JPH07308058A - Spindle motor for driving disc - Google Patents

Abstract

PURPOSE:To provide a spindle motor for driving a disc by enhancing productivity, realizing a low cost and further making the size thinner. CONSTITUTION:Provided are a plurality of coils 3 arranged in a housing 1, a main magnet 5 facing to the coil 3 through an air gap, a rotor yoke 4 for holding this main magnet 5, a turn table 6 provided above the rotor yoke for mounting a disc 9, and a hole portion 4a or a thin wall portion as magnetic flux leakage means which is provided at the rotor yoke 4 and leaks the magnetic flux of the main magnet 5, thereby fixing the disc 9 to the turn table 6 by the magnetic flux leakage means.

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, for example, a disk drive spindle motor such as a magneto-optical disk drive device.

[0002]

2. Description of the Related Art A conventional disk drive device, for example, a disk drive spindle motor of a magneto-optical disk drive device is shown in FIG. In FIG.
The stator A includes a housing 1 and a plurality of coils 3 attached to the housing 1 via a stator substrate 1a.

The rotor B has a rotor yoke 4, a main magnet 5 mounted on the rotor yoke 4 through a gap in the coil 3, and a turntable provided above the rotor yoke 4 for mounting a disk 9. 6 and a chuck magnet 8 arranged inside the turntable 6 for fixing the disc 9 to the turntable 6. The rotor B is rotatably supported by the stator A via the shaft 2. The turntable 6 is made of a hard non-magnetic material such as stainless steel, and is formed with high precision by cutting or the like.

When the disc 9 is inserted into a device equipped with such a disc driving spindle motor, the disc hub 10 made of a magnetic material provided at the center of the disc 9 is attached to the turntable 6 side by the chuck magnet 8. Is sucked into. At that time, the shaft 2 is inserted into the center hole 10a formed in the disc hub 10, and finally the disc 9 is fixed to the turntable 6.

[0005]

However, in the above-mentioned configuration, the chuck magnet 8 and the main magnet 5 are separately configured, so that the cost is increased due to an increase in the number of parts. It was
Further, since the chuck magnet 8 and the main magnet 5 are separately configured, there is a problem that the number of working steps is increased by that much, workability is deteriorated, and productivity thereof is significantly reduced.

Further, since the chuck magnet 8 and the main magnet 5 are respectively arranged in the thickness direction of the apparatus, it is necessary to secure a space in the thickness direction in advance, and the motor becomes thicker accordingly. ,
As a result, there is a problem that the entire device becomes thicker. Furthermore, when it becomes necessary to adjust the attraction force of the disk hub, another chuck magnet 8 must be newly selected, which is very troublesome.

Therefore, the present invention intends to solve the above-mentioned problems, improve productivity, realize cost reduction, and provide a disk drive spindle motor which can be easily thinned. To do.

[0008]

DISCLOSURE OF THE INVENTION A disk drive spindle motor according to the present invention holds a plurality of coils arranged in a housing, a main magnet that faces the coils through a gap, and the main magnet. A rotor yoke, a turntable provided above the rotor yoke for mounting the disk, and a magnetic flux leaking unit provided on the rotor yoke for leaking the magnetic flux of the main magnet are provided. It is fixed on the turntable. Further, the magnetic flux leakage means is a hole portion or a thin portion provided on the top surface of the rotor yoke.

[0009]

1 is a cross-sectional view of the essential parts of a disk drive spindle motor of a magneto-optical disk drive according to an embodiment of the present invention. FIG. 2 is a sectional view of a main part of a disk drive spindle motor of a magneto-optical disk drive device according to another embodiment of the present invention. FIG. 3 is a plan view showing the shape of the magnetic flux leakage means shown in FIG. 1 or 2.

In the embodiment shown in FIG. 1, the stator A
Is composed of a housing 1 and a plurality of coils 3 attached to the housing 1 via a stator substrate 1a. In addition, the rotor B includes a rotor yoke 4 having a plurality of holes 4a formed all around, and the coil 3 described above.
The main magnet 5 is attached to the rotor yoke 4 via a space, and the turntable 6 is provided above the rotor yoke 4 for mounting the disk 9. The rotor B is rotatably supported by the stator A via a shaft 2.

The turntable 6 is made of a hard non-magnetic material such as stainless steel, and is formed with high precision by cutting or the like. In this embodiment, a part of the top surface of the rotor yoke 4 is bored as a magnetic flux leakage means to provide a plurality of holes 4a.

Further, the embodiment shown in FIG. 2 shows a structure of magnetic flux leakage means different from that of FIG. In Figure 2,
The magnetic flux leakage means is configured by providing a plurality of thin wall portions 4b on a part of the top surface of the rotor yoke 4. In this embodiment, the thin wall portion 4b is formed integrally with the rotor yoke 4. However, for example, after the top surface of the rotor yoke 4 is once drilled, the rotor yoke 4
A method of fixing a member thinner than the wall thickness with an adhesive or the like may be used.

The shape of the magnetic flux leakage means is as shown in FIG.
A substantially rectangular shape as shown in C of (a) or a round shape as shown in D of FIG. 3 (b) is conceivable, but the present invention is not limited to these, and it is possible to suck a disc Various modifications are possible.

When the disk 9 is inserted into the device having the disk driving spindle motor having the above-described structure, the main magnet 5 provided on the rotor yoke 4 leaks through the hole 4a or the thin portion 4b as the magnetic flux leaking means. A magnetic flux is generated, and due to this leakage magnetic flux, the disk hub 10 made of a magnetic material provided at the center of the disk 9 is attracted to the turntable 6 side. that time,
The shaft 2 is inserted into a central hole 10a formed in the disc hub 10, and finally the disc 9 is turned into a turntable 6
Fixed to.

In the present invention, it is not necessary to separately form a magnet for fixing the disk 9 to the turntable 6, and the chuck magnet 8 which has been conventionally used is not necessary. When adjusting the suction force of the disc hub 10, it is only necessary to change the magnetic flux leakage means to an arbitrary shape according to the suction force required for fixing the disc 9.

Further, in this embodiment, the magnetic flux leakage means is constituted by providing the hole portion 4a or the thin portion 4b on the top surface of the rotor yoke 4, but the magnetic flux leakage means is not limited to these, and in addition to this. Also, various modifications can be made without departing from the scope of the present invention. Further, in this embodiment, the disk drive spindle motor of the magneto-optical disk drive device is described in detail, but the present invention is not limited to this, and can be applied to disk drive spindle motors of all disk drive devices.

[0017]

As described above, according to the present invention, the magnetic flux leakage means for leaking the magnetic flux of the main magnet is provided in the rotor yoke, and the magnetic flux leakage means fixes the disk to the turntable. Since the main magnet can also be configured to be used for fixing the disk and the chuck magnet that has been used conventionally is not required, the number of parts can be reduced and the work process can be simplified accordingly.
It is possible to improve productivity and reduce costs.

Further, with this configuration, the chuck magnet can be reduced in thickness as much as it is not necessary, and the motor can be easily thinned, and the entire device can be easily thinned. Can be achieved. Further, by providing the magnetic flux leakage means, when the attraction force of the disk hub needs to be adjusted, the magnetic flux leakage means only needs to be changed to an arbitrary shape, and the adjustment can be easily performed.

[0019]

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a disk drive spindle motor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of essential parts of a disk drive spindle motor that is another embodiment of the present invention.

FIG. 3 is a plan view showing the shape of the magnetic flux leakage means in FIG. 1 or FIG.

FIG. 4 is a sectional view of a main part of a conventional disk driving spindle motor.

[Explanation of symbols]

 A: Stator B: Rotor 1 ... Housing 2 ... Shaft 3 ... Coil 4 ... Rotor yoke 4a ... Hole 4b ... Thin part 5 ... Main magnet 6 ... Turntable 8 ... Chuck magnet 9 Disc 10 Disc hub 10a Center hole

Claims (3)

[Claims] 1. A plurality of coils disposed in a housing, a main magnet facing the coils with a gap, a rotor yoke holding the main magnet, and a rotor yoke above the rotor yoke for mounting a disk. A disk rotation drive spindle motor comprising: a turntable provided; and a magnetic flux leakage means provided on the rotor yoke and for leaking the magnetic flux of the main magnet, the magnetic flux leakage means fixing a disk to the turntable. 2. The spindle motor for driving a disk according to claim 1, wherein the magnetic flux leakage means is a hole provided on a top surface of the rotor yoke. 3. The disk drive spindle motor according to claim 1, wherein the magnetic flux leakage means is a thin portion provided on a top surface of the rotor yoke.