JPH11356023A - Brushless motor provided with turntable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to ensure the sufficient perpendicularity without use of an expensive turntable formed by cutting brass or the like and thus reduce cost. SOLUTION: The brushless motor comprises a rotor R with a turntable for medium placement integrated with a rotor case on the negative side and a magnet placed on the other side, a shaft 5 supporting the rotor, a housing for supporting the shaft, and a stator 4 which is placed on part of the housing and drives the rotor. A medium placement portion 6a which functions as a turntable is formed on the circumference of the rotor case 6, and a recess 6b is formed inside the medium placement portion. The rotor case thus obtained is press fit onto the shaft, and then the medium placement portion is cut relative to the shaft to ensure the perpendicularity of the shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a CD-ROM,
The present invention relates to a brushless motor having a turntable unit suitable for driving a medium such as a DVD-ROM.

[0002]

2. Description of the Related Art Conventionally, as a brushless motor for driving a medium such as a CD, a turntable T for mounting a medium formed by cutting free-cut brass on one side of a shallow cylindrical rotor case K as shown in FIG. A rotor R integrated with a magnet M on the other side, a shaft S supporting the rotor R, and the shaft S are supported by a housing H including a shaft holder J and a stator base B. Some include a stator ST mounted on a part to drive the rotor R.

[0003]

However, such a media mounting turntable T is formed by cutting free-cutting brass, so that the cost and the time and labor for mounting the media become problems. Particularly in recent years, since the degree of perpendicularity to the shaft is strictly required, accuracy when mounted on the shaft has become a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a brushless motor having a turntable section which can perform its function without using an expensive turntable formed by cutting free-cutting brass and has a cost-effective turntable. Is provided.

[0005]

Means for Solving the Problems To solve the above-mentioned problems, a rotor in which a turntable portion is integrated on one side of a rotor case and a magnet is arranged on the other side as described in claim 1 is provided. A shaft for supporting the rotor,
In a brushless motor including a housing supporting the shaft and a stator mounted on a part of the housing to drive the rotor, a media mounting portion functioning as a turntable is formed on the outer periphery of the rotor case. This can be attained by forming a concave portion on the inside thereof, press-fitting the rotor case thus formed into the shaft, and then cutting the medium mounting portion with reference to the shaft so that the perpendicularity of the shaft is obtained. Further, it is preferable that a slip prevention means which also serves as rust prevention is formed on the cut surface of the media mounting portion of the rotor case.

According to the first aspect of the present invention, the verticality of the shaft can be sufficiently ensured, and there is no need to specially prepare a turntable for mounting a medium made of brass. According to the second aspect of the present invention, slipping can be prevented even with a high-speed type, while also providing rust prevention on the cut surface.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a brushless motor provided with a turntable according to a first embodiment of the present invention, which shows a configuration of a radial gap type cored type. FIG. 2 is an enlarged view of a main member of the motor. It is a fragmentary sectional view.

In FIG. 1, reference numeral 1 denotes a stator base made of a thin stainless steel plate or the like constituting a housing. A circuit board 2 made of a glass cloth epoxy plate is arranged on the upper surface, and a bridge portion 1a is left in the center. Pieces of the bone bone 1b
And a shaft holder 3 is formed by integrally molding the portion of the support bone piece 1b with a highly slidable resin. On the outer periphery of the shaft holder 3, two cores 4d formed by winding armature coils 4b # around a plurality of salient poles 4a #, respectively.
Are fixed by means such as adhesion or welding, and the terminal 4c of each of the armature coils 4b # is soldered to a predetermined pattern of the circuit board 2 to form the stator 4.

On the other hand, the rotor R includes a shaft 5 directly rotatably mounted on the shaft holder 3, a rotor case 6 mounted by press-fitting the shaft 5, and the core 5 inside the rotor case 6. A medium that functions as a turntable on the outer periphery of the rotor case 6 and is formed by ring-shaped rubber magnets 7 that are curled and press-fitted and fixed to a plate-shaped material so as to face the salient poles 4a # of the 4d through radial gaps. The mounting portion 6a is formed and the inside thereof is formed into a concave portion 6b. After the rotor case 6 is press-fitted into the shaft 5, the media mounting portion 6a is cut with reference to the shaft 5 to form a shaft. The verticality is given. Preferably, a flat knurl is formed in the press-fit portion of the shaft 5 in order to obtain the press-fit strength.

FIG. 2 shows a high-speed rotating type medium.
It is preferable to form a slip prevention film 6c by applying a rust-preventive rubber-based paint to the cut media mounting portion 6a as shown in FIG.

A sheet of a similar material may be attached instead of applying a rubber-based paint. Further, in the above-described embodiment, although a thin type in which two cores are laminated is shown, it is needless to say that a tens of laminated cores long in the axial direction can be employed.

[0012]

According to the first aspect of the present invention, the verticality of the shaft can be sufficiently ensured, and there is no need to prepare a special turntable for mounting the media. Can be omitted. According to the second aspect of the present invention, slipping can be prevented even with a high-speed type, while also providing rust prevention on the cut surface.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a configuration of a radial gap type cored type as a first embodiment of a brushless motor having a turntable section of the present invention.

FIG. 2 is an enlarged sectional view of an essential part of a main member of the motor.

FIG. 3 is a sectional view of a main part of a brushless motor having a conventional turntable unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator base 1a Bridge part 1b Support piece 1c Notch 2 Circuit board 3 Axis holder 3a Armature coil 3c Core cover 4 Several stator core salient poles 4a 4a Salient pole 4b Armature coil 5 Axis 6 Rotor case 6a Media mounting Place 6b Recess 6c Anti-slip membrane 7 Ring-shaped rubber magnet

Claims (2)

[Claims] 1. A rotor having a turntable unit integrated on one side of a rotor case and a magnet disposed on the other side, a shaft supporting the rotor, a housing supporting the shaft, and a part of the housing. In a brushless motor having a stator mounted on the rotor to drive the rotor, a media mounting portion functioning as a turntable is formed on the outer periphery of the rotor case, and the inside of the media mounting portion is formed into a concave portion. After press-fitting on the shaft,
A brushless motor provided with a turntable section, wherein the media mounting section is cut with reference to the axis to obtain a degree of perpendicularity to the axis. 2. The brushless motor provided with a turntable according to claim 1, wherein a slip prevention means which also serves as rust prevention is formed on a cut surface of the media mounting portion of the rotor case.