JP2003173645A - Apparatus for aligning and fixing disk and method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an apparatus for aligning and fixing a disk by which the disk can be accurately aligned and fixed toward a center shaft and to provide a method for the same. <P>SOLUTION: The apparatus for aligning and fixing the disk has a tape spacer in which the disk and its outer peripheral surface are taper surfaces and a sensor shaft in which aligning is performed by utilizing an inner peripheral surface of the taper spacer and air. The disk is aligned and fixed to the center shaft by contacting-fixing an inner peripheral surface of the disk and the taper surface of the taper spacer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk centering and fixing device and a method for centering and fixing a disk, which is mounted on a spindle motor or the like and fixedly mounts the disk with both axes coaxial (centering). Especially used in fields that require a high-precision alignment mechanism (chuck mechanism), including production equipment for magnetic recording devices and optical information recording devices that enable high-precision attachment by automatically aligning when a disc is attached. It is suitable when

[0002]

2. Description of the Related Art Conventionally, a magnetic recording device such as a hard disk or a large-capacity removable disk requires an operation of writing magnetic information on the disk in advance in a manufacturing process (servo writing step). The disk is mainly made of aluminum or glass blank material (on a disc) coated with a magnetic material. In the servo write process, it is necessary to attach / detach the disc to / from the chuck mechanism of the spindle motor of the servo writer.

In the conventional chuck mechanism, a method of inserting a disc into a shaft and fixing the disc from above and below with a spacer or the like is mainly used. FIG. 4 is a schematic view of a main part of a conventional chuck mechanism. The disc 100 is fixed to the center shaft 111 by a lock spacer 112. The lock spacer 112 is mounted on the center shaft 111 by a lock screw (lock screw) 113 via a washer 114.
It is fixed to. Center shaft (shaft) 11
The outer diameter of 1 is machined to a size corresponding to the inner diameter tolerance of the disc 100, and a gap is provided so that it can be smoothly inserted without any galling at the time of insertion.

However, when the coaxiality between the disc center and the shaft center when the disc 100 is mounted is observed by this method,
Since a gap corresponding to "disc inner diameter-shaft outer diameter" is generated and biased in any direction, the disc 100 is eccentrically mounted with respect to the shaft 111 in the mounted state in most cases. In the magnetic recording device, the current method has been put to practical use, but in the servo write process of hard disks and large capacity removable disks whose recording density improves year by year, even higher accuracy of coaxiality when mounting the disk is required. With the chuck, there are obstacles as the recording density is increased.

When the disk 100 is mounted eccentrically with respect to the shaft 111, the dynamic balance is lost, and the spindle's original accuracy, asynchronous runout, and synchronous component (NRRO,
RRO) worsens.

FIG. 5 is a schematic view in which a large number of discs are mounted on a center shaft by a conventional method. In general, when a servo writer that simultaneously writes on a large number of disks at high speed is manufactured, the above-mentioned problems of NRRO and RRO become serious. Alternatively, it is possible to use the conventional method to strictly control the dimensional accuracy and reduce the gap between the shaft outer diameter and the disc inner diameter to the utmost limit, but there is a limit when considering workability, and there is a problem of galling between the shaft and the disc. Will end up. A method of aligning the outer periphery of the disc when mounting the discs can be considered, but it is not efficient and unsuitable to carry out the disc one by one in a mass production line.

As described above, the high-accuracy alignment mechanism at the time of mounting the disk is an important element in the magnetic recording apparatus, but the optimum method has not been established.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk centering and fixing device and a disk centering step method capable of accurately centering and fixing a disk with respect to a center shaft. .

[0009]

According to a first aspect of the present invention, there is provided a centering and fixing device for a disc, wherein the disc and the outer peripheral surface are tapered spacers, and the inner peripheral surface of the tapered spacer and air are used for centering. The disk is characterized in that it is fixed by contacting and fixing the inner peripheral surface of the disk and the tapered surface of the tapered spacer to the center shaft.

The invention of claim 2 is characterized in that, in the invention of claim 1, the air is supplied from the air supply port provided on the outer peripheral surface of the center shaft to the inner peripheral surface of the tapered spacer.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, it has parallel spacers for aligning and fixing the disk to the tapered spacer.

According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, the tapered spacer is made of metal or resin, and a fluororesin is coated on the contact surface with the inner peripheral surface of the disk. It is characterized by that.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the taper surface of the taper spacer and the inner peripheral surface of the taper spacer are machined with the same chuck. Is characterized by.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the angle of the taper surface of the outer peripheral surface of the taper spacer is a surface corresponding to the inner peripheral surface of the disk. It is characterized by that.

The invention of claim 7 is characterized in that, in the invention of any one of claims 1 to 6, a plurality of disk units aligned and fixed to the tapered spacer are mounted on the center shaft. There is.

An eighth aspect of the present invention is a spindle motor having the disc centering and fixing device according to any one of the first to seventh aspects and a motor unit for rotating the disc.

According to a ninth aspect of the present invention, there is provided a servo track having the disk centering and fixing device according to any one of the first to seventh aspects.

According to a tenth aspect of the present invention, there is provided a method for centering and fixing a disk, wherein the inner surface of the disk is pressed against the outer surface of a tapered spacer having an outer peripheral surface, and the inner diameter of the tapered spacer is utilized by using air pressure. It is characterized in that the disk is centered and fixed to the center shaft by utilizing the step of centering the surface with respect to the center shaft.

In the method of fixing the centering of the disk according to the invention of claim 11, the step of centering the disk at the center of the tapered spacer by contacting the inner peripheral surface of the tapered spacer of the tapered outer surface with the tapered surface of the tapered spacer. And a step of forming an air layer having a constant thickness on the circumference of the inner peripheral surface of the tapered spacer and the outer peripheral surface of the center shaft to align the axes of both, and when aligning and fixing the disc to the tapered spacer. A step of forming an air gap between the parallel spacer used for the above and the disk, and statically supporting the disk in a direction perpendicular to the axis of the center shaft, thereby aligning the disk with the center shaft. It is characterized by fixing.

[0020]

1 is a schematic view of the essential portions of Embodiment 1 of a disk centering and fixing device (chuck device) 1 of the present invention. In this embodiment, the outer diameter (taper) slope 102a of the tapered spacer 102 contacts the inner diameter surface 100a of the disk 100, and the upper side of the tapered spacer 102 is pressed by the coil spring 104 so that the disk 1
00 is aligned along the tapered surface 102a.

Then, at a portion opposed to the inner diameter side (inner wall) 102b of the tapered spacer 102 and the outer diameter (outer wall) 101b of the center shaft 101 of the spindle motor, air (from the air supply means) is passed through a passage in the spider motor. Air) is supplied from the high pressure air supply port 101a. As a result, the gap between the inner diameter 102b of the tapered spacer and the outer wall 101b of the center shaft 101 is kept constant by the air and self-aligned.

When the lock nut 106 is tightened, the lock spacer 105 and the parallel spacer 103 are moved in the axial direction (rotational axis direction) 101 of the center shaft 101.
When the air d drops and is released to the outside from the center shaft 101 side through the inner diameter gap with the tapered spacer 102 (the gap formed between the tapered spacer inner diameter 102b and the center shaft outer diameter 101b), the disk 1
00 is supported by static pressure in the direction perpendicular to the rotating shaft 101d between the surface 103a of the parallel spacer 103 and the surface 101c of the center shaft 101 until just before contacting the parallel spacer 103, so that it can freely slide. Therefore, the alignment mechanism between the tapered spacer 102 and the center shaft 101 is not disturbed.

Further, by tightening the lock nut 106, the disc 100 is aligned according to the taper 102a of the taper spacer 102, and finally fixed so as to be sandwiched between the upper and lower parallel spacers 103 and the center shaft 101. The alignment accuracy at this time depends on the concentricity of the inner diameter 102b of the tapered spacer 102 and the tapered surface 102a, but high accuracy can be obtained by processing with the same chuck on a lathe. Therefore, the mounting accuracy depending on the conventional disc inner diameter tolerance is used. Compared to, it is possible to mount a disc with a much higher degree of coaxiality.

As described above, in the disc centering / fixing device of this embodiment, when the disc 100 is mounted on the center shaft (spindle) 101, the inner diameter surface 100a of the disc 100 is a taper surface of the outer diameter of the taper spacer 102 ( It is adapted to be pressed against the slope 102a.

At this time, the angle of the tapered surface 102a is a surface having an angle or curvature corresponding to the inner diameter surface 100a of the disk 100. Then, air pressure is applied by air supplied from the high-pressure air supply port 101a provided in the center shaft to automatically align the inner diameter 102b of the tapered spacer 102 with respect to the center shaft 101. As a result, the disc 100 is accurately aligned with the center shaft 101.

Next, the features of this embodiment will be described.

(A-1) The disk 100 is centered on the taper spacer 102 by arranging the inclined surface portion 102a of the taper spacer 102 in contact with the inner diameter 100a of the disk 100. Then, air is supplied between the inner diameter 102b of the tapered spacer and the center shaft 100 to form an air layer having a constant thickness on the circumference, and the center shaft 101 and the tapered spacer 102 are formed.
The concentricity of is matched with high precision. As a result, the disc 100 and the center shaft 101 are coaxially aligned with high precision.

(A-2) When the air supplied to the gap between the center shaft 101 and the tapered spacer 102 is discharged, an air gap is formed between the disc 100 and the parallel spacer 103, so that the disc 100 is horizontal. Since it is supported by static pressure in the direction, it is in a free state and functions so as not to hinder the center shaft 101 and the tapered spacer 102 during alignment. Since the free state continues until the parallel spacer 103 gradually descends from the axial direction and is completely fixed, the aligning and fixing can function without any problem.

(A-3) The taper spacer 102 may be made of metal, resin, etc.
The contact surface with 00a is preferably made of a material having high abrasion resistance in order to maintain high accuracy. On the other hand, since slipperiness is also required, long-term durability can be obtained even when used as a mass production device, for example, by using a material such as hard metal coated with fluororesin.

(A-4) The centering accuracy of the disc 100 and the center shaft 101 is largely due to the concentricity of the inclined surface 102a of the tapered spacer 102 and the cylindrical surface of the disc inner diameter 100a. So this taper spacer 102
The inclined surface 102a and the inner diameter surface 100a are worked with the same chuck at the time of lathe processing to finish with high accuracy. At this time, we devised a toy to make it relatively easy, including mass production.

(A-5) In the aligning mechanism of this embodiment, air is leaked through the gap between the parallel spacer 103 and the disk surface until just before the disk 100 is fixed, and as a result, dust, metal powder, etc. on the disk surface are cleaned. is doing. Therefore, it is possible to accurately position the disk 100 and reduce errors during servo writing.

(A-6) High-pressure air and clean air can be applied to the operation of the aligning mechanism of the present embodiment, but various high-pressure gases may be used depending on the operating conditions and environment of the apparatus.

FIG. 2 is a sectional view of an essential part of a second embodiment of the present invention, showing an air bearing unit (air bearing shack unit).

A disc centering and fixing device 1 of this embodiment
Is a tapered spacer 102 as compared with the first embodiment in FIG.
The centering of the disk 100 with respect to the center shaft 101 using air is the same as that of the above. A large number of discs 100 are aligned at the same time.

In FIG. 2, 201 is a thrust plate, 202 is a porous material having a large number of air outlets, 206
Is a shaft and 203 is a housing.

The center shaft 101, the thrust plate 201, and the shaft 206 are floated with respect to the housing 203 and the porous body 202 by the air introduced from the air inlet 205 for the air bearing. The air that has flowed in from the high-pressure air inlet 204 for alignment passes through the groove 202a provided in the porous material 202, the high-pressure air flows out from the air supply port 101a via the passage of the thrust plate 201 and the center shaft 101.

According to this embodiment, in addition to the effects of the first embodiment, the tapered spacer 102, the parallel spacer 103,
If a large number of coil springs 104 are prepared in advance as one unit, any number of discs can be fixed to the center shaft 101 by changing the length of the center shaft 101. Further, since the units are compatible with each other, they can be used for another device as long as the disc inner diameter is the same. Cost can be reduced by mass-producing units.

FIG. 3 is a schematic view of a main portion of a spin Doha motor having a disc centering and fixing device of the present invention.

In FIG. 3, the thrust plate 201,
The housing 203 and the flange portion 301 form one element of the air bearing portion 302. Reference numeral 303 is a motor unit (driving unit). A power line 304 supplies a direct current to the motor unit 303. An encoder unit (rotary encoder) 305 detects rotation information of the motor unit 303. A power line 306 supplies electric power to the encoder unit 305.

In this embodiment, a spindle motor in which the disc is centered and fixed to the center shaft with high precision is achieved by the above configuration.

[0041]

As described above, the present invention can achieve a centering and fixing device for a disc and a method for performing a centering process for a disc that can accurately align and fix the disc with respect to the center shaft.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a spindle motor according to the present invention.

FIG. 4 is a sectional view of a main part of a conventional chuck mechanism for a disc.

FIG. 5 is a sectional view of an essential part of a conventional chuck mechanism for a disk.

[Explanation of symbols]

100 discs 101 Center shaft (for centering mechanism) 101a High pressure air supply port 102 taper spacer 103 parallel spacer 104 coil spring 105 lock spacer 106 lock nut 110 magnetic recording head 111 Center shaft (conventional type) 112 Lock Spacer 113 lock screw 114 washers

Claims (11)

[Claims] 1. A disk, a taper spacer having an outer peripheral surface having a taper surface, an inner peripheral surface of the taper spacer, and a sensor shaft for aligning using air, the disk being an inner peripheral surface of the disk. A centering and fixing device for a disk, wherein the taper surface of the taper spacer is fixed in contact with the center shaft so as to be centered and fixed to the center shaft. 2. The centering and fixing device for a disk according to claim 1, wherein the air is supplied from an air supply port provided on an outer peripheral surface of the center shaft to an inner peripheral surface of the tapered spacer. 3. The disk centering and fixing device according to claim 1, further comprising a parallel spacer for centering and fixing the disk to the tapered spacer. 4. The disk according to claim 1, wherein the tapered spacer is made of metal or resin, and a fluororesin is coated on the contact surface with the inner peripheral surface of the disk. Aligning and fixing device. 5. The disk alignment according to claim 1, wherein the taper surface of the taper spacer and the inner peripheral surface of the taper spacer are machined by a lathe with the same chuck. Fixing device. 6. The disk according to claim 1, wherein an angle of a taper surface of an outer peripheral surface of the taper spacer is formed by a surface corresponding to an inner peripheral surface of the disk. Aligning and fixing device. 7. The disk centering and fixing device according to claim 1, wherein a plurality of disk units centered and fixed to the taper spacer are mounted on the center shaft. . 8. A spindle motor, comprising: the disc centering and fixing device according to claim 1; and a motor unit for rotating the disc. 9. A servo writer comprising the disc centering and fixing device according to claim 1. Description: 10. A step of pressing an inner diameter surface of the disk with an outer circumference surface of a tapered spacer having an outer circumference surface of a tapered shape,
A method for centering and fixing a disk, wherein a step of centering an inner diameter surface of the tapered spacer with respect to a center shaft using air pressure is used to center and fix the disk with respect to the center shaft. 11. A step of aligning the center of the disk with the inner peripheral surface of the disk by contacting the inner surface of the disk with the tapered surface of the tapered spacer having an outer surface of the tapered spacer, and the inner surface of the tapered spacer and the center shaft. A step of forming an air layer having a constant thickness on the circumference of the outer peripheral surface and aligning both axes, and an air gap between the parallel spacer and the disk used for aligning and fixing the disk to the tapered spacer And the center of the disk is supported by static pressure in a direction perpendicular to the axis of the center shaft, and the center of the disk is fixed to the center shaft. Method.