JP2002269881A - Magnetic disk driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic disk driving device with high accuracy and sufficient strength and easy to manufacture. SOLUTION: The motor hub 3a is constituted of a main body section 13 supporting a disk 10 and an engaging section 17 with higher rigidity than the main body section 13, mounted on the main body section 13 and engaged with a tightening means 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor used in a magnetic disk drive, and more particularly to a motor hub on which a disk is mounted.

[0002]

2. Description of the Related Art FIG. 5 shows a spindle motor used in a magnetic disk drive. The motor hub 3c is rotatably supported between the outer periphery of the shaft 2 supported by the base 1 and the inner periphery of the motor hub 3c via ball bearings 4a and 4b. A labyrinth seal 5 is provided above the shaft 2 to prevent oil mist generated between the bearings 4a and 4b from scattering on the disk 10. The outer periphery of the labyrinth seal 5 is press-fitted and fixed inside the motor hub 3c, a slight gap is provided between the inner peripheral portion and the outer periphery of the shaft 2, and the outside of the press-fit portion is an adhesive (not shown). Sealed with.

A magnet 6 constituting a magnetic circuit is attached to the inside of the outer peripheral portion of the motor hub 3c via a back yoke 7 made of a magnetic material. A coil 8 is provided on a surface of the base 1 facing the magnet 6. The wound stator core 9 is fixed to the magnet 6 with an adhesive so as to have a certain gap, and a rotating force is generated in the motor hub 3 c by an AC magnetic field formed by a current flowing through the coil 8 and a magnetic field of the magnet 6. Have been.

A disk-shaped clamp 1 for fixing a magnetic disk 10 mounted on a flange of a motor hub 3c.
1, a screw hole 16 is formed at equal intervals on the same circumference, and a screw hole 15c is formed at the same position as the screw hole 16 of the motor hub 3c. And screw hole 1
Due to the tightening force of the screws 12 inserted into the motor hubs 3 and 15c, the inner peripheral portion thereof is sandwiched between the motor hub 3c and the clamp 11, and is fixed so as to rotate with the motor hub 3c. 14
Is a spacer provided between the stacked magnetic disks 10.

[0005]

The motor hub 3c of the spindle motor configured as described above requires a predetermined strength, and is generally manufactured using a metal member in the following procedure.

First, the shape of the motor hub 3c is formed by forging mainly using a non-magnetic light alloy such as aluminum. Since the motor hub 3c is made of a high-precision forging die, it retains a relatively high-precision shape immediately after being taken out of the forging die. , And the accuracy is greatly deteriorated.

Therefore, in order to finish the motor hub 3c with high precision, a reference portion is cut in advance in the inside, and a two-stage cutting process of gripping and cutting the cut portion is performed to obtain a predetermined accuracy.

However, as described above, the manufacturing of the motor hub 3c by processing the metal member has a problem in that the manufacturing process is complicated, the processing takes a long time, and the material and processing costs are high and the cost increases.

There is also a method of forming a motor hub 3c by cutting a magnetic material such as an iron material. In this method, since the motor hub 3c itself is a magnetic material, the back yoke 7 is not required, and the assembling step of the back yoke 7 can be omitted. However, the manufacturing process is also complicated and the cost is increased as described above.

Although a motor hub 3c made of a resin molded product has been proposed for the purpose of simplifying the manufacturing process and reducing material costs, a resin hub 3c cannot provide sufficient strength. In particular, the motor hub 3 of the magnetic disk 10
The screw 12 is inserted into the screw hole 16 of the clamp 11 and the screw hole 15c of the motor hub 3c by the tightening force as described above.
In the case of c, cracks are apt to occur due to insufficient strength of the screw hole 15c, and cannot be used in actual use.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a magnetic disk drive having high accuracy, sufficient strength, and which can be easily manufactured.

[0012]

A magnetic disk drive according to the present invention is characterized in that the motor hub is composed of a main body and an engaging portion having a higher strength than the main body.

According to the present invention, a magnetic disk drive having high accuracy and sufficient strength can be easily realized.

[0014]

According to a first aspect of the present invention, there is provided a magnetic disk drive device comprising: a disk set on a motor hub sandwiched between clamps; and the clamp and the motor hub are connected to each other by tightening means. What is claimed is: 1. A magnetic disk drive device which is fixedly driven to rotate, comprising: a main body portion supporting a disk; And characterized in that:

According to this configuration, it is possible to realize a magnetic disk drive device which is accurate, has sufficient strength, and can reduce the occurrence of cracks. According to a second aspect of the present invention, in the magnetic disk drive according to the first aspect, the engaging portion is embedded in the main body.

According to a third aspect of the present invention, in the magnetic disk drive according to the first aspect, the engaging portion is provided on a side of the main body opposite to a contact surface with a clamp. According to a fourth aspect of the present invention, there is provided a magnetic disk drive device comprising:
Preferably, the engaging portion is made of a magnetic material, and one end of the engaging portion is extended to a position where a magnetic circuit is formed.

According to this structure, the number of steps for assembling the back yoke can be reduced, and the strength can be improved. The magnetic disk drive according to claim 5 of the present invention is characterized in that:
5. The method according to claim 4, wherein the main body is formed of a resin, and the engaging portion is formed of a metal member.

According to a sixth aspect of the present invention, in the magnetic disk drive according to the fifth aspect, the main body and the engaging portion are integrated by insert molding. According to this configuration, the assembling of the engagement portion to the main body portion is assured.

According to a seventh aspect of the present invention, in the magnetic disk drive according to any one of the first to fifth aspects, the fastening means is a screw, and the engaging portion is provided with a screw hole. And

A magnetic disk drive according to claim 8 of the present invention is a magnetic disk drive for rotating a disk by attaching the disk to a motor hub, wherein the motor hub is
It is characterized by comprising a resin main body for supporting the disk and a metal member provided at a place where the strength of the main body is to be ensured.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. Components having the same configuration as that of FIG. 5 showing a conventional example are denoted by the same reference numerals and described.

(Embodiment 1) FIGS. 1 and 2 show (Embodiment 1) of the present invention. FIG. 1 shows a finished shape of the spindle motor, and FIG. 2 shows an assembled shape.

In the spindle motor constructed in the same manner as in FIG. 5 showing the conventional example, in this (Embodiment 1), the motor hub 3a is provided with a main body 13 for supporting the disk 10 and a stronger strength than the main body 13. Is different from the above-described conventional example in that the engaging portion 17a is attached to the main body portion 13 and is engaged with the screw 12 as a fastening means.

Specifically, the main body 13 is formed of a resin such as polycarbonate. The engaging portion 17a engages with the screw 12 when the clamp 11 for fixing the magnetic disk 10 is attached, and thus requires higher strength than the main body portion 13. Therefore, for example, the screw hole 1 is formed of a metal member such as iron,
5a are formed.

The attachment of the engaging portion 17a to the main body 13 is not particularly limited. However, if the engaging portion 17a is insert-molded when the main body 13 is molded with resin, it can be easily integrated, and the assembling process can be performed. Can be reduced. When the engaging portion 17a is embedded in the main body 13, the assembling of the engaging portion 17a to the main body 3 can be performed more reliably.

When the motor hub 3a configured as described above is used, the screw 12 used for mounting the magnetic disk 10 is engaged with the high-strength engaging portion 17a and tightened. A spindle motor having sufficient strength can be realized.

Further, unlike the conventional motor hub 3c formed by forging of aluminum or the like, the motor hub 3a does not require a heat treatment or the like for removing a strain to be performed after the forming, thereby simplifying the manufacturing process. In addition, since the dimensional change after removal from the mold is small and the precision of the motor hub 3a is determined by the precision of the resin molding mold, a high-precision motor hub 3a is obtained, and the spindle motor using this motor hub 3a has a high precision. It will be good.

(Embodiment 2) FIGS. 3 and 4 show (Embodiment 2) of the present invention. FIG. 3 shows a finished shape of the spindle motor, and FIG. 4 shows an assembled shape.

In this (Embodiment 2), the motor hub 3
Although the configuration of the engaging portion 17b of b is different, the other basic configuration is the same as that of the above embodiment. Specifically, the engaging portion 17b is provided not only at the engaging portion with the screw 12 but also at the main body portion 1.
3 is extended to the back surface side, and one end thereof reaches the position where the magnetic circuit is formed. When the engaging portion 17 is extended not only to the screw hole 15b but also to the back side of the main body 13, cracks in the screw hole can be prevented and the strength of the motor hub 3b can be improved.

Further, when the engaging portion 17b is formed of a ferromagnetic material such as iron, the engaging portion 17b can be used also as the back yoke 7 for forming the magnetic circuit with the magnet 6, and the mounting process of the back yoke 7 can be reduced.

The engaging portion 17b and the main body 13 can also be easily integrated by insert molding in the same manner as described above. If the engaging portion 17b is insert-molded, for example, as a press-formed product obtained by press-forming an iron plate, Easy motor hub 3
b can be created.

In each of the above embodiments, the screw 12 has been described as an example of the fastening means. However, the present invention is not limited to this, and a fastening means by press-fitting may be used.

Although the description has been made with reference to polycarbonate as the resin material, the present invention is not limited to this, and any resin material that is thermoplastic and can be injection-molded, such as liquid crystalline polyester, can be applied.

[0034]

As described above, according to the magnetic disk drive of the present invention, the disk set on the motor hub is sandwiched by the clamps, and the clamp and the motor hub are connected by the fastening means to fix the disk to the motor hub. A magnetic disk drive device that rotates and drives the motor hub, the motor hub comprising: a main body that supports a disk; and an engaging portion that is higher in strength than the main body and is attached to the main body and engages with the fastening means. With this configuration, it is possible to easily realize a magnetic disk drive having high accuracy, sufficient strength without cracks, and a small number of man-hours.

[Brief description of the drawings]

FIG. 1 is a sectional view of a finished shape of a spindle motor according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part for explaining an assembled shape of FIG. 1;

FIG. 3 is a cross-sectional view of a finished shape of a spindle motor according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an essential part for explaining an assembled shape of FIG. 3;

FIG. 5 is a sectional view of a conventional magnetic disk drive.

[Explanation of symbols]

 3a, 3b Motor hub 10 Magnetic disk 11 Clamp 12 Screw 13 Main body 17a, 17b Engagement

Claims (8)

[Claims] 1. A magnetic disk drive device comprising: a disk set on a motor hub sandwiched by a clamp; and a clamp connecting the clamp and the motor hub by fastening means to fix the disk to the motor hub and to rotate the disk. A magnetic disk drive device comprising: a main body for supporting a disk; and an engaging portion which is higher in strength than the main body and is attached to the main body and engages with the fastening means. 2. The magnetic disk drive according to claim 1, wherein said engaging portion is embedded in said main body. 3. The magnetic disk drive according to claim 1, wherein said engaging portion is provided on a side opposite to a contact surface of said main body portion with a clamp. 4. The magnetic disk drive according to claim 3, wherein said engaging portion is made of a magnetic material, and one end of said engaging portion is extended to a position where a magnetic circuit is formed. 5. The magnetic disk drive according to claim 1, wherein said main body is formed of a resin, and said engaging portion is formed of a metal member. 6. The magnetic disk drive according to claim 5, wherein said main body and said engaging portion are integrated by insert molding. 7. The magnetic disk drive device according to claim 1, wherein said fastening means is a screw, and said engaging portion is provided with a screw hole. 8. A magnetic disk drive for mounting a disk on a motor hub and rotating the motor hub, wherein the motor hub is provided in a resin main body for supporting the disk and at a location where the strength of the main body is to be ensured. Magnetic disk drive comprising: a metal member;