JPS61123059A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of leakage of magnetic flux from a spindle motor and to prevent heating, by providing porous magnetic shield material between the magnetic disc and spindle motor, and flowing the cooling air of the spindle motor to the magnetic disc direction through the magnetic shield material. CONSTITUTION:To prevent the leakage of magnetic flux from a magnetic part material 10, a magnetic shield part material 11 provided at the outside of each magnetic part material 10 is sintered with ferromagnetic metal particle, and formed as porous sintering metal. The circulating air generated in a housing 1 by the rotation of magnetic disc is guided into a magnet 9 through a vent 24 of a disc clamp and an air inlet 17 of a spindle valve 14, and cools down each magnetic part material 10 and status coil 8. After this, the air goes through the numerous number of perforation formed on the cylindrical part 12 of the magnetic shield part material 11 and outflows outside of each air outlet 18 of the spindle valve 14, and then the air is ejected to the surface of the magnetic disc 20 through the air vent 22 of each spacer 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device for loading and reading information from a magnetic disk, and in particular, a spindle motor is installed in a spindle hub on which a magnetic disk is mounted. The present invention relates to a magnetic disk device equipped with a magnetic disk drive.

[Conventional technology]

2. Description of the Related Art In recent years, as magnetic disk drives have become smaller and have larger capacities, magnetic disk drives equipped with so-called insight knob type spindle motors have become known. This type of magnetic disk device includes a housing, a spindle motor provided in the housing and composed of a stator coil and a magnet, and a spindle motor provided on the outer circumferential side of the magnet and driven to rotate by the spindle motor. It consists of a spindle knob) and a magnetic disk mounted on the spindle hub, and rotates the stator coil or magnet by exciting the stator coil.
The magnetic disk is rotated by the rotational force.

In the above-mentioned magnetic disk drive equipped with an inside hub type spindle motor, the leakage magnetic flux that interferes with the magnetic recording characteristics when the magnetic head writes and reads information to and from the magnetic disk is transmitted to the spindle motor.
There are problems mainly caused by magnets. By the way, the spindle hub that is rotationally driven by the spindle motor generally uses non-magnetic aluminum material in order to reduce its load. Therefore, in order to prevent the leakage magnetic flux, the spindle hub and the magnet are connected. It has a structure in which a magnetic shielding ring made of a magnetic material is interposed between the two. As a result, it is not possible to provide a vent in the peripheral wall of the spindle hub through which air for cooling the spindle motor flows, and the temperature of the spindle motor increases, causing seizure of the motor bearings and damage to the motor. This has the drawback that the characteristics of the electrical parts deteriorate, resulting in a decrease in the reliability and performance of the magnetic disk device.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and the problem to be solved by the present invention is to prevent the generation of leakage magnetic flux and heat generation from the spindle motor, and improve the durability and characteristics of the motor. An object of the present invention is to provide a magnetic disk device having the following structure.

[Means for solving problems]

A feature of the means of the present invention configured to solve the above-mentioned problems is that a porous magnetic shielding member is provided between the magnetic disk and the spindle motor, and the air that cools the spindle motor is passed through the magnetic shielding member. The object is to allow the liquid to pass through the member and flow out toward the magnetic disk.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

1 to 4 show a first embodiment of the invention.

In the figure, reference numeral 1 denotes a housing whose interior is sealed to prevent dust from entering, and the housing 1 is composed of a bottomed housing body 2 and a cover 3. 4
is an opening 2B formed at the bottom of the housing body 2.
A hollow cylindrical support shaft 6 is erected at the center of the inside of the motor mounting plate 4, which is fitted into the motor mounting plate 4 and fixed to the two bottom parts with set screws 5.

7 is a spindle motor provided in the housing 1 for rotationally driving a magnetic disk 20 to be described later; 8 is a stator coil of the spindle motor 7; the stator coil 8 is fixed to the outer periphery of the support shaft 6; There is.

On the other hand, 9 is a magnet provided on the outer circumferential side of the stator coil 8, and the magnet 9 integrates four curved plate-shaped magnet members 1O110... and each of the magnet members]O into four parts. and a magnetic shielding member 11 that prevents the generation of leakage magnetic flux from each magnet member 10. Here, the magnetic shielding member 11 is made of a porous sintered metal body made by sintering iron-based ferromagnetic powder so as to form a large number of ventilation holes, and the magnetic shielding member 11 is formed of a porous sintered metal body formed by sintering iron-based ferromagnetic powder to form a large number of ventilation holes. A cylindrical portion 12 in which four recessed portions 12A, 12A, . A pair of shielding rings 13.1
It is composed of 3. Then, each magnet member 10 is fitted into each concave portion 12A of the cylindrical portion 12, and each shielding ring 13 is fixed to both ends of the cylindrical portion 12 in the axial direction by adhesive or other means. 9 is assembled.

Reference numeral 14 denotes a spindle hub that is externally fitted from one axial end side of the magnet 9 in order to mount a plurality of magnetic disks 20. The spindle knob 14 is made of a non-magnetic lightweight metal material such as aluminum. A peripheral wall portion 14A that fits into the cylindrical portion 12 of No. 9, an upper surface portion 14B provided at one end in the axial direction of the peripheral wall portion 14A and having a shaft fitting hole 15 formed in the center, and an axis of the peripheral wall portion 14A. It is integrally formed with a flange portion 14C provided at the other end in the direction.

The upper surface 14B of the spindle hub 14 has a plurality of screw holes 16, 16 located around the shaft fitting hole 15.
Air inlets 17, 17, . . . are formed alternately with air inlets 17, 17, . It is formed in the axial direction (see Figure 3).

Reference numeral 19 denotes a rotating shaft that is inserted into the support shaft 6 via a bearing in order to rotatably support the magnet 9 and the spindle hub l4 with respect to the stator coil 8. The spindle hub 14 is integrally supported by fitting the shaft fitting hole 15 in a non-rotatable manner.

20, 20... are a plurality of magnetic disks mounted on the spindle hub 14, and 21, 21... are mounted on the spindle hub 14 to hold the respective magnetic disks 20 at a predetermined distance in the axial direction. Each spacer 21 is fitted into a thick annular spacer, and air circulation holes 22 corresponding to each air outlet 18 of the spindle hub 14 are formed in the radial direction of each spacer 21 .

23 is screwed to the upper side of the upper surface portion 14B of the spindle hub 14 in order to integrally sandwich each magnetic disk 20 and spacer 21 fitted in a stacked manner on the spindle hub 14 between the flange portion 14C of the spindle hub 14. In the axial direction of the disk clamp 23, vent holes 24, 24, . . . are formed which communicate with each air inlet 17 of the spindle hub 14.

Next, reference numeral 25 denotes a guide plate for circulating air flow generated in the radial direction from the rotation center of the magnetic disk 20 toward the rotation center side by the rotation of the magnetic disk 20. The guide plate 25 is attached to the disk clamp 23. A flat bottom portion 25A having a width shorter than the diameter and a length slightly longer than the diameter of the magnetic disk 20, and a side wall portion 25B integrally erected in the longitudinal direction along both edges of the bottom portion 25A. , 25B, the middle part of the guide plate 25 extends over the outer diameter of the disk clamp 23 and bulges out in a curved shape, and the bottom part 2.5A has a circular opening 25C. is formed. By screwing the guide plate 25 to the housing body 2, the guide plate 25 and the cover 3 form an air flow path 26 along the radial direction of the magnetic disk 20.
is formed.

In addition, 27 in the figure is an air filter located near the tip of one side of the guide plate 24 and provided in the housing body IA;
28 is a magnetic head for writing and reading information on each magnetic disk 2o; 29 is a magnetic head moving mechanism for moving the magnetic head 28 in the radial direction of the magnetic disk 20;
The magnetic head moving mechanism 29 is driven by a stepping motor 30 provided outside the housing body 2.

The present embodiment is constructed as described above, and by exciting the stator coil 8, the magnet 9 is rotated, and each magnetic disk 20 is rotated via the spindle hub 14 which rotates together with the magnet 9, and the magnetic head The operation of writing and reading information to and from each magnetic disk 20 by 28 is no different from that of the prior art.

By the way, in the device of this embodiment, the spindle motor 7
When the magnetic disk 20 is rotated in the direction of arrow R in FIG. 1 by driving the magnetic disk 2o, an air stream is generated on the disk surface of the magnetic disk 2o in the radial direction from the center of rotation. On the other hand, since the rotation center side of the magnetic disk 2o becomes negative pressure, the magnetic disk 2o
The air flowing toward the outer peripheral edge of the disk flows into the air filter 27 and is purified, and then passes through the air flow passage 26 between the guide plate 25 and the cover 3 and onto the disk clamp 23 from the central opening 25C. It's blown out. Then, the air flows from each vent 24 of the disk clamp 23 to the spindle hub 14 through each air inlet 17 of the spindle hub 14.
flow inside.

In this embodiment, the magnetic shielding member 11 provided on the outside of each magnet member 10 in order to prevent leakage magnetic flux generated from the magnet member 10 is made of sintered iron-based ferromagnetic powder, The spindle hub 14 is formed of a porous sintered metal body having properties such as:
7 and an air outlet 18 through which the air flows out in the radial direction of the magnetic disk 20. Therefore, the circulating air generated in the housing 1 due to the rotation of the magnetic disk 20 is circulated through the air inlets 24 of the disk clamp 23 and the air inlet 17 of the spindle hub 14 in sequence, as shown in FIG. After cooling each magnet member 10 and stator coil 8, each air flow of the spindle hub 14 passes through a number of ventilation holes formed in the magnetic shielding member 110 and the cylindrical portion 12, as shown in FIG. The air flows out from the outlet 18 to the outside, and the air flows through the air circulation hole 2 of each spacer 21.
2 onto the disk surface of the magnetic disk 20.

According to this embodiment configured as described above, since the magnetic shielding member 11 is provided on the outside of each magnet member 10, the generation of leakage magnetic flux can be prevented, and the magnetic shielding member 11
Because it is porous to have breathability, it is
The spindle motor 7 installed inside the dolphin can be constantly cooled by circulating air while the motor 7 is being driven.
It is possible to prevent the performance of the electrical components constituting the motor 7 from deteriorating.

Next, FIGS. 5 and 6 show a second embodiment of the present invention. Note that the same reference numerals are given to the same components as those of the first embodiment described above, and the explanation thereof will be omitted.

The feature of the second embodiment is that the peripheral wall portion 3
The spindle hub 31 consisting of the 1A1 upper surface part 31B and the flange part 31C is formed of a porous sintered metal body made by sintering ferromagnetic powder so that a large number of ventilation holes are formed. The reason is that it is itself a magnetic shielding member. The peripheral wall portion 31A of the spindle hub 31 has a shape in which thick portions 32A and thin portions 32B are alternately formed in the circumferential direction, and each magnet member 10 is housed on the inner surface of the thick portion 32A. A recess 33 is formed. Note that 34 in the figure is a ring provided at the inner lower end of the peripheral wall portion 31A of the spindle hub 31 in order to prevent the magnet member 10 from falling off.

This embodiment is configured as described above, but each magnetic disk 2
The operation of writing and reading information to and from 0 is the same as in the first embodiment. According to this embodiment, the air that has flowed into the spindle hub 31 and taken away the heat of the spindle motor 7 flows through the thin wall portion 32 of the spindle hub 31.
The air can flow out between each magnetic disk 20 from the air circulation hole 22 of the spacer 21 through the air hole B. With this configuration, the magnetic shielding member 12 according to the first embodiment can be eliminated, and the load on the spindle motor 7 can be reduced.

17 is provided to guide cooling air into the spindle hubs 14, 31 from above through each vent 24 of the disk flange 23. It may be configured as follows. Furthermore, although each embodiment has been described using an outer rotor type spindle motor as an example, the present invention can also be applied to an inner rotor type spindle motor.

〔Effect of the invention〕

According to the present invention configured as detailed above, it is possible to prevent the generation of leakage magnetic flux from the spindle motor, and also to cool the spindle motor with the air circulating in the housing, thereby removing the stains caused by burning on the bearings of the motor. Since it is possible to prevent the performance of the components from deteriorating, it is possible to improve the reliability and performance of the magnetic disk device.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, FIG. 1 is a partially cutaway front view of a magnetic disk device according to an embodiment of the present invention, and FIG. Figure 3 is an explanatory diagram showing the flow of air flowing from the inside of the magnet to the outside of the spindle hub. Figure 4 is an exploded perspective view of the spindle motor and spindle hub. Figure 5 6 shows a second embodiment of the present invention, FIG. 5 is a partially cutaway front view of the magnetic disk drive, and FIG. 6 is an explanation showing the airflow flowing from the inside of the spindle hub to the outside. It is a diagram. 1...Housing, 7...Spindle motor, 8.
...Stator coil, 9...Magnet, 10...
Magnet member, 11... Magnetic shielding member, 14, 3
1 Spindle hub for 17... air inlet J18.
...Air outlet, 20...Magnetic disk.

Claims (1)

[Claims] A magnetic disk device comprising a housing, a spindle motor provided in the housing and composed of a stator coil and a magnet, and a magnetic disk provided on the outer peripheral side of the magnet and rotationally driven by the spindle motor, A porous magnetic shielding member is provided between the magnetic disk and the spindle motor, and the air that cools the spindle motor passes through the magnetic shielding member and flows out toward the magnetic disk. magnetic disk device.