JPH04132061A - Magnetic disk device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device that can prevent deformation of a magnetic disk during clamping and can realize a thinner overall device.

[Conventional technology]

Generally, this type of magnetic disk device is shown in FIGS. 3 and 4.
It has the configuration shown in the figure.

In the figure, 1 indicates a housing, and the housing 1 is composed of a bottomed cylindrical housing body 2 and a cover 3 that covers the housing body 2, and has a sealed structure to prevent dust from entering. . Reference numeral 4 indicates an in-hub type spindle motor as a disk drive motor attached to the bottom plate 2A of the housing body 2, and the in-hub type spindle motor 4 has a motor attached to the bottom plate 2A of the housing body 2, as shown in FIG. A support member 5 is attached so as to close the hole 2B and constitutes a part of the housing 1, and has a boss portion 5A serving as a cylindrical shaft support portion extending upwardly in the center thereof; A stator coil 6 wound around the outer periphery of the boss portion 5A, a magnet rotor 7 facing the stator coil 6 and fixed to the inner peripheral surface of a hub member 10 (described later) via a magnet yoke 7A, and a support member 5. Rotatably disposed within the boss portion 5A via bearings 8, 8,
It is generally composed of a hub member 10 and a rotating shaft 9 that rotates integrally with the hub member 10.

Reference numeral 10 denotes a hub member that is fixed to the rotating shaft 9 of the in-hub type spindle motor 4 and rotates together with the rotating shaft 9. a portion 10A, a lid portion 10B that covers the upper end side of the cylindrical portion 10A, and a magnetic disk 1 which extends radially outward from the lower end side of the cylindrical portion 10A, and which will be described later.
1, and an annular flange 10C supporting the flange 1. Furthermore, the lid portion 10B of the hub member 10 has a rotating shaft 9.
A fitting hole 10D fitted into the upper end side of the fitting hole 10D;
a fitting protrusion 10E that is formed by raising the peripheral edge of the disc clamp 12 and fits into a fitting hole 12B of the disk clamp 12, which will be described later;
For example, four screw holes 10F (only one is shown) are provided on the radially outer side of the fitting protrusion 10E to securely support the disk clamp 12. The hub member 10 has a magnet rotor 7 attached to the inner peripheral surface of the cylindrical portion 10A.
is fixed and supplies power to the stator coil 6,
The stator coil 6 and the magnet rotor 7 rotate together with the rotating shaft 9.

Reference numeral 11 indicates a magnetic disk as a recording medium disposed on the outer circumferential side of the hub member 10, and the magnetic disk 11 is held between the annular flange 10C of the hub member 10 and a disk clamp 12, which will be described later. It is attached to the outer periphery of the cylindrical portion 10.

12 is screwed to the upper surface of the lid portion 10B of the hub member 10, and the magnetic disk 11 is secured to the flange portion 10C of the hub member 10.
The disk clamp 12 is formed into a disk shape as a whole, and its peripheral edge is a contact surface 12A with the magnetic disk 11. Further, the disk clamp 12 includes, for example, four disk clamps provided at positions that are aligned with the fitting hole 12B that fits into the fitting protrusion 10E of the hub member 10 and the screw holes 10F, IOF, . . . of the hub member 10. screw insertion holes 12C (only one is shown), and four screws 13.13. ... is fixed to the hub member 10, and the magnetic disk 11 is held between the disk clamp 12 and the flange 10C of the hub member 10.

Reference numeral 14 denotes a swing arm swingably supported by a pivot shaft 15 embedded in the bottom plate 2A of the housing body 2, and the swing arm 14 is supported by a carrier directly supported by the pivot shaft 15, as shown in FIG. 16 and the carrier 1
6 and extends toward the magnetic disk 11, and a plate spring 18 attached to the tip of the head arm 17 and extending to the surface of the magnetic disk 11. A magnetic head 19 for recording and reproducing information by seeking the surface of the magnetic disk 11 is attached to the tip of the leaf spring 18. The magnetic head 19 is placed on the magnetic disk 11 by 0.2 to 0.
．． It is arranged so that it can float with a flying height of about 4 μm.

Reference numeral 20 denotes a voice coil motor that controls the swinging of the swing arm 14, and the voice coil motor 20 includes a magnet 21 fixed to the bottom plate 2A side of the housing main body 2 and a voice coil motor fixed to the carrier 16 side of the swing arm 14. , and a coil 22 that rotates the swing arm 14 in conjunction with a magnet 21.

In the magnetic disk device configured as described above, the in-hub spindle motor 4 drives the magnetic disk 11 fixed to the hub member 10 with the disk clamp 12, and the voice coil motor 20 drives the swing arm 14. move.

As a result, the magnetic head 19 attached to the tip of the swing arm 14 is floated by the airflow, and the magnetic head 19 seeks the surface of the magnetic disk 11 and moves to an arbitrary track to record and reproduce information. .

[Problem to be solved by the invention] However, in the above-mentioned conventional technology, the magnetic disk 1
1 between the hub member 10 with the disc clamp 12 and tightened and fixed with each screw 13.
3 is inserted into each screw insertion hole 12c provided on the peripheral edge of the disk clamp 12 and presses the peripheral edge of the disk clamp 12 downward. The force pressing the magnetic disk 11 is especially strong near the screw holes 12C (but the pressing force is weaker between the two adjacent screw insertion holes 12C, making it impossible to press the magnetic disk 11 uniformly. As a result,
The magnetic disk 11 may slide in the circumferential direction and cause waviness. In such a state, the magnetic head 19
There is a problem in that it is not possible to maintain a constant flying height between the magnetic disk and the surface of the magnetic disk 11, resulting in inaccurate recording and reproduction of information.

Furthermore, in the prior art, the magnetic disk 11 is connected to the hub member 10.
Since the magnetic disk 11 is held between two separate members of the disk clamp 12, there is also the problem that the magnetic disk 11 may warp due to temperature rise.

Furthermore, in the prior art, the rotating shaft 9 and the hub member 10 are formed as separate members, and the upper end side of the rotating shaft 9 is connected to the lid portion 1 of the hub member IO.
It is configured to be press-fitted into the fitting protrusion 10E and the fitting protrusion 0B through the fitting hole 10D. In this case, unless the lid portion 10B and the fitting protrusion 10E, which serve as the upper surface of the hub member 10, are formed thickly to ensure sufficient press-fitting allowance for the rotary shaft 9, the rigidity will be insufficient and the fitting protrusion 10E will not be sufficiently rigid. When the hub member 10 is subjected to vibrations, etc., the hub member 10 deforms, causing a surface runout phenomenon of the magnetic disk 11.If the upper surface of the hub member 10 is formed thick in this way, the magnetic disk device There is a problem in that it cannot respond to thinner and smaller sizes.

The present invention has been made in view of the above-mentioned problems of the prior art.The present invention provides a magnetic disk device that can prevent deformation of the magnetic disk when it is clamped, and that can reduce the overall thickness of the device. The purpose is to

[Means to solve the problem]

A feature of the configuration adopted by the present invention in order to solve the above-mentioned problems is that the magnetic disk is configured by a disk/hub molded member integrally molded with a hub member.

Further, the disk hub molding member may be molded integrally with the rotating shaft.

[Effect]

With the above configuration, the hub member and the magnetic disk are integrated, eliminating the need for a disk clamp and preventing deformation of the magnetic disk.

Moreover, high rigidity can be imparted to the disc/hub molded member, and no press-fitting allowance is required, so that the axial dimension can be reduced accordingly.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2. In addition, in the embodiment, the same reference numerals are given to the same components as those of the prior art described above, and the explanation thereof will be omitted.

FIG. 1 shows a magnetic disk device according to a first embodiment of the present invention.

In the figure, 31 is the rotating shaft 9 of the in-hub spindle motor 4.
The disk/hub forming member 31 is fixed to and rotates integrally with the rotating shaft 9, and the disk/hub forming member 31 is formed into a covered cylinder shape with a disk portion 31C, which will be described later, and is connected to the in-hub type spindle motor 4. A cylindrical portion 31A surrounding the
It is generally composed of a lid part 31B that covers the upper end side of the cylindrical part 31A, and an annular disk part 31C that extends radially outward from the lower end side of the cylindrical part 31A and forms a magnetic disk 32, which will be described later. has been done. The lid portion 31B of the disk hub molding member 31 is provided with a fitting hole 31D into which the upper end of the rotating shaft 9 is fitted.

Here, in the disk/hub molded member 31, similarly to the hub member 10 described in the prior art, the magnet rotor 7 is fixed to the inner circumferential surface of the cylindrical portion 31A, and by supplying power to the stator coil 6, the stator coil 6 and a magnet rotor 7 together with the rotating shaft 9.

Reference numeral 32 indicates a magnetic disk, and the magnetic disk 32 is formed by coating the surface of the disk portion 31C of the disk hub molding member 31 with a magnetic recording layer made of a magnetic material.

The magnetic disk device according to this embodiment has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

Therefore, to explain the method of molding the disc/hub molding member 31, which is a feature of this embodiment, the disc/hub molding member 31 is formed, for example, in a mold section (none of which is shown) between an upper mold and a lower mold. The parting line 33, which becomes the abutment surface between the upper mold and the lower mold, is shown as an imaginary in FIG. As shown by the line, it extends along the circumferential direction on the outer peripheral surface of the disk portion 31C. For this reason,
The parting line 33 does not remain on the upper and lower surfaces of the disk portion 31C, and the magnetic recording layer of the magnetic disk 32 can be easily formed.

Thus, in this embodiment, since the hub member and the magnetic disk 32 are integrally formed by the disk/hub molding member 31, there is no need to clamp the magnetic disk 32, and deformation such as waviness occurs in the magnetic disk 32. In addition to being able to reliably prevent this, it is also possible to effectively suppress the surface runout phenomenon during assembly, ensuring a flying height of about 0.2 to 0.4 μm between the magnetic head 19 and the magnetic disk 32. Therefore, according to this embodiment, it is possible to accurately maintain a constant flying height between the magnetic head 19 and the surface of the magnetic disk 32.
It becomes possible to record and reproduce information with high precision, and the reliability of the magnetic disk device is greatly improved. In addition, the disk clamp 12 described in the prior art
Since it is not necessary, the entire device can be made thinner.
In addition to being smaller and lighter, it is possible to prevent the magnetic disk 32 from warping due to temperature changes, and it is also possible to effectively prevent the magnetic disk 32 from shifting due to external impacts.

Next, FIG. 2 shows a second embodiment of the present invention, and the feature of this embodiment is that the disk hub molding member 41 is molded integrally with the rotating shaft 42. Here, the disc hub molding member 41 has a cylindrical portion 41A, a cylindrical portion 41A,
It consists of a lid part 41B and a disk part 41C, and a magnetic disk 43 is formed by coating the surface of the disk part 41C with a magnetic recording layer.

A rotary shaft 42 is integrally provided at the center of the lid portion 41B of the disk hub molding member 41 and projects downward. In addition, when the disc/hub molding member 41 is molded using means such as aluminum die casting, the parting line 44 is formed along the circumferential direction on the outer peripheral surface of the disc portion 41C as shown by the imaginary line in FIG. and expand.

Thus, this embodiment configured in this manner can also obtain substantially the same effects as the first embodiment, but in particular, in this embodiment, the rotating shaft 42 is integrated with the disk hub molded member 41. Since it is molded, it is possible to eliminate the press-fitting allowance that was necessary with the conventional technology, and the overall axial dimension can be set short, making it possible to further reduce the overall thickness of the magnetic disk device. High rigidity can be imparted to the disk hub molding member 41 including the rotating shaft 42.

In each of the above embodiments, the disk drive motor is
Although the explanation has been given using the in-hub type spindle motor 4 as an example, even if other types of motors such as an outer rotor type spindle motor are used instead, the same functions and effects as in the above embodiments can be achieved. be able to. In the case of an outer rotor type spindle motor, for example, a disk/hub molding member 31 may be fixed to a rotating shaft extending within the housing 1.

Further, in the embodiment described above, the magnetic head 19 is moved along an arcuate trajectory by the swing arm 14 that swings around the pivot shaft 15, but the present invention is not limited to this. However, the same functions and effects as described above can be achieved even when a linear slide type head carrier that moves along a linear trajectory is used.

〔Effect of the invention〕

As detailed above, according to the present invention, a magnetic disk can be
Since the structure is made of a disk/hub molding member that is integrally molded with the hub member, it is possible to eliminate the need for a disk clamp that was necessary in the conventional technology, and it is possible to reliably prevent deformation such as waviness from occurring in the magnetic disk. Accurate information recording and reproduction can be performed. As a result, the reliability of the magnetic disk device can be significantly improved.

In addition, by integrally molding the disc/hub molding member and the rotating shaft, the press-fitting allowance required with conventional technology can be eliminated.
The overall axial dimension can be set short, the entire magnetic disk device can be made thinner, and the rigidity can be increased.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a main part of a magnetic disk device showing a first embodiment of the present invention, FIG. 2 is a half-sectional view of a main part of a magnetic disk device showing a second embodiment, FIG. 4 shows the prior art, FIG. 3 is a plan view showing the overall configuration of a magnetic disk device, and FIG. 4 is an enlarged sectional view in the direction of arrow IV-IV in FIG. 3. DESCRIPTION OF SYMBOLS 1... Housing, 4... In-hub spindle motor, 5... Support member, 5A... Boss part (shaft support part) 9.42... Rotating shaft, 31.41... Disc.
Hub molding member, 32.43...magnetic disk.

Claims (2)

[Claims] (1) A housing having a shaft support part, a rotary shaft rotatably supported by the shaft support part of the housing via a bearing, a hub member that rotates integrally with the rotary shaft, and mounted on the hub member. What is claimed is: 1. A magnetic disk device comprising a magnetic disk, wherein the magnetic disk is constituted by a disk/hub molding member integrally molded with a hub member. (2) The magnetic disk device according to claim 1, wherein the disk hub molding member is molded integrally with the rotating shaft.