JP4094741B2 - Spindle motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spindle motor for rotationally driving a hard disk medium. More specifically, the present invention relates to a hard disk which minimizes the generation of heat by air friction when the spindle motor is driven at a high speed. The present invention relates to a spindle motor provided with attachment means.
[0002]
[Prior art]
Increasing the rotational speed of the hard disk drive device is a very important factor in improving the functionality of the disk medium so as to shorten the access time on the hard disk medium and perform efficient recording and / or reading operations. It is known. However, when the rotational speed of the hard disk drive device is increased, the relative speed difference between the hard disk medium and the ambient air increases, and this speed difference generates frictional heat on the hard disk medium, and this frictional heat It is also known today to those skilled in the art that the occurrence of this is a major cause that hinders the improvement of the recording density for hard disk media. For this reason, as a method for improving the functionality and improving the recording density, a method of reducing the diameter of the hard disk medium has been conventionally used.
[0003]
[Problems to be solved by the invention]
However, if the rotational speed of the hard disk drive device is increased in order to improve functionality, the generation of frictional heat hinders the improvement of recording density. On the other hand, if an attempt is made to prevent the generation of frictional heat in order to improve the recording density. Therefore, it is necessary to reduce the rotational speed of the drive device, and in order to solve such a trade-off problem at the same time, if the diameter of the hard disk medium is reduced as before, the recording capacity of the disk medium is insufficient accordingly. A new problem arises. Accordingly, it is required to solve the above-mentioned trade-off problem and simultaneously solve the problem relating to the insufficient recording capacity of the disk medium.
[0004]
[Means for Solving the Problems]
A spacer for laminating and arranging hard disks is provided with a wing-shaped part on the outer periphery so that the amount of heat generated by the hard disk medium due to air friction when the spindle motor is driven at a high speed is minimized. As a result, when the hard disk is rotated by the spindle motor, the wings move the surrounding air in synchronization with the rotation of the hard disk, and the relative speed difference between the moving speed of the surrounding air and the rotating speed of the hard disk is minimized. Therefore, the amount of heat generated when the hard disk medium rotates is minimized.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a hard disk drive device 10 showing a state in which three hard disks are stacked and mounted via a spacer according to the present invention. FIG. 2 is a partially enlarged cross-sectional view showing a part of FIG. 1 in an enlarged manner. In these drawings, the hard disk drive device 10 includes a shaft 12, a stator 14 fixed to the shaft 12, a hub 18 rotatably held with respect to the shaft 12 via a bearing 16, A hard disk 20 mounted on the outer peripheral portion of the hub 18, a yoke 22 mounted on the inner peripheral portion of the hub 18 at a position facing the stator 14, and a rotor magnet fixed to the yoke 22 24. However, the hard disk drive device 10 itself is not limited to a device having such a configuration, and may be, for example, a device in which a hub rotates together with a shaft.
[0006]
In the illustrated example of the present invention, three hard disks 20 are mounted on the drive device 10, and the lowermost hard disk medium 20 c is preferably formed integrally with the hub 18 on the outer periphery of the lower end of the hub 18. It is mounted on the flange 26. A hard disk 20b and a hard disk 20a are stacked on the hard disk 20c. Between the hard disks 20a and 20b and between the hard disks 20b and 20c, spacers 28 and 28 each having a substantially cylindrical shape are interposed, whereby the hard disks are stacked with a certain distance from each other. Yes. Further, a substantially disc-shaped clamp 30 is disposed on the upper surface of the uppermost hard disk 20a. The clamp 30 is fixed to the hub 18 by a known fastening means 32. Thus, the hard disk 20 is held in a fixed relation to the hub 18 while maintaining a constant distance from the hub 18, and when the hub 18 rotates. Along with that, it is designed to rotate together.
[0007]
As shown in FIG. 3, the generally cylindrical spacers 28, 28 having a predetermined thickness are formed with a circular hole 40 having a diameter somewhat larger than the outer diameter of the hub 18 at the center. Thus, it can be inserted into the hub 18. Further, to form a recessed portion has been cut off in a generally triangular shape toward the rotational direction forwardly as shown generally at right angles to the arrow 44 from the beginning towards the direction of the center point 42 and then its inner end to its outer circumference A plurality of wing-like portions 46 are formed (four in the illustrated example). As a result, each wing-like portion 46 formed over the entire thickness direction of the spacer 28 is a surface in the axial direction including a radial straight line extending radially from the center of the spacer 28 or a parallel straight line parallel to the radial straight line. Are defined by a radial vertical surface 46a , a rotational horizontal surface 46b that is a surface in the axial direction including a straight line perpendicular to the radial straight line or a parallel straight line, and a rotational circumferential surface 46c. (Hereafter, a detailed description of the radial vertical plane and the rotational horizontal plane is omitted.)
[0008]
On the other hand, as shown in FIG. 4, the clamp 30 pressing the upper surface of the uppermost hard disk 20a has an outer shape having a plurality of wing-like portions 50 on the outer periphery substantially similar to the spacer 28 shown in FIG. Have. However, the clamp 30 does not have a central hole to be inserted into the hub 18. Instead, the clamp 30 has a plurality of fastening means receiving holes 52 for fixing to the hub 18 by fastening means 32 such as screws (in the illustrated example). 4). As a result, each wing-like portion 50 formed over the entire thickness of the clamp 30 is defined by the radial direction vertical surface 50a, the rotational direction horizontal surface 50b, and the rotational direction circumferential surface 50c.
[0009]
In the present invention, as shown in FIG. 3, the hard disk recording medium 20 is kept isolated from each other by spacers 28, 28 having wings 46 on the outer peripheral portion, and the uppermost hard disk medium 20a has an upper surface as shown in FIG. Similarly, it is pressed by the clamp 30 having the wing-like portion 50 on the outer peripheral portion. For this reason, when the spindle motor is rotated in the direction of rotation as indicated by the arrow 44, the surrounding air facing in this direction of rotation is trapped by these wings 46, 50, in particular the radial vertical surfaces 46a, 50a. The ambient air trapped in the airfoil rotates together with the spacers 28, 28 and the clamp 30. For this reason, the relative speed difference between the hard disk medium 20 and the air around the spacers 28, 28 and the clamp 30 is reduced, and the reduction in the speed difference reduces the generation of frictional heat transmitted to the hard disk medium, Such reduction in frictional heat makes it possible to improve the recording density on the hard disk medium 20.
[0010]
Here, a similar wing-like portion can be formed on the flange 26 provided at the lower outer end portion of the hub 18. As a result, the reduction in frictional heat can be further increased, and the recording density on the hard disk medium can be further improved.
[0011]
5 to 9 are views showing other embodiments 28a, 28b, 28c and 28d of the spacer 28 shown in FIG. The embodiment shown in FIGS. 5 to 9 is different from the embodiment shown in FIG. 3 in the shape of the wing-like portion. In the spacer 28 of FIG. 3, the radial vertical surfaces 46a of the wings 46 are all cut in the direction of the center point 42, and then cut off from the inner end position substantially perpendicularly to the front in the rotational direction. In the airfoil 54, the radial vertical surface 54a of the airfoil is cut away from the center point 42a toward the rear in the rotation direction, and then cut off from the inner end position toward the front in the rotation direction at a substantially right angle. This lengthens the front shape of the wing-like part. Further, in the wing-like portion 56 in FIG. 6, the radial vertical surface 56a of the wing-like portion is cut away from the center point 42b toward the front in the rotation direction, and then cut off from the inner end portion thereof at a substantially right angle toward the front in the rotation direction. ing. This shortens the front shape of the wing-like part. Further, the radial vertical surfaces 46a, 54a, and 56a can be formed to be appropriately deep or shallow. As a result, an optimum amount of air reservoir can be provided in accordance with the rotational speed of the spindle motor and the width of the spacer 28. In these embodiments, the air overflowing from the wing-like portion overflows backward from the radial outer peripheral portion of the radial vertical surface along the rotational circumferential surface.
[0012]
7 and 8 show a spacer 28c having a groove 60 extending in the rotational direction circumferential surface direction along the width direction, unlike the conventional spacers. In this embodiment, part of the air accumulated in the wing-like portion 58 flows rearward through the groove 60 when the drive device is driven, and the air overflowing from the wing-like portion as in the above-described embodiment is in the radial direction. The amount of overflow from the radially outer peripheral portion of the vertical surface to the rear along the rotational circumferential surface is reduced. For this reason, while the wall surface which forms this groove | channel 60 provides the effect of a heat radiating fin, the accumulation effect of the air in the wing | blade-shaped part 58 increases further.
[0013]
FIG. 9 shows still another embodiment. In this embodiment, the radial direction vertical surface 62a, the rotational direction horizontal surface 62b, and the rotational direction circumferential surface 62c constituting the wing-like portion 62 are composed of circular components. In this embodiment, air accumulated in the wing-like portion 62 is difficult to escape from the wing-like portion 62, and it is easier to achieve a reduction in relative speed.
[0014]
In the embodiment of FIG. 9, the groove 64 in the width direction is formed as in the embodiment shown in FIG. 7, but this groove may not be provided. Further, in the embodiment shown in FIGS. 3, 5 and 6, it is possible to have a groove extending in the peripheral portion along the width direction of these spacers. Similarly, the outer shape of the clamp shown in FIG. 4 may have a shape as shown in FIGS. 5 to 10 and may have a groove extending in the peripheral portion along the width direction.
[0015]
Further, the number of wing-shaped portions is all four in this embodiment, but is not limited to this. For example, two shapes are the same as those in FIG. 3, and the other two are in FIG. It is also possible to have the shape of, and various combinations are possible as required.
[0016]
In the illustrated embodiment, the number of hard disks to be stacked is three. However, the number of hard disks to be stacked is not limited to this, and may be larger or smaller. The good will be obvious to those skilled in the art.
[0017]
【The invention's effect】
As described above, in the present invention, by making the shape of the spacer and / or the clamp with a wing-shaped portion, the surrounding air during rotation of the hard disk drive device is actively rotated in the rotation direction of the hard disk drive device, It is possible to reduce the relative speed difference between the hard disk and the air around the hard disk, thereby suppressing the amount of heat generated by the hard disk, thereby achieving an improvement in recording density.
[0018]
By combining the present invention with the same techniques as before, such as reducing the diameter of the hard disk medium, enclosing the hard disk in a dust-proof container and forming a cylindrical wall around the hard disk, etc. A more effective temperature rise reduction of the hard disk media can be achieved. Furthermore, by adopting a linear head as shown in Japanese Patent Publication No. 4-21275, it becomes possible to form a larger peripheral wall, and further excellent effects can be expected.
[Brief description of the drawings]
FIG. 1 is a diagram showing a hard disk drive device 10 known per se showing a state in which three hard disks are mounted by means of attachment means according to the present invention.
FIG. 2 is a partially enlarged cross-sectional view showing a part of FIG. 1 in an enlarged manner.
FIG. 3 is a plan view showing an example of a spacer in the present invention.
FIG. 4 is a plan view showing an example of a clamp in the present invention.
FIG. 5 is a plan view showing an example of a spacer showing another embodiment of the present invention.
FIG. 6 is a plan view showing a spacer showing still another embodiment of the present invention.
FIG. 7 is a plan view showing a spacer showing still another embodiment of the present invention.
8 is a cross-sectional view taken along line 8-8 in FIG.
FIG. 9 is a plan view showing a spacer showing still another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Hard disk drive apparatus 12 Shaft 14 Stator 16 Bearing 18 Hub 20 Hard disk 22 Yoke 24 Rotary magnet 26 Flange 28 Spacer 30 Clamp 32 Tightening means 40 Circular hole 42 Center point 44 Arrow 46, 50 Wing-like part 52 Tightening means receiving hole 54, 56, 58 Wings 60 Grooves 62 Wings

Claims (3)

A spindle motor for rotating a plurality of hard disk at the same time, the plurality of hard disk are spaced from each other by spacers respectively, said being pressed and held plurality of hard disk is by a clamp, it said on each outer periphery of each spacer Includes a radial vertical plane which is a radial line including a radial straight line extending in the radial direction from the center of the spacer or a parallel straight line parallel to the radial straight line, and a perpendicular to the radial straight line or parallel straight line. by the rotation direction horizontal plane is a plane in the axial direction, including a straight line, by providing the substantially triangular shape of the groove that opens toward the rotation direction and portions plurality of wings are formed, surrounding air of the spacer, the hard disk It is arrested in the airfoil with the high-speed rotation of the moving in the rotational direction of the hard disk, this movement , The relative speed difference between the rotating speed of the moving speed of the ambient air hard disk to a minimum, with the hard disk medium a plurality of said hard disk, characterized in that to minimize the amount of heat generated during rotation a spindle motor which is stacked by the spacer with the wings. 2. The spindle motor according to claim 1, wherein the clamp has a wing-like portion on the outer periphery. 3. A spindle motor according to claim 1, wherein the hub means for supporting the lowermost hard disk has a wing-like portion on the outer periphery.

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