JPH03242857A - Fitting method and fitting structure for magnetic disk - Google Patents

Abstract

PURPOSE:To correctly position and fitting a magnetic disk on the concentric circle of a spindle hub by giving physical quantity to an insert, and deforming this insert. CONSTITUTION:The insert 6 made of shape memory alloy formed into an annular shape has a wave-shaped initial shape in which the circular arcs of radius (r) are connected between the circle of the radius R1 and the circle of the radius R2. Besides, the circle of the radius R1 is a little smaller than the outer circumference of a spindle hub 2 and the circle of the radius R2 is a little larger than the fitting hole of the magnetic disk 3. Then, the insert 6 having such the initial shape is deformed into the circular shape of the radius R3 (R1<R3<R2), and is fitted to the outer circumference of the spindle hub 2, and the fitting hole 4 of the magnetic disk 3 is fitted to the spindle hub 2 through the insert 6. Thus, the magnetic disk 3 can be fitted to the spindle hub 2 by positioning it correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and structure for attaching a magnetic disk to a spindle hub constituting a spindle motor.

[Prior Art] A conventional magnetic disk mounting structure will be explained with reference to FIG.

In the figure, the symbol l is a spindle motor.

A spindle hub 2 is supported on the spindle motor l so as to be rotatable about the axis of the spindle motor l.
It is designed to rotate by supplying power to it.

A plurality of magnetic disks 3.3 are attached to the outer periphery of the spindle hub 2.

That is, the magnetic disk 3.3 has fitting holes 4, 4 formed in the center thereof, each having a diameter larger than the outer circumference of the spindle hub 2. While fitting the outer periphery, insert the disk spacer 5 above and below.
The magnetic disk 3 is placed on the outer periphery of the spindle hub 2 by stacking the magnetic disk 3 in layers through the 5.
3 can be attached at a predetermined distance from each other.

[Problems to be Solved by the Invention] In recent years, magnetic disk drives have adopted smaller spindle motors (in-hub motors) in which a ferromagnetic material is provided inside the spindle hub 2 that constitutes the spindle motor l. has been done.

On the other hand, the magnetic disk 3.3 is made of a material (eg, glass, aluminum, etc.) that has a different shrinkage rate due to temperature changes than the spindle hub 2 provided with a ferromagnetic material.

By the way, during the assembly stage, as shown in FIG. 7, the magnetic disk 3 may be attached to the spindle hub 2 with a part of the inner peripheral surface of the fitting hole 4 in contact with the spindle hub 2.
In this case, for example, due to the shipping route of the magnetic disk drive, when the magnetic disk drive goes through a low-temperature process, the points of contact may interfere with each other due to the difference in shrinkage rates, causing the temperature to drop to room temperature. When the magnetic disk 3 returns to its original position, a so-called slip phenomenon occurs in which the center position of the magnetic disk 3 shifts, as shown in FIG. 8, which may cause an off-track error.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic disk mounting method and mounting structure that allows a magnetic disk to be accurately positioned and mounted on a spindle hub without being affected by temperature changes. The purpose is

[Means for Solving the Problems] A magnetic disk mounting method according to the first invention includes fitting an insert around a spindle hub, fitting a magnetic disk having a fitting hole around the insert, and A physical quantity is applied to the insert, the insert is displaced between the outer peripheral surface of the spindle hub and the inner peripheral surface of the fitting hole, and the magnetic disk is positioned and attached on a concentric circle of the spindle hub. It is said that

A magnetic disk mounting structure according to a second aspect of the present invention is a magnetic disk mounting structure in which a magnetic disk having a fitting hole is fitted around a spindle hub, in which an outer peripheral surface of the spindle hub and an inner periphery of the fitting hole are provided. The present invention is characterized in that an insert is provided between the spindle hub and the spindle hub to be displaced by the supply of a physical quantity to position the magnetic disk on a concentric circle of the spindle hub.

[Operation] According to the magnetic disk mounting method of the first invention, when a physical quantity is applied to the insert, the insert is displaced, thereby accurately positioning and mounting the magnetic disk on the concentric circle of the spindle hub.

According to the magnetic disk mounting structure of the second invention, the insert that is displaced by the supply of a physical quantity is provided between the outer circumferential surface of the spindle hub and the inner circumferential surface of the fitting hole of the magnetic disk. is due to the displacement of the insert.
Accurately positioned on the concentric circle of the spindle hub.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Note that the same reference numerals are given to the parts having the same structure as in the prior art, and the description thereof will be omitted.

In FIG. 1, the reference numeral 6 indicates an annularly formed thickness t.
This is an insert made of shape memory alloy.

This insert 6 is provided between the outer circumference of the spindle hub 2 and the inner circumference of the magnetic disk 3 fitting hole 4.

This insert 6 is set so as to be restored to its initial shape as shown in FIG. 2 at a predetermined temperature T.

That is, the insert 6 has a wavy initial shape in which circular arcs with a radius r are connected between a circle with a radius R1 and a circle with a radius R2 over the circumferential direction.

Here, the circle with radius R1 is slightly smaller than the outer circumference of spindle hub 2, and the circle with radius R2 is slightly larger than the fitting hole of magnetic disk 3.

Then, the insert 6 with such an initial shape is
As shown in FIG. 3, it is deformed into a circular shape with a radius R3 (R1<R3<R2) and fitted onto the outer periphery of the spindle hub 2,
The fitting hole 4 of the magnetic disk 3 is fitted into the spindle hub 2 via the insert 6.

In this way, as shown in FIG. 4, a circular insert 6 with a radius R3 is interposed between the outer circumference of the spindle hub 2 and the inner circumference of the fitting hole 4 of the magnetic disk 3.

In this state, when the insert 6 is heated to a predetermined temperature T, the insert 6 is restored to its initial shape, and as shown in FIG. Due to the restoring force of insert 6,
The magnetic disks 3 and the spindle hub 2 are always uniformly biased in the direction away from each other, and the magnetic disks 3 and the spindle hub 2 are accurately positioned at the same central position.

In this way, the center position of the fitting hole 4 of the magnetic disk 3 and the center position of the spindle hub 2 can be aligned, so even if the spindle hub 2 and the magnetic disk 3 contract or expand due to temperature changes, these spindle hubs Since the hub 2 and the magnetic disk 3 contract or expand at the same central position, it is possible to prevent the center positions of the spindle hub 2 and the magnetic disk 3 from shifting or slipping. .

In addition, by aligning the center position of the magnetic disk 3 and the center position of the spindle hub 2, the spindle hub 2
Even if the magnetic disk 3 is rotated at high speed, vibrations due to eccentric rotation of the magnetic disk 3 can be prevented from occurring, and good rotation characteristics can be obtained.

Incidentally, since the insert 6 itself of the above embodiment is also formed in a symmetrical shape and has good balance, no vibration is generated even if the spindle hub 2 rotates at high speed.

Further, the insert 6 in the above embodiment is formed into a corrugated ring shape, but the insert 6 is formed in a corrugated ring shape, and the insert 6 is formed in a corrugated ring shape.
Any initial shape may be used as long as the space between the fitting hole 4 and the fitting hole 4 is widened at a constant interval in the circumferential direction.

In addition, as the material for the insert 6, in the above embodiment, a shape memory alloy that restores to its initial shape at a predetermined temperature T is used, but any material that is displaced by the supply of physical quantities (e.g., heat, light, force, etc.) may also be used. Of course, any material may be used. For example, a piece of spring steel formed into the shape shown in FIG. The corrugated portions are maintained in a stretched state by applying a pulling force downward on the circumference so that the ends of the cut portions overlap each other, and the fitting hole 4 of the magnetic disk 3 is inserted into the spring steel. The magnetic disk 3 may be positioned on the outer periphery of the spindle hub 2 by fitting them together, and then releasing the tensile force to restore the shape shown in FIG.

[Effects of the Invention] As explained above, according to the magnetic disk mounting method and mounting structure of the present invention, the following effects can be obtained.

When a physical quantity is given to the insert provided between the spindle hub and the magnetic disk, this insert is displaced and the magnetic disk is accurately positioned on the outer circumference of the spindle hub, so that the center position of the spindle hub and the magnetic disk are It is possible to very easily and accurately match the center position of the .

Therefore, even if the spindle hub and magnetic disk contract or expand due to temperature changes, these spindle hubs and magnetic disks will contract or expand around the same position, resulting in a shift in the center position of the spindle hub and magnetic disk. , or it is possible to prevent the occurrence of center position slip due to interference between the spindle hub and the magnetic disk, and it is possible to prevent off-track errors due to center position deviation, and it is possible to prevent data writing to the magnetic disk, or It is possible to read data from a magnetic disk in a good manner.

In addition, by aligning the center position of the magnetic disk with the center position of the spindle hub, even if the spindle hub is rotated at high speed, vibrations due to eccentric rotation of the magnetic disk can be prevented, resulting in good rotation. characteristics can be obtained.

A10□ 0

[Brief explanation of drawings]

1 to 5 are diagrams explaining the present invention in detail, in which FIG. 1 is a cross-sectional view of a magnetic disk, spindle hub, and disk spacer, and FIG. 2 is a plane view of the insert to explain the initial shape of the insert. Figure 3 is a plan view of the insert to explain the mounting shape of the insert, Figure 4 is a sectional view taken along line A-A to explain the state of the insert after installation, and Figure 5 is a diagram of the insert after it has been restored to its initial shape. A explaining the condition
-A sectional view. Furthermore, FIGS. 6 to 8 are diagrams for explaining the conventional example, in which FIG. 6 is an exploded configuration diagram for explaining the mounting structure of the magnetic disk, and FIG. 7 is for explaining the mounting state of the magnetic disk. FIG. 8 is a plan view of the spindle hub and magnetic disk illustrating a slip phenomenon at the center position due to interference between the magnetic disk and the spindle hub. ...Spindle hub, 3. - Magnetic disk, - Fitting hole, 6. ... Insert.

Claims (2)

[Claims] (1) Fit the insert around the spindle hub,
fitting a magnetic disk having a fitting hole around the insert, applying a physical quantity to the insert, and displacing the insert between an outer circumferential surface of the spindle hub and an inner circumferential surface of the fitting hole; A method for attaching a magnetic disk, comprising positioning and attaching the magnetic disk on a concentric circle of the spindle hub. (2) In a magnetic disk mounting structure in which a magnetic disk having a fitting hole is fitted around a spindle hub, a physical quantity is supplied between the outer circumferential surface of the spindle hub and the inner circumferential surface of the fitting hole. 1. A mounting structure for a magnetic disk, characterized in that an insert is provided for displacing the magnetic disk to position the magnetic disk on a concentric circle of the spindle hub.