JP2002272037A - Rotating drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating drive device in which rotor magnets can be attached to a rotary unit without deformations and crackings, and with high precision, which can suppress rotation unevenness and vibration caused by the eccentricity of the rotor magnets, and to realize stable drive over a long term. SOLUTION: Bearing surfaces 17, which restrict the radial attachment positions of magnets 12, are provided on a rotary unit 6. The magnets 12, positioned by the bearing surfaces 17 are attached to the rotary unit 6 by clearance fit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive used for information equipment and the like.

[0002]

2. Description of the Related Art Recently, CD-ROM drives and CD-Rs have been developed.
2. Description of the Related Art In a disk device for recording / reproducing data such as a drive, the data transfer speed is increasing.

[0003] In order to increase the data transfer speed, it is necessary to rotate the disk at a high speed. Therefore, the rotation drive of the disk is also rotated at a high speed. The unbalance of the rotating drive itself that has not been generated causes vibration at the time of high-speed rotation, which causes problems such as generation of noise and shortened life.

FIGS. 3 and 4 show a conventional rotary drive device. As shown in FIG. 3, in the finished rotary drive device, a cylindrical shaft holding member 1 is fixed to a base 2 as a fixed side, and the outer periphery of the radial bearing 3 is fixed inside the shaft holding member 1. Have been. A shaft 4 is rotatably supported on the base 2 inside the radial bearing 3. The lower side of the shaft 4 is held by a thrust receiver 5 fixed to the shaft holding member 1.

[0005] A stator core 9 and a stator coil 10 wound around the stator core 9 are provided as stators on the outer periphery of the shaft holding member 1.
Numeral 0 is electrically soldered to a motor board 11 fixed to the base 2.

A turntable 6 as a rotating body for supporting the disk 14 is attached to a tip of the shaft 4. A rubber-made turntable 6 is provided on the support surface of the turntable 6 for preventing the disk 14 from slipping. A turntable sheet 7 is provided. A ring-shaped turntable yoke 8 made of a magnetic material is provided on the upper surface of the central part of the turntable 6. The disc is
Turntable yoke 8 and this turntable yoke 8
The disk is held on the turntable sheet 7 by the magnetic attraction of a chucking member (not shown) provided with a magnet at a position facing the disk, and the disk is driven to rotate together with the rotation of the motor.

[0007] A cup-shaped rotor yoke 13 is mounted on the outer periphery of the turntable 6 so as to face the stator core 9, and the outer periphery of the annular rotor magnet 12 is fixed inside the outer periphery of the rotor yoke 13. .

A magnetic circuit is formed between the rotor magnet 12 and the rotor yoke 13 which is a magnetic material, and the rotational driving force of the motor is generated by the magnetic field of the rotor magnet 12 and the rotating magnetic field generated by supplying power to the stator coil 10. I do.

In the rotary drive device configured as described above, the attachment of the rotor yoke 13 and the rotor magnet 12 to the turntable 6 is performed according to the steps shown in FIG.

As shown in FIG. 4A, a surface of the turntable 6 opposite to the disk supporting surface has an annular shape which engages with an inner peripheral portion of a hole 15 formed in the center of the rotor yoke 13. A step 16 is formed. The inner diameter R2 of the hole 15 is formed to be larger than the inner diameter R1 of the stepped portion 16. When the rotor yoke 13 is attached to the turntable 6, the hole 15 of the rotor yoke 13 is connected to the stepped portion 16 as shown in FIG. It is carried out by fitting with an adhesive or caulking.

As shown in FIG. 4 (c), the outer periphery of the annular rotor magnet 12, whose outer diameter is set smaller than the inner diameter R3 of the rotor yoke 13, is fixed to the inner wall of the outer periphery of the rotor yoke 13 with an adhesive. Is done.

[0012]

However, in the rotary drive device assembled as described above, rattling occurs when the rotor yoke 13 shown in FIG. 4B is attached, and the rotor shown in FIG. The rattling also occurs when the magnet 12 is attached. If the two rattles overlap in phase during assembly, the concentricity of the inner diameter of the rotor magnet 12 with respect to the shaft 4, which is the center of rotation, becomes large.

Further, even when the dimensional accuracy of the concentricity between the inner diameter and the outer diameter of the rotor magnet 12 is not good, the concentricity of the inner diameter of the rotor magnet 12 with respect to the shaft 4 may be affected.

As described above, if the accuracy of the concentricity of the inner diameter of the rotor magnet with respect to the shaft 4 is deteriorated due to the variation in assembly and the dimensional accuracy of parts, the eccentricity of the rotating body becomes large and vibration occurs, 1
The gap between the inner diameter of the stator core 2 and the outer diameter of the stator core 9 is deviated, and the magnetic attraction force is deviated, the rotation balance is lost, rotation unevenness and vibration occur, and stable driving cannot be performed.

The reason why the press-fitting assembly method cannot be adopted so that there is no play between the rotor yoke 13 and the rotor magnet 12 is because the press-fitting causes deformation of the rotor yoke 13 and cracking of the rotor magnet 12.

The present invention solves the above-mentioned problems and can accurately attach the rotor magnet to the rotating body without causing deformation or cracking, and suppresses the occurrence of rotation unevenness and vibration due to the eccentricity of the rotor magnet, so that the rotor magnet is stable for a long time. It is an object of the present invention to provide a rotary drive device capable of realizing a controlled drive.

[0017]

A rotary drive device according to the present invention is characterized in that a rotary body is provided with a contact surface for regulating a mounting position of a magnet in a radial direction, and the magnet is loosely fitted to the rotary body.

According to the present invention, the rotor magnet can be attached to the shaft with high precision without causing deformation or cracking, the weight is balanced, and the gap between the stator core and the rotor magnet is uniform. The occurrence of rotation unevenness and vibration can be reduced, and stable driving can be realized for a long time.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary drive device according to a first aspect of the present invention comprises a rotary member rotatably supported from a fixed side and a magnet provided to face the stator on the fixed side. Wherein the rotating body is provided with a contact surface for regulating a mounting position of the magnet in a radial direction, and the magnet is loosely fitted on the contact surface and attached to the rotating body.

According to a second aspect of the present invention, there is provided a rotary driving device.
In claim 1, the contact surface is provided so as to contact the inner periphery of the magnet. The rotation drive device according to claim 3 of the present invention, wherein the base end of the shaft is inserted into a shaft holding member formed on the fixed side, and a rotation body is mounted on the tip end to rotatably support the rotation body. A rotary driving device having an annular rotor magnet attached to the outer periphery of a shaft provided on the outer periphery of the shaft holding member so as to face the outer periphery of the stator core. A contact surface is provided for restricting a mounting position of the magnet in the radial direction by abutting, and the magnet is loosely fitted to the contact surface and attached to the rotating body.

According to a fourth aspect of the present invention, there is provided a rotary drive device comprising:
In claim 3, the rotating body is a turntable that supports a disk. Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2 based on specific examples.

The components having the same configuration as in FIGS. 3 and 4 showing the conventional example will be described with the same reference numerals. Figure 1
Shows a rotary drive device of the present invention, and a turntable 6 as a rotating body is provided with a contact surface 17 that regulates a mounting position in a radial direction so as to reduce a deviation of concentricity between an inner diameter and an outer diameter of the rotor magnet 12. This is different from the above-mentioned conventional example in that the rotor magnet 12 is loosely fitted on the turntable 6.

More specifically, as shown in FIG. 2A, the contact surface 17 is formed on the surface of the turntable 6 opposite to the surface on which the disk 14 is supported, and comes into contact with the inner periphery of the rotor magnet 12. It is constituted by the outer peripheral surface of the provided annular convex portion 17a.

The outer diameter r1 of the projection 17a is set slightly smaller than the inner diameter r2 of the rotor magnet 12. When such a contact surface 17 is provided, as shown in FIG. 2B, the rotor magnet 12 is inserted along the contact surface 17 until the upper end surface of the rotor magnet 12 contacts the turntable 6. The rotor magnet 12 is positioned in the radial direction, and is closely fitted to the turntable 6 with high accuracy by reducing the difference in concentricity between the inner diameter and the outer diameter. The rotor magnet 12 is fixed not only by loose fit but also by an adhesive.

The outer periphery of the rotor magnet 12 is shown in FIG.
As shown in (c), the rotor yoke 13 is fitted until the upper end thereof comes into contact with the turntable 6, and is fixed with an adhesive.

By mounting the rotor magnet 12 positioned by the contact surface 17 on the turntable 6 by loose fit, the mounting accuracy of the rotor magnet 12 can be reduced to the component accuracy of the turntable 6 and the turntable 6 and the rotor magnet 12. It is determined only by the mounting accuracy and is not affected by the assembling accuracy and component dimensional accuracy of the rotor yoke 13 as in the conventional example described above, and furthermore, it is possible to realize an accurate assembly without deformation or cracking.

Also, since the rotor magnet 12 is hardly affected by the deviation of the concentricity between the inner diameter and the outer diameter of the rotor magnet 12, the rotor magnet 12 can be accurately assembled to the shaft 4, which is the center of rotation, and the eccentricity is reduced. small,
A rotating body having a uniform clearance between the stator core 9 and the rotor magnet 12 can be obtained.

As a result, the occurrence of rotation unevenness and vibration can be suppressed, and stable driving can be realized for a long period of time. In addition,
In the above description, the annular convex portion 17 is provided on the turntable 6 as a rotating body, but the same effect can be obtained if the convex portion 17 is provided on a part of the rotating body interposed between the shaft 4 and the rotor magnet 12. Is obtained.

In the above description, the contact surface 17 is constituted by the outer periphery of the annular projection 17a. However, the contact surface 17 is brought into contact with the inner periphery of the rotor magnet 12, or both the inner and outer periphery, and
The second mounting portion may restrict the mounting position in the radial direction. Further, instead of making the convex portion 17a annular, a plurality of circumferentially divided convex portions may be used.

Further, the above-described configuration can be applied not only to a rotary drive of a rotary shaft type but also to a rotary drive of a fixed shaft type.

[0031]

As described above, according to the rotary drive device of the present invention, a rotary drive device is provided in which a magnet is provided on a rotating body rotatably supported from a fixed side so as to face the stator on the fixed side. A contact surface that abuts the inner or outer periphery of the magnet on the rotating body to regulate a mounting position of the magnet in a radial direction, and that the magnet positioned on the contact surface is inserted into the rotating body. By doing so, the rotor magnet can be accurately attached to the rotating body without deformation or cracking, and the clearance between the stator core and the rotor magnet can be made uniform. Is suppressed, and stable driving can be realized for a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotary drive device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating an assembling process of main parts in FIG. 1;

FIG. 3 is a cross-sectional view of a conventional rotary drive device.

FIG. 4 is a schematic cross-sectional view for explaining an assembling process of main parts in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Axis holding member 2 Base 4 Shaft 9 Stator core 10 Stator coil 12 Rotor magnet 13 Rotor yoke 14 Disk 17 Contact surface 17a Convex part

Continued on the front page F term (reference) 5H615 AA01 BB01 BB14 PP02 PP07 PP28 SS08 SS09 SS19 SS53 TT05 5H621 BB07 GA01 GA04 HH01 JK05 JK07 JK15 5H622 CA01 CA05 CA10 CB05 PP03 PP10 PP11 PP19

Claims (4)

[Claims] 1. A rotary drive device comprising: a rotating body rotatably supported from a fixed side; and a magnet provided to face the stator on the fixed side, wherein the magnet is mounted on the rotating body in a radial direction. A rotary drive device having a contact surface for regulating a position, wherein the magnet is loosely fitted to the contact surface and attached to the rotating body. 2. The rotary drive device according to claim 1, wherein said contact surface is provided so as to abut on an inner periphery of said magnet. 3. A shaft holding member formed on a fixed side, wherein the base end of the shaft is inserted, a rotating body is mounted on the tip end and rotatably supported, and an outer periphery of the shaft holding member is provided inside the rotating body. A rotary drive device provided with an annular rotor magnet so as to face an outer periphery of a stator core provided with a coil and wound around a coil, wherein the rotor is in contact with an inner periphery of the rotor magnet in a radial direction of the magnet. A rotary drive device provided with a contact surface for regulating the mounting position of the magnet, and the magnet is loosely fitted to the contact surface and attached to the rotating body. 4. The rotary drive device according to claim 3, wherein said rotating body is a turntable for supporting a disk.