KR100714877B1 - Hard disk drive - Google Patents

Abstract

The hard disk drive is started. The hard disk drive of the present invention includes at least one disk in which data is recorded and stored; A spindle motor hub supporting the disk to be rotatably concentric with the disk with an axis of rotation; And an inertia increasing portion coupled to the spindle motor hub to increase the rotational moment of inertia (I) of the spindle motor hub. According to the present invention, the rotational moment of inertia of the spindle motor (Inertia) can be increased, thereby reducing the revolutions per minute (RPM) and jitter changes caused during the head disk interference (HDI), which can be reduced. In addition, data errors due to disk surface damage and malfunction of the head can be reduced.

Hard disk drive (HDD), spindle motor, spindle motor hub, inertia

Description

Hard Disk Drive {Hard Disk Drive}

1 is a perspective view of a hard disk drive according to a first embodiment of the present invention.

2 is a partially exploded perspective view of FIG. 1.

3 is a perspective view of an essential part of the hard disk drive of FIG. 1;

4 is a perspective view of an essential part cut according to a second embodiment of the present invention.

5 is a perspective view of an essential part cut according to a third embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

  10: spindle motor 11: spindle motor hub

12: hub body 13: support body

15: flange 20: inertia increase

30: disk 40: clamp

41: clamp screw 51: head

The present invention relates to a hard disk drive, and more particularly, to increase the rotational moment of inertia (I) of the spindle motor and to reduce the RPM (RPM) generated during the head disk interface (HDI) and It relates to a hard disk drive that can improve jitter variation.

Hard disk drive (Hard Disk Drive) is a storage device that consists of electronic devices and mechanical devices to convert the digital electronic pulse (Pulse) into a more permanent magnetic field to record and play data. Since a large amount of data can be processed at high speed, it is widely used as an auxiliary storage device such as a computer system and a digital mobile device.

The hard disk drive includes a spindle motor, a disk that is coupled to and rotates with the spindle motor, and a head that moves the disk surface.

Spindle motor is a small motor capable of energy conversion that converts electrical energy into rotational energy by using magnetic phenomenon. When a current flows through a coil of a stator composed of an electromagnet, the rotor composed of a permanent magnet receives magnetic attraction and repulsive force. This force causes the rotor to rotate, and by changing the magnetic poles of the stator surrounding the rotor at regular intervals, the rotor can continuously rotate at a constant speed.

The performance of the spindle motor is expressed in RPM (Rotation Per Minuet). The RPM of a spindle motor has the greatest impact on the performance of a hard disk drive. The faster the data, the shorter the access time.

Comparing the performance of the two types of hard disks spinning at 5,400 RPM and 7,200 RPM on the same interface, we can see that the 7,200 RPM products run at 20% faster speeds. The speed of the hard disk drive was initially 3,600 RPM, but has since been improved to 4,500 RPM. Currently, 5,400 RPM and 7,200 RPM are the dominant drivers.

In addition, it is essential to maintain accurate rotation at the proper speed because the spindle motor can read the data accurately only by maintaining the constant speed with a rotational error of 0.1%.

On the other hand, the disk is made of an aluminum alloy, which is covered with a magnetic medium which is easily magnetized. A disk, called a platter, is a recording medium that rotates along the axis of a spindle motor and allows the head to move around its surface and store or reproduce information. Therefore, the rotation rate of the disk must be precisely maintained so that the small magnetic area of the disk can pass at the exact ratio required by the head. The discs and heads should be spaced apart from each other at approximately 1 / 100,000 inches.

The head travels near the surface of the disk to impart a magnetic field to the magnetic area so that data can be read or written on the disk. The head is moved on the disk by an actuator. The head moved to the disk surface by this actuator must move very quickly on the surface of the disk, so it must be very close to the disk surface. In addition, the head is slowly lowered onto the disk when the hard disk drive is started, and goes to a rest position when the power is stopped and the rotation of the hard disk drive stops.

As described above, the hard disk drive has a structure of recording and reproducing information through interaction between a disk driven by a spindle motor and a head approaching the disk surface.

Therefore, it is necessary to maintain the proper RPM per minute (RPM) of the spindle motor and the precise clearance height (FH, Flying Height) between the disk surface and the head. It can be avoided.

In addition, even if the head disk interference phenomenon (HDI) occurs, the spindle motor can control the disc with the proper RPM to control the jitter change, which is a decrease in the RPM and vibration, within an appropriate error range. It is designed to rotate. The head thus floats on the disk surface with a corresponding air lubrication surface (ABS), maintaining a precise gap.

In recent years, hard disk drives have been miniaturized and installed in notebooks. Small disk drives with a diameter of 1 inch and 0.85 inch are mainly designed to be mounted in mobile devices such as mobile phones and PDAs.

However, since the hard disk drive is mainly installed in a portable mobile device, a method of reducing power consumption is adopted as much as possible because power must be limited rather than fixedly powered. In that way, the torque and maneuverability of the spindle motors are reduced compared to conventional 3.5-inch or 2.5-inch hard disk drives, and they run at approximately 3,600 RPM or 4,200 RPM.

In small hard disk drives, where the torque and maneuverability of the spindle motors are relatively small, the disks rotate at a relatively slow speed. This relatively slow rotating disk has a smaller air-lift surface (ABS) flotation force that floats the head compared to 3.5 inches or 2.5 inches. Therefore, in a small hard disk drive, head disk interference (HDI) is more likely to occur than before.

In particular, since the linear velocity in the inner circumferential region ID of the disk is smaller than the outer circumferential region OD, the floating force of the air lubricating surface ABS that floats the head becomes smaller. Therefore, the head disk interference phenomenon (HDI) may occur more in the inner peripheral area ID than in the outer peripheral area OD of the disk.

On the other hand, when a head disk interference (HDI) occurs in a small hard disk drive with a relatively small torque and maneuverability of the spindle motor, the result is a reduction in the RPM of the spindle motor (RPM) and the disk It can cause jitter.

These phenomena directly affect the performance of the hard disk drive. Structurally, disc surface defects and head wear and breakage occur and errors occur in the precise gap FH between the head and the disc. Therefore, the disc may lose its data area and the head may malfunction, thereby causing a problem in which data cannot be recorded or played back intact.

Therefore, an object of the present invention, the rotational moment of inertia (Inertia) of the spindle motor can be increased, reducing the revolutions per minute (RPM) and jitter changes caused during head disk interference (HDI) than conventional It also provides a hard disk drive that can reduce data errors due to disk surface damage and head malfunction.

The object is, according to the present invention, at least one disk on which data is recorded and stored; A spindle motor hub supporting the disk to be rotatably concentric with the disk with an axis of rotation; And an inertia increase coupled to the spindle motor hub to increase the rotational moment of inertia (I) of the spindle motor hub.

The spindle motor hub has a hub body; A support body extending from the sidewall of the hub body to the radially outer side of the disk to support the disk; And a flange extending radially outward from the side wall of the support body, wherein the inertia increase portion may be provided separately from the spindle motor hub and coupled to the flange.

At this time, the inertia increasing portion is preferably a ring-shaped inertia increasing ring.

Here, the inertia increase ring may be adhesively bonded to the flange.

In addition, the inertia increase portion may be formed integrally with the spindle motor hub.

And, the spindle motor hub, the hub body; A support body extending from the side wall of the hub body in the radial direction of the disk to support the disk; And a flange extending radially from the side wall of the support body, wherein the inertia increase portion is formed integrally with the flange.

In this case, the upper surface of the inertia increasing portion may have a shape inclined downward toward the radially outer side.

On the contrary, the inertia increasing part may have a shape extending from the flange and bent downward.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a hard disk drive according to a first embodiment of the present invention, FIG. 2 is a partially exploded perspective view of FIG. 1, and FIG. 3 is a perspective view of an essential part of the hard disk drive of FIG. 1.

As shown in these figures, the hard disk drive 1 according to the first embodiment of the present invention, a disk (30) for recording and storing data, and recorded or recorded data on the disk 30 A head stack assembly 50 having a head 51 for reproducing data and having an actuator 52 for moving the head 51 to access the data on the disk 30. HSA), a spindle motor 10 for supporting the disk 30 and a spindle motor 10 for rotating the disk 30, and an inertia increase portion coupled to the spindle motor hub 11 (HSA). 20, a printed circuit board assembly (PCBA) on which various circuit components are mounted, a base (70) on which these components are assembled, and a cover (not shown) covering the base (70). ).

The head stack assembly 50 is a carrier for recording data on the disk 30 or reading the recorded data. The head stack assembly 50 includes a head 51 for writing or reading data on the disk 30. And an actuator 52 coupled to the head 51 to move the head 51 onto the disk 30, and a voice coil motor 57 to move the actuator 52.

The actuator 52 pivots an actuator arm 53 which pivots on the disk 30 around the predetermined pivot shaft 55 so that the head 51 can access the data on the disk 30, and the pivot. A pivot shaft holder 56 rotatably supporting the shaft 55 and having an actuator arm 53 coupled thereto, and extending from the pivot shaft holder 56 in the opposite direction to the actuator arm 53, and being provided with a voice coil A VCM coil (not shown) is provided with a bobbin (not shown) wound between the magnets 59 of the motor 57.

The voice coil motor 57 (VCM) is a kind of drive motor that rotates the actuator arm 53 to move the head 51 to a desired position on the disk 30, and uses Fleming's left hand law. In other words, when a current flows through a conductor in a magnetic field, a force is generated. By applying a current to a VCM coil (not shown) located between the magnets 59, a force is applied to the bobbin (not shown). ) Rotated. Thus, the actuator arm 53 extending in the opposite direction to the bobbin (not shown) in the pivot shaft holder 56 is rotated so that the head 51 supported at its end moves in the radial direction on the rotating disk 30. It searches for and accesses tracks and signals the accessed information.

On the other hand, the spindle motor hub 11 includes a hub body 12, a support body 13 extending radially outward from the side wall of the hub body 12 to support the disk 30, A flange 15 extending radially outward from the sidewall of the support body 13.

Hub body 12 is an area that is coupled to the clamp 40 and the clamp screw 41 to support the disk 30 to the spindle motor hub 11, the spindle motor stator (not shown) and magnetic attraction The part rotates with the disk 30 due to the interaction by the repulsive force.

The support body 13 extends radially outward from the side wall of the hub body 12 and supports the disk 30. The upper surface of the support body 13 is in contact with a portion of the inner region of the rear of the disk 30 and has a predetermined width and width so as to mount the disk 30. In addition, the support body 13 supports the disk 30 and the minimum strength is required to withstand the load of the disk 30, it is typically formed integrally with the hub body 12.

The flange 15 extends radially outward from the side wall of the support body 13 and is typically formed integrally with the hub body 12 and the support body 13. Flange 15 has a vertical cross-section of the "b" shape with the outer surface of the support body (13).

The inertia increasing unit 20 is provided separately to increase the rotational moment of inertia of the spindle motor 10. As shown in FIGS. 2 and 3, the inertia increasing portion 20 is an inertia increasing ring 20 coupled to the flange 15 in the present embodiment.

Some objects have an inherent nature of continuing to be stationary or in motion. This property is called Inertia, and the moment of inertia of a rotating object is represented by I = MR ² .

I = MR ² of the moment of inertia As shown in the equation, the moment of inertia (I) of an object rotating about one axis is proportional to the mass (M) located from that axis and is the square of the radius (R), which is the distance from the axis. It becomes proportional to and becomes large. Since the rotational inertia (I) is proportional to the square of the radius (R), it can be seen that the influence of the radius (R) is greater than the mass (M) in the rotational inertia (I). Thus, by appropriately adjusting the mass distribution and the distance from the axis, it is possible to set the desired rotational moment of inertia (I).

On the other hand, a large rotational moment of inertia (I) means that the external force added to rotate the object must be large, while the external force to stop when the object is rotating also increases. do.

In the hard disk drive 1 according to the first exemplary embodiment of the present invention, the rotational inertia moment I of the rotating spindle motor hub 11 is increased by the inertia increase unit 20 so that the spindle motor ( Even if the torque and maneuverability of 10) are relatively small, the RPM reduction and jitter change caused during the head disk interference (HDI) can be reduced.

In addition, the inertia increasing part 20 may be implemented in various forms, but as described above, the inertia increasing part 20 is the inertia increasing ring 20 coupled to the flange 15.

The inertia increasing ring 20 is formed in a ring shape, the vertical cross section of the inclined shape to form a shape corresponding to the contact surface and has a rectangular shape. The inertia increasing ring 20 is tightly coupled between the support body 13 side of the spindle motor hub 11 and the upper surface of the flange (15). In addition, the inertia increase ring 20 is provided of a homogeneous material having a load distribution with equal cross sections. This is for the inertia increasing ring 20 to have an even rotational moment of inertia I when rotating. In addition, the inertia increase ring 20 is adhesively bonded to the flange 15 so as to reduce the gap that can occur between the two materials produced separately from each other to a minimum.

When the spindle motor 10 to which the inertia increasing ring 20 is added is coupled to an appropriate position of the base 70 of the hard disk drive 1, the disk (on the upper surface of the support body 13 of the spindle motor hub 11) 30) is located. At this time, the clamp 40 is positioned on the upper surface of the disk 30 so that the disk 30 is tightly coupled to the support body 13, and the clamp screw 41 is fastened thereon to finally fix the disk 30. . The disk 30 thus supported is rotated together by the rotation of the spindle motor 10.

With this configuration, the operation of the hard disk drive 1 according to the first embodiment of the present invention will be described as follows.

When power is supplied to the hard disk drive 1 and an electrical signal is input to the spindle motor 10, the spindle motor hub 11 starts to rotate to reach an appropriate RPM per minute. At this time, the spindle motor hub 11 equipped with the inertia increasing ring 20 supports the disk 30 and rotates together with the disk 30.

On the other hand, when the head disk interference phenomenon (HDI) occurs, the impact force of the head 51 is one external force to suppress the rotation of the disk 30 affects the rotational state of the disk 30.

However, since the rotational moment of inertia (I) of the spindle motor 10 is increased by the inertia increase ring 20, even if the head disk interference phenomenon (HDI) occurs, the revolutions per minute (RPM) and jitter The jitter phenomenon is reduced than before.

In this way, when the inertia increase ring 20 is appropriately adjusted to the required rotational moment of inertia (I), even if the head disk interference phenomenon (HDI) occurs, the rotational revolution per minute (RPM) or jitter change is appropriate. Can be improved within the margin of error.

4 is a perspective view illustrating a main part cut according to the second embodiment of the present invention, and only the parts different from the first embodiment of the present invention will be described, and the same reference numerals are used for the same parts as the first embodiment for the sake of explanation. All other parts shall be cited. Reference numerals with the addition of 'a' shall be cited.

As shown in the figure, the inertia increase portion 20a of the hard disk drive 1a according to the second embodiment of the present invention is different from the above-described first embodiment in that it is formed integrally with the flange 15.

The inertia increasing portion 20a has a shape in which the upper surface thereof is inclined downward toward the radially outer side and extends as long as possible. In this way, the length (R) and the mass (M) is further increased to obtain a large rotational moment of inertia (I). In addition, since the upper surface of the inertia increasing portion 20a has a shape inclined downward, the head 51 can move the rear surface of the disk 30 without interference.

FIG. 5 is a perspective view illustrating an essential part cut according to a third embodiment of the present invention, and only a different part from the first embodiment of the present invention will be described, and the same reference numerals will be used for the same parts as the first embodiment when necessary for explanation. Citations shall be made and other parts shall be quoted with the addition of a 'b'.

As in the second embodiment, the hard disk drive 1b according to the third embodiment of the present invention has the above-described point in which the inertia increasing portion 20b is extended from the flange 15 and is bent downward. It is different from the embodiment.

Increasing the inertia increasing portion 21b may cover the rear surface of the disk 30 and interfere with the head 51, so that it should be designed to have an appropriate length in consideration of this.

As such, by combining the inertia increasing ring 20 provided separately to the spindle motor hub 11, or by providing the inertia increasing portion 20 formed integrally with the flange 15 of the spindle motor hub 11, It is possible to increase the rotational moment of inertia I of the spindle motor 10. Accordingly, even when the head disk interference phenomenon (HDI) occurs, the influence of the external force acting can be minimized to improve the RPM reduction and jitter change.

In the first embodiment described above, the inertia increasing portion 20 was a single inertia increasing ring 20 having a homogeneous load distribution separately provided. However, the inertia increasing portion 20 can be installed on the flange 15 locally by distributing loads differently. There may be a plurality of inertia increase unit 20.

In addition, in the above-described first embodiment, the inertia increasing ring 20 has been described above with respect to a rectangular shape having an angle in cross section, but may be manufactured in various shapes instead of angles.

In the above-described second and third embodiments, the inertia increase part 20 is integrally formed with the flange 15, and the upper surface thereof is inclined downward or bent downward toward the radially outer side. If the length is not long so as not to interfere with the head 51 may be a shape to be parallel to the disk side.

As described above, the present invention is not limited to the described embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention, which will be apparent to those skilled in the art. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

As described above, according to the present invention, the rotational moment of inertia (Inertia) of the spindle motor can be increased to reduce the revolutions per minute (RPM) and jitter changes caused during the head disk interference (HDI). It can further reduce data errors due to disk surface damage and head malfunction.

Claims (8)

At least one disk on which data is recorded and stored; A spindle motor hub supporting the disk to be rotatably concentric with the disk with an axis of rotation; And It is coupled to the spindle motor hub includes an inertia increase to increase the rotational moment of inertia (I) of the spindle motor hub, The spindle motor hub is Herb body; A support body extending from the sidewall of the hub body to the radially outer side of the disk to support the disk; And A flange extending radially outwardly of the disk from the sidewall of the support body, The inertia increasing unit is provided separately from the spindle motor hub, the hard disk drive, characterized in that coupled to the flange. delete The method of claim 1, The inertia increasing portion is a hard disk drive, characterized in that the ring-shaped inertia increasing ring. The method of claim 3, And the inertia increasing ring is adhesively bonded to the flange. delete At least one disk on which data is recorded and stored; A spindle motor hub supporting the disk to be rotatably concentric with the disk with an axis of rotation; And It is coupled to the spindle motor hub includes an inertia increase to increase the rotational moment of inertia (I) of the spindle motor hub, The spindle motor hub is Herb body; A support body extending from the side wall of the hub body in the radial direction of the disk to support the disk; And A flange extending radially from the sidewall of the support body, And the inertia increasing portion is formed integrally with the flange. The method of claim 6, The upper surface of the inertia increase portion has a shape inclined downward toward the radially outer side. The method of claim 6, And the inertia increasing portion has a shape extending from the flange and bent downward.

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