This application claims priority under 35 U.S.C. §119 (a) Korean Patent Application No. 10-2005-0084253, filed on Sep. 9, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present general inventive concept relates to a spindle motor assembly that can be applied to a hard disk drive, and more particularly, to a spindle motor assembly that can prevent flexing of a disk and increase storage capacity.
2. Description of the Related Art
A hard disk drive (HDD) and an optical disk drive (ODD) are data storage devices that read and write data from and to a disk rotatably mounted on a spindle motor.
A clamp member 150 is located above the hub 135 to press the disk 140 onto the hub 135. The clamp member 150 has an inner edge fixed by the screw member 160 and an outer edge extending toward the data storage disk 140. A pressure portion 151 is formed on the outer edge. The pressure portion 151 is curved and protrudes toward the information storage disk 140. The information storage disk 140 is tightly clamped between the pressure portion 151 and the flange portion 135c. The information storage disk 140 fitted around the hub 135 is deflected downward by gravity. Also, a pressure point P′1 of the pressure portion 151 is located further from the center than the supporting center P′2 of the flange portion 135c. If a relationship between the radius R′1 of the pressure point P′1 and the radius R′2 of a supporting center P′2 of the flange portion 135c is expressed by the following equation, then a direction of an applied rotational moment aggravates the flexing of the information storage disk.
R1′>R2′ [Equation]
Meanwhile, the flange portion 135c is provided with a U-shaped groove 135′. The U-shaped groove 135′ is inevitably formed while machining the sidewall portion 135b perpendicular to the flange portion 135c. The U-shaped groove 135′ is formed in the flange portion 135c, adjacent to a junction of the flange portion 135c and the sidewall portion 135c. However, since the U-shaped groove 135′ is formed in the flange portion 135c, a supporting area of the flange portion 135c is reduced and thus a supporting structure for the information storage disk 140 is weakened. This aggravates the flexing of the information storage disk.
The present general inventive concept provides a spindle motor assembly usable in a hard disk drive, which can suppress flexing of a data storage disk.
The present general inventive concept further provides a spindle motor assembly usable in a hard disk drive, which can increase an effective data region of a data storage disk by reducing an ineffective disk area used to clamp the date storage disk.
Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
The foregoing and/or other aspects of the present general inventive concept may be achieved by providing a spindle motor assembly usable in a hard disk drive, the spindle motor assembly including at least one data storage disk, a spindle motor to drive the disk, the spindle motor having a hub to which the data storage disk is fixed, and a clamp member to fix the data storage disk to the hub by pressing the data storage disk axially toward the hub, wherein when the clamp member presses a first location of the data storage disk and the hub has a supporting center corresponding to a second location of the data storage disk, the first location is closer to a center of the data storage than the second location.
The clamp member may seat on the data storage disk fixed to the hub, and the spindle motor assembly may include a screw member to couple the clamp member to the hub. In addition, the clamp member may have a pressure portion to protrude toward the data storage disk to contact the first location.
The hub may have a supporting surface having an inner circumference with a radius Ri from a rotational axis thereof and an outer circumference with a radius Ro from the rotational axis, and the second location is located on a circumference having a mean radius ((Ri+Ro)/2) of the radii Ri and Ro.
The hub may have a sidewall portion around which the data storage disk is fitted and a flange portion on which the data storage disk seats, the flange portion extending from the sidewall portion in a radial direction of the data storage disk. The hub may have a groove formed in a portion of the sidewall portion which is adjacent to a junction between the sidewall portion and the flange portion.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a spindle motor assembly usable in a hard disk drive, the spindle motor assembly including at least one data storage disk, a spindle motor to rotate the data storage disk, the spindle motor having a hub about which the data storage disk rotates, the hub having a sidewall portion around which the data storage disk is fitted and a flange portion on which the data storage disk seats, the flange portion extending from the sidewall portion in a radial direction of the data storage disk, and a clamp member to fix the data storage disk to the hub by pressing the data storage disk axially toward the hub, wherein, when the clamp member presses a first location of the data storage disk and the hub has a supporting center corresponding to a second location of the data storage disk, the first location is closer to a center of the data storage than the second location, and the hub include a groove formed in a portion of the sidewall portion which is adjacent to a junction between the sidewall portion and the flange portion.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a spindle motor assembly usable in a hard disk drive, the spindle motor assembly including at least one data storage disk having a first surface, a second surface, and a third surface, a spindle motor having a hub to rotate the data storage disk, the hub having a sidewall portion to correspond to the first surface of the data storage disk and a flange portion to support the second surface of the data storage disk, the flange portion extending from the sidewall portion in a direction along one of the second and third surfaces of the data storage disk, and a clamp member to fix the data storage disk to the hub by pressing the third surface of the data storage disk toward the hub in a direction having an angle with the redial direction, wherein the hub comprises a groove formed on the sidewall portion, and the groove is not extended to the flange portion.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a hard disk drive, including a frame member having an inside space therein, and a spindle motor assembly disposed in the inside space of the frame, the spindle motor assembly having at least one data storage disk, a spindle motor to drive the disk, the spindle motor having a hub on which the data storage disk is fixed, and a clamp member to fix the data storage disk to the hub by pressing the data storage disk axially toward the hub, wherein, when the clamp member presses a first location of the data storage disk and the hub has a supporting center corresponding to a second location of the data storage disk, the first location is closer to the center of the data storage disk than the second location.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a hard disk drive, including a frame member having an inside space therein, and a spindle motor assembly disposed in the inside space of the frame, the spindle motor assembly having at least one data storage disk having a first surface, a second surface, and a third surface, a spindle motor having a hub to rotate the data storage disk, the hub having a sidewall portion to correspond to the first surface of the data storage disk and a flange portion to support the second surface of the data storage disk, the flange portion extending from the sidewall portion in a direction along one of the second and third surfaces of the data storage disk, and a clamp member to fix the data storage disk to the hub by pressing the third surface of the data storage disk toward the hub in a direction having an angle with the redial direction, wherein the hub comprises a groove formed on the sidewall portion, and the groove is not extended to the flange portion.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a spindle motor assembly usable in a hard disk drive, the spindle motor assembly at least one data storage disk having a first portion and a second portion extended from the first portion, a spindle motor having a hub to support the first portion of the at least one data storage disk, and a clamp member to clamp the at least one data storage disk to the hub of the spindle motor such that the spindle motor drives the disk to rotate together with the hub, the clamp member having a pressure portion to press the first portion of the data storage disk toward the hub, the pressure portion having a first distance from a rotation center of the data storage disk shorter than a second distance between the rotation center of the data storage disk and a center of the first portion of the at least one data storage disk.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a spindle motor assembly usable in a hard disk drive, the spindle motor assembly including at least one data storage disk, a spindle motor having a hub having a flange portion to support a portion of the at least one data storage disk, and a clamp member having a pressure portion disposed between a rotation center of the at least one data storage disk and a center of the portion of the at least one data storage disk to clamp the portion of the at least one data storage disk to the flange portion of the hub of the spindle motor such that the spindle motor drives the disk to rotate together with the hub.
These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.
The base frame 11 may be formed of aluminum or aluminum alloy and may be formed by die-casting. A space to receive the spindle motor assembly and the actuator 20 is formed in the base frame 11. The space may be formed between the base frame 11 and the cover member 13.
The cover member 13 is fixed to a top portion of the base frame 11 by, for example, screws 15 to enclose and protect the data storage disk 40, the spindle motor 30, and the actuator 20, to exclude dust and moisture, and to prevent noise generated in the hard disk drive from passing out thereof.
The spindle motor assembly includes the spindle motor 30, the data storage disk 40, and a clamp member 50. The spindle motor 30 rotates the data storage disk 40, and includes a shaft 31 fixed to the base frame 11, a stator 33 fixed around the shaft 31, and a rotor, such as a hub 35, disposed to surround the stator 33. The data storage disk 40 includes one or more surfaces fitted around the hub 35.
The clamp member 50 is provided to securely fix the data storage disk 40 to the hub 35 of the spindle motor 30. The clamp member 50 is coupled to an upper end of the shaft 31 of the spindle motor 30 by a screw member 60 to press the data storage disk 40 downward.
The actuator 20 records data on the data storage disk 40 and reads the data stored on the data storage disk 40 by accessing a target track of the data storage disk 40 while pivoting in a clockwise or counterclockwise direction with respect to a pivot 21 above the rotating data storage disk 40. The actuator 20 includes a swing arm 23, a suspension 25, and a voice coil motor 29. The swing arm 23 is pivotally coupled to the pivot 21 installed on the base member 11. The suspension 25 is coupled to a tip of the swing arm 23 to bias a slider having a read/write head onto a surface of the data storage disk 40. The voice coil motor 29 provides a driving force to control the swing arm 23 to pivot with respect to the pivot 21. The voice coil motor 29 is controlled by a servo control system. The swing arm 32 pivots about the pivot 21 in a direction according to the Fleming's left-hand rule by an interaction between a current applied to a coil of a voice coil motor (VCM) and a magnetic field formed by a magnet thereof. That is, when the hard disk drive is switched on and the data storage disk 40 starts rotating, the swing arm 32 pivots in the counterclockwise direction around the pivot 21 by the voice coil motor 29 to position the read/write head above a recording surface of the data storage disk 40. When the hard disk drive is switched off and the data storage disk 40 stops rotating, the swing arm 23 pivots in the clockwise direction around the actuator pivot 21 to allow the read/write head to leave the recording surface of the data storage disk 40. After leaving the recording surface of the data storage disk 40, the read/write head rests on a ramp 27 disposed on a rest area of the data storage disk 40 or disposed on a position adjacent to the data storage disk 40.
The data storage disk 40 is securely fixed between the flange portion 35c of the hub 35 and the clamp member 50 since the first, second, and third surfaces of the data storage disk 40 may tightly contact the sidewall portion 35b, the flange portion 35c, and the pressure portion 51, respectively. A top surface of the flange portion 35c constitutes a supporting plane that is evenly formed to contact the second surface of the data storage disk 40. The supporting plane is delimited (or defined) by an inner circumference having an inner radius Ri and an outer circumference having an outer radius Ro. The data storage disk 40 is securely clamped between the supporting plane of the flange portion 35 and the pressure portion 51 of the clamp member 50 to rotate together with the hub 35.
In the present embodiment, the pressure portion 51 of the clamp member 50, i.e., the pressure point P1 of the data storage disk 40, is closer to the center of the data storage disk 40 than a supporting center P2 of the flange portion 35c. The supporting center P2 represents a location to which an imaginary concentrated load can be equally applied when a predetermined distributed load applied from the supporting plane to the data storage disk 40 is equivalently transformed to the imaginary concentrated load. The supporting center P2 is located on a circumference having a second radius R2 that may be a mean ((Ri+Ro)/2) of the inner and outer radii Ri and Ro. Generally, a data storage disk that is locally clamped at its center is deflected further by gravity according to a distance from the center towards the outer edge thereof. However, since the pressure portion 51 or the pressure point P1 is closer to the center than the supporting center P2, a rotational moment may be generated in a direction from the second surface to a surface on which the third surface is disposed and may be applied in a direction opposite to a gravity direction to prevent the flexing of the data storage disk 40.
In the case A, the deflection is small. A maximum deflection, which represents a degree of flexing of the data storage disk 40, is limited to a narrow range. In the case B, the deflection varies linearly in proportion to the normalized distance, and the maximum deflection is greater than that of the case A.
Referring back to
In the graph of
In the present embodiment, a further effect can be realized in addition to the increase of the supporting area. That is, since the supporting surface is expanded inward, the pressure portion 51 of the clamp member can be moved further inward. Therefore, an ineffective disk region that is used for clamping can be reduced. Accordingly, an effective data zone is increased. As a result, a capacity of the hard disk drive 40 can increase. For example, the effective area of the data storage disk 40 can be increased by about 45% according to the present general inventive concept.
The spindle motor assembly of the present general inventive concept may further include two or more data storage disks. In this case, spacers may be interposed between the data storage disks to maintain gaps between the data storage disks.
According to the spindle motor assembly of the present embodiment, the flexing of the data storage disk can be suppressed by improving the clamping structure for the data storage disk. Furthermore, the data zone of the data storage disk can be maximized by reducing the ineffective disk area that is used for clamping.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.
Number | Date | Country | Kind |
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2005-84253 | Sep 2005 | KR | national |