JPH10127004A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which has a simple structure and a rotary shaft of a rotor being surely held in the axial direction, and can get an improvement in vibration-proof. SOLUTION: A motor 20 is constituted of a stator section 21 including a bearing 26 mounted on a fixed stator substrate 22, and a rotor section 30 including a rotary shaft 31 rotatably supported by the bearing 26. The rotary shaft 31 is formed of magnetic substance and a magnet 29 for attraction is so disposed as to face one end face of the rotary shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor used as a spindle motor for rotating an optical disk such as a compact disk (CD) or a CD-ROM.

[0002]

2. Description of the Related Art Conventionally, such a motor is, for example, shown in FIG.
It is configured as shown in FIG. In FIG.
Is composed of a fixedly arranged stator section 2 and a rotor section 3 rotatably supported with respect to the stator section 2.

[0003] The stator section 2 includes a stator substrate 2a, a bearing holder 2b mounted on the stator substrate 2a, an iron core 2d mounted so as to surround the bearing holder 2b in the circumferential direction, and a winding around the iron core 2d. Turned winding coil 2c
And the bearing 2 held by press fitting or the like in the bearing holder 2b
e. The bearing 2e includes a thrust receiver 2f for supporting one end of a rotating shaft (described later) to be supported in the thrust direction, and a pressing plate 2g for pressing the thrust receiver 2f against the end surface of the rotating shaft.

On the other hand, the rotor unit 3 includes a rotating shaft 3a rotatably held by a bearing 2e and a rotating shaft 3a.
a, and a cylindrical rotor yoke 3c having an open lower end surrounding the winding coil 2c from the outside in the radial direction, and a rotor magnet 3d mounted on the inner surface of the rotor yoke 3c.
And Here, the lower end surface of the rotating shaft 3a is supported by the thrust receiver 2f in the bearing 2e, so that the rotating shaft 3a is prevented from falling down.

According to the motor 1 configured as described above,
By appropriately energizing the winding coil 2c, the magnetic field generated in the winding coil 2c interacts with the magnetic field generated by the rotor magnet 3d and the rotor yoke 3c of the rotor unit 3 via the iron core 2d, and The unit 3 is driven to rotate. In this case, the axial center of the rotor magnet 3d of the rotor portion 3 is slightly shifted upward with respect to the axial center of the iron core 2d of the stator portion 2. This allows
The rotor magnet 3d of the rotor section 3 acts to magnetically attract the iron core 2d. Accordingly, the rotating shaft 3a of the rotor unit 3 is urged downward in the axial direction by the magnetic attraction and gravity, and the stator unit 2
It is held so that it does not fall upward from.

[0006]

However, in the motor 1 constructed as described above, the rotor portion 3 is prevented from dropping above the rotating shaft 3a by an axial displacement between the rotor magnet 3d and the iron core 2d. This is done by the magnetic attraction force. Accordingly, there is a limit to the magnetic attraction force thus obtained, and there is a problem that a sufficient attraction force may not be obtained.

In particular, when the motor 1 is used as a spindle motor for driving the rotation of a disk of a CD-ROM drive, extremely intense vibration is applied to the motor 1 with the recent increase in the rotation speed of the disk of a CD-ROM drive. Will be communicated. For this reason, if the magnetic attraction force of the rotor magnet 3a of the rotor 3 described above is not sufficient, the rotor section 3 vibrates violently with the disk.
For this reason, there has been a problem that accurate signal reading from the disk cannot be performed.

Further, when the CD-ROM drive is placed in a so-called vertical position, the rotating shaft 3a of the motor 1 is disposed horizontally, so that the rotating shaft 3a cannot be pressed in the axial direction by the action of gravity. Therefore, since the above-mentioned vibrations appear more remarkably, there is a problem that it is practically difficult to use the apparatus vertically.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a motor having a simple configuration, whereby the rotating shaft of the rotor can be securely held in the axial direction and vibration resistance can be improved. And

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a motor comprising: a stator having a bearing; and a rotor comprising a rotating shaft rotatably supported by the bearing. In the above, the rotation shaft is formed of a magnetic material, and a suction member is provided to face an end surface of one end of the rotation shaft.

According to the above construction, since the attraction magnet is disposed at one end of the rotating shaft of the rotor, the attraction magnet magnetically attracts the one end of the rotating shaft. Accordingly, the rotating shaft of the rotor unit is urged in the axial direction. Therefore, the rotating shaft and the rotor section are held in the bearing of the stator section in a stable state in the axial direction. As a result, when the motor is used as a spindle motor of a CD-ROM drive, the rotor section is driven at a high speed and the rotor section is held in a stable state even when severe vibration is applied. Thus, the reading of the disk does not become impossible, and accurate reading is performed. In particular, even when the rotating shaft of the motor is disposed horizontally, the rotating shaft is reliably urged in the axial direction by the attraction magnet, so that one end thereof is stably held. Will be.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. still,
Since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are added.
The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIG. 1 shows a CD-ROM incorporating a first embodiment of a motor according to the present invention as a spindle motor.
Indicates a drive. In FIG. 1, a CD-ROM drive 10 includes a turntable 12 on which a CD-ROM 11 to be reproduced is mounted, a spindle motor 13 for rotating and driving the turntable 12, and a CD-ROM 1
1 for reading a signal.

Thus, the CD-ROM 11 is fixedly held on the turntable 12 and is driven to rotate by the spindle motor 13. Then, a light beam such as a laser beam for reading a signal from the optical pickup 14 is applied to the CD-ROM 11 that is rotationally driven in this manner.
By irradiating a predetermined track on the signal recording surface of the D-ROM 11, a return light beam from the signal recording surface is detected by the photodetector in the optical pickup 14 and recorded on the CD-ROM 11. Reproduction of data is performed.

FIG. 2 shows the CD-ROM drive 1 described above.
1 shows a first embodiment of a motor according to the invention used as spindle motor 13 at 0; In FIG. 2, a motor 20 includes a fixedly arranged stator section 21.
And a rotor unit 30 rotatably supported by the stator unit 21.

The stator portion 21 includes a stator substrate 22 and
A bearing holder 23 attached to the stator substrate 22;
An iron core 25 attached so as to surround the bearing holder 23 in the circumferential direction, and a winding coil 24 wound around the iron core 25
And the bearing 2 held in the bearing holder 23 by press fitting or the like.
6 is included. The bearing 26 further includes a thrust receiver 27 for supporting one end of a rotating shaft (described later) to be supported in the thrust direction, and a pressing plate 28 for pressing the thrust receiver 27 against the end surface of the rotating shaft. .

On the other hand, the rotor portion 30 is
A rotating shaft 31 rotatably held by the rotor, a cylindrical rotor yoke 33 attached to the rotating shaft 31 via a rotor boss 32 and having an open lower end surrounding the winding coil 24 from outside, and a rotor yoke 33 And a rotor magnet 34 provided on the inner surface of the rotor. In this case, the lower portion of the rotating shaft 31 is supported by the thrust receiver 27 in the bearing 26, so that the rotating shaft 31 is prevented from falling down.

The above structure is substantially the same as that of the conventional motor 1 shown in FIG. 4, but in the motor 20 according to the embodiment of the present invention, the thrust receiver 27 of the bearing 26, the pressing plate 28 Between them, an attraction magnet 29 is inserted as an attraction member. The attracting magnet 29 is disposed between the thrust receiver 27 and the holding plate 28.
Fixedly held. On the other hand, the rotation shaft 31 is formed of a magnetic material.

The CD-ROM drive 10 according to the embodiment of the present invention is configured as described above. The CD-ROM 11 is mounted on the turntable 12 and the CD-ROM 11 is rotated by rotating the spindle motor 13. -ROM1
1 is driven to rotate, and recording data is read by an optical pickup 14 with respect to a predetermined track on a signal recording surface of the CD-ROM 11. Here, as the spindle motor 13, a motor 20 having a configuration as shown in FIG. 2 is used. Accordingly, by appropriately energizing the winding coil 25 of the motor 20, the magnetic field generated in the winding coil 25 interacts with the magnetic field generated by the rotor magnet 34 and the rotor yoke 33 of the rotor unit 30, and Is driven to rotate.

At this time, the rotating shaft 31 of the rotor unit 30 is formed of a magnetic material, and an attraction magnet 29 is disposed to face one end (the lower end in the figure) of the rotating shaft 31. Have been. Thereby, the rotating shaft 3
1 is magnetically attracted by the attracting magnet 29. Therefore, since the rotating shaft 31 is urged toward the thrust receiver 27 in the axial direction, the end face of one end thereof comes into contact with the surface of the thrust receiver 27 with a sufficient suction force. Thereby, for example, a CD-ROM
Even if the drive 10 is of a high-speed type, the vibration does not cause the rotating shaft 31 to separate from the surface of the thrust receiver 27, and can be kept in a stable state in the axial direction. Thus, CD-R
The OM drive 10 is installed in a so-called vertical position, and the rotary shaft 3
Even if 1 is arranged horizontally, the rotating shaft 31
By the magnetic attraction by the attraction magnet 29, it is surely brought into contact with the thrust receiver 27 in the axial direction. As a result, even if the rotating shaft 31 receives vibration, the rotating shaft 31 surely comes into contact with the thrust receiver 27, and the vibration resistance is improved.

FIG. 3 shows a second embodiment of the motor according to the present invention. In FIG. 3, the motor 40 is
Is substantially the same as the motor 20 shown in FIG.
The configuration is different only in that the pressing plate 41 for pressing the thrust receiver 27 in the axial direction is configured as a magnet.

According to the spindle motor 40 having the above-described structure, the rotating shaft 31 is provided in the same manner as the motor 20 shown in FIG.
Is held by suction in the axial direction by the holding plate 41, so that the rotor unit 30 is held in a stable state in the axial direction. Therefore, the vibration resistance of the rotor unit 30 is improved.

In this case, the holding plate 28 and the attracting magnet 29 in the motor 20 shown in FIG.
Because it is configured as, the number of parts is small,
Parts and assembly costs are reduced.

In the above-described embodiment, the rotor yoke 33 and the rotor magnet 34 provided on the inner surface thereof are arranged so as to surround the winding coil 24 arranged in an annular shape from the outside. However, the present invention is not limited to such a configuration, and the present invention can be applied to a motor in which a rotor yoke and a rotor magnet are disposed so as to face the winding coil in the axial direction, or a motor in which the rotor yoke is omitted. Clearly applicable. In the above-described embodiment, the motor 10 used as the spindle motor for rotating the CD-ROM has been described. However, the present invention is not limited to this, and the motor for rotating and driving an optical disk and any rotating member may be used. It is clear that the present invention can be applied to the present invention.

As described above, according to the embodiment of the present invention, the attraction magnet 29 is attached to the end face of one end of the rotating shaft 31 of the rotor section 30 via the thrust receiver 27.
Is provided, this attracting magnet 29 is
By magnetically attracting the end surface of one end of the rotating shaft 31, the rotating shaft 31 of the rotor unit 30 is urged in the axial direction with respect to the thrust receiver 27. Therefore, this rotating shaft 3
1 and the rotor section 30 is held in the bearing of the stator section 21 in a stable state in the axial direction. Thereby, when the motors 20 and 40 are used as the spindle motor 13 of the CD-ROM drive,
Even if the rotor unit 30 is driven to rotate at a high speed and violent vibration is applied, the rotor unit 30 is kept in a stable state, so that the reading of the disk 11 does not become impossible and accurate reading is performed. Will be performed.
In particular, even when the rotating shafts 31 of the motors 20 and 40 are horizontally arranged, the rotating shaft 31 is
9 ensures that it is urged in the axial direction,
The one end thereof is stably held in a state of being in contact with the thrust receiver 27.

[0026]

As described above, according to the present invention, it is possible to provide a motor having a simple structure in which the rotating shaft of the rotor can be securely held in the axial direction and vibration resistance can be improved. .

[Brief description of the drawings]

FIG. 1 is a schematic side view of a CD-ROM drive incorporating a first embodiment of a motor according to the present invention as a spindle motor.

FIG. 2 is a schematic sectional view showing a motor in the CD-ROM drive of FIG.

FIG. 3 is a schematic sectional view showing a second embodiment of the motor according to the present invention.

FIG. 4 is a schematic sectional view showing an example of a conventional spindle motor.

[Explanation of symbols]

10: CD-ROM drive, 11: CD-R
OM, 12: turntable, 13: spindle motor, 14: optical pickup, 20: motor, 21: stator part, 22: stator substrate, 23: bearing holder, 24 ... iron core, 25 ...
・ Wound coil, 26 ・ ・ ・ Bearing, 27 ・ ・ ・ Thrust receiver, 28 ・ ・ ・ Pressing plate, 29 ・ ・ ・ Adsorption magnet, 30 ・ ・ ・ Rotor part, 31 ・ ・ ・ Rotating shaft, 32 ・ ・
· Rotor boss, 33 ··· rotor yoke, 34 ··· rotor magnet, 40 ··· motor, 41 ··· holding plate (also used as suction magnet).

Claims (3)

[Claims] 1. A motor comprising: a stator having a bearing; and a rotor including a rotating shaft rotatably supported by the bearing, wherein the rotating shaft is formed of a magnetic material. In addition, a suction member is provided to face an end face of one end of the rotating shaft. 2. The bearing according to claim 1, wherein the bearing includes a thrust receiver disposed so as to contact one end of the rotary shaft, and a pressing plate pressing the thrust receiver against the rotary shaft. 2. The motor according to claim 1, comprising a magnet, wherein the magnet is provided between the thrust receiver and the holding plate. 3. The bearing comprises a thrust receiver disposed so as to contact one end of a rotary shaft, and a pressing plate for pressing the thrust receiver against the rotary shaft. The motor according to claim 1, comprising a magnet, wherein the magnet is formed integrally with the holding plate.