JPH02143968A - Spindle hub - Google Patents

Abstract

PURPOSE:To easily form the rotation unbalance quantum so as to become small by a cutting machine work by forming the outside peripheral surface of a cylindrical body to which a magnetic disk is fitted to a polygon, and also, forming each corner part to a circular arc shape and using it as the contact surface to the fitting surface of the magnetic disk. CONSTITUTION:The outside peripheral surface of a cylindrical body to which a magnetic disk 21 is fitted is formed to a polygon, and also, each corner part thereof is formed to a circular arc shape and used as the contact surface to the fitting surface of the magnetic disk 21. The outside peripheral surface of the cylindrical body to which the magnetic disk 21 is fitted can be formed to a polyhedral shape having plural planes 34 by leaving plural disk 21 contact circular arc parts 33 for securing the fitting center position of the magnetic disk 21 and cutting successively other peripheral surface part to the surface being parallel to the rotation center of the cylindrical body by, for instance, a milling machine, etc. Therefore, working can be executed easily, and also, wall thickness of a hub 31 becomes axially symmetric with high accuracy, and a deviation of a mass distribution is eliminated. In such a way, the rotation unbalance quantum is formed easily so as to become small by a cutting machine work.

Description

[Detailed Description of the Invention] [(Already required)] Regarding the improvement of a spindle hub for stacking and fixing magnetic disks in a magnetic disk mount, etc., there is provided a spindle having a structure that allows the amount of rotational unbalance to be easily reduced by cutting machining. A spindle hub consisting of a cylindrical body that fixes a plurality of magnetic disks stacked together with a spacer ring having ventilation holes in between, with an air circulation gap formed in part, in order to obtain a hub. The outer peripheral surface of the cylindrical body into which the magnetic disk is fitted is formed into a polygonal shape, and each corner thereof is formed into an arc shape to serve as a contact surface with the fitting surface of the magnetic disk.

[Industrial application field]

The present invention relates to an improvement of a spindle hub for stacking and fixing magnetic disks in a magnetic disk device or the like.

In magnetic disk devices, it is required to fix the magnetic disk to the spindle hub without eccentricity, but on the other hand, even in the spindle hub, that is, the spindle hub having a cylindrical shape, the wall thickness of the cylindrical portion may be uneven. When this happens, the mass distribution of the spindle hub becomes biased and the rotational hook interaction increases, and eccentric vibrations are likely to occur during rotation, reducing the positioning accuracy of the magnetic head with respect to the rotating magnetic disk attached to the spindle hub. Tend. Therefore, there is a demand for a spindle hub that minimizes the amount of rotational hook engagement caused by such wall thickness variations.

[Conventional technology]

Conventionally, a typical spindle hub 11 for stacking and fixing magnetic disks in a magnetic disk device is configured as shown in the plan view of FIG. 5 and the cross-sectional view of FIG. 6 taken along the cutting line A-A'. . That is, this spindle hub 11 has a cylindrical shape with a disk-shaped stopper flange 12 at the lower end, and an air circulation gap is provided between the outer peripheral surface into which the magnetic disk is fitted and the fitting surface of the magnetic disk. A plurality of arcuate protrusions 13 are provided at equal intervals along the circumferential surface to provide the magnetic disk and to define the fitting center position of the magnetic disk.

As shown in FIG. 7, a plurality of magnetic disks 21 are fitted into the spindle hub 11 in a stacked manner with spacer rings 22 each having a ventilation hole 22a sandwiched therebetween, and an air circulation hole 23a is formed above the topmost disk. are fixed at a predetermined interval by tightening the clamp ring 23 with a bolt 24. Then, the spindle no-hub 11 is attached to the fixed shaft 27 via the bearing 26,
Connected to a rotating motor (not shown).

In this way, when the motor rotates, the magnetic disk group also rotates,
As a result, the air near the surface of the magnetic disk 21 flows outward due to centrifugal force, so that an air circulation gap is formed between the outer circumferential surface of the spindle hub 11 and the inner circumferential surface of each magnetic disk 21. 25 becomes negative pressure, and air flows through the air circulation hole 23a of the clamp ring 23 as shown by the arrow.
The air flows out from the air holes 22a of each spacer ring 22 through the air circulation gap 25.

Vibrations (flanks) during rotation of the magnetic disk 21 are reduced by this airflow circulation path, and internally generated dust is removed by inserting a filter into a portion of the airflow circulation path.

[Problem to be solved by the invention]

By the way, when forming the conventional spindle hub 11 as described above, the outer circumferential surface of the hub 11 is formed by forming a plurality of arcuate protrusions 13 at equal intervals along the circumferential surface, and between the arcuate protrusions 13. It is difficult to machine the peripheral surface portion into a curved surface, and it is necessary to apply machining using NC (numerical control), but this increases the processing cost and poses a problem. Therefore, generally, a cylindrical body having a plurality of arcuate protrusions 13 protruding at equal intervals on the outer peripheral surface and a disk-shaped stopper flange 12 at the lower end is formed by casting, and the magnetic disk 21 is formed by casting.
The surface of each arcuate protrusion 13 that fits into the flange portion 12, the inner cylinder surface, etc. are finished by cutting machining.

However, since the surfaces other than the machined surfaces that have been subjected to the cutting machining, such as the curved surfaces between the respective arcuate protrusions 13, remain cast surfaces, the wall thickness of the spindle hub 11 may not be completely axially symmetrical. First, there is a problem that the mass repellency distribution with respect to the rotation center A is biased, resulting in a large amount of rotational unbalance during rotation.

This rotational imbalance causes eccentric vibrations as the magnetic disk 21 rotates, resulting in a drawback that the positioning accuracy of the magnetic head with respect to the magnetic disk surface is significantly reduced. In order to prevent such drawbacks, the rotational balance adjustment is usually performed in one step, but this increases the number of assembly steps.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional situation, it is an object of the present invention to provide a novel spindle hub that can easily form a small amount of rotational unbalance by cutting machining.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention uses a cylindrical body in which a plurality of magnetic disks stacked with a spacer ring having ventilation holes interposed therebetween are fixed in a fitting manner with an air circulation gap formed in a part thereof. The spindle hub has a configuration in which the outer peripheral surface of the cylindrical body into which the magnetic disk is fitted is formed in a polygonal shape, and each corner thereof is formed into an arc shape to be a contact surface with the fitting surface of the magnetic disk. do.

0 operation] In the spindle hub of the present invention, the outer circumferential surface of the cylindrical body into which the magnetic disk is fitted is formed with a plurality of disk contact arc portions for maintaining the fitting center position of the magnetic disk at l + distance, and the other circumference is Since the surface portion can be sequentially cut into a plane parallel to the center of rotation of the cylindrical body using a milling machine or the like to form a multifaceted shape having a plurality of planes, processing is easy and the hub meat P1 can be formed with high precision. is axially symmetrical,
The bias in mass distribution with respect to the center of rotation is eliminated. Therefore,
The amount of rotational unbalance is greatly reduced, and the generation of eccentric vibration due to the rotation of the magnetic disk can be enjoyed even without performing rotational balance adjustment.

[Ability stone side]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of a spindle hub according to the present invention, and FIG. 2 is a sectional view taken along the section line ``---'' shown in FIG.

In both of these figures, the outer peripheral surface of a cylindrical spindle hub 31 into which a magnetic disk is fitted is connected to a flange portion 32 provided at the lower end for preventing disk removal and a plurality of disks for securing the fitting center position of the magnetic disk. Leaving the contact circular pipe portions, in this example six disk contact circular arc portions 33, the peripheral surface portion between each of the other disk contact circular arc portions 33 is cut into a plane parallel to the rotation center A of the hub as shown in the figure. The configuration is made into a hexagonal shape having a plurality of planes, that is, six planes 34.

In order to make the outer circumferential surface of the spindle hub 31 into which the magnetic disk is fitted into a six-sided shape, leave six disc contact arc portions 33 on the outer circumferential surface and cut the other six circumferential surface portions using a milling machine or the like. By sequentially cutting planes parallel to the center of rotation A, it is possible to relatively easily process the resulting spindle hub 31 into a multifaceted shape having six planes 34, and the thickness distribution of the resulting spindle hub 31 can be accurately aligned with the shaft. Become symmetrical.

Therefore, such a spindle hub 31 as shown in FIG.
As in the conventional case, a plurality of magnetic disks 21 are fitted in a stacked manner through spacer rings 22 having ventilation holes 22a around the periphery, and a clamp ring 23 having air circulation holes 23a is further tightened with bolts 24. By fixing the spindle hub 31, there is no bias in the quality distribution with respect to the rotation center A, and the rotational unbalance "tk" is significantly reduced. The air circulation hole 23 of the clamp ring 23 is connected between the inner peripheral surface of each magnetic disk and the clamp ring 23 as in the conventional case.
an air circulation gap 25 communicating with the ventilation hole 22a of each spacer ring 22 is ensured.

The spindle hub 31 on which a plurality of magnetic disks 21 are mounted in this way is attached to the fixed shaft 27 via the bearing 26, and the magnetic disks 21 are rotated by a rotating motor (not shown).
1, a path is created in which the airflow circulates from the airflow 3m hole 23a of the clamp ring 23 to the outside of the airflow hole 22a of the spacer ring 22 through the air circulation gap 25 as shown by the arrow.

FIG. 4 is a side sectional view showing another embodiment of the spindle hub according to the present invention, and the same parts as in FIG. 3 are given the same reference numerals.

The embodiment shown in this figure differs from the example shown in FIG. 3 in that a hair ring is provided on the inner surface of the spindle hub 31 having the structure explained in FIGS. 53, and a shaft fixing part 41 for fixing the hub 31, a horizontal hole 42 is provided in each flat surface 34 portion of the outer peripheral surface of the spindle hub 31, and A filter 4 for removing dust is installed in each plane 34 portion where the hole 42 is provided so as to cover the horizontal hole 42.
3 is attached. In addition, the upper and lower supports 51 and 52
Since there is a gap between the spindle hub 31 and the spindle hub 31 through which air flows through the inner surface of the spindle hub 3I, the clamp ring 44 is used, which does not require an air circulation hole.

The configuration of this embodiment also achieves the same purpose as the embodiment shown in FIG. The effect is good.

In addition, in the above embodiment, the outer peripheral surface of the spindle hub is 6
An example will be explained in which one disk contact arc portion is left and the peripheral surface portion between the other disk contact arc portions is cut into a plane parallel to the rotation center A of the hub to form a six-sided shape with six planes. However, the present invention is not limited to such examples, and can be implemented with various modifications, such as making the outer circumferential surface a seven-sided shape with seven planes, or an eight-sided shape with eight planes. be able to.

〔Effect of the invention〕

As is clear from the above description, according to the spindle hub according to the present invention, the outer peripheral surface of the cylindrical body into which the magnetic disk is fitted has a plurality of disk contact arc portions for ensuring the fitting center position of the magnetic disk. , and cut the remaining peripheral surface portions in parallel to the center of rotation of the cylindrical body to form a plurality of flat surfaces that ensure air circulation gaps that communicate with the air circulation holes of the clamp ring and the air circulation holes of the spacer ring. This facilitates processing into a multifaceted shape. What's more, the thickness of the hub is made axially symmetrical with high accuracy due to the offshore construction, which eliminates any bias in mass distribution with respect to the center of rotation.

Therefore, the amount of rotational unbalance is significantly reduced, the occurrence of eccentric vibrations accompanying the rotation of the magnetic disk is eliminated, and the step of adjusting rotational balance can be omitted. In addition, horizontal holes are provided in the plurality of planes, and when a dust removal filter is attached to the planes, the adhesion of the filter is improved, and other practical effects are achieved.

[Brief Description of the Drawings] Fig. 1 is a plan view showing an embodiment of the spindle hub according to the present invention, Fig. 2 is a sectional view of the spindle hub along the cutting line nn' shown in Fig. 1, FIG. 3 is a side sectional view showing one embodiment of a disk assembly in which a magnetic disk is mounted on a spindle hub according to the present invention, and FIG. 4 is a side sectional view showing another embodiment of a spindle hub according to the present invention in which a magnetic disk is mounted. Fig. 5 is a plan view showing an example of a conventional spindle hub, Fig. 6 is a sectional view of the spindle hub along the A-A' cutting line shown in Fig. 5, and Fig. 7 is a sectional view of the spindle hub. FIG. 2 is a side sectional view illustrating a disk assembly in which a magnetic disk is mounted on a conventional spindle hub. In Figures 1 to 4, 21 is a magnetic disk, 22 is a spacer ring, 22a is a ventilation hole, 23.44 is a crumbling ring, 23a is an air circulation hole, 24 is a bolt, 25 is an air circulation gap, 26.53
is a bearing, 27 is a fixed shaft, 3I is a spindle hub,
32 is a flange part for preventing disc removal, 33 is a disc contact arc part, 34 is a plane, 41 is a shaft fixing part, 42 is a horizontal hole, 43 is a dust removal filter, 51°, 52 are upper and lower supports,
54 each indicates a rotation axis. , Keizuka Sun Moon n sub; 1x) L Huff's smile 9'IG
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A' Cross-sectional view A ■ Zupishi p Wataru hub f = J Shuten Days 7 Me 1 Discharge Jukkai Tree 1 Fallen face Modification Fig. 7

Claims (1)

[Claims] A spindle made of a cylindrical body for fixing a plurality of magnetic disks (21) stacked with a spacer ring (22) having ventilation holes (22a) in between, in a fitting manner with an air circulation gap formed in a part. The hub has a cylindrical body into which the magnetic disk (21) is fitted, and has a polygonal outer circumferential surface, and each corner (33) of the hub has an arcuate shape to form a fitting surface of the magnetic disk (21). A spindle hub characterized by having a contact surface of