JPH0258764A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To make the title device thinner in thickness by forming a spindle pulley section and a chucking member integrally and at the same time, arranging the spindle pulley section on a magnetic disk side and putting belt for transmitting driving force around the spindle pulley section. CONSTITUTION:A pulley section 16a which is a spindle pulley is integrally formed with a flange 16 and also works as the chucking member of a magnetic disk. A central shaft 15 is incorporated at the central part of the flange 16. A bearing 17 is fixed to a chassis 14 and the central shaft 15 is put in and supported by the bearing 17 in a rotatable state. Moreover, a magnet 18 is fitted to the chassis 14 side of the pulley section 16a and the flange 16 is held on the chassis 14 side with a gap by the attracting force of the magnet 18. A belt 7 is put around the pulley section 16a and the rotation of a spindle motor is transmitted to the flange 16 through the belt 7 and pulley section 16a, resulting in the driving of a drive pin 3. Therefore, this magnetic disk device can be reduced in thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compact and thin magnetic disk device.

[Prior Art] A magnetic disk is centered by a central axis and a triso pin supported at a predetermined distance from the central axis, and the triso pin provides driving force to rotate the magnetic disk. Disk devices are conventionally used, particularly in 3.5-inch floppy disk drives.

Conventionally, this type of device uses a direct trites motor or belt drive system to provide driving force to the drive pin. Especially for belt drive type, the second
It has a structure like the one shown in the figure.

In Fig. 2, l is the chassis that serves as the substrate of the magnetic disk device, 2 is the central shaft, 3 is the triso pin, and 4 is the central shaft 2.
5 is a hub of the magnetic disk; 6 is a flange for positioning the hub 5 of the magnetic disk at a predetermined height; 7 is a belt for transmitting the rotation of a spindle motor (not shown); 8 1 is a spindle pulley which is a driven pulley for winding the belt 7, 9 is a triso pin board, 1O is a shaft for supporting the triso pin 3, 1
1 is a guide shaft for holding the triso pin board 9 on the flange 6, and 12 is a wire spring for biasing the drive pin 3 in the outer circumferential direction.

In the above configuration, the bearing 4 is fixed to the chassis l by caulking or the like. A flange 6, which is a component of the magnetic disk chucking member, is fixed to the central shaft 2 by press-fitting, insert molding, or the like. A guide shaft 11 and a shaft lO are caulked to the drive pin board 9.
A drive pin 3 is pivotally supported at O. The drive pin board 9 is attached from the back side (lower side in the figure) of the flange 6 in the above state. The flange 6 is made of magnetic plastic, and the back side thereof is magnetized. Drive pin board 9
Since it is made of a steel plate, it is held horizontally by adhering to the flange 6. There is a wire spring 1 on the outside of the guide shaft 11.
2 is incorporated and always urges the drive pin 3 in the outer circumferential direction.

The central shaft 2 is inserted into the bearing 4 from above in the figure, and the flange 6
The spindle pulley 8 is press-fitted into the part located on the opposite side of the
It is fixed with adhesive etc. In this state, center axis 2. Flange 6
The spindle pulley 8 is integrated with the bearing 4 in between, and is rotatably supported by the bearing 4. Additionally, thrust washers 13 are inserted above and below the bearing 4 to ensure smooth rotation. A belt 7 is wound around the spindle pulley 8, and driving force is transmitted to the drive pin 3 by a spindle motor (not shown).

Next, a method for centering the 8-5 magnetic disk will be briefly explained. An explanatory diagram is shown in FIG. A rectangular center hole 5b is provided in the center of the hub 5, and the center shaft 2 is engaged with this center hole 5b. Further, a drive hole 5a having a rectangular cross section is provided at a position a predetermined distance away from the center of the hub 5. This drive hole 5a has a hub 5.
The drive pin 3, which applies rotational force to the As explained above, since the drive pin 3 is biased toward the outer circumference by the wire spring 12, the center hole 5b of the hub 5
The center shaft 2 comes into contact with the center shaft 2, and centering is performed.

[Problems to be Solved by the Invention] As mentioned above, in conventional magnetic disk drives, the flange and spindle pulley are each composed of separate members, and furthermore, they are located at opposite positions across the chassis. However, the disadvantage was that the entire device became thicker.

The present invention has been made to solve this problem, and it is an object of the present invention to provide a magnetic disk device in which the overall thickness of the device is reduced by constructing the flange and the pulley from the same member.

[Means for Solving the Problems] In order to achieve the above object, the magnetic disk device of the present invention has a spindle pulley portion integrally formed with the chucking member, and the spindle pulley portion is disposed on the magnetic disk side. The driving force is transmitted by winding the belt around the spindle pulley portion.

[Function] According to the present invention, the pulley portion corresponding to the spindle pulley and the flange are integrally formed of the same material and disposed on the magnetic disk side to serve as a chucking member for the magnetic disk. By using a structure in which the belt is directly hung on the magnetic disk drive, the thickness of the magnetic disk drive can be made thinner.

[Embodiment] FIG. 1 is a sectional view showing the configuration of the main parts of an embodiment of the present invention. In FIG. 1, the same members as those in the conventional example are given the same reference numerals, so the explanation here will be omitted.

Here, 14 is a chassis serving as a substrate of the magnetic disk device, 15 is a central shaft, 16 is a flange, 16a is a pulley portion as a spindle pulley, 17 is a bearing, and 18 is a magnet.

In the above configuration, the pulley portion 16a serving as a spindle pulley is formed integrally with the flange 16, and also serves as a chucking member for the magnetic disk. Further, the central shaft 15 is incorporated into the center of the flange 16 by press-fitting, insert molding, or the like. Back side of flange 16 (
As in the conventional example shown in FIG. 2, a drive pin board 9 is incorporated in the lower part of the drawing.

A bearing 17 is fixed to the chassis 14 by press fitting, adhesive, etc. The central shaft 15 is inserted into the bearing 17 and rotatably supported. A thrust washer 13 is interposed between the bearing 17 and the flange 16 to ensure smooth rotation.

Further, a magnet 18 is attached to the chassis side of the pulley portion 16a.
is attached to maintain a constant gap with the chassis 14.

The chassis 14 is made of iron, and the flange 16 is always held at the position where the gap is maintained on the chassis 14 side by the attraction force of the magnet 18. A belt 7 is wound around the pulley portion 16a.

With the above configuration, the rotation of the spindle motor (not shown) is transmitted by the heald 7 to the flange 16 via the pulley portion 16a, and provides a driving force to the drive pin 3.

With the configuration of the embodiment as described above, the same effects as those of the conventional example shown in FIG. 2 can be obtained, and in addition, the thickness of the entire device can be reduced.

[Effects of the Invention] As explained above, in the magnetic disk device of the present invention, the flange, which is a chucking member, and the spindle pulley are made of the same material, and the spindle pulley portion is arranged on the magnetic disk side with respect to the chassis. By using it as a chucking member for a magnetic disk and then directly hooking a belt to this chucking member, it became possible to reduce the overall thickness, thereby making the magnetic disk device thinner.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a schematic configuration of the main part of an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a schematic structure of the main part of a conventional magnetic disk device, and FIG. 3 is a sectional view of a magnetic disk drive. It is an explanatory view of centering of. In the figure. 1: Chassis 2: Center shaft 3 Drive pin 4: Bearing 5: Magnetic disk hub 5a Drive hole 5b: Center hole 6: Flange 7: Belt 8, spindle pulley 9/drive bin board 10: Shaft 11 Guide shaft 12: Wire spring 13 Nilast washer 14, chassis 15: center shaft 16: flange 16a: pulley portion 17, bearing 18: McNet agent patent attorney 1) Haru Kitatake

Claims (1)

[Claims] It has a chucking member for centering the hub of the magnetic disk and rotationally driving the magnetic disk, a belt for transmitting driving force to the chucking member, and a spindle pulley for winding the belt. In the magnetic disk device, the spindle pulley portion is integrally formed with the chucking member, the spindle pulley portion is placed on the magnetic disk side, and the belt is wound around the spindle pulley portion to transmit driving force. A magnetic disk device characterized by: