Cross-Reference to Related Applications
This application makes reference to, incorporates the same herein, and claims all benefits incurring under 35 U.S.C. .sctn.119 from an application for A Hard Disk Drive Using A Rotary Actuator And Having An Isolated Voice Coil Motor filed in the Korean Industrial Property Office on 18 Dec. 1994, and assigned Ser. No. 28,428/1993.
Background of the Invention
The present invention relates to a hard disk drive used as an auxiliary memory of a computer, and more particularly to a hard disk drive using a rotary actuator for positioning a voice coil motor with the voice coil motor housed in a section of the hard disk drive isolated from a section of the hard disk drive housing the hard disk.
Typically, a hard disk drive (HDD) as a computer auxiliary memory includes a disk rotated at a high speed by a spindle motor and an actuator with a magnetic head for writing and reading data recorded in a track of the disk. The actuator is installed to turn on its pivot. A magnetic head is installed at one end portion of the actuator, and a bobbin and a coil constituting a voice coil motor are installed at the other portion thereof. If the power, i.e., voice coil current, is applied to the coil, the actuator rotates around its pivot. Then, the magnetic head moves along and adjacent to the surface of the disk, thereby enabling writing or reading of data on the track of the disk.
Under such a state, when the disk is rotated at a high speed by a spindle motor, the magnetic head is separated by a minute interval from the surface of the disk and moves while maintaining the minute interval.
In an actuator of a conventional hard disk driver, because the bobbin and the coil which drive the actuator are disposed in the interior portion of the hard disk driver, if a defect occurs in the bobbin and the coil, the cover of the hard disk drive has to be opened in order to correct the defect. At this time, however, in order to minimize the risk of contamination and introduction of foreign matter into the hard disk drive, the cover has to be opened only in a clean room since the interior portion of the hard disk drive body requires a high degree of cleanliness of both its environment and ambient air.
U.S. Pat. No. 4,700,246 by Luoma et al. entitled DISK DRIVE WITH ISOLATED VOICE COIL MOTOR MAGNET, discloses a disk storage device having a sealed enclosure in which the heads and disks are located. The voice coil motor is positioned exterior to the sealed enclosure. Instead of a pivoting actuator, however, Luoma et al.'s device uses a linear or horizontally movable actuator such as that disclosed in U.S. Pat. No. 4,439,699 by Brende et al. entitled LINEAR MOVING COIL ACTUATOR.
Summary of the Invention
It is therefore an object of the present invention to provide a hard disk drive.
It is another object to provide a hard disk drive that prevents a magnetic head or a disk as recording media thereof from being adversely affected by gas generated from an adhesive such as a bonding agent used when a coil is attached to a bobbin.
It is another object to provide a hard disk drive which can observe a bobbin and a coil at an exterior portion thereof in an environment of contaminated air, when a defect occurs in the bobbin and the coil, by providing access to the bobbin and coil without exposing the hard disk to the contaminated air when constructing or repairing a voice coil motor.
It is still object of the present invention to provide a hard disk drive which can be repaired or re-worked outside of a clean room.
According to an aspect of the present invention, there is provided a hard disk drive in which a bobbin, a coil, yokes and magnets as components of a voice coil motor are installed in an exterior portion of the hard disk driver.
Brief Description of the Drawings
These and other objects, features, and advantages of the present invention are better understood by reading the following detailed description of the invention, taken in conjunction with the accompanying drawings. In the drawings, it should be noted that like elements represent like symbols or reference numerals, wherein:
FIG. 1 is an abstract cross-sectional view illustrating main component parts of a conventional hard disk drive; and
FIG. 2 is a cross-sectional view illustrating main component parts of a hard disk constructed drive according to principles of the present invention.
Detailed Description of the Preferred Embodiment
Turning now to the drawings, in as shown in FIG. 1, a pivot 34 for assembling the actuator is fixed by a screw 36 on the bottom surface of a base 32 defining the boundary between the interior and exterior portions of the hard disk driver. A ring-shaped pivot housing 38 is inserted onto the pivot 34 so that the pivot housing 38 can be rotated. The actuator is installed in the pivot housing 38. An E-shaped block 40 is located at one portion of the actuator and a bobbin 41 and a coil 42 are installed for driving the actuator itself at the other portion thereof. The coil 42 is attached to the bobbin 41 by an adhesive such as a bond. Yokes 44 with a magnet 46 are respectively installed on the upper and bottom portions of a position separated from the bobbin 41 and the coil 42. A cover 48 is fixed to the base 32. In the conventional hard disk drive constructed as represented by FIG. 1, if the power is applied to the coil 42 according to an electric signal, the actuator turns on its pivot 34 by electromagnetic force induced to the coil 42. As previously discussed, in such a conventional hard disk driver the bobbin and the coil which drive the actuator are disposed in the interior portion of the hard disk driver.
In a hard disk drive constructed according to the present invention, as shown in FIG. 2, a housing 14, defining the boundary between the interior and exterior portions, or chambers, of the hard disk drive, is comprised of three portions, i.e., a front portion, middle portion and rear portion, the middle portion having a pivot housing 16 installed therein for insertion of a pivot 18, wherein the pivot 18 extends from the interior chamber of the hard disk drive to the exterior chamber of the hard disk drive through the pivot housing 16. A recording medium (not shown) is installed in the interior chamber of the hard disk drive.
The pivot housing 16 is assembled to rotate the pivot 18. An E-shaped block 20, also known as an actuator arm, for installing head gimbals (not shown), is attached to a first portion of the pivot 18, the first portion being positioned at the interior chamber of the hard disk drive. A bobbin 21 and a coil 22 constituting a voice coil motor are attached to a second portion of the pivot 18, the second portion being positioned at the exterior chamber of the hard disk drive. Magnetic heads (not shown) are installed on the head gimbals.
Yokes 24 with magnets 26, further constituting the voice coil motor, are respectively disposed between the front portion of housing 14 and a base 15, wherein the magnets 26 are separated by a predetermined distance from the bobbin 21 and the coil 22.
A cover 12 is fixed to the front end portion of the housing 14 in order to close the interior chamber of the hard disk drive. A base 15, which is easily opened and closed, is positioned to abut the rear portion of the housing 14 adjacent to the second portion of pivot 18. The front portion of housing 14 in combination with the base 15 enclose the components of the voice coil motor for protecting the bobbin 21, coil 22, yokes 24 and magnets 26. The components of the voice coil motor are easily accessible when the base is opened. Further, a first one of the yokes may be attached to the front portion of the housing 14, and a second one of the yokes may be attached to the base 15. Accordingly, when the base is opened the second one of the yokes and its corresponding magnet are moved away from the bobbin 21 and coil 22 to give easy access to the bobbin 21 and coil 22.
In an actuator of the hard disk drive constructed according to the present invention, as mentioned above, if the power is applied to the coil 22 in accordance with an electric signal, the pivot 18 of the actuator rotates at the pivot housing 16 by electromagnetic force induced to the coil 22. Thereby, the E-shaped block 20, attached at the first portion of pivot 18, rotates or pivots to move the magnetic heads along a predetermined path adjacent to the magnetic recording medium. The magnetic heads are separated by a minute interval from the surface of the disk, wherein the minute interval between each head and the recording medium is maintained by an air current generated when the recording medium rotates.
As can be appreciated from the foregoing description, there is provided a hard disk drive constructed according to the present invention which prevents a magnetic head or a disk as recording media thereof from being contaminated, e.g., by gas generated from, for example, a bonding adhesive used when a coil is attached to a bobbin, since a bobbin, a coil, yokes and magnets as components of a voice coil motor are installed in an exterior chamber of the hard disk drive. Further, there is provided a hard disk drive which positions a bobbin, a coil, yokes and magnets in an exterior chamber thereof, and when a defect, for example, vibration arises in the components comprising the voice coil motor those components can be re-worked without exposing the disks and heads in the interior chamber, thus obviating a need to enter a clean room.