JP2003317435A - Disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk drive which can improve the positioning accuracy of a magnetic head while suppressing an increase of a manufacturing cost. <P>SOLUTION: A case 10 has a freely rotatable hub 44, is mounted with a spindle motor 18 and is fitted with disks 16a and 16b on the outer periphery of the hub. A disk clamper 56 holding a disk at the hub is fixed to the end of the hub. The disk clamper is integrally provided with a clamping section 58 which is fixed to the end of the hub and holds the central part of the disk and a nearly annular current rectifying section 60 which extends outward in a diametral direction from the clamp and faces the surface of the disk apart the prescribed spacing therefrom. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device such as a magnetic disk device having a disk rotating at high speed.

[0002]

2. Description of the Related Art Generally, a magnetic disk device includes a magnetic disk arranged in a case, a spindle motor for supporting and rotating the magnetic disk, a carriage assembly for supporting a magnetic head, a voice coil motor for driving the carriage assembly, It is configured to include a substrate unit and the like.

The spindle motor has a cylindrical hub,
A plurality of magnetic disks and spacer rings are alternately stacked on this hub. The magnetic disk and the spacer ring are fixed to the outer circumference of the hub by a disk clamper attached to the tip of the hub.

In such a magnetic disk device, it is necessary to increase the rotational speed of the magnetic disk in order to perform high-speed data processing. Therefore, in recent years, high-speed rotation type magnetic disk devices have been studied. However, when the magnetic disk rotates at a high speed, an airflow in the same rotation direction as the magnetic disk is generated, and a phenomenon called disk flutter occurs in which the magnetic disk vibrates due to the turbulence of the airflow. In this case, the positioning accuracy of the magnetic head with respect to the magnetic disk is lowered, which hinders the improvement of the recording density.

[0005]

In order to solve the above problems, for example, according to a magnetic disk device disclosed in Japanese Unexamined Patent Publication No. 10-162548, an inner circumference is provided near a magnetic disk when the magnetic disk rotates. A circulatory flow path that generates a forced flow from the to the outer circumference is formed, and turbulence of the air flow is suppressed to reduce disk flutter.

In this magnetic disk device, in order to form a circulation flow path, a hub or spacer of a spindle motor is machined with cutouts or tapered portions for passing air, and at the same time, an airflow is introduced into these cutouts or tapered portions. Therefore, the air introduction path is formed so as to match the base and top cover of the magnetic disk device.

However, in a magnetic disk device which is required to have a high recording density, the processing accuracy of each component directly affects the device performance. Therefore, when processing individual parts to form the circulation flow path, an increase in processing and finishing costs is inevitable as the number of processing locations increases.

In order to prevent the above-mentioned disc flutter, the shape of the top cover is changed, or
Magnetic disk devices with separate parts installed have also been proposed, but both devices have undergone major shape changes and an increase in the number of parts.
There are many problems that must be solved, such as ensuring assembly accuracy.

The present invention has been made in view of the above points, and it is an object of the present invention to drive a disk capable of suppressing vibration of the disk and improving head positioning accuracy with respect to the disk while suppressing increase in manufacturing cost. To provide a device.

[0010]

In order to achieve the above object, the disk drive apparatus according to the embodiment of the present invention increases the outer diameter of the disk clamper for fixing the disk to the hub of the motor, and With the configuration in which the disc and the disc are rotated integrally with each other while maintaining the optimum distance from the disc, the airflow near the disc is rectified and the disc flutter is effectively reduced.

That is, the disk drive device according to the embodiment of the present invention has a case, a motor having a rotatable hub and attached to the case, and an inner hole into which the hub is inserted, respectively. A disc fitted to the outer periphery and a disc clamper fixed to the end of the hub and holding the disc on the hub are provided, and the disc clamper is fixed to the end of the hub to fix the disc. The present invention is characterized by integrally including a clamp portion that holds the center portion and a substantially annular rectifying portion that extends radially outward from the clamp and faces the surface of the disk with a predetermined gap therebetween.

According to the disk drive apparatus constructed as described above, the shape of the top cover can be changed or a separate dedicated member can be added by providing the rectifying portion on the disk clamper which rotates integrally with the hub of the motor. It is possible to rectify the air flow on the disk surface without doing so. As a result, even when the disc rotates at high speed, it is possible to reduce the turbulence of the air flow generated near the disc and reduce the disc flutter. As a result, it is possible to obtain a disk drive device in which vibration of the magnetic disk is reduced and head positioning accuracy with respect to the magnetic disk is improved while suppressing an increase in manufacturing cost.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hard disk drive (hereinafter referred to as HDD) as a magnetic disk device according to an embodiment of the present invention will be described in detail below with reference to the drawings. As shown in FIGS. 1 and 2, the HDD includes a case 10, which is a rectangular box-shaped base 12 having an open upper surface and a plurality of screws that are screwed to the base to close the upper opening of the base. It is composed of the top cover 11.

Inside the case 10, a spindle motor 18 attached to the bottom wall of the base 12 and two magnetic disks 16a, 16b supported and rotatably driven by the spindle motor are arranged. Further, in the case 10, a plurality of magnetic heads for recording / reproducing information on / from the magnetic disks 16a, 16b, a carriage assembly 22 for movably supporting these magnetic heads on the magnetic disks 16a, 16b, A voice coil motor (hereinafter referred to as VCM) 24 that rotates and positions the carriage assembly, and a ramp load mechanism 2 that holds the magnetic head in a retracted position separated from the magnetic disk when the magnetic head moves to the outermost circumference of the magnetic disk.
5, a board unit 21 having a preamplifier and the like is housed.

On the outer surface of the bottom wall of the base 12, a spindle motor 18 and a VCM 2 are provided via a substrate unit 21.
4, and a printed circuit board (not shown) that controls the operation of the magnetic head is screwed.

As shown in FIGS. 1 and 2, the carriage assembly 22 includes a bearing portion 26 fixed on the bottom wall of the base 12 and a plurality of arms 32 extending from the bearing portion.
And are equipped with. These arms 32 are located parallel to the surfaces of the magnetic disks 16a and 16b and at a predetermined distance from each other, and extend from the bearing portion 26 in the same direction. The carriage assembly 22 also includes an elastically deformable elongated plate-shaped suspension 38. The suspension 38 is composed of a leaf spring, and its base end is fixed to the tip of the arm 32 by spot welding or adhesion and extends from the arm. Each suspension 38 has a corresponding arm 32.
It may be formed integrally with.

A magnetic head 40 is attached to the extended end of the suspension 38. The magnetic head 40 has a substantially rectangular slider and an MR (magnetoresistive) head for recording and reproduction formed on the slider, and is fixed to a gimbal portion formed at the tip of the suspension 30. The four magnetic heads 40 respectively attached to the suspensions 38 are located so as to face each other two by two, and are arranged so as to sandwich each magnetic disk from both sides.

On the other hand, the carriage assembly 22 has a support frame 45 extending from the bearing portion 26 in the direction opposite to the arm 32, and the voice coil 47 forming a part of the VCM 24 is supported by the support frame 45. There is. Support frame 45
Is integrally formed on the outer circumference of the voice coil 47 with synthetic resin. The voice coil 47 is located between a pair of yokes 49 fixed on the base 12, and constitutes the VCM 24 together with these yokes and a magnet (not shown) fixed to one of the yokes. By energizing the voice coil 47, the carriage assembly 22 rotates around the bearing portion 26, and the magnetic head 40 is moved and positioned on a desired track of the magnetic disks 16a and 16b.

The ramp load mechanism 25 is provided on the bottom wall of the base 12 and the magnetic disks 16a and 16a.
It has a ramp 51 arranged outside b and a tab 53 extending from the tip of each suspension 38. The carriage assembly 22 has magnetic disks 16a, 1
When rotating to the retracted position outside 6b, each tab 53
It engages with the ramp surface formed on the ramp 51, and is then pulled up by the inclination of the ramp surface to unload the magnetic head.

As shown in FIGS. 1 and 2, the magnetic disks 16a and 16b are formed to have a diameter of 65 mm (2.5 inches), have an inner hole 42 in the center thereof, and have magnetic recording layers on the upper and lower surfaces. have. The spindle motor 18 is composed of an outer rotor type spindle motor. The spindle motor 18 includes a cylindrical hub 44 that functions as a rotor. The two magnetic disks 16a and 16b are coaxially fitted to the hub, and the hub 44 has a predetermined shape along the axial direction of the hub. Stacked at intervals. The magnetic disks 16a and 16b are rotationally driven integrally with the hub 44 at a predetermined speed by the spindle motor 18.

More specifically, a flange 50 that functions as a disk receiving portion is formed on the outer circumference of the lower end portion of the rotatable hub 44. And spindle motor 1
8 is fixedly arranged at a predetermined position in the case 10 by screwing the motor bracket 52 to the bottom wall of the base 12.

The two magnetic disks 16a and 16b are fitted on the outer peripheral surface of the hub 44 with the hub 44 inserted through the inner hole 42, and are stacked on the flange 50. Also,
A spacer ring 54 is fitted around the outer periphery of the hub 44, and is stacked in a state of being sandwiched between the magnetic disks 12a and 12b. Then, these magnetic disks 16a, 16b
The spacer ring 54 is fastened and fixed to the hub 44 by a disk clamper 56 screwed to the upper end surface of the hub 44. Then, the disk clamper 56 is rotationally driven integrally with the hub 44 and the magnetic disks 16a and 16b.

The disk clamper 56 has a disk-shaped clamp portion 58 having an outer diameter slightly larger than the diameter of the hub 44.
And a substantially annular rectifying portion 60 that extends radially outward from the clamp portion. This disk clamper 5
6 is integrally formed by bending a stainless plate having a plate thickness of about 0.6 mm, for example.

The clamp portion 58 is screwed and fixed to the hub 44 with a screw 57 and is in close contact with the upper end surface of the hub. The outer peripheral portion of the clamp portion 58 abuts the upper surface of the central portion of the upper magnetic disk 16a and presses the two magnetic disks 16a and 16b and the spacer ring 54 toward the flange 50 of the hub 44. Thereby, the magnetic disks 16a and 16b and the spacer ring 54
Is clamped between the flange 50 and the clamp portion 58,
The hubs 44 are fixedly held in a state of being in close contact with each other.

The rectifying section 60 of the disk clamper 56
Are formed to be one step higher than the clamp portion 58 and face the surface of the magnetic disk 16a with a predetermined gap.
The surface of the rectifying unit 60 facing the magnetic disk 16a is formed into a smooth flat surface. The distance between the rectifying unit 60 and the surface of the magnetic disk is set to a minimum value as long as the magnetic head 40 moving on the magnetic disk 16a and the carriage assembly 22 do not interfere with the rectifying unit 60. For example, this interval is set to 0.85 mm or less, and is set to 0.85 mm in this embodiment.
Further, the distance between the rectifying section 60 and the inner surface of the top cover 11 is
The minimum clearance that the rectifying section and top cover do not contact,
The dimension is set to 0.7 mm or less. In this embodiment, it is set to 0.7 mm.

The outer peripheral radius d of the rectifying portion 60 is 50 to 110% of the outer peripheral radius D of the magnetic disk, preferably the outer diameter of the magnetic disk, in consideration of the rectifying effect of the rectifying portion and interference with other components. It is formed in 75 to 100%. In the present embodiment, the outer circumference radius d of the rectifying portion 60 is about 90 times the outer circumference radius D of the magnetic disks 16a and 16b.
It is set to%.

According to the HDD configured as described above,
By enlarging the outer radius of the disk clamper 56 fixing the magnetic disks 16a and 16b to the same extent as the outer radius of the magnetic disk, the space between the magnetic disk and the top cover 11 can be effectively made by the disk clamper. Can be reduced. At the same time, the magnetic head 40
The rectifying section 60 of the disk clamper 56 is close to the magnetic disk 16a within a range where it does not interfere with the carriage assembly 22. Further, the disk clamper 56 is screwed to the hub 44, and the magnetic disks 16a, 16b
Rotates together with. Therefore, without changing the shape of the top cover or adding a dedicated separate member, the rectification unit 6
The disk clamper 56 having 0 makes it possible to rectify the air flow on the surface of the magnetic disk.

As a result, even when the magnetic disks 16a and 16b rotate at a high speed, the airflow generated near the magnetic disks, especially the airflow between the magnetic disk and the top cover, is rectified and the disk flutter due to the turbulence of the airflow is eliminated. It can be reduced. This makes it possible to obtain an HDD in which vibration of the magnetic disk is reduced and head positioning accuracy with respect to the magnetic disk is improved while suppressing an increase in manufacturing cost.

An HDD including the disk clamper according to the above-described embodiment and an H including the conventional disk clamper
DD was prepared, and the disk flutter in the direction perpendicular to the magnetic disk surface was measured for each HDD. FIG. 3 shows the measurement results of the HDD according to this embodiment.
3A shows the measurement results of the conventional HDD, respectively. Further, FIG. 4 shows the results of comparison by enlarging the portion indicated by the circle A of these measurement results. A laser Doppler vibrometer (LDV) was used for the measurement of the disk flutter, and the spectrum of each frequency was measured by the FFT analyzer.

In FIGS. 3 (a) and 3 (b), the peak of the spectrum is an integral multiple of the rotation speed due to the undulation of the magnetic disk surface, the disk flutter component of the vibration caused by the turbulence of the air flow, Is included. In FIG. 4, three points indicated by circles are peaks due to the disk flutter component, and it can be seen that the disk flutter is reduced by about 5% in the HDD according to this embodiment as compared with the conventional HDD. .

The present invention is not limited to the above-described embodiments, but can be variously modified within the scope of the present invention. For example, in the above-described embodiment, 3
Although the configuration provided with one magnetic disk has been described, the number of magnetic disks can be increased or decreased as necessary. Further, the present invention is applicable not only to the magnetic disk device but also to other disk drive devices.

[0032]

As described in detail above, according to the present invention,
It is possible to provide a disk drive device capable of suppressing the vibration of the disk while suppressing an increase in manufacturing cost and improving the positioning accuracy of the head with respect to the disk.

[Brief description of drawings]

FIG. 1 is a plan view showing the inside of an HDD according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a case of the HDD, a spindle motor, and a magnetic disk.

FIG. 3 is a diagram showing an HDD according to the above embodiment and a conventional HD.
The figure which shows the measurement result of the disk flutter of D, respectively.

FIG. 4 is a diagram showing an HDD according to the above-described embodiment and a conventional HD.
The figure which compares and shows the measurement result of the disk flutter of D.

[Explanation of symbols]

10 ... Case 11 ... Top cover 12 ... Base 16a, 16b ... magnetic disk 18 ... Spindle motor 22 ... Carriage assembly 40 ... Magnetic head 44 ... Hub 56 ... Disk clamper 58 ... Clamp part 60 ... Rectifier

Claims (6)

[Claims] 1. A case, a motor having a rotatable hub attached to the case, a disk fitted with an outer periphery of the hub, each having an inner hole into which the hub is inserted, and the hub. A disc clamper fixed to the end of the disc and holding the disc to the hub, the disc clamper being fixed to the end of the hub and holding the center of the disc; A disk drive device integrally provided with a substantially annular rectifying portion that extends radially outward and faces the surface of the disk with a predetermined gap therebetween. 2. The outer diameter of the rectifying portion of the disk clamper is
2. The disk drive device according to claim 1, wherein the disk outer diameter is 50 to 110%. 3. The outer diameter of the rectifying portion of the disk clamper is
3. The disk drive device according to claim 2, wherein the disk outer diameter is 75% to 100%. 4. The distance between the rectifying portion of the disk clamper and the surface of the disk is set to a minimum distance that does not contact the head, and the dimension thereof is set to 0.85 mm or less. 4. The disk drive device according to any one of 3 above. 5. The case includes a base to which the motor is attached and which has an upper opening, and a top cover which closes the upper opening of the base and faces the rectifying portion of the disk clamper. 5. The distance between the top cover and the rectifying portion is a minimum distance at which the top cover and the rectifying portion do not come into contact with each other, and the dimension thereof is set to 0.7 mm or less.
The disk drive device according to any one of 1. 6. A head assembly for recording / reproducing information on / from the disk, and a carriage assembly provided on the base for movably supporting the head with respect to the disk. Item 5. The disk drive device according to item 5.