JP2885018B2 - Magnetic disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to a magnetic disk drive having a structure in which a magnetic disk drive for a 5-inch magnetic disk cartridge and a magnetic disk drive for a 3.5-inch magnetic disk cartridge are stacked. About.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show a conventional magnetic disk drive 10 as an example.

The magnetic disk drive 10 includes a magnetic disk drive main body 11 for a 5-inch magnetic disk cartridge,
A top plate 13 having a mounting portion 12 for mounting a magnetic disk device for a 3.5-inch magnetic disk cartridge is mounted, and a magnetic disk device 14 for a 3.5-inch magnetic disk cartridge is mounted on the top plate 13. And a front bezel 15 attached thereto.

[0004] The magnetic disk drive 10 has a predetermined height h and is incorporated in a personal computer.

The top plate 13 must have sufficient rigidity, and the thickness t ₁ is as thick as about 1 mm.

The 3.5-inch magnetic disk drive 14 comprises:
It has a structure that can be a product by itself.

The portion around the flat motor 17 for rotating the magnetic disk of the 3.5-inch magnetic disk drive 14 is as shown in FIG. 4B.

Reference numeral 20 denotes a chassis, 21 denotes a slider, 22 denotes a holder, and 23 denotes a cover.

The motor 17 is mounted on a motor base 24.

The motor base 24 is housed in a shallow concave portion 20a formed on the lower surface side of the chassis 20, that is,
It does not protrude from the lower surface of the chassis 20 and fits within the thickness of the chassis 20 and is attached.

The motor 17 includes a rotating shaft 30, a hole bearing 31, a slide bearing 32, a flat cup-shaped yoke 33, and a stator 35 wound around an iron core 34 radially arranged on the motor base 24. And a ring-shaped permanent magnet 36 fixed to the inner peripheral surface of the yoke 33.

[0012]

Since the motor base 34 is housed in the recess 20a of the chassis 20, the motor 16 of the 3.5-inch magnetic disk drive 14 is used.
Is limited to a small height dimension a.

For this reason, the space in which the stator coil 35 and the permanent magnet 36 are incorporated is narrow, the number of turns of the stator coil 35 is limited to a small number, and the height b of the permanent magnet 36 is limited to about 3.8 mm. Was.

Under such circumstances, in order to obtain predetermined characteristics, a material having a high neodymium content is used for the permanent magnet 36 to obtain a predetermined magnetic force.

However, a material containing a large amount of neodymium is expensive, the price of the permanent magnet 36 is high, the price of the motor 17 is high, and finally the price of the magnetic disk device 10 is high.

Further, the magnetic disk drive 10 has a configuration in which the 3.5-inch magnetic disk drive 14 is mounted in the middle of the top plate 13, and the top plate 13 has a structure in which the weight is supported in the middle. When an impact is applied to the magnetic disk drive 10, the 3.5-inch magnetic disk drive 14 is likely to vibrate with the bending of the top plate 13.

In particular, regarding the 3.5-inch magnetic disk drive 14, adjustments are made at the stage when the 3.5-inch magnetic disk drive 14 is assembled alone and at the time when the 3.5-inch magnetic disk drive 14 is assembled.
The step after mounting the magnetic disk drive for inch 14 on the top plate 13 of the magnetic disk drive main body 11 for 5 inch has to be performed twice, which is troublesome.

Accordingly, an object of the present invention is to provide a magnetic disk drive which has solved the above-mentioned problems.

[0019]

According to the first aspect of the present invention, there is provided the following:
1st size magnetic disk cartridge of the size
And a second magnetic disk drive main body on which a second size magnetic disk cartridge smaller than the first size magnetic disk cartridge is mounted. The second magnetic disk drive main body has a chassis having a size corresponding to the first magnetic disk drive main body, and a flat motor for rotating the magnetic disk is provided on the chassis; The first magnetic disk device main body has a configuration without a top plate, and the chassis of the second magnetic disk device main body covers the upper part of the first magnetic disk device main body so as to cover the first magnetic disk device main body. It is configured to be attached to.

[0020]

According to the first aspect of the present invention, the chassis of the second magnetic disk drive main body has a size corresponding to the size of the first magnetic disk drive main body, and the chassis acts so as to cover the first magnetic disk drive main body. It works so that the top plate of the first magnetic disk device main body becomes unnecessary.

The structure in which the top plate of the first magnetic disk drive main body is not required acts so as to allow the thickness of the flat motor for rotating the magnetic disk of the second magnetic disk drive main body to be increased.

Increasing the thickness of the motor acts to increase the thickness of the permanent magnet in the motor, which in turn requires less expensive permanent magnet material.

[0023]

1 and 2 show a magnetic disk drive 50 according to an embodiment of the present invention.

The magnetic disk drive 50 includes a magnetic disk drive main body for a 5-inch disk cartridge (hereinafter referred to as a 5-inch magnetic disk drive main body) 51 and a magnetic disk drive main body for a 3.5-inch magnetic disk cartridge (hereinafter referred to as 3). (It is called the magnetic disk drive body for .5 inch)
52, a front bezel 5 having an insertion port 53 for a 5-inch magnetic disk cartridge 40 and an insertion port 54 for a 3.5-inch magnetic disk cartridge 41.
5, and the height is the same as before.
It is.

The 5-inch magnetic disk device main body 51
As shown in FIG. 1, a die-cast chassis 56
It has a general configuration in which a magnetic disk rotation motor 57, a magnetic head carriage device 58, and a magnetic disk clamp device 59 are assembled. On both sides of the chassis 56,
A column 61 is provided integrally with the side wall 60.

A screw hole 62 is provided at the top 61 a of the support 61.
Is formed.

The 5-inch magnetic disk drive main body 51
Does not have a top plate (cover).

3.5-inch Magnetic Disk Unit 52
Has a chassis 70, a slider 71, a holder 72, and a cover 73 (see FIG. 2), as shown in FIG.

The holder 72 and the slider 71 have a size corresponding to the 3.5-inch magnetic disk cartridge 41.

The chassis 70 has projections 77 and 78 projecting outward from holder holders 75 and 76 for supporting the holder 72, and is wider than the holder 72. Approximately the same width W
_{With one} .

The chassis 70 is provided with a motor 17A for rotating a 3.5-inch magnetic disk and a magnetic head carriage device 79.

The chassis 70 is formed with mounting feet 80 projecting from both sides.

The chassis 70 has the same thickness as the chassis 20 (see FIG. 4B) of the 3.5-inch magnetic disk drive 14 in FIG. 5, and as shown in FIG. A rising rib 81 for reinforcement is formed along the front surface, and has sufficient rigidity. As shown in FIGS. 1 and 2, the 3.5-inch magnetic disk device main body 51 having the above-described configuration is configured such that the mounting foot portion 80 is brought into contact with the top surface 61 a of the support portion 61 and is screwed with the screw 82. The chassis 70 covers the upper surface of the 5-inch magnetic disk device main body 51.

The chassis 70 is, as shown in FIGS. 4A and 4B, a chassis 20 of the conventional magnetic disk drive 10.
It is located at a height corresponding to.

Further, the magnetic disk device 50 has a 5
After assembling the 3.5-inch magnetic disk drive 52 on the inch-size magnetic disk drive main body 51, various adjustments are made at once to complete the process.

In FIG. 3, reference numeral 85 denotes a screw for adjusting the index detection, which is provided in the overhang portion 78, and
It is located more laterally. Therefore, the index detection adjustment is easily performed from the upper side of the magnetic disk device 50.

Next, the motor 17A of the 3.5-inch magnetic disk device main body 51 will be described with reference to FIG.

The structure of the motor 17A is substantially the same as that of the motor 17 shown in FIG.
The same reference numerals with are appended. The recess 20a shown in FIG. 4B is not formed on the lower surface of the chassis 70. The motor base 24A has a lower surface 70a on the lower surface 70a of the chassis 70.
a.

The thickness t ₂ of the motor base 24A is about 0.5.
6 mm.

Since the magnetic disk drive 50 is not provided with the top plate 13 provided in the conventional magnetic disk drive 10, even if the motor base 24A protrudes from the lower surface 70a of the chassis 70, it will not hit the top plate. There is no problem.

Further, since the chassis 70 is located at a height corresponding to the chassis 20, even if the motor base 24A protrudes from the lower surface 70a of the chassis 70, the motor base 24A can be mounted on the top plate shown in FIG. 13 and is not lower than the height of the top 13, and there is no problem in this regard.

The motor 17A includes a rotating shaft 30A, a ball bearing 31A, a sliding bearing 32A, a flat cup-shaped yoke 33A, and a stator coil wound around an iron core 34A radially arranged on a motor base 24A. 35
A and a ring-shaped permanent magnet 36A fixed to the inner peripheral surface of the yoke 33.

The upper surface 33Aa of the yoke 33A functions as a turntable, and has the same height as the upper surface 33a of the yoke 33 in FIG. 4B.

The thickness t ₃ of the chassis 70 is set to be 0.4 mm thicker than the thickness of the conventional chassis 20. This 0.4 mm is a size corresponding to (t ₁ -t ₂ ).
As a result, the lower surface of the motor base 34A is
The height is the same as the lower surface of the top plate 13 in (B).

The motor base 34A has a thickness t which is larger than the height of the motor base 34 shown in FIG.
_The thickness obtained by adding 0.4 mm to ₂ above, that is, the thickness t ₁ of the top plate 13 is reduced by 1.0 mm.

The amount by which the motor base 34A is lower than the height of the motor base 34, that is, the thickness t ₁ of the top plate 13,
Height a ₁ of the motor 16A is increased from the conventional height a.

Therefore, the space in which the stator coil 35A and the permanent magnet 36A are incorporated expands in the height direction, and the stator coil 35A has a larger number of turns than the conventional stator coil 35.

The height b ₁ of the permanent magnet 36a is
The height of the conventional permanent magnet 36 is 4.8 mm, which is 1 mm larger than the height of 3.8 mm. The rate of this increase is as large as about 20%.

For this reason, in order for the motor 17A to have the same characteristics as the conventional one, the permanent magnet 36A may be made of a material having lower magnetic characteristics than the conventional one, and specifically, the content of neodymium is lower than that of the conventional one. Uses less material. This material is cheaper than the conventional one and has a permanent magnet 36A.
Are less expensive than conventional permanent magnets 36.

Therefore, the motor 17A is a conventional motor 1A.
7 is less expensive.

The magnetic disk device 50 is different from the conventional magnetic disk device 10 in that the price of the motor 17A is inexpensive, the number of components is reduced by eliminating the top plate 13, and the adjustment process is performed only once. It is cheap.

Since the chassis 70 does not bend,
The 3.5-inch magnetic disk device 50 has better vibration resistance than the conventional magnetic disk device 10.

[0053]

As described above, according to the first aspect of the present invention, since the first magnetic disk drive has no top plate,
It is possible to increase the thickness of the motor for rotating the magnetic disk of the magnetic disk drive, thereby increasing the thickness of the permanent magnet of the motor and making the material of the permanent magnet cheaper than the conventional one. In addition, the magnetic disk device can be made less expensive than the conventional one.

Further, the number of components can be reduced by omitting the top plate of the first magnetic disk drive.

Further, since the second magnetic disk device main body has its chassis fixed and supported to the last, it does not vibrate more than the first magnetic disk device main body and has good vibration resistance.

The adjustment may be performed only once after assembling the first magnetic disk device main body and assembling the second magnetic disk device main body thereon, so that the assembling work can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a magnetic disk drive of one embodiment of the present invention.

FIG. 2 is a perspective view showing a magnetic disk drive of one embodiment of the present invention.

FIG. 3 is an exploded perspective view of the 3.5-inch magnetic disk device in FIG.

4 is a diagram showing a structure near a disk rotation motor of the magnetic disk device of FIG. 1 in comparison with a structure near a disk rotation motor of the conventional magnetic disk device of FIG. 5;

FIG. 5 is a perspective view of a conventional example of a magnetic disk drive.

FIG. 6 is an exploded perspective view of the magnetic disk device of FIG.

[Explanation of symbols]

24A Motor base 30A Rotary shaft 31A Ball bearing 32A Sliding bearing 33A Yoke 34A Iron core 35A Coil 36A Permanent magnet 40 Magnetic disk cartridge for 5 inch 41 Magnetic disk cartridge for 3.5 inch 50 Magnetic disk device 51 Magnetic disk for 5 inch magnetic disk cartridge Main unit 52 3.5-inch magnetic disk cartridge main unit for magnetic disk cartridge 53 5-inch magnetic disk cartridge insertion slot 54 3.5-inch magnetic disk cartridge insertion slot 55 Front bezel 56, 70 Chassis 57 Motor 58 Magnetic head carriage unit 69 Magnetic disk clamp device 60 Side wall 61 Post 61a Top 62 Screw hole 70 Chassis 70a Lower surface 71 Slider 72 Holder 73 Cover 75 Holder struts 77 and 78 projecting part 79 a magnetic head carriage assembly 80 mounting foot 81 rising rib 82 Screw 85 index detection adjusting screw

Claims (1)

(57) [Claims] 1. A first magnetic disk device main body on which a first size magnetic disk cartridge is mounted, and a second size magnetic disk cartridge smaller than the first size magnetic disk cartridge are mounted. A magnetic disk drive having a configuration in which a second magnetic disk drive main body is overlapped with a second magnetic disk drive main body, wherein the second magnetic disk drive main body has a chassis having a size corresponding to the first magnetic disk drive main body; A flat motor for rotating a magnetic disk is provided on a chassis. The first magnetic disk device main body has no top plate. The chassis of the second magnetic disk device main body is Wherein the magnetic disk drive is mounted on the first magnetic disk drive main body so as to cover an upper part of the first magnetic disk drive main body. Qi disk device.