JPS6128311Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device that achieves uniform temperature within a head disk assembly.

Conventionally, this type of magnetic disk device includes a group of magnetic disks, a support/rotation mechanism that supports and rotates the group of magnetic disks, a group of magnetic heads for recording/reproduction, and a support/rotation mechanism that supports and moves the group of magnetic heads. A head disk assembly (hereinafter abbreviated as HDA) consisting of a moving mechanism housed in a sealed case, and the above
The support/rotation mechanism is equipped with an electric blower that blows cooling air into the HDA from the outside. It is constructed by sequentially stacking multiple data disks at intervals.

However, a magnetic disk device having such a support/rotation mechanism has the following drawbacks. That is, for about 20 minutes after the spindle starts rotating, the temperature inside the HDA rises rapidly due to the windage loss of the magnetic disk group, so the electric blower is used to uniformly blow cooling air between the surfaces of each magnetic disk.

However, heat conduction is different between a servo disk installed directly on the flange surface of the spindle hub and multiple data disks stacked sequentially through a spacer ring, and the heat from the servo disk is easily transferred to the spindle hub, which has a large heat capacity. Since the data disk has less heat conduction to the spindle hub than the servo disk, the heat between the servo disk and the data disk is as shown in Figure 4.
Generates a temperature difference of approximately 0.7℃. Therefore, in the worst case, there will be a temperature difference of about 1° C. between when information is written to and read from the data disk, resulting in a thermal off-track amount of about 4 μm.

The present invention provides a heat insulating layer on the flange surface of a spindle hub that constitutes a support and rotation mechanism for a group of magnetic disks in a magnetic disk device equipped with an HDA and an electric blower that blows cooling air into the HDA from the outside. An object of the present invention is to provide a magnetic disk device in which the amount of thermal off-track for about 20 minutes after the start of spindle rotation is reduced as much as possible.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a partially cutaway plan view showing an embodiment of the magnetic disk device of the present invention, FIG. 2 is a partially cutaway front view showing the above embodiment, and FIG. 3 is a spindle hub used in the above embodiment. It is an enlarged front view. In these figures, the magnetic disk device of the present invention includes a magnetic disk group 8, a support/rotation mechanism 9 that supports and rotates the magnetic disk group 8, a magnetic head group 10 for recording/reproduction, and the magnetic head group 10. HDA3, which is made up of a support/movement mechanism consisting of a carriage 11 that supports and moves the HDA3, which is housed in a sealed case;
It is composed of an electric blower 25 that blows cooling air into the HDA 3 from the outside, and a heat insulating layer 20 is provided on the flange surface 17a of the spindle hub 17 that constitutes the support/rotation mechanism 9.

The above HDA3 is a linear motor magnet 2,
It is removably mounted on a base plate 1 together with a spindle motor 4, and is constructed by housing a magnetic disk group 8 and the like in a sealed case consisting of a top cover 5, a bottom cover 6, and a shield plate 7.

The magnetic disk group 8 includes a plurality of data disks 12 and a servo disk 13, and is supported by a support/rotation mechanism 9, which will be described later.

The support/rotation mechanism 9 consists of a spindle 16 and a spindle hub 17, and the spindle hub 17 has a heat insulating layer 20 provided on a flange surface 17a that directly horizontally supports the servo disk 13. A servo disk 13 is mounted and fixed on the heat insulating layer 20, and a plurality of data disks 12 are sequentially stacked at equal intervals on this servo disk 13 via a spacer ring 19, and are fixed at the top by a clamp ring 18. Ru. This support/rotation mechanism 9
The rotational drive of the spindle motor 4 is transmitted to the spindle 16 via the motor pulley 22, the belt 23, and the spindle pulley 21, and the magnetic disk group 8 is rotated.

The magnetic head group 10 consists of a lowermost servo head 15 and a plurality of data heads 14 stacked thereon at regular intervals, and these are attached to a carriage 11 constituting a support/movement mechanism. This magnetic head group 10 receives the magnetic field of the linear motor magnet 2 and the linear motor magnet 2.
Carriage coil (not shown)
Due to the interaction with the magnetic field generated by passing a current through the
moves back and forth in the radial direction with respect to the spindle 16;
Positioning is performed by a servo head 15.

The electric blower 25 is arranged outside the HDA 3 and sends clean air that has passed through the primary filter 24 and the secondary filter 26 into the HDA 3 via the duct hose 27, the air duct 28, and the air guide 29. The injected clean air flows between the surfaces of the magnetic disks 12 and 13 while cooling them, as shown by the arrows in FIGS. 1 and 2, and is discharged from the carriage 11 to the outside of the HDA 3.

The heat insulating layer 20 is provided on the flange surface 17a of the spindle 17 by forming a layer of a material with low thermal conductivity. For example, epoxy resin, etc.
On the flange surface 17a by powder coating, filling, etc.
It is formed by depositing it with a thickness of about 0.7mm. This heat insulating layer 20 prevents the transfer of heat between the servo disk 13 and the spindle hub 17, so the cooling rate against the temperature rise of the magnetic disk group 8 due to windage during the 20 minutes immediately after the spindle 16 starts rotating is measured. Both the disk 12 and the servo disk 13 can be made substantially equal. FIG. 5 shows the temporal change in the temperature difference between the data disk 12 and the servo disk 13 in this embodiment. As is clear from the comparison with the conventional temperature difference between the two shown in FIG. The amount of thermal off-track due to temperature difference can be minimized (1.5 μm).

As explained above, the present invention has a simple configuration in which a heat insulating layer is provided on the flange surface of the spindle hub, which dramatically reduces the temperature difference between the data disk and servo disk at the initial stage of rotation, and minimizes the amount of thermal off-track. There are benefits to be gained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing an embodiment of the magnetic disk device of the present invention, FIG. 2 is a partially cutaway front view showing the above embodiment, and FIG. 3 is a spindle hub used in the above embodiment. An enlarged front view, FIG. 4 is a graph showing the temporal change in the temperature difference between the data disk and the servo disk in a conventional magnetic disk device, and FIG. 5 is a graph showing the temporal change in the temperature difference between the data disk and the servo disk in the present invention. This is a graph showing. 1...Base plate, 2...Linear motor magnet, 3...HDA (head/disk assembly), 4...Spindle motor, 8...Magnetic disk group, 9...Support/rotation mechanism, 10...Magnetic head Group, 11... Carriage, 12... Data disk, 13... Servo disk, 14... Data head, 15... Servo head, 16... Spindle, 17... Spindle hub, 17a... Flange surface, 20... Heat insulation layer, 25...Electric blower, 29...Air guide.

Claims (1)

[Scope of utility model registration request] A flange portion having a larger diameter than the cylindrical member is formed at one end of the cylindrical member that engages with the inner peripheral edge of the magnetic disk, and a flange portion that engages with the flange portion is connected to a spindle hub connected to a rotational drive mechanism. a first magnetic disk whose inner peripheral edge is supported by the cylindrical member; a heat insulating layer adhered to the contact surface of the flange portion with the first magnetic disk; a second magnetic disk whose inner peripheral edge is supported by the cylindrical member while maintaining a predetermined distance from the magnetic disk; and a sealed case that seals the spindle hub and the first and second magnetic disks from the outside. A magnetic disk device comprising: