JP2591428B2 - Magnetic disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to a magnetic disk drive having a plurality of magnetic disks mounted thereon.

[0002]

2. Description of the Related Art A magnetic head positioning mechanism in a magnetic disk drive has a dedicated servo head for positioning, and this servo head reads positioning information recorded in advance on a magnetic disk surface and performs positioning based on the read information. ing. Therefore, the relative position error between the servo head and the data head for writing and reading other information becomes the deviation amount from the track amount that should originally be followed, that is, the off-track amount. The smaller the off-track amount, the higher the positioning accuracy.

[0003]

However, in practice, an unacceptable amount of off-track occurs due to various factors. Of these off-track amounts, the off-track caused by a rise in the temperature of the apparatus or a change in the environmental temperature is called a thermal off-track, and the main difference is the difference in the linear expansion coefficient between the various mechanical components constituting the magnetic disk drive. Is considered to be a factor.

As shown in FIG. 2, a magnetic disk drive generally includes a magnetic disk 51 and a spacer 54.
Are alternately stacked in contact with the side surface of the spindle motor hub 52. Therefore, if the temperature changes as described above, the magnetic disk 51 may be shifted in an extreme case.

Further, the magnetic disk drive generally has an environmental temperature condition during storage of "-40.degree. C. to 60.degree. C." Therefore, the materials of the magnetic disk 51 and the spacer ring 54 and the spindle motor hub 52 on which the magnetic disk 51 and the spacer ring 54 are mounted are different. Due to the difference in coefficient, the magnetic disk 51 shifts with the contact point as a fulcrum along with the temperature change. As a result, an irreversible relative displacement between the positioning information recorded on the servo disk and the data information recorded on the data head, that is, a thermal off-track occurs, and a reading error of the data information due to this occurs. There was an inconvenience that it occurred.

[0006]

An object of the present invention is to improve the disadvantages of the prior art, and in particular, an irreversible relative displacement between the positioning information recorded on the servo disk and the data information recorded by the data head. It is an object of the present invention to provide a magnetic disk drive that suppresses the occurrence of data information and thereby reduces the occurrence of data information read errors.

[0007]

According to the present invention, a spindle motor having a cylindrical spindle hub and a plurality of spacer rings alternately stacked around an outer periphery of the spindle hub along a central axis of the spindle hub are provided. A magnetic disk, a magnetic head provided corresponding to each magnetic disk, and a positioning mechanism for the magnetic head are provided.

[0008] A cylindrical member is provided between the spindle hub and the plurality of magnetic disks so as to secure a predetermined gap with respect to the spindle hub. Further, a configuration is adopted in which a circumferential groove for fixing the cylindrical member is provided at the base of the flange portion of the spindle hub. This aims to achieve the above-mentioned object.

[0009]

When the magnetic disk drive according to the present invention is exposed to the storage environment temperature condition of -40 ° C. to 60 ° C., the magnetic disk 1 and spacer ring 4 mounted in the apparatus and the Since the material of the spindle motor hub 2 to be mounted is different from that of the spindle motor hub 2, the gap 7 between the magnetic disk 1 and the spacer ring 4 and the spindle motor hub 2 becomes smaller due to thermal expansion or thermal contraction. However, since the gap 7 is set in advance in consideration of the linear expansion coefficient between the spindle motor hub 2 and the cylindrical member 3, the contact between the spindle motor hub 2 and the cylindrical member 3 is effectively avoided. Further, the displacement of the magnetic disk 1 is effectively prevented by the cylindrical member 3. Therefore, the occurrence of irreversible relative displacement between the positioning information recorded on the servo disk and the data information recorded on the data head can be effectively prevented in advance.

[0010]

An embodiment of the present invention will be described below with reference to FIG. The embodiment shown in FIG. 1 shows a spindle motor provided with a cylindrical spindle hub 2 and a plurality of spindle motors alternately stacked around an outer periphery of the spindle hub 2 with spacer rings 4 along the center axis of the spindle hub 2. And a magnetic head provided corresponding to each of the magnetic disks 1 and a positioning mechanism for the magnetic head.

A spindle hub 2 and a plurality of magnetic disks 1
Between the spindle hub 2 and the spindle hub 2, a predetermined gap 7 is secured and the cylindrical member 3 is provided. The circumferential groove 6 for fixing the cylindrical member 3 is provided with a flange 2A of the spindle hub 2.
It is provided around the base of the part.

The cylindrical member 3 is fitted into the outer wall of the circumferential groove 6 with a gap. The cylindrical member 3 is made of the same material as the magnetic disk 1 and spacer 4.

The magnetic disk 1 and spacer ring 4
As described above, they are alternately stacked on the spindle motor hub 2 along the outer surface of the cylindrical member 3. The clamper 5
The laminated magnetic disk 1 and spacer ring 4 are locked.

When the magnetic disk device is exposed to the environmental temperature condition during storage of "-40.degree. C. to 60.degree. C.", the magnetic disk 1 and spacer 4 mounted in the device are exposed.
And the material of the spindle motor hub 2 on which they are mounted is different, so that the gap 7 between the magnetic disk 1 and the spacer ring 4 and the spindle motor hub 2 becomes smaller due to thermal expansion or thermal contraction. However, this gap 7
Is set in advance in consideration of the linear expansion coefficient between the spindle motor hub 2 and the cylindrical member 3. For this reason, the structure is such that contact between the spindle motor hub 2 and the cylindrical member 3 is effectively avoided.

As described above, in the above-described embodiment, even if the storage temperature of the magnetic disk device or the temperature of the device changes, the positioning information recorded on the servo disk and the data information recorded by the data head are not changed. Irreversible relative displacement can be effectively avoided in advance.

[0016]

Since the present invention is constructed and functions as described above, according to this, even if the storage temperature of the apparatus or the temperature of the apparatus changes, the clearance formed by the cylindrical member mounted in the groove of the spindle motor hub is increased. Since the contact between the magnetic disk and the spacer and the spindle motor hub is avoided in advance, the irreversible position between the positioning information recorded on the servo disk and the data information recorded by the data head is secured. No relative displacement occurs, so that it is possible to effectively avoid the occurrence of an error in reading data information,
Further, by the action of the circumferential groove provided around the root of the spindle hub, it is possible to maintain the cylindrical member constantly attached to the magnetic disk and the spacering side,
As a result, it is possible to effectively avoid the gap between the magnetic disk and the spacer and to provide an unprecedented excellent magnetic disk device capable of smoothly performing the work of attaching the cylindrical member to the spindle hub. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a spindle unit showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a spindle unit showing one conventional example.

[Explanation of symbols]

 Reference Signs List 1 magnetic disk 2 spindle motor hub 3 cylindrical member 4 spacerer 6 circumferential groove

Claims (2)

(57) [Claims] 1. A spindle motor having a cylindrical spindle hub, a plurality of magnetic disks alternately stacked with spacer rings around an outer periphery of the spindle hub along a central axis of the spindle hub, and each of the magnetic disks In a magnetic disk device comprising a magnetic head mounted corresponding to a disk and a positioning mechanism for the magnetic head, a predetermined gap is secured between the spindle hub and a plurality of magnetic disks with respect to the spindle hub. A magnetic disk drive comprising: a cylindrical member; and a circumferential groove for fixing the cylindrical member is provided at a root of a flange portion of the spindle hub. 2. The magnetic disk drive according to claim 1, wherein the cylindrical member is formed of the same material as the disk.