JPH04195980A - Magnetic disk drive - Google Patents

Abstract

PURPOSE:To suppress the change in the relative position between the magnetic disk and a magnetic head due to impact and to prevent head crash by providing a spring means which always press the spindle hub part of the disk in one direction between the disk side bearing and the case main body. CONSTITUTION:In the disk device, plural numbers of magnetic disks 2 are mounted with a specified interval on a spindle hub 3 and supported so that the disk can be freely rotated with a disk supporting axis 5a through the disk side bearings 4a, 4b fixed to the inner diameter side of the spindle hub 3a on both ends. Plural magnetic heads 9 are disposed near the magnetic disks 2 and the case main body 1 supports the both ends of the disk supporting axis 5a. The disk bearings 4a, 4b are provided so that the inner diameter side to the bearings can slide freely on the disk supporting axis 5a and the spindle hub can move back and forth by 0.3 mm at large along the axis 5a. Then a spring 6a is provided between the disk side bearings 4a and the case main body 1 in order to always press the spindle hub in one direction. Thereby, changes of the relative position of the magnetic disk to a magnetic head due to impact is suppressed and head crash can be prevented.

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 equipped with a rotation mechanism and a positioning mechanism supported by bearings.

[Prior Art] Generally, this type of magnetic disk device reads and writes magnetic recording by floating a magnetic head at minute intervals using air pressure generated as the magnetic disk rotates at high speed. The carriage of this magnetic disk device uses a servo head to read a positioning pattern written on a magnetic disk, and performs positioning by forming a servo loop.

In addition, progress is being made in the direction of improving the recording density of magnetic disk devices, and methods for improving this recording density include increasing the bit density of the track, and increasing the track density by reducing the track width. There is. Also, recently, while increasing the recording density, such as magnetic disk drives that accommodate 5-inch disks, about 10 magnetic disks can be stored.

Achieves high-density mounting with several dozen magnetic heads,
A large capacity of nearly 2 GB per spindle has been achieved.

In this type of magnetic disk device, as shown in FIG. 3, a magnetic disk 2 is supported by a spindle hub 3a, and the spindle hub 3a is connected to a disk rotating shaft 5 through bearings 4a and 4b.
It is rotationally supported by a.

Both ends of the disk rotating shaft 5a are fixed to the substrate 1, and is a so-called fixed shaft type spindle. This drive is carried out by motor 7a.
carried out by

The bearings 4a, 4b are fitted with a clearance to be slidable in the axial direction on the disk rotation shaft 5a, and are biased in the axial direction by a preload spring 6a for removing backlash. On the other hand, a magnetic head 9 corresponding to the magnetic disk 2 is supported by a carriage lO,
It is rotatably supported by the head rotating shaft 12 via bearings 11a and llb.

The bearings 11a and llb are fit into the head rotation shaft 12 so as to be able to slide in the axial direction, and are biased in the axial direction by a preload spring 6b for removing looseness, and both ends of the head rotation shaft 12 are fixed to the substrate 1. This is a so-called fixed shaft positioning mechanism.

On the other hand, when a conventional magnetic disk drive is subjected to shock from the outside due to handling, transportation, etc. - When fishing on a boat, anti-vibration rubber (not shown) is used in the device to soften this shock. However, if the impact is large in the direction opposite to the preload direction,
There is a risk that the spindle rotating section or the magnetic head rotating section will move in their respective axial directions. In other words, if the mass of the side member that applies the preload of the spindle section is M and the amount of preload is F, then the allowable impact value A is A=F/M from the formula MA=F.

Similarly, regarding the head positioning mechanism, if the mass of the side member applying preload is m and the amount of preload is f, then the allowable impact value is a=f/m.

Therefore, when an impact acceleration of A or a or more is applied to the device, the magnetic disk in the spindle section or the magnetic head in the head positioning mechanism causes a relative instantaneous positional change, which causes the magnetic head to rub against the magnetic disk. or in the worst case, cause damage.
This is a major cause of head crashes.

[Object of the invention] The present invention improves the disadvantages of such conventional examples, and (
Another object of the present invention is to provide a magnetic disk device that can suppress changes in the relative position of a magnetic head due to impact and effectively prevent head crashes.

[Means to solve the problem]

In the present invention, a plurality of magnetic disks are installed on a cylindrical spindle hub at predetermined intervals, and a disk support shaft is rotatably supported via disk-side bearings fixed to the inner diameter side of both ends of the spindle hub. , a plurality of magnetic heads installed close to at least one surface of each magnetic disk, and a case body that fixedly supports both ends of the disk support shaft, and the inner diameter side of the disk side bearing slides on the disk support shaft. The spindle hub part including this disk side bearing is equipped to allow reciprocating movement of about 0.3 mm at maximum in the direction along the center line of the disk support shaft. The structure is such that a spring means is provided between the case body and the spindle hub portion to always press the spindle hub portion in one direction. This aims to achieve the above-mentioned purpose.

[First Embodiment] Hereinafter, a first embodiment of the present invention will be described based on FIG. 1.

Here, the same reference numerals are used for the same constituent members as in the conventional example described above.

The embodiment shown in FIG. 1 has a cylindrical spindle hub 3.
a, a plurality of magnetic disks 2 installed at predetermined intervals on the spindle hub 3a; a disk support shaft 5a rotatably supported via disk-side bearings 4a and 4b fixed to the inner diameter side of both ends of the spindle hub 3a; It includes a plurality of magnetic heads 9 mounted close to at least one surface of each magnetic disk 2, and a case body 1 that fixedly supports both ends of a disk support shaft 5a.

The disk-side bearings 4a, 4b are slidably mounted on the disk support shaft 5a at their inner diameter sides.

Spindle hub 3 including these disk side bearings 4a and 4b
The portion a is equipped to allow reciprocating movement of about 0.3 mm at most in the direction along the center line of the disk support shafts 4a and 4b.

A compression spring 6a is provided between the disk-side bearings 4a, 4b and the case body and is provided with an appropriate preload as a spring means for constantly pressing the spindle hub 3a portion in one direction.

On the other hand, the plurality of magnetic heads 9 described above are supported by the carriage 10 via the arm portion 9A.

The carriage 10 is rotatably mounted on a head support shaft 12 via head side bearings 11a and 11b.

The entire spindle hub including the head support shaft 12 is allowed to reciprocate about 0.3 mm in the direction along its rotation center line.

A compression spring 6b is provided between the head-side bearing and the case body and is provided with an appropriate preload as a spring means for always pressing the carriage 10 portion in one direction.

To explain this in more detail, the spindle hub 3a supporting the magnetic disk 2 is rotatably supported by the disk rotating shaft 5a via bearings 4a, 4b.

Both ends of the disc rotation shaft 5a are fixed to the case body 1,
This is a so-called fixed shaft type spindle. Bearings 4a, 4b
is fitted with a clearance to be slidable in the axial direction on the disk rotating shaft 5a, and is biased in the axial direction by a preload spring 6a for removing looseness via a collar 8a.

On the other hand, a magnetic head 9 corresponding to the magnetic disk 2 is supported by a carriage O, and is rotatably supported by a head rotating shaft 12 via bearings 11a and llb. Bearing 1
1a and llb are fit into the head rotation shaft 12 so as to be able to slide in the axial direction, and are biased in the axial direction by a preload spring for removing backlash through the collar 8b, and both ends of the head rotation shaft 12 are connected to the case body. This is a so-called fixed shaft positioning mechanism. In this magnetic disk device, when an external impact is applied in a direction opposite to the preload direction due to transportation or the like, the relative position of the magnetic disk and the magnetic head changes when the impact value exceeds A or a as described above. However, in the present invention, the spindle part has a collar 8a, and the positioning mechanism part has a collar 8b, and since the clearance with the substrate is less than 0.3 mm, if the magnetic disk or [air head] moves due to an impact, However, the amount will be within this clearance. Practically speaking, this clearance is desirably 20 to 50 μm.

[Second example] Next, a second embodiment will be described based on FIG. 2.

In the embodiment shown in FIG. 2, the preload spring 6c surrounds and fixes the outer ring portion of the bearing 4d to the housing 1.
In addition to the housing 3b, another housing 3a that surrounds and fixes the outer ring portion of the other bearing 4c is brought into contact with the case body 1. This is a so-called shaft rotation type rotation mechanism. In this case, a stopper 14 with an axial clearance of 0.3 mm or less is attached to the case body 1 with respect to the housing 13a.

The other configurations are the same as the conventional example described above.

Therefore, the relative position of the magnetic disk and magnetic head will change if the preload direction is shifted by more than the allowable impact value in the opposite direction to the preload direction, but due to this spacing, the amount will be within 0.3 mm. It can be suppressed. In this case as well, the above-mentioned clearance is preferably 20 to 501 μm.

〔Effect of the invention〕

As explained above, the present invention provides a mass-produced motor in which the rotating part is axially opposite to the preload applied to the bearing against an external shock in the rotating mechanism or positioning mechanism of a magnetic disk drive. We have provided a stopper mechanism to prevent this from happening, so changes in the relative position of the magnetic disk and magnetic head due to impact can be minimized.
It is possible to provide an unprecedented and excellent magnetic disk device that can prevent head crashes.

Another effect is that by preventing the above-mentioned change in relative position, it is possible to minimize the off-track caused by this.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view showing a second embodiment of the invention, and FIG. 3 is a sectional view showing a conventional example. l:...Body case 2:...Magnetic disks 3a, 3b:...Spindle hub 4a, 4b, 4c, 4d Knee...Bearings 5a, 5b:...
...Disk support shafts 6a, 6b, 6c Knee compression spring 9: ...Magnetic head 10: ...Carriage 11a, llb: ...Head side bearing 12: ...Head support shafts 13a, 13b: ...・Housing] 4: Stopper applicant Japan Electric Co., Ltd. Agent Patent attorney Isamu Takahashi

Claims (3)

[Claims] (1) A disk support that rotatably supports a plurality of magnetic disks mounted on a cylindrical spindle hub at predetermined intervals, and disk-side bearings fixed to the inner diameter side of both ends of the spindle hub. a shaft, a plurality of magnetic heads installed close to at least one surface of each of the magnetic disks, and a case body that fixedly supports both ends of the disk support shaft, the inner diameter side of the disk-side bearing being connected to the disk. It is equipped to be able to slide freely on the support shaft, and is also equipped so that the spindle hub portion including this disk side bearing is allowed to reciprocate by a maximum of about 0.3 mm in the direction along the center line of the disk support shaft. A magnetic disk drive characterized in that a spring means is provided between the disk-side bearing and the case body to constantly press the spindle hub portion in one direction. (2) A plurality of magnetic disks installed at predetermined intervals on a cylindrical spindle hub, a plurality of magnetic heads installed close to at least one surface of each of the magnetic disks, and the spindle hub are integrated. a case body that rotatably supports both ends of the disk support shaft via a disk side bearing and a housing for the disk side bearing, the disk side bearing including the housing; 0.3 at maximum in the direction along the center line of the disc side bearing.
The apparatus main body is equipped to allow reciprocating movement on the order of millimeters, and a spring means is provided between the housing and the apparatus main body to constantly press the entire disk side bearing including the housing in one direction. A magnetic disk device characterized by: (3), comprising a plurality of magnetic disks installed at predetermined intervals on a cylindrical spindle hub, and a disk support shaft rotatably supporting the spindle hub via a disk-side bearing, each of the magnetic disks; A plurality of magnetic heads are provided in close proximity to at least one surface of a disk, a cylindrical carriage that supports the plurality of magnetic heads via an arm portion, and a cylindrical carriage that rotatably supports the carriage via a head-side bearing. a case body that fixedly supports both ends of the disk support shaft and the head support shaft, the inner diameter side of the head side bearing being slidably mounted on the head support shaft; , the entire spindle hub portion including the head side bearing is allowed to reciprocate by a maximum of about 0.3 mm in the direction along the center line of the head support shaft. A magnetic disk drive characterized in that a spring means is provided between the head-side bearing and the case body to always press the carriage portion in one direction.