JPH0450602Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a disk rotating table suitable for magnetically attracting and rotating a magnetic disk generally called a 3.5-inch floppy disk.

[Prior Art] The disk chucking mechanism of a conventional 3.5-inch floppy disk device was developed, for example, in the 1980s.
As disclosed in Japanese Patent No. 163547, it is constructed by arranging permanent magnets in a metal rotary table. Furthermore, in order to reduce costs, it has been proposed to use a plastic magnet 1 as shown in FIGS. 5 and 6. In the case of Fig. 5, the bushing 3 is integrated with the rotating shaft 2,
A plastic magnet 1 is arranged so as to surround this bush 3. In the case of FIG. 6, the plastic magnet 1 is directly integrated into the rotating shaft 2 without using a bush.

[Problems to be solved by the invention] By the way, when permanent magnets are used as disclosed in Japanese Utility Model Application No. 60-163547, the total thickness of the rotating shaft and permanent magnets is 3 mm or more. However, there are problems in that it is difficult to reduce the thickness of the device, and that the cost is high. On the other hand, the suction rotary table shown in Fig. 5 can reduce costs, but it is difficult to reduce the thickness to 3 mm or less because the plastic magnet 1 surrounds the bush 3 to include the top surface. There are problems. In addition, the suction rotary table shown in Fig. 6 has the advantage that the thickness can be reduced to approximately 1.5 mm because it does not use a bushing, but on the other hand, distortion occurs in the rotary table due to repeated disk chucking. , there is a problem that the surface run-out of the suction surface increases and the head touch becomes poor.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a disk rotating table that can be made thinner and lower in cost, as well as having greater mechanical stability.

[Means for Solving the Problems] To achieve the above object, the present invention will be described with reference to the reference numerals in the drawings showing the embodiments.The present invention is provided with a magnetically attractable metal hub 18 in the center. It is for sucking and holding the recording medium disk 17, and has a rotary shaft 10, a diameter smaller than that of the hub 18, fixed to the rotary shaft 10, and having a concave portion 19 or a convex portion on the side surface. metal bushing 11
and a highly slippery resin ring 16 which has a smaller diameter than the hub 18, is fixed to the upper surface of the bushing 11, and is formed to place the hub 18, and the bushing 11 is formed into a ring shape. The bushing 1 is arranged so as to surround the bushing 11 and engage with a side surface having the concave portion 19 or the convex portion of the bushing 11.
1, has an upper surface lower than the upper surface of the resin ring 16, and has a thickness substantially the same as the thickness of the outer peripheral portion of the bushing 11. This invention relates to a disk rotating table characterized by:

[Functions and effects of the idea] The present invention has the following effects.

(a) The plastic magnet 12 is integrally molded with the bushing 11 so as to engage with the side surface of the bushing 11 having a concave portion 19 or a convex portion.
Since it is formed to the same thickness as the outer periphery of
The disk rotary table can be made thinner, and the mechanical stability of the plastic magnet 12 can be maintained even though it is made thinner.

(b) Since the highly slippery resin ring 16 is placed on the bush 11 and the height of the top surface of the plastic magnet 12 is lower than the top surface of the resin ring 16, the hub 18 and the plastic magnet 1
2 and the hub 1 of the plastic magnet 12.
Contact with 8 can be prevented. As a result, deformation of the plastic magnet 12 can be prevented.

[Embodiment] Next, a disk rotary table of a magnetic disk device according to an embodiment of the present invention will be explained with reference to FIGS. 1 to 4. This disc rotating table was developed in the 1980s.
The 3.5-inch floppy disk disclosed in Japanese Patent No. 163547 is held by suction and rotated, and the rotating shaft 10 is connected to a motor (not shown).
It consists of a disk mounting base 11 fixed thereto, a plastic magnet 12 integrally molded on the outer periphery of the disk mounting base 11, and a drive pin 14 supported by a leaf spring 13.

The disk mounting table 11 is a metal bushing 1 (made of brass, aluminum, etc.) fixed to the rotating shaft 10.
5 and a fluororesin ring 16 with high slipperiness fixed thereon, the bushing 15 and the ring 1
6 has a smaller diameter than the diameter of the magnetic metal hub 18 fixed to the center of the magnetic disk 17;
8 is formed so that the inner peripheral side portion thereof is placed thereon.

The plastic magnet 12 attracts the hub 18 and is formed so as to face the outer circumference of the hub 18. This plastic magnet 12 does not cover the upper surface of the bushing 15, but is integrally molded so as to engage with the outer peripheral surface of the bushing having a recess 19. Therefore, the bushing 15 and the plastic magnet 12 are formed to have substantially the same thickness.

The plastic magnet 12 has a drive pin 1.
A hole 20 for inserting the plate spring 13 and a hole 21 for use in fixing the leaf spring 13 are provided. In addition,
The leaf spring 13 is formed as shown in FIG.
A fixing hole 22 is provided between the drive pin attachment portion 13a and the bushing engagement portion 13b. The magnetization of this plastic magnet 12 is divided into north and south poles in the circumferential direction.
The poles are arranged alternately.

When the floppy disk is inserted onto the disk rotating table configured as described above, the tip of the rotating shaft 10 is inserted into the central hole of the hub 18. On the other hand, the drive pin 14 is not necessarily inserted into the hole provided in the hub 18 immediately, but is inserted based on the rotation of the rotary table and the hub.

Since the height of the top surface of the plastic magnet 12 is lower than the height of the top surface of the ring 16 of the disk rotating table 11, the hub 18 does not come into contact with the plastic magnet 12. However, because the air gap between the hub 18 and the plastic magnet 12 is extremely narrow, a magnetic circuit is formed from the north pole of the plastic magnet 12 through the hub 18 and back to the south pole.
The hub 18 can be suctioned.

According to this embodiment, the plastic magnet 1
2 is formed to have the same thickness as the bushing 15,
Thinness is achieved. In addition, the plastic magnet 1 is inserted so as to engage with the recess 19 on the side surface of the bush 15.
2 are integrated, a stable bonding of the plastic magnet 12 is achieved.

[Modifications] The present invention is not limited to the above-described embodiments, but can be modified. For example, Bushiyu 1
A convex portion may be provided on the outer peripheral surface of the magnet 5, and the plastic magnet 12 may be integrally molded thereon. Alternatively, the magnetization in the plastic magnet 12 may be carried out so that north poles and south poles are alternately arranged in a striped manner.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a disk rotating table according to an embodiment of the present invention, Fig. 2 is a plan view showing the rotating table with the drive pin and leaf spring removed, and Fig. 3 is a sectional view taken along the line - - in Fig. 2. , FIG. 4 is a plan view of the leaf spring of FIG. 1. FIG. 5 is a sectional view showing a conventional rotary table. FIG. 6 is a sectional view showing another conventional rotary table. 10... Rotating shaft, 11... Disk mounting stand, 1
2... Plastic magnet, 15... Bush, 16... Ring, 18... Hub, 19... Recess.

Claims (1)

[Claims for Utility Model Registration] A device for attracting and holding a recording medium disk 17, which is equipped with a magnetically attractable metal hub 18 in the center, and has a rotary shaft 10 and a diameter smaller than the hub 18. a metal bushing 11 having a diameter smaller than that of the hub 18 and fixed to the rotating shaft 10 and having a concave portion 19 or a convex portion on the side surface; A highly slippery resin ring 1 formed so as to place the hub 18 thereon.
6, which is disposed so as to surround the bushing 11 in a ring shape, is integrally molded with the bushing 11 so as to engage with the side surface of the bushing 11 having the concave portion 19 or the convex portion, and is lower than the upper surface of the resin ring 16; A disk rotary table comprising a plastic magnet 12 having a low upper surface and having a thickness substantially the same as the thickness of the outer circumference of the bushing 11.