JPH03266257A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To make thermal off-track small so as to position a magnetic head correctly to a magnetic disk by giving radial direction load correctly to a magnetic disk by giving radial direction load by a radial spring so that a spindle system and a carriage system are inclined in the same direction. CONSTITUTION:The inclination of a shaft 4 which is given the load in the radial direction by a first radial spring 14 and the inclination of a cylinder 6 which is given the load in the radial direction by a second radial spring 15 are made the same direction. For this purpose, the position of a first bearing 9, the position of a second bearing 10, and the direction of the load in the radial direction by the first radial spring 14, the direction of the load in the radial direction by the second radial spring 15 are set. Thus, the thermal off- track is made small, and the correct positioning of the magnetic head 16 to the magnetic disk 1 becomes possible.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic disk device, and in particular, to a spindle hub in which a plurality of magnetic disks are stacked and mounted at a predetermined interval, and a magnetic disk device. The present invention relates to a magnetic disk device including a cylinder that carries a plurality of magnetic heads for recording and reproducing information and that performs rotational movement.

[Conventional technology]

2. Description of the Related Art In recent years, the storage density of magnetic disk devices has increased as the storage capacity has increased, and along with this, it has become necessary to improve the positioning accuracy of the magnetic head with respect to the magnetic disk.

The magnetic head positioning means in a magnetic disk device includes a dedicated magnetic head (servo head) for positioning operation, and preliminary positioning information is recorded on a storage surface (servo surface) of a magnetic disk corresponding to this servo head. This positioning information is then read by a servo head. Therefore, the relative displacement between the servo head and other magnetic heads and the relative displacement between the servo surface and the storage surface of other magnetic disks are the amount of deviation with respect to the track that should originally be followed, that is, the off-track The smaller the off-track amount, the higher the positioning accuracy.

However, in actual magnetic disk drives, an amount of off-track exceeding the allowable limit may occur due to various factors. In particular, off-track caused by an increase in the temperature of the magnetic disk drive itself or a change in the environmental temperature,
It is called thermal off-track, and the eel is one of the major factors.

Thermal off-track is caused by differences in thermal expansion coefficients between the mechanical parts that make up the magnetic disk drive.

FIG. 2 is a sectional view showing an example of a conventional magnetic disk device.

The magnetic disk device shown in FIG. 2 has a plurality of magnetic disks 2.
1 are stacked at a predetermined interval and mounted on a spindle hub 22, and the spindle hub 22 is fixed to a shaft 24 and rotated. A driving motor 23 is attached to the lower end of the shaft 24, and these constitute a spindle system.

On the other hand, a plurality of magnetic heads 36 for recording and reproducing information on the magnetic disk 21 are held by a plurality of magnetic head arms 35.
5 is fixed to the cylinder 26. The cylinder 26 is rotatably held by a pivot shaft 27, and a voice coil motor 28 is provided to drive the magnetic head 36 and magnetic head arm 35, which constitute a carriage system.

Two bearings are provided above and below the shaft 24 of the spindle system to maintain the accuracy of its rotational movement.
The inner ring of the lower bearing 29 is the shaft 24
The outer ring of the bearing 29 and the base plate 31
A radial spring 34 is provided between the bearing 2
By applying a load in the radial direction of bearing 29
The play between the base plate 31 and the base plate 31 is removed. Similarly, two bearings are provided above and below the pivot shaft 27 of the carriage system in order to maintain the accuracy of its rotational movement, and the outer ring of the upper bearing 30 is fixed to the inner circumference of the cylinder 26. , a radial spring 3 is installed between the inner ring of the bearing 30 and the pivot shaft 27.
5 is provided to apply a load to the bearing 30 in the radial direction to remove looseness between the bearing 30 and the pivot shaft 27. Also bearings 29 and 30
By providing thrust springs 32 and 33, respectively, to apply a thrust load to the bearings 29 and 30, play between the inner and outer rings of the bearings 29 and 30 is eliminated.

[Problem to be solved by the invention]

In the conventional magnetic disk drive described above, the direction of the radial load is the same for the spindle system and the carriage system, and the positions of the bearings that apply the radial load to the shaft 24 of the spindle system and the pot shaft 27 of the carriage system are different. Because they are located on opposite sides, the directions of inclination of the spindle system and carriage system caused by temperature changes are different, which increases the relative displacement between the magnetic head and the magnetic tilt, which is bad for off-track. It has the disadvantage of having an impact.

[Means to solve the problem]

A magnetic disk device of the present invention includes: a spindle hub on which a plurality of magnetic disks are stacked and mounted at predetermined intervals; a shaft to which the spindle hub is fixed and rotates;
two first bearings installed above and below the shaft; a first radial spring that applies a load in a radial direction to an outer ring of one of the two first bearings; a plurality of magnetic heads for recording and reproducing information; a plurality of magnetic head arms for holding the magnetic heads; a cylinder to which the magnetic head arms are fixed and rotated; A radial load is applied to the two attached second bearings, the pivot shaft rotatably held by the second bearings, and the inner ring of one of the two second bearings. and a second radial spring that applies a radial load, the inclination of the shaft to which a radial load is applied by the first radial spring, and the inclination of the cylinder to which a radial load is applied by the second radial spring. a position of the first bearing to which a radial load is applied by the first radial spring and a position of the second bearing to which a radial load is applied by the second radial spring such that , the direction of the load in the radial direction by the first radial spring, and the direction of the load in the radial direction by the second radial spring.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention.

The magnetic disk device shown in FIG. 1 includes a plurality of magnetic disks 1
are stacked at a predetermined interval and mounted on a spindle hub 2, and the spindle hub 2 is fixed to a shaft 4 and rotated. A driving motor 3 is attached to the lower end of the shaft 4, and these constitute a spindle system.

On the other hand, a plurality of magnetic heads 16 for recording and reproducing information on the magnetic disk 1 are connected to a plurality of magnetic head arms 5.
This magnetic head arm 5 is held by
It is fixed to the cylinder 6. The cylinder 6 is rotatably held by a pivot shaft 7, and the magnetic head 16
A voice coil motor 8 is provided to drive the magnetic head arm 5, and these constitute a carriage system.

Bearings are provided above and below the shaft 4 of the spindle system in order to maintain the accuracy of its rotational movement.The inner ring of the lower bearing 9 is fixed to the shaft 4, and the outer ring of the bearing 9 and the base plate 11 A radial spring 14 is provided between the bearing 9 and the base plate 1 to apply a load in the radial direction of the bearing 9.
1. Similarly, bearings are provided above and below the pivot shaft 7 of the carriage system in order to maintain the accuracy of its rotational movement, and the outer ring of the upper bearing 10 is fixed to the inner circumference of the cylinder 6, and the bearing A radial spring 15 is provided between the inner ring of the bearing 10 and the pivot shaft 7, and a load is applied to the bearing 10 in the radial direction to eliminate looseness between the bearing 10 and the pivot shaft 7. Moreover, by providing thrust springs 12 and 13 to the bearings 9 and 10, respectively, and applying a thrust load, play between the inner and outer rings of the bearings 9 and 10 is eliminated. In order to reduce the thermal off-track, the shaft 4 and the pivot shaft 7 may be tilted in the same direction. Therefore, for the shaft 4, the radial spring 14 applies a radial load to the lower bearing 9 from right to left, and for the pivot shaft 7, the radial spring 15 applies a radial load to the upper bearing 10. Give from left to right.

〔Effect of the invention〕

As explained above, the magnetic disk drive of the present invention reduces thermal off-track and accurately operates the magnetic head by applying a radial load by a radial spring so that the spindle system and carriage system are tilted in the same direction. This has the effect that positioning can be performed on the magnetic disk, and therefore a highly reliable magnetic disk device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing an example of a conventional magnetic disk device. 1.21...Magnetic disk, 2.22...
・・Spindle hub, 3・23・・・・Motor, 4
・Shaft for 24, 5, 25, magnetic head arm, 6, 26, cylinder, 7, 27
・・・・・・Pivot shaft, 8・28・・・・・・
Voice coil motor, 9/10/29/30...
・Bearing, 11, 31...Base plate, 12, 13, 32, 33...Thrust spring, 14, 15, 34, 35...Radial spring, 16, 36... ...magnetic head.

Claims (1)

[Claims] 1. A spindle hub on which a plurality of magnetic disks are stacked and mounted at predetermined intervals, a shaft to which the spindle hub is fixed and rotates, and two disks attached above and below the shaft. a first radial spring that applies a radial load to the outer ring of one of the two first bearings, and a plurality of magnetic disks that record and reproduce information on the magnetic disk. a plurality of magnetic heads, a plurality of magnetic head arms that hold the magnetic heads, a cylinder that fixes the magnetic head arms and performs rotational movement, and two second bearings installed above and below the cylinders. a pivot shaft rotatably held by the second bearing; and a second radial spring that applies a load in the radial direction to the inner ring of one of the two second bearings. In the magnetic disk drive, the inclination of the shaft to which a radial load is applied by the first radial spring and the inclination of the cylinder to which a radial direction load is applied by the second radial spring are in the same direction. a position of the first bearing that is radially loaded by a first radial spring; a position of the second bearing that is radially loaded by the second radial spring; A magnetic disk device characterized in that a direction of a radial load by a radial spring and a direction of a radial load by the second radial spring are set. 2. A spindle hub on which a plurality of magnetic disks are stacked and mounted at predetermined intervals, a shaft that fixes the spindle hub and rotates, and two first bearings installed above and below the shaft. , a first radial spring that applies a load in a radial direction to an outer ring of one of the two first bearings, and a plurality of magnetic heads that record and reproduce information on the magnetic disk; a plurality of magnetic head arms that hold the magnetic head; a cylinder to which the magnetic head arm is fixed and rotates; two second bearings installed above and below the cylinder; In the magnetic disk device, the magnetic disk device includes a pivot shaft rotatably held by a bearing, and a second radial spring that applies a load in a radial direction to an inner ring of one of the two second bearings. The position of the first bearing to which a load in the radial direction is applied by the first radial spring and the position of the second bearing to which the load in the radial direction is applied by the second radial spring are vertically opposite to each other. year,
A magnetic disk drive characterized in that the direction of the radial load applied to the outer ring of the first bearing and the direction of the radial load applied to the inner ring of the second bearing are opposite directions.