JPH04139678A - Spindle construction for disk device - Google Patents

Abstract

PURPOSE:To prevent off-track to be caused at the edge part of a disk by laying a stepped ring spacer whose outside diameter is smaller than the outside diameter of a spacer ring between the disk build-up surface of a spindle housing and the lowermost disk. CONSTITUTION:The stepped ring spacer 16 whose outside diameter at a part in contact with the housing 2 is smaller than the outside diameter of the spacer ring 8 is laid at the lower side of the spindle housing 2 side edge part of the magnetic disk 1, that is, between the disk build-up surface A of the housing 2 and the lower-most disk 1. When the temperature of a magnetic disk device is changed, and temperature difference is caused between the disks 1 at both ends and the other disks 1, the difference of the stress of fixed parts in contact with the rings 8 is caused. Accordingly, by making the diameter of the part in contact with the housing 2 of the spacer 16 smaller than the outside diameter of the ring 8 so as to reduce a contact surface, restriction force to the lower- most disk 1 is reduced, and deformation is prevented, and the off-track is prevented.

Description

[Detailed Description of the Invention] [Summary] Regarding the spindle structure of a disk device, the difference in stress applied to the disk fixing part caused by the temperature difference between disks and the difference in fixing conditions is eliminated, and the disk near the bottom disk in the stacking order is The purpose of the present invention is to provide a spindle structure that reduces off-track related to a rotatable spindle shaft. A stepped ring spacer is provided in which the portion that contacts the spindle housing has a smaller outer diameter than the outer diameter of the spacing ring that is interposed between the spacers and maintains the spacing.

[Industrial application field]

The present invention relates to a spindle structure of a disk device such as a magnetic disk device.

A disk device consists of a plurality of disks rotated by a spindle, a carriage for driving heads, and an arm having a head attached to the carriage. It performs regeneration.

The space between the head and the disk is very narrow and has a sealed structure to prevent dust from entering and damaging the head and disk. For that reason,
Temperature distribution occurs inside, which causes distortion in various structural materials, and the throat tends to be misaligned with respect to the target track (off-track).

[Prior Art] FIG. 3 shows a schematic diagram of a conventional magnetic disk device. A magnetic disk l, which is a magnetic recording medium, is held in a spindle housing 2 fixed to a spindle shaft 10 and rotated by a spindle motor 3.

On the other hand, a magnetic head 4 floating above the magnetic disk 1 with a small gap is used to write information to or read information from the magnetic disk 1.

These plurality of magnetic nodules 4 are supported by a head arm 5, and the head arm 5 is supported by a carriage 6. And 1. There is a mechanism section that has the function of moving the magnetic disk 4 in the radial direction of the magnetic disk 1 by moving the second carrier white and positioning it at a predetermined position.

Detection of the position of the magnetic head 4 during movement is carried out by a servo head, which is a throat dedicated to position detection, which is provided per carriage 6, and constantly reads position information (servo information) written on the magnetic disk 1. It is done by things. Therefore, information recording/reproducing heads other than the servo head are indirectly positioned by the servo head.

FIG. 4 is an explanatory diagram of a conventional spindle structure, and FIG. 5 is an enlarged view of the vicinity of the conventional lowermost magnetic disk.

In the figure, the spindle portion is a spindle shaft 10
The magnetic disks 1 and the spacing ring 8 for securing the distance between the magnetic disks 1 and 1 are assembled by stacking them alternately on the disk stacking surface A of the spindle housing 2 fixed to the The magnetic disk l and the spacing ring 8 are assembled by tightening them with a clamp ring 9.

Note that 11 is a VCM that drives the carriage 6, 12 is a bushing that holds the hair ring 13, and 14 is a housing that seals the device. j7 is a screw.

[The problem that the idea aims to solve]

As the capacity of magnetic disk devices increases, the recording density in the radial direction of the magnetic disk 1 is increasing. Accordingly, more accurate positioning of the magnetic head 4 in the radial direction of the magnetic disk 1 is required.

There are several issues that must be resolved in order to achieve this high-precision positioning, one of which is preventing off-trunk and reducing the amount of off-track.

The causes of this off-track occurrence are wide-ranging, but the present invention targets those caused by the magnetic disk 1 side, which is a magnetic storage medium. This is caused by the magnetic disk 1 near the bottom in the order.

Of the magnetic disk group, the magnetic disks 1 at both ends have different fixing conditions for their fixing parts compared to the other magnetic disks 1. That is, the disk group except for the magnetic disks 1 at both ends are tightened by spacing rings 8 from above and below to ensure spacing, as shown in FIG. However, the magnetic disk 1 at both ends (see FIGS. 4 and 5) is connected to the laminated surfaces A and 9 of the spindle housing 2 via the spacing ring 8 on one side and the spacer rings 15b and 15a on the opposite side to the crumbling ring 9. It can be held down.

Furthermore, while the magnetic disk device is in operation, the magnetic disk 1 rotates at high speed, which causes friction with the air, and the temperature of the magnetic disk I increases due to the frictional heat.

At this time, the temperature of the magnetic disks 1 at both ends of the stacked disk group becomes lower than the temperature of the magnetic disk 1 at the center. In particular, when focusing on the temperature difference between adjacent magnetic disks 1, the largest difference is between the temperature of the magnetic disks 1 at both ends, where there is nothing rotating on the outside, and the magnetic disk one position inside.

For the above reasons, when the temperature of the magnetic disk device changes, the temperature difference between the magnetic disks 1 at both ends and the other magnetic disks 1 may change due to the difference in temperature and the difference in fixing conditions. Due to the difference in stress in the fixed parts, only the magnetic disks at both ends may not move in the same way relative to the other disks, and as a result, the off-track caused by the disks will be reduced by the difference in movement. Occur.

Conventionally, in order to deal with the off trunk that occurs in this way, the shape of the clamp ring 9 (effective tightening method) and the magnetic disk 1 As a countermeasure, a spacer ring 15a has been sandwiched between the clamp ring 9 and the clamp ring 9.

On the other hand, the end magnetic disk 1 on the spindle housing 2 side
, we have placed a spacer ring 15b under it. However, the materials of the spindle housing 2 and the spacing ring 8 are aluminum, Sl, Cu, Mn, and F.
It is an alloy containing elements such as e. Further, the spindle housing 2 is made of cast metal, the spacing ring 8 is made of sawn material, and the magnetic disk 1 is made of plate material, and the amounts of other metals mixed are changed in consideration of formability, cutting properties, etc., respectively. Therefore, the coefficient of thermal expansion is, for example, 21 to 22 for cast metal and 24 to 2 for sawn metal.
3x10-', and the current situation was that this was not a sufficient countermeasure because of the difference in stress in the fixed part due to the temperature difference.

Therefore, the present invention provides a spindle structure that eliminates the difference in stress applied to the disk fixing part caused by differences in temperature and fixing conditions between magnetic disks, and reduces off-track on disks near the lowest disk in the stacking order. The purpose is to

[Means for Solving the Problems] As shown in FIG. 1, the problem is that in a magnetic disk device, the disk stacking surface A of the spindle housing 7 fixed to the rotatable spindle shaft 10, and the A stage is provided between the magnetic disks 1 stacked on the stacked magnetic disks 1 and has an outer diameter portion that is smaller in contact with the spindle housing 2 than the outer diameter of a spacing ring 8 that is interposed between the stacked magnetic disks 1 and maintains the gap therebetween. With ring spacer 16
This problem is solved by the spindle structure of the magnetic disk device of the present invention.

[Function] That is, between the disk stacking surface A of the spindle housing 2 and the lowest magnetic disk 1 in the stacking order, there is provided a stepped ring spacer whose outer diameter is smaller at the part that contacts the spindle housing 2 than the outer diameter of the spacing ring 8. 16, when the temperature of the magnetic disk device changes, the temperature difference that occurs between the magnetic disks 1 at both ends and the other magnetic disks 1, and the fixing part that occurs due to the temperature difference and the difference in fixing conditions. The difference in stress is eliminated by the small restraining force of the stepped ring spacer 16, whose part in contact with the spindle housing 2 has a small outer diameter, on the spindle housing 2 that the small ring spacer 16 is in contact with. It is possible to prevent off-trunk caused by the end magnetic disk on the side of the second disk stacking surface.

〔Example] FIG. 1 is an explanatory diagram of an embodiment of the present invention.

Note that the same reference numerals indicate the same objects throughout the figures.

In FIG. 1, reference numeral 2 denotes a spindle housing of a magnetic disk device, and on the disk stacking surface A of the spindle housing 2, there are magnetic disks 1 and a spacing ring 8 for ensuring a distance between the magnetic disks 1 and the magnetic disks 1. , they are assembled by stacking them alternately, and finally the stacked magnetic disks 1 group and spacing ring 8 groups are connected to the clamp ring 9 and screws.
Tighten and assemble with step 17. Note that 10 is a spindle shaft that fixes the spindle housing 2.

In the present invention, the end portion of the magnetic disk 1 on the side of the spindle housing 2 is placed on the lower side of the magnetic disk 1, that is, between the disk stacking surface A of the spindle housing 2 and the lowermost magnetic disk 1. A stepped ring spacer 16 with a small outer diameter is laid on the part that comes into contact with the spacer.

When the temperature of the magnetic disk device changes, a temperature difference occurs between the both-end C magnetic disk 1 and the other disks 1. For example, the upper and lower ends of the laminated magnetic disk 1 are low, and the center is high. Due to the difference in row strength, a difference occurs in the response of the fixed portion that contacts the spacing ring 8.

Further, the materials of the spindle housing 2 and the spacing ring ε are an alloy of aluminum containing Si, CtMn, Fe, etc. Furthermore, the spindle housing 2 is made of cast metal, and the spacing ring 8 is made of pressed metal. , have different coefficients of thermal expansion, for example A! The coefficient of thermal expansion of is 24X10-”
However, depending on the amount of other metals mixed, it is 21~22X for castings.
For 10-6 ground product, it will be 24-23X10-'. In the present invention, the stepped ring spacer 16 has a smaller outer diameter (
In the embodiment, the outer diameter was set to about 2/3 of the outer diameter of the spacer ring 8, and the thickness was set to about 1/2 of the thickness of the spacer ring 8), so that the contact surface with the spindle housing 2 was reduced, and the lowermost magnetic disk 1 to prevent deformation and prevent off-track caused by the lowermost magnetic disk 1.

[Effect of idea]

As explained above, according to the present invention, between the disc stacking surface of the spindle housing and the lowest disc in the stacking order, there is provided a stepped ring whose outer diameter is smaller than the outer diameter of the spacing ring at the part that contacts the spindle housing 2. By placing a spacer, it is possible to eliminate the difference in stress applied to the magnetic disk fixing part caused by the temperature difference between the disks and the difference in fixing conditions, and thereby reduce the off-trunk that occurs at the edge of the stacked magnetic disk. can.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an embodiment of the present invention, Figure 2 is a schematic diagram of a magnetic disk drive, Figure 3 is an explanatory diagram of a conventional spindle structure, and Figure 4 is an enlarged view of the vicinity of the conventional lowermost magnetic disk. It is a diagram. In the figure, 1 is a magnetic disk, 2 is a spindle housing, 8 is a spacing ring, 9 is a clamp ring, 10 is a spindle shaft, 16 is a stepped ring spacer, and 17 is a screw. Explanatory diagram of conventional spindle box structure Foil 3 Figure α〕 Heisei-Month L Co. Patent Office Commissioner Tonohira $c May 218. Relationship between display case and suspension of presentation case

Claims (1)

[Claims] In a disk device, a disk stacking surface (A) of a spindle housing (7) fixed to a rotatable spindle shaft (10) and a disk stacked thereon (
1), the step has an outer diameter portion that is smaller in contact with the spindle housing (7) than the outer diameter of the spacing ring (8) that is interposed between the stacked disks (1) and maintains the distance therebetween. A spindle structure for a disk device, characterized in that a ring spacer (16) is provided.