotor inside the barring processing part of the bracket. The metal is press-fixed, and the stator is press-fixed on the outside with the armature in which the copper wire is wound and layered on the iron core through the insulator and the cylindrical magnet magnetized in the circumferential direction. Adhesive or press-fit fixed to the frame formed by press working,
A motor having a stator that is directly press-fitted and fixed to the shaft by subjecting a burring process to a central portion of the frame, wherein at least two through holes are provided on a top surface of the frame of the rotor. Small brushless motor. 2. The small brushless motor according to claim 1, wherein a printed circuit board on which at least a part of a circuit for driving and controlling the motor is mounted on the flat surface portion of the bracket is adhesively fixed to the flat surface portion of the bracket with a double-sided tape. 3. A mechanism for preventing the rotor from slipping out in the thrust direction by press-fitting and fixing a metal ring formed by metal pressing on the other end of the rotor shaft.
Small brushless motor described. 4. A wear resistant resin is placed on a steel plate formed by metal pressing to support a load in the thrust direction of the rotor, and the steel plate is press-fitted and fixed to the burring inlet of the bracket. Small brushless motor.