Abstract:
A covering device of a hard disk drive including a spindle motor having a rotating shaft for rotating a disk, an actuator pivoting about a pivot shaft and having at its distal end a head for reading/writing data while pivoting over the disk, a base for mounting the spindle motor and the actuator thereon, and a cover locked to the base and made of plastic. The covering device comprises at least one thin plate attached to the cover such that it is coaxially arranged with the rotating shaft and/or the pivot shaft, for dampening vibration and noise transferred from around the rotating shaft and/or the pivot shaft to the cover. In one embodiment, the thin plate contains slits to more effectively dampen noise and vibrations generated from the spindle motor and the actuator. In another embodiment, the thin plate for the actuator has the same shape as the operating area of the actuator and contains ruffles to further dampen noise and vibrations generated from the pivot shaft of the actuator.

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for Covering Device of Hard Disk Drive earlier filed in the Korean Industrial Property Office on Apr. 11, 1998 and there duly assigned Serial No. 12940/1998. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hard disk drive, and more particularly to a covering device of a hard disk drive, which is assembled to a base of the hard disk drive. 
     2. Description of the Related Art 
     Generally, a hard disk drive performing a function of an auxiliary memory is regarded as an important element of a computer. High capacity of a hard disk drive through high density recording is considered as an unavoidable factor in a multimedia environment of modem times. According to this, there is keen competition in the art of a hard disk drive, to occupy high ground where the situation of high capacity can be met by producing a new head and media through more innovative technical development. 
     A hard disk drive is a precise mechatronics product which has electronic parts and mechanical parts. The hard disk drive being used as one of auxiliary memories serves to record and reproduce information to and from a disk having magnetic susceptibility by transmitting a digital signal to a head which functions as an electromagnet. 
     However, the cover of the hard disk drive of the related art suffers from defects in that since the cover of the hard disk drive is manufactured by aluminum die casting, dimensional precision is deteriorated, and a post-process for removing a burr created when the cover is die-casted is additionally needed. 
     Further, since the separate coating must be applied to the cover after the aluminum die casting is completed, a high grade cleansing procedure has to be provided, which in turn increases manufacturing cost. 
     Also, the cover manufactured by die casting aluminum or press working a aluminum plate amplifies the vibration transferred thereto from the rotating shaft of the spindle motor and/or the pivot shaft of the actuator, thereby to boost vibration transmissibility. To overcome this problem, although a damper is used between the cover and the rotating shaft and/or the pivot shaft, since bond is used, outgasing is caused and manufacturing cost is increased. 
     In addition, even in the case that the cover is made of plastic according to the related art, vibration and noise generated when the spindle motor is rotated and the actuator is pivoted, are not sufficiently dampened, and rigidity thereof is reduced. Furthermore, since the cover is locked to the base by screws made of stainless steel, plastic particles are created and flowed into the hard disk drive when the screws are passed through locking holes defined in the cover. This creation of plastic particles and the inflow thereof into the hard disk drive severely diminishes reliability of the hard disk drive. 
     U.S. Pat. No. 5,483,397 for a Damping Configuration For Improved Disk Drive Performance to Gifford et al discloses a viscoelastic damper positioned within a hard disk drive enclosure in contact with the top cover of the disk enclosure and the top of the spindle shaft. However, the damper forms the shape of a solid washer. I have not seen the use of slits in a washer or a damper to more effectively reduce the noise and vibrations created during use of a hard disk drive. Also, I have not seen a damper for the pivot shaft of the actuator that is in the shape of the operating area of the actuator. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made in an effort to solve the problems occuring in the related art, and a primary object of the present invention is to provide a covering device of a hard disk drive, which can minimize vibration and noise generated when a spindle motor or an actuator is rotated. 
     Another object of the present invention is to provide a covering device of a hard disk drive, which can reduce manufacturing cost and improve productivity. 
     Still another object of the present invention is to provide a covering device of a hard disk drive, which can prevent unwanted plastic particles from being produced at a contact area between a cover and a base or when a screw is initially passed through a locking hole and hinder the inflow of the unwanted plastic particles into the hard disk drive. 
     It is yet another object to provide a covering device for a hard disk drive in the shape of a washer having slits extending radially from the outer radius of the washer inward in order to more effectively absorb the vibrations and noise created by the actuator and the spindle motor during operation of a hard disk drive. 
     It is still yet another object to produce a damper that attaches to the cover of a hard disk drive in the shape of the operating area of the actuator for positioning above the actuator, the damper containing repeating depressions and prominences in the form of a ruffle to reduce noise and vibrations generated by the actuator. 
     In order to achieve the above object, according to the present invention, there is provided a covering device of a hard disk drive including a spindle motor having a rotating shaft for rotating a disk, an actuator pivoting about a pivot shaft and having at its distal end a head for reading/writing data while pivoting over the disk, a base for mounting the spindle motor and the actuator thereon, and a cover locked to the base and made of plastic, the covering device comprising: at least one thin plate attached to the cover such that it is coaxially arranged with the rotating shaft and/or the pivot shaft, for dampening vibration and noise transferred from around the rotating shaft and/or the pivot shaft to the cover. The thin plate contains slits in it to more effectively reduce vibrations and noise generated from the hard disk drive. In a second embodiment, the thin plate for the actuator is in the shape of the operating area of the actuator and contains ridges and troughs throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
     FIG. 1 an exploded perspective view illustrating a hard disk drive according to the related art; 
     FIGS. 2 through 2B together form a partially enlarged cross-sectional view illustrating a structure of the hard disk drive of FIG. 1; 
     FIG. 3 is a perspective view illustrating an independent appearance of a cover of the hard disk drive of FIG. 1; 
     FIGS. 4 and 4A together form a perspective view illustrating a cover of a hard disk drive wherein a first thin plate is attached to the cover in accordance with a first embodiment of the present invention; 
     FIG. 5 is a perspective view illustrating an independent appearance of the first thin plate of FIG.4; 
     FIG. 6 is a partial cross-sectional view illustrating an installation structure of the first thin plate of FIG. 4; 
     FIGS. 7 through 7B together form a partially enlarged cross-sectional view illustrating a state in which the first thin plate is attached to the hard disk drive; 
     FIG. 8 is a perspective view illustrating a cover of a hard disk drive wherein a second thin plate is attached to the cover in accordance with a second embodiment of the present invention; 
     FIG. 9 is a plan view of FIG. 8; 
     FIG. 10 is a bottom view of FIG. 8; 
     FIG. 11 is a perspective view illustrating an independent appearance of the second thin plate of FIG. 8; and 
     FIG. 12 is a partially broken away and sectioned perspective view illustrating a state in which the second thin plate is attached to the hard disk drive. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2 through  2 B, there is illustrated a hard disk drive according to the related art. 
     As best shown in FIG. 1, the hard disk drive according to the related art includes a base  100 , a cover  200  locked to the base  100 , and a sealing gasket  150  intervened between the base  100  and the cover  200 . 
     In the hard disk drive, an actuator  20  pivoting around a pivot shaft  160  is mounted to the base  100 , and at least one disk rotating at high rotational velocity is mounted to a hub of a spindle motor  10 . 
     The drawing reference numeral A 1  represents a rotational axis of the spindle motor  10 , and the drawing reference numeral A 2  represents a pivot axis of the pivot shaft  160  of the actuator  20 . 
     As shown in FIGS. 1 and 3, the cover  200  of the hard disk drive according to the related art is locked to the base  100  at eight supporting points by screws S 1  through S 4 . In other words, the cover  200  is formed at its four corner portions with four locking holes  110 , respectively, through which four screws S 1  are to be passed to lock the cover  200  to the base  100 . Also, the cover  200  is formed at middle portions of its two long sides with two locking holes  120 , respectively, through which two screws S 2  are to be passed to lock the cover  200  to the base  100 , respectively. Further, the cover  200  is formed with two locking holes  130  and  140  in positions which correspond to the pivot axis of the pivot shaft  160  of the actuator  20  and the rotational axis of the spindle motor  10 , respectively. Two screws S 4  and S 3  are passed through the locking holes  130  and  140  to lock the cover  200  to the pivot shaft  160  of the actuator  20  and the rotating shaft of the spindle motor  10 , respectively. 
     At this time, the cover  200  according to the related art is manufactured by die casting of aluminum of about 120 g. Moreover, a lower surface of the cover  200  is applied with a coating for dampening vibration and noise generated when the spindle motor  10  is rotated at high rotational velocity and the actuator  20  is pivoted around the pivot shaft  160  and for resisting against corrosion of the base  100  and the cover  200 . 
     FIGS. 4 and 4A together form a perspective view illustrating a cover of a hard disk drive wherein a first thin plate is attached to the cover in accordance with a first embodiment of the present invention. FIG. 5 is a perspective view illustrating an independent appearance of the first thin plate of FIGS. 4 and 4A. FIG. 6 is a partial cross-sectional view illustrating an installation structure of the first thin plate of FIGS. 4 and 4A. 
     As shown in FIGS. 4 and 4A, a cover  400  of a hard disk drive of the present invention is made of plastic, and is assembled to the base  100  at predetermined positions by a plurality of screws in a longitudinal direction. 
     The cover  400  is formed at its four corner portions with four locking holes  410 , respectively, through which four screws are to be passed in the longitudinal direction to lock the cover  400  to the base  100 . Also, the cover  400  is formed at middle portions of its two long sides with two locking holes  420 , respectively, through which two screws are to be passed in the longitudinal direction to lock the cover  400  to the base  100 , respectively. Further, the cover  400  is formed with a pair of openings  404  in positions which correspond to the rotating shaft of the spindle motor  10  and the pivot shaft  160  of the actuator  20 , respectively. 
     According to the present invention, a pair of first plates  40  are provided to the pair of openings  404  such that their axes are in line with the rotational axis A 1  of the spindle motor  10  and the pivot axis A 2  of the pivot shaft  160  of the actuator  20 , respectively, to dampen vibration and noise which are generated when the spindle motor  10  is rotated and the actuator  20  is pivoted around the pivot shaft  160 . When the cover  400  is manufactured, the pair of first plates  40  are attached to cylindrical walls of the cover  400 , which define the pair of openings  404 , respectively, by insert molding. 
     As shown in FIG. 5, the first plate  40  according to the first embodiment of the present invention is a circular thin plate and is made of stainless steel. Each of the first thin plates  40  has a recessed bottom wall portion  40   a,  a cylindrical side wall portion  40   e  which is integrally formed at its lower end with the bottom wall portion  40   a,  and an outward flange portion  40   d  which is integrally formed at an upper end of the cylindrical side wall portion  40   e.  The recessed bottom wall portion  40   a  has a center opening  40   b  through which a screw is to be passed to lock the cover  400  to the rotating shaft of the spindle motor  10  or to the pivot shaft  160  of the actuator  20 . A plurality of slits  40   c  are formed in the outward flange portion  40   d  such that they extend radially and are circumferentially spaced apart one from another. Since the vibration and noise due to the high rotational velocity of a hard disk drive disperse radially, slits  40   c  in first plate  40  can better absorb the vibration and noise more effectively than if the slits were not present. 
     As shown in FIG. 6, when the pair of first thin plates  40  are insert molded to the cover  400 , the respective outward flange portions  40 d each being formed with the plurality of slits  40   c,  are embedded into the cylindrical walls of the cover  400 , which define the pair of openings  404 , respectively, and the recessed bottom wall portions  40   a  project downward to some extent beyond a lower surface  402  of the cover  400 . 
     A pair of circular recesses  403  to each of which a sealing label is to be attached, are formed around the pair of openings  404  on an upper surface of the cover  400 , respectively. The pair of first thin plates  40  are arranged below the pair of circular recesses  403 , respectively. Further, as described above, the bottom wall portions  40   a  of the first thin plates  40  project downward to some extent beyond the lower surface  402  of the cover  400 . 
     As shown in FIGS. 7 through 7B, the first thin plates  40  which are insert molded to the cover  400 , are fastened to the rotating shaft of the spindle motor  10  and the pivot shaft  160  of the actuator  20  by the screws S 3  and S 4  which pass through the center openings  40   b,  respectively. At this time, since the screws S 3  and S 4  and the first thin plates  40  are made of the same material, outside particles are prevented from flowing into the hard disk drive. This is because a contact between elements which are made of the same material renders an excellent sealing effect. 
     Moreover, due to the fact that vibration and noise generated when the rotating shaft of the spindle motor  10  is rotated and the pivot shaft  160  of the actuator  20  is pivoted are absorbed by the first thin plates  40  to be transferred to the cover  400 , the vibration and noise are dampened by the plastic cover  400 . 
     FIG. 8 is a perspective view illustrating a cover of a hard disk drive wherein a second thin plate is attached to the cover in accordance with a second embodiment of the present invention. FIG. 9 is a plan view of FIG.  8 . FIG. 10 is a bottom view of FIG.  8 . 
     A cover  800  according to the present embodiment is formed at its four corner portions with four locking holes  810 , respectively, through which four screws are to be passed in the longitudinal direction to lock the cover  800  to a base. Also, the cover  800  is formed at middle portions of its two long sides with two locking holes  820 , respectively, through which two screws are to be passed in the longitudinal direction to lock the cover  800  to the base, respectively. 
     As shown in FIGS. 8 through 10, the first thin plate  40  according to the first embodiment is insert molded to the cover  800  such that its axis is in line with the rotational axis A 1  of the spindle motor  10 , and a second thin plate  80  according to this second embodiment is provided over an operating area of the actuator  20 . The second thin plate  80  has a configuration which is different from that of the first thin plate  40 . 
     Upon operation of the hard disk drive, when the rotating shaft of the spindle motor  10  is rotated, vibration and noise are generated from around the rotational axis A 1 , and when the actuator  20  is pivoted around the pivot axis A 2 , vibration and noise are generated from the operating area of the actuator  20 . 
     In other words, the operating area of the actuator  20  which is pivoted around the pivot axis A 2  has a sector-shaped contour, and according to this, the second thin plate  80  is manufactured to have a sector-shaped configuration to be insert molded to the cover  800 . 
     The second thin plate  80  is provided for dampening the vibration and noise generated from the operating area having the sector-shaped contour when the actuator  20  is pivoted around the pivot axis A 2 . The second thin plate  80  is made of the same material as the first thin plate  40 . When the second thin plate  80  is locked to the pivot shaft  160  of the actuator  20  by a screw, since the screw and the second thin plate  80  are made of the same material, satisfiable sealing effect is obtained. This is because a contact between elements which are made of the same material renders an excellent sealing effect. 
     As shown in FIGS. 11 and 12, the second thin plate  80  which is insert molded to the cover  800 , has a plurality of prominences  80   d  and depressions  80   c  which are alternately formed such that they are positioned above the operating area of the actuator  20  for dampening vibration and noise generated from the operating area. The plurality of prominences  80   d  and depressions  80   c  effectively absorb the vibration and noise after the second thin plate  80  is insert molded to the cover  800 . 
     The second thin plate  80  has at its one end a circular bottom wall portion  80   a  having a center opening  80   b  and a cylindrical side wall portion integrally formed at its lower end with the circular bottom wall portion  80   a  and at its upper end with the plurality of prominences  80   d  and depressions  80   c.  The circular bottom wall portion  80   a  and the cylindrical side wall portion are coaxially arranged with the pivot shaft  160  of the actuator  20  for dampening vibration and noise generated from around the pivot shaft  160 . 
     When the cover  800  is assembled to the base, the circular bottom wall portion  80   a  faces the pivot shaft  160  of the actuator  20 , and the plurality of prominences  80   d  and depressions  80   c  face the actuator  20 . In addition, when the second thin plate  80  is insert molded to the cover  800 , the depressions  80   c  are exposed to the outside on the lower surface of the cover  800  and the prominences  80   d  are exposed to the outside on the upper surface of the cover  800 . 
     As a result, the covering device of the present invention has a structure that the thin plates made of a material which is different from that of the cover, are attached to the cover by insert molding, in consideration of transfer directions of vibration and noise generated when the spindle motor and/or the actuator are rotated, to thereby minimize them. 
     Hence, as described above, the covering device of the hard disk drive according to the present invention provides advantages in that since at least one thin plate made of a material which is different from that of a cover, is attached to the cover by insert molding in consideration of transfer directions of vibration and noise generated when a spindle motor and/or a actuator is rotated, the vibration and noise are effectively minimized. Further, according to the present invention, productivity and reliability of the end product are improved. 
     While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but, on the contrary, it is intended to cover various modifications within the spirit and scope of the appended claims.