JPH08115562A - Disk driving device - Google Patents

Abstract

PURPOSE: To prevent a shaft from falling off from a holder by arranging a magnetic member at an end part of the disk table side of the holder and magnetically attracting an attraction magnet to the magnetic member together with the disk table. CONSTITUTION: The disk driving device is constituted so that the disk table 5 is attracted to the side of a substrate 9 by the attracting force between the magnetic member 8 arranged on the side of disk table 5 of the holder 3 and the attracting member 6, in addition to the attracting force due to the deviation of a magnetic center A of a magnet and a magnetic center B of a stator core 1, to depress the shaft on a thrust bearing 11. Furthermore, at the time of mounting the attraction magnet 6 to the disk table 5, it is mounted directly to the disk table 5 without through a york, therefore, the shaft 7 is prevented from falling off from the holder 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device in which an optical disk or the like is used.

[0002]

2. Description of the Related Art For example, as a disk drive device used in an optical disk drive device, there is one having a structure shown in FIG. In FIG. 4, a disk-shaped thrust bearing 41 is mounted on the substrate 39. Also, the substrate 3
The cylindrical holder 3 is provided on the outer periphery of the thrust bearing 41 on the shaft 9.
3 is attached. The holder 33 has a flange portion 33b on the outer peripheral surface on the lower side, and the stator core 31 is attached to the flange portion 33b. The stator core 31 is formed by laminating a plurality of magnetic plates, and a plurality of salient poles are formed on the outer circumference. A coil 40 is wound around each salient pole.

Bearings 32 and 32 'are vertically press-fitted and fixed in the inner hole 33a of the holder 33. Bearing 32, 32 '
Is a sintered oil-impregnated bearing having innumerable pores, and the pores are impregnated with lubricating oil. Bearing 32,
32 'has a hole in the center, and the shaft 3
7 is inserted. The lower end of the shaft 37 is the substrate 39.
It is in contact with the upper end surface of the upper thrust bearing 41. Therefore, the shaft 37 is supported by the bearings 32 and 32 'in the radial direction and is also supported in the thrust direction by the thrust bearing 41, and is rotatable.

A disk table 35 made of a non-magnetic material is attached to the upper end of the shaft 37. The disk table 35 has a cylindrical rotor case 42 attached to the outer peripheral side of the lower end surface thereof, and the outer peripheral surface of the annular drive magnet 34 attached to the inner peripheral surface of the peripheral wall of the rotor case 42. The inner peripheral surface of the drive magnet 34 faces the salient poles of the stator core 31 with a constant gap. Therefore, by energizing the coil 40 wound around the salient poles of the stator core 31, the drive magnet 34 is biased, and the rotor case 42, the disk table 35, and the shaft 37 are rotationally driven.

When the magnetic center of the drive magnet 34 in the axial direction is A and the magnetic center of the stator core 31 in the axial direction is B, the magnetic center A of the drive magnet 34 is A.
Is shifted upward from the magnetic center B of the stator core 31. By doing so, the magnetic center A of the drive magnet 34 tries to coincide with the magnetic center B of the stator core 31, and the drive magnet 34 is urged downward, that is, in the direction of arrow F1. The lower end of 37 is pressed to the side of the thrust bearing 41 and is mounted on the disk table 35.
However, it is designed to be rotated while maintaining a constant height without swinging up and down.

On the inner peripheral side of the upper end surface of the disk table 35, a circular disk guide portion 35a is integrally provided so as to project. A concave portion is formed in the disc guide portion 35a along a circle centered on the rotation center axis line, and an attracting magnet 36 is mounted in the concave portion via a yoke 46. The attraction magnet 36 serves to attract a clamper (not shown) and fix the disc 44 on the disc table 35 by the clamper.

A disk rubber 45 is attached to the outer peripheral side of the upper end surface of the disk table 35.
The disc 44 is placed on the disc rubber 45.

[0008]

In recent years, in the disk drive device having the above structure, the number of laminated magnetic materials forming the stator core 31 can be reduced, or the drive magnet 34 can be used.
It has been made thinner by suppressing the height dimension of the.

However, if the disk drive device is made thinner than a certain extent, the magnetic center A of the drive magnet 34 and
The deviation of the magnetic center B of the stator core 31 cannot be increased, and as a result, the force for pressing the shaft 37 having the drive magnet 34, the rotor case 42, the disk table 35, etc. toward the substrate 39 side becomes weak. I will end up.

When the force for pressing the shaft 37 against the substrate 39 becomes weak, when the disc 44 is rotationally driven, the disc table 35 floats and vibrates, so that the disc can be maintained at a constant height. Therefore, the signal on the disc could not be read stably.

Further, when the force for pressing the shaft 37 toward the substrate 39 side becomes weak, a disk clamp made of a magnetic material for pressing the disk 44 and the attracting magnet 36 when the disk 44 is released from the disk table 35.
However, there is a problem in that the disk table 35 and the like are not lifted up together with the disk clamp and the shaft 37 is pulled out from the holder 33 because they are not separated by mutual suction force.

The present invention has been made in order to solve the problems of the prior art as described above, can be made thinner, can maintain a constant disk height during rotation, and can be used when releasing a disk. Another object of the present invention is to provide a disk drive device in which the shaft does not come out of the holder.

[0013]

According to the first aspect of the present invention,
A holder that holds the stator core and that has a bearing housed in its inner hole, a drive magnet that is placed opposite to the stator core and that is magnetized in multiple poles, and a non-magnetic disk that mounts the disk and rotates integrally with the drive magnet. A table,
In a disk drive device including an attracting magnet fixed to the disk table for attracting a disk clamp, and a shaft fixed to the center of the disk table and rotatably supported by a bearing, at the end of the holder on the disk table side. Is provided with a magnetic member, and the attraction magnet is magnetically attracted to the magnetic member together with the disk table.

According to a second aspect of the present invention, a holder for holding the stator core and having a bearing housed in the inner hole, a drive magnet facing the stator core and subjected to multi-pole magnetization, and a disk are mounted. A non-magnetic disk table that rotates integrally with the drive magnet, an attraction magnet that is fixed to the disk table to attract the disk clamp, and a shaft that is fixed to the center of the disk table and rotatably supported by a bearing. In the disk drive device, the holder is made of a magnetic material, and the attraction magnet is magnetically attracted to the holder together with the disk table.

[0015]

According to the present invention, since the attraction magnet of the disc table and the magnetic member disposed at the end of the holder on the disc table side are magnetically attracted, the disc table and the drive magnet are attached. The shaft is pressed against the substrate, and the disc mounted on the disc table is rotationally driven at a constant height.

According to the second aspect of the present invention, since the attraction magnet of the disk table and the holder made of a magnetic material are magnetically attracted, the shaft on which the disk table and the drive magnet are attached is pressed against the substrate. The disc mounted on the disc table is rotationally driven at a constant height.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk drive device according to the present invention will be described below with reference to the drawings. In FIG. 1, a disk-shaped thrust bearing 11 is mounted on a substrate 9. A cylindrical holder 3 is attached to the outer periphery of the thrust bearing 11 on the substrate 9 by caulking or other appropriate means. The holder 3 has a collar portion 3 on the outer peripheral surface on the lower side.
b, and the stator core 1 is attached to the upper end surface of the collar portion 3b.

The stator core 1 is constructed by laminating a plurality of magnetic plates, and a plurality of salient poles are formed on the outer circumference. A coil 10 is wound around each salient pole.

In the inner hole 3a of the holder 3, the bearing 2 is vertically arranged,
2'is press-fitted and fixed. The bearings 2 and 2 ′ are sintered oil-impregnated type bearings having innumerable pores, and the pores are impregnated with lubricating oil. Each of the bearings 2 and 2'has a hole in the center, and the shaft 7 is inserted through this hole.
The lower end of the shaft 7 is in contact with the upper end surface of the thrust bearing 11. Therefore, the shaft 7 is supported in the radial direction by the bearings 2 and 2 ', and the thrust bearing 11
It is supported by the thrust direction and is freely rotatable.

A disk table 5 made of a non-magnetic material is attached to the upper end of the shaft 7. The disk table 5 has a cylindrical rotor case 12 attached to the outer peripheral side of the lower end surface thereof, and the outer peripheral surface of the annular drive magnet 4 attached to the inner peripheral surface of the peripheral wall of the rotor case 12. The inner peripheral surface of the drive magnet 4 faces the salient poles of the stator core 1 with a certain gap. Therefore, by energizing the coil 10 wound around the salient poles of the stator core 1, the drive magnet 4 is energized, and the rotor set including the rotor case 12, the disk table 5, and the shaft 7 is integrally driven to rotate. It

When the magnetic center of the drive magnet 4 in the axial direction is A and the magnetic center of the stator core 1 in the axial direction is B, A and B do not coincide with each other, and A is displaced upward from B. It looks like this. By doing so, the magnetic force of the drive magnet 4 acts so that the magnetic center A coincides with the magnetic center B of the stator core 1, so that the drive magnet 4 is urged downward, that is, in the direction of arrow F1. As a result, the shaft 7 to which the drive magnet 4 is attached is pressed against the thrust bearing 11.

On the inner peripheral side of the upper end surface of the disk table 5,
A circular disk guide portion 5a is integrally formed.
A recess is formed in the disk guide portion 5a along a circle centered on the rotation center axis, and the attraction magnet 6 is directly attached to the inside of the recess without a yoke. A disc rubber 15 on which the disc 14 is actually placed is attached to the outer peripheral edge of the upper end surface of the disc table 5.

A magnetic member 8 is attached to the end of the holder 3 on the disk table 5 side. The magnetic member 8 has a peripheral wall portion 8a on the outer peripheral side, and the peripheral wall portion 8a covers the outer peripheral surface of the portion where the diameter of the tip of the holder 3 is reduced. Further, the upper end of the peripheral wall portion 8a is an inward flange portion 8b, and the flange portion 8b covers the upper end surface of the holder 3 and the upper end surface of the bearing 2. The collar portion 8b is
With the disk table 5 in between, the attraction magnet 6
Is facing.

A clamper 13 made of a magnetic material for fixing the disk 14 mounted on the disk table 5 is arranged above the disk drive device.
When the disk 14 is mounted on the disk table 14, the clamper 13 descends, and the lower end surface of the peripheral wall of the clamper 13 comes into contact with the inner peripheral edge of the upper end surface of the disk 14. Also,
The clamper 13 made of a magnetic material is an attraction magnet 6 attached to the disc guide portion 5a of the disc table 5.
Since it is magnetically attracted by the disk 14, the disk 14 is pressed onto the disk table 5 by the clamper 13, and the fixing of the disk 14 on the disk table 5 is maintained.

According to the disk drive device having the above-mentioned structure, in addition to the attraction force due to the deviation between the magnetic center A of the drive magnet 4 and the magnetic center B of the stator core 1, the magnetic force is placed on the disk table 5 side of the holder 3. The magnetic force of the magnetic member 8 and the attracted magnet 6 attracts the disk table 5 to the side of the substrate 9 and the shaft 7 to the thrust bearing 1.
The substrate 9 of the rotor group is pressed because it is pressed onto
The suction force to the side can be dramatically improved. For this reason, even if the disk drive device is thin and the magnetic center A of the drive magnet 4 and the magnetic center B of the stator core 1 are not displaced so much that the attractive force between the magnetic centers A and B is small, the attraction magnet Since the force of pressing the rotor set to the substrate 9 side can be sufficiently secured by the attraction force between the magnetic member 6 and the magnetic member 8, vibration during rotation of the disc can be prevented and the height of the disc can be kept constant and stable. The read signal can be read.

Further, the force for pressing the rotor set to the substrate 9 side is sufficient, and since the attraction magnet 6 is attached directly to the disc table 5 without a yoke, the attraction magnet 6 and the disc clamp 1 are attached.
Since the attraction force of 3 is not so strong, the attraction magnet 6 of the disc table 5 is released when the disc 14 is released.
Can be easily separated without being attracted to the disc clamp 13 side. Therefore, the shaft 7 can be prevented from coming off the holder 3.
Further, since the attraction magnet 6 is attached to the disc table 5 without passing through the yoke,
It is possible to reduce the thickness of the disk drive device itself, and thus to further reduce the thickness of the entire disk drive device.

Further, as shown in FIG. 2, the collar portion 8b of the magnetic member 8 is extended to the outer peripheral surface side of the shaft 7 to form the collar portion 8b.
A minute gap C may be formed between the inner peripheral surface of the shaft 7 and the outer peripheral surface of the shaft 7. The minute gap C serves as a labyrinth, and the dust generated in the bearings 2, 2'can be blocked by the minute gap C. Therefore, in addition to the above effects, the dust from the bearings 2, 2'has a bad influence on the surface of the disk 14. Can be prevented.

Further, the holder 3 and the magnetic member 8 are integrated, and the holder 2 made of a magnetic material as shown in FIG.
0 may be formed. The holder 20 has a cylindrical shape, and an inward flange portion 20b that generates an attractive force between the holder 20 and the attraction magnet 6 of the disk table 5 is provided on the upper end portion, and a flange portion on which the stator core 1 is placed on the outer peripheral surface of the lower end portion. 20c is formed. Further, the outer peripheral surfaces of the sintered oil-impregnated type bearings 2 and 2 ′ are press-fitted and fixed in the inner hole 20a of the holder 20. By thus forming the holder 20 with a magnetic material and having a role of attracting the attraction magnet 6 attached to the disc table 5, a special member for attracting the attraction magnet 6 is not required, so that In addition to the effects of the embodiment, it is possible to reduce the number of parts and improve productivity. Since other configurations are similar to those of the embodiment shown in FIG. 1, the same components are designated by the same reference numerals and the description thereof will be omitted.

[0029]

According to the first aspect of the invention, a magnetic member is arranged at the end of the holder on the side of the disk table, and an attracting magnet for attracting the disk clamp is used. Since the magnetic attraction force is generated between them, it is possible to increase the attraction force of the rotor set including the disk table and the shaft to the side of the stator set including the stator core and the holder. Therefore, even if the size of the disk drive device is reduced, the attraction force to the stator assembly side of the rotor assembly can be increased, and the height of the disk during rotation can be maintained constant. Further, since it is possible to increase the attraction force of the rotor set to the stator set side, it is possible to prevent the rotor set from coming off from the holder when the disc is released.

According to the second aspect of the present invention, the holder is made of a magnetic material, and a magnetic attraction force is generated between the holder and the attraction magnet integrated with the disk table. It is possible to increase the attraction force of the rotor set to the side of the stator set including the stator core and the holder. For this reason,
Even if the physical structure of the disk drive device is made thin, the magnetic attraction force between the rotor set and the stator set can be increased,
It is also possible to keep the height of the disk constant during rotation. Further, since it is possible to increase the attraction force between the rotor set and the stator set, it is possible to prevent the rotor set from coming off from the holder when the disc is released.

[Brief description of drawings]

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

FIG. 2 is an enlarged sectional view of an essential part showing another embodiment of the disk drive device according to the present invention.

FIG. 3 is a sectional view showing a further embodiment of the disk drive device according to the present invention.

FIG. 4 is a sectional view showing an example of a conventional disk drive device.

[Explanation of symbols]

 1 Stator core 2 Bearing 3 Holder 3a Inner hole 4 Drive magnet 5 Disk table 6 Adsorption magnet 7 Shaft 8 Magnetic member

Claims (2)

[Claims] 1. A holder for holding a stator core and having a bearing housed in an inner hole, a drive magnet which is arranged to face the stator core and is magnetized in multiple poles, and a disk is mounted on the holder to be integrated with the drive magnet. A disk having a non-magnetic disk table that rotates in the direction of the disk, an attracting magnet that is fixed to the disk table to attract a disk clamp, and a shaft that is fixed to the center of the disk table and rotatably supported by the bearing. In the drive device, a magnetic member is provided at an end of the holder on the disc table side, and the attraction magnet is magnetically attracted to the magnetic member together with the disc table. 2. A holder for holding a stator core and having a bearing housed in an inner hole, a drive magnet which is arranged to face the stator core and is magnetized in multiple poles, and a disk is placed on the holder to be integrated with the drive magnet. A disk having a non-magnetic disk table that rotates in the direction of the disk, an attracting magnet that is fixed to the disk table to attract a disk clamp, and a shaft that is fixed to the center of the disk table and rotatably supported by the bearing. In the drive device, the holder is made of a magnetic material, and the attraction magnet is magnetically attracted to the holder together with the disc table.