JPH09140089A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a motor as the one for rotating at a high speed a disk-like storage medium with a large capacity, absorbing the irregularity of the generative torque of its rotor, by interposing between its base and its stator an absorbing means for absorbing the rotary-torque-irregularity-based vibration of its rotor in its rotary direction. SOLUTION: The rotary-irregularity-based vibration of a rotor 40 of a motor 14 in its rotary direction is absorbed by an absorbing means 70 interposed between a stator 50 and a base 12 of the supporting portion of the stator 50. That is, the absorbing means 70 of an elastic body made of rubber or plastic and having a nearly lateral-U-shaped section is interposed both between a flange 56 of a bearing housing 52 and the base 12 and between an attachment member 57 and the base 12. Thereby, absorbing the irregularity of the generative torque of the rotor 40, the motor 14 can be used as the motor for rotating at a high speed a disk-like storage medium with a large capacity, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a motor for holding and rotating a disc-shaped recording medium, for example.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show an optical disk device. A base 1 of this optical disk device includes a spindle motor 2 and an optical pickup OP. The spindle motor 2 includes a rotor 3 and a stator 4. The shaft 3a of the rotor 3 is rotatably supported by the bearing 4a of the stator 4. The turntable 3b of the rotor 3 holds the optical disc D detachably. The rotor 3 has a magnet 5, and the stator 4 has an iron core 6 and a coil 7. The stator 4 is directly fixed to the base 1. By energizing this coil 7 in a predetermined energizing pattern, the rotor 3 rotates with respect to the stator 4. Therefore, the optical disc D is continuously rotated, and the optical pickup OP moves in the radial direction of the optical disc D so that the signal recorded on the optical disc D can be read or the signal can be written to the optical disc D. It has become.

[0003]

However, since the spindle motor 2 used for the purpose of rotating the optical disc D is required to be small in size and to have a high torque, it is necessary to use the coil for the iron core 6 as described above. A so-called iron core type motor for winding 7 is used. In this iron core type motor, the magnetic attraction force acting on the magnet 5 in the rotor 3 and the iron core 6 in the stator 4 changes depending on the rotation angle of the rotor 3, so that So-called cogging occurs, which is an uneven rotation force.

In recording a signal on the optical disc D or reproducing a signal from the disc D, the optical disc D
The rotational speed and the positional relationship between the optical pickup OP and the optical disk D must be accurately maintained. However, if there is unevenness in the rotational force of the rotor 3, not only the rotational speed cannot be maintained at a predetermined value, but also the unevenness in rotational force is transmitted to the base 1 as vibrations, and the optical pickup OP that is a portion for reading and writing. Will affect the positional relationship between the optical disc D and the optical disc D. Particularly, in recent years, the recording capacity of the optical disk D has increased, higher rotational accuracy and position accuracy are required, the recording and reading speed is increasing, the torque of the motor is also increasing, and as a result, the unevenness of the rotating force is increased. It is in. Therefore, the present invention has been made in order to solve the above problem, and provides a motor that can be used for rotation of a disk-shaped recording medium that rotates at high speed with high capacity by absorbing unevenness of the generated rotational force. Is intended.

[0005]

In the present invention, the above object is rotatably supported by a stator and the stator, and the stator is supported by energizing the stator. A rotor supporting the rotating rotor and the stator, and absorbing means arranged between the base and the stator for absorbing vibration in the rotation direction generated by the unevenness of the rotating force of the rotor. Achieved by the motor. The rotor rotates with respect to the stator via an axis. Since the absorbing means is arranged between the base and the stator, the absorbing means absorbs vibrations in the rotation direction due to unevenness of the rotating force of the rotor. Therefore, for example, the magnetic attraction force acting on the magnet in the rotor of the motor and the iron core in the stator changes depending on the rotation angle of the rotor. Can be absorbed.

[0006]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limitations are given, the scope of the present invention is not limited to these modes unless otherwise specified to limit the present invention.

FIG. 1 is a plan view showing an optical disk device equipped with the motor of the present invention. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 and 2, an optical disc device 10 includes a base 12, a motor 14, and an optical pickup 1.
6 and a moving mechanism 18 for the optical pickup 16 and the like.

The base 12 supports a motor 14 and a moving mechanism 18. The moving mechanism 18 has the following structure so that the optical pickup 16 can be moved in the arrow R direction (radial direction of the optical disc D). The gear 19a of the motor 19 of the moving mechanism 18 meshes with the gear 20 via the gears 19b and 19c. This gear 20 is a lead screw 2
1 is attached. The feed screw 21 can move the nut 22 in the arrow R direction by rotating the nut 22. The nut 22 is integrated with the optical pickup 16, and when the nut 22 and the optical pickup 16 move in the arrow R direction, they are linearly moved along the guide rod 23. The optical pickup 16 has an objective lens 24, a laser light source, an optical system (not shown), and the like. The laser light from the laser light source passes through the optical system and the objective lens 2
After passing 4, the signal recording surface of the optical disc D is irradiated as outgoing light. Then, the return light from the signal recording surface of the optical disc D is sent to the signal processing unit side via the optical system and the light receiving unit. Thereby, the signal recorded on the optical disc can be reproduced and the signal can be recorded on the optical disc D.

The motor 14 is a spindle motor, and as shown in FIGS. 1 and 2, the optical disk D can be removably attached via a turntable 30. The turntable 30 can firmly hold the optical disc D detachably by, for example, magnetic attraction. The optical disc D is, for example, a magneto-optical disc (MO).

The motor 14 comprises a rotor 40, a stator 50, a base 12 for supporting the stator 50, an absorbing means 70 and the like. The rotor 40 of FIGS.
Shaft 41, turntable 30, rotor housing 42,
The magnet 43 and the like are provided. Rotor housing 42
Fixes the magnet 43. This magnet 4
3 is attached in the circumferential direction along the inner peripheral surface of the rotor housing 42 made of iron or the like, and the S pole and the N pole are multi-pole magnetized. The rotor housing 42 is fixed to the lower surface of the turntable 30. The upper portion of the shaft 41 is fixed to the turntable 30 and the rotor housing 42 by press fitting or the like.

The stator 50 shown in FIGS. 2 to 4 is the rotor 4
0 is rotatably supported via a shaft 41. That is, the bearings 51, 51 of the stator 50 rotatably support the shaft 41. As the bearings 51, 51, a normal rolling bearing, a sliding bearing, an oil-impregnated bearing, or the like can be adopted. The bearings 51, 51 are the bearing housing 5 of the stator 50.
2 is set at a predetermined interval. The shaft end 41a of the shaft 41 is connected to the thrust receiving portion 53a of the bearing housing 52.
Is axially supported by. Bearing housing 52
Includes an iron core 53 and a coil 54. The coil 54 is wound around the iron core 53. For example, in the case of a three-phase motor, the coil 54 is a multiple of 3 along the circumferential direction, and three, six,
Nine ... allocated at equal intervals.

As shown in FIG. 2, the base 12 also serves as the device base of the optical disk device 10. Moreover, the base 12 is the bearing housing 5 of the stator 50 as shown in FIGS.
2 is attached via the absorbing means 70. Absorption means 70
Are held between the flange 56 of the bearing housing 52, the hollow disk-shaped mounting member 57, and the base 12.

The magnet 43 of the rotor 40 of the motor 14
And the magnetic attraction force acting between the iron core 53 of the stator 50 changes depending on the rotation angle of the rotor 30. Therefore, vibration in the rotation direction based on the rotation unevenness (cogging) of the rotor 40 is generated. The absorbing means 70 arranged between the base 12 which is a supporting portion of the stator 50 of the motor 14 and the stator 50 absorbs it. In this way, if the absorbing means 70 can absorb the vibration in the rotating direction generated by the uneven rotation of the rotor 40, the optical disc D that is desired to be rotated at high speed with high capacity
Can be realized by this motor 14.
In a normal optical disk motor, in order to maintain the positional relationship between the optical pickup 16 and the optical disk D, it is necessary to maintain the perpendicularity of the shaft (rotation shaft) 41 of the motor 14 with respect to the base 12 with high accuracy, and the motor 14 simply Stator 50 and base 1
If an elastic body is packed between the two, the positional relationship between the optical pickup 16 and the optical disk D cannot be maintained.

Therefore, in the embodiment of the present invention, the absorbing means 70, which is made of, for example, rubber or plastic or the like and has a substantially U-shaped cross section, is sandwiched between the flange 56 of the bearing housing 52 and the mounting member 57 and the base. It is arranged so as to be sandwiched between the stands 12. With such an arrangement structure of the absorbing means 70, in the rotation direction R of the rotor 40 of the motor 14 of FIG. 3, the force F2 in the shearing direction of the absorbing means 70, and the direction of the shaft 41 (axial vertical direction). ) V can be divided into the force F1 in the compressive tension direction.
The force F2 in the shearing direction and the force F in the axial direction of the absorbing means 70.
By adjusting 1 with the thickness shape of the absorbing means 70, the required vibration suppressing force in the rotation direction R and the required rigidity in the axial direction V can be realized.

That is, the absorbing means 70 has a substantially U-shaped cross section as described above, has the portions 71 and 72 and the connecting portion 73, and has the rotating direction R and the axial direction V of the rotating body 40.
Therefore, the rigidity of the absorbing means 70 is different. The thickness W2 of the portions 71 and 72 plays a role of holding the rigidity in the rotation direction R (corresponding to the vibration control force) and also plays a role of holding the rigidity in the axial direction V. That is, the parts 71, 72
The rigidity of the rotor 40 in the rotation direction R is
In comparison with the rigidity of the shaft 41 in the vertical direction (the direction perpendicular to the shaft) V, the rigidity of both is set to different values. In this case, the rigidity in the rotation direction R is set to be larger than the rigidity in the axial direction V.

Next, the operation of the above-mentioned optical disk device 10 will be described. The coil 5 of the stator 50 of FIGS. 2 and 3
4 is externally energized in a predetermined energization pattern, a magnetic field is generated in the coil 54, and the magnetic field lines thereof pass through the iron core 53 and interact with the magnetic field lines passing from the magnet 43 of the rotor 40 to the rotor housing 42. Act on.

As a result, the rotor 40 and the optical disk D continuously rotate about the shaft 41 with respect to the stator 50 at a predetermined speed. When the rotor 40 and the optical disk D rotate, the magnetic attraction force acting on the magnet 43 of the rotor 40 and the iron core 53 of the stator 50 changes due to the rotation angle of the rotor 40. The unevenness of the rotating force that causes the vibration in the rotation direction R, the absorbing means 70 can absorb the vibration in the rotation direction R.
That is, as shown in FIG. 3, the rotation direction of the rotor 40 can be divided into the force F2 in the rotation direction (shear direction) R of the absorbing means 70, the vertical direction V, and the force F1 in the compression pulling direction. The forces F2 and F1 can be corrected appropriately by the thicknesses W2, W2 and W1 of the absorbing means 70.
As a result, the required vibration suppressing force of the rotor 40 in the rotation direction R and the required rigidity in the axial direction V can be realized.

In the above-described embodiment of the present invention, an example of a magneto-optical disk is given as the optical disk D, but the present invention is not limited to this, and other kinds of optical disks may be used. For example, the motor of the present invention can be applied to an optical disk device that reproduces information from a read-only memory CD-ROM using a compact disk. In addition to rotating the disk-shaped recording medium, the motor of the present invention can be used to rotate other objects to be rotated. Further, the absorbing means 70 is not limited to the illustrated cross-sectional shape, and other shapes can be adopted. Absorbing means 7
0 may be ring-shaped or may be divided into a predetermined number in the circumferential direction.

[0019]

As described above, according to the present invention,
It can be used for rotation of a disk-shaped recording medium which has a high capacity and rotates at a high speed by absorbing the unevenness of the generated rotational force.

[Brief description of the drawings]

FIG. 1 is a plan view showing an optical disc device using a preferred embodiment of a motor of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the optical disk device of FIG.

3 is an enlarged cross-sectional view showing the motor of FIG.

FIG. 4 is an exploded view of the motor shown in FIG.

FIG. 5 is a sectional view showing a conventional optical disc device.

FIG. 6 is a sectional view showing a conventional motor.

[Explanation of symbols]

 12 base 14 motor 30 turntable (supporting part) 40 rotor 50 stator 70 absorbing means

Claims (4)

[Claims] 1. A stator, a rotor rotatably supported by the stator via an axis, and a rotor that rotates with respect to the stator when energized and a base that supports the stator. A motor, comprising: an absorption unit that is disposed between the base and the stator and that absorbs vibration in a rotational direction generated by unevenness of the rotational force of the rotor. 2. The motor according to claim 1, wherein the absorbing means is an elastic body, and the rigidity in the rotation direction of the rotor is different from the rigidity in the axial direction. 3. The motor according to claim 1, wherein the shaft of the rotor includes a support portion that supports the disk-shaped recording medium. 4. The stator has an iron core, the rotor has a magnet, and the absorbing means absorbs the unevenness of the rotating force generated when a magnetic attractive force is applied between the iron core and the magnet. The motor described in.