Patent Publication Number: US-2007115592-A1

Title: Hard disk drive and method of fabricating the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 10-2005-0111997, filed on Nov. 22, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present general inventive concept relates to a hard disk drive, and more particularly, to a voice coil motor (VCM) to fix an upper VCM block and a lower VCM block so that the upper VCM block is disposed at a predetermined position with respect to the lower VCM block in a hard disk drive.  
      2. Description of the Related Art  
      A hard disk drive (HDD), an auxiliary memory device used in a computer system, an MP3 player, and a mobile phone, etc., records data on a disk, i.e., a storage medium, or reproduces the data recorded on the disk using an actuator having a magnetic head. The actuator is mounted on a base member and pivots clockwise or counterclockwise so that the magnetic head can search a location where data is to be recorded on the disk or a location where the data is recorded in order to reproduce the data. The actuator is driven by an electromagnetic force generated by an interaction between a current input to a voice coil motor (VCM) coil at a rear portion of the actuator and a magnetic field formed by a magnet of the VCM.  
       FIG. 1  is an exploded perspective view partially illustrating a conventional VCM  10 . Referring to  FIG. 1 , the VCM  10  includes a lower VCM block  11  and an upper VCM block  15  separated from each other so that a rear portion of the actuator (not shown) can be interposed between the lower VCM block  11  and the upper VCM block  15 . The lower VCM block  11  is mounted on a base member  1 . At least one combining protrusion  17  is disposed in the upper VCM block  15 , and at least one combining groove  13  is disposed in the lower VCM block  11  to accommodate the combining protrusion  17 . In order to fix the upper VCM block  15  in the lower VCM block  11 , the lower VCM block  11  and the upper VCM block  15  are combined with each other by placing an adhesive  20  in the combining groove  13  and inserting the combining protrusion  17  in the combining groove  13  when assembling the VCM  10 . Reference numeral  5  denotes a crash stopper mounted on the base member  1  so as to restrict a pivot range of the actuator (not shown).  
      However, it is difficult to automatize an operation of assembling the VCM  10  using the adhesive  20  for mass production and mounting the actuator (not shown) in the hard disk drive. Consequently, productivity of the hard disk drive is low.  
     SUMMARY OF THE INVENTION  
      The present general inventive concept provides a hard disk drive (HDD) in which an upper voice coil motor (VCM) block of a VCM is fixed without using an adhesive, and a method of fabricating the same.  
      The present general inventive concept also provides a hard disk drive (HDD) in which an upper voice coil motor (VCM) block of a VCM is fixed using a crash stopper to restrict a pivot range of an actuator, and a method of fabricating the same.  
      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 hard disk drive comprising a base member and a cover member of which outer circumferences are combined with each other to form an internal space, an actuator mounted on the base member to be pivoted, a voice coil motor (VCM) including a lower VCM block and an upper VCM block separated from each other so that a rear portion of the actuator is interposed therebetween, and a crash stopper to collide with the rear portion of the actuator and to restrict a pivot range of the actuator, and having an upper-end to be accommodated in the upper VCM block to prevent a location change of the upper VCM block caused by an external disturbance.  
      The crash stopper may include a pin having an upper-end to be accommodated in the upper VCM block, and a damper to surround an outer circumference of the pin.  
      The upper and lower VCM blocks each may include a magnet and a yoke to support the magnet, and a through hole formed in the yoke of the upper VCM block to accommodate the upper-end of the pin.  
      The upper end of the pin may include a first chamfer formed on the upper-end of the pin, and the through hole of the upper VCM block may include a second chamfer formed at a lower side of the through hole to correspond to the first chamfer of the pin.  
      The crash stopper may be inserted into and mounted on the base member.  
      The crash stopper may restrict a clockwise or counterclockwise pivot range of the actuator.  
      The upper VCM block may include at least one guide protrusion, and the lower VCM block may include at least one guide groove to accommodate the guide protrusion so that the upper VCM block is arranged with respect to the lower VCM block.  
      The upper VCM block may include at least one spacer supported on the lower VCM block so that a distance between the upper VCM block and the lower VCM block can be maintained.  
      The hard disk drive may include a pressing pad formed of an elastic material and attached to an inside of the cover member to prevent separation of the lower VCM block and the upper VCM block by pressing the upper VCM block toward the base member.  
      The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a method of fabricating a hard disk drive, the method comprising installing a voice coil motor (VCM) including a lower VCM block and an upper VCM block on a base member, mounting an actuator on the base member to be pivoted so that a rear portion of the actuator is interposed between the lower VCM block and the upper VCM block, forming a crash stopper to collide with the rear portion of the actuator and to restrict a pivot range of the actuator to protrude from the lower VCM block, and combining a cover member with an outer circumference of the base member by disposing an upper-end of the crash stopper to be accommodated in the upper VCM block to prevent a location change of the upper VCM block caused by an external disturbance.  
      The installing of the VCM and mounting of the actuator may include disposing the lower VCM block on the base member, mounting the actuator on the base member so that the rear portion is disposed on the lower VCM block, and disposing the upper VCM block on the lower VCM block and the rear portion of the actuator.  
      The forming of the crash stopper may include forming the crush stopper to protrude from the lower VCM block before disposing the upper VCM block, and the combining of the cover member and the base member may include disposing the upper VCM block on the lower VCM block and the rear portion of the actuator so that the upper-end of the crash stopper is accommodated in the upper VCM block.  
      The disposing of the upper VCM block on the lower VCM block may include inserting and mounting the crash stopper into and on the base member. The combining of the cover member and the base member may include attaching a pressing pad to an inside of the cover member and combining the cover member with the outer circumference of the base member so that the pressing pad presses the upper VCM block toward the base member to prevent the separation of the lower VCM block and the upper VCM block.  
      The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a hard disk drive including a base member, a cover member to form an internal space with the base member, an actuator mounted on the base member to be disposed in the internal space, a voice coil motor (VCM) including a lower VCM block and an upper VCM block which are separated from each other so that a rear portion of the actuator is interposed therebetween, and a crash stopper formed on one of the base member and the lower VCM block and coupled to the upper VCM block to restrict a movement of the actuator and to prevent a movement of the upper VCM block with respect to the one of the base member and the lower VCM block.  
      The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a hard disk drive including a base member, a cover member to be assembled with the base member, a voice coil motor (VCM) including a lower VCM block disposed on the base member and an upper VCM block disposed to be spaced-part from the lower VCM block by a distance, an actuator having a rear portion disposed between the lower VCM block and the upper VCM block, and a crash stopper having a pin to protrude from one of the base member and the lower VCM block and to be received by the upper VCM block to prevent a movement of the upper VCM block with respect to the one of the base member, and a damper disposed around the pin to restrict a movement of the actuator.  
      The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a hard disk drive including a base member, a cover member to be assembled with the base member, a voice coil motor (VCM) including a lower VCM block and an upper VCM block, an actuator disposed between the lower VCM block and the upper VCM block, a crash stopper to protrude from one of the base member and the lower VCM block to restrict a movement of the actuator, and having a distal end to be received by the upper VCM block to prevent a movement of the upper VCM block with respect to the base member, a pad disposed between the upper VCM block and the cover member, and a space disposed to maintain a distance between the upper VCM block and the lower VCM block. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      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:  
       FIG. 1  is an exploded perspective view partially illustrating a conventional voice coil motor (VCM);  
       FIG. 2  is a plane view illustrating a hard disk drive (HDD) according to an embodiment of the present general inventive concept;  
       FIG. 3  is an exploded perspective view partially illustrating a VCM of the hard disk drive illustrated in  FIG. 2 ; and  
       FIG. 4  is a cross-sectional view illustrating the VCM taken along line IV-IV of  FIG. 3 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      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.  
       FIG. 2  is a plane view illustrating a hard disk drive (HDD)  100  according to an embodiment of the present general inventive concept. Referring to  FIG. 2 , the hard disk drive (HDD)  100  includes a spindle motor  112 , a disk  110  mounted on the spindle motor  112 , an actuator  120  that moves a magnetic head to record and reproduce data on or from a predetermined location of the disk  110 , and a voice coil motor (VCM)  140  to pivot the actuator  120  inside a base member  101  and a cover member  105  (see  FIG. 4 ), which are combined with each other. The base member  101  and the cover member  105  may be formed in a single monolithic body. The actuator  120  includes a swing arm  122  combined with a pivot center  121  disposed on the base member  101  of the HDD  100  to be rotated, and a suspension  123  installed on a front-end of the swing arm  122  to support a slider  125  which is mounted on the swing arm  122  to be elastically biased toward a surface of the disk  110 . A VCM coil  135  is wound around a rear portion  130  of the actuator  120 .  
      The VCM  140  includes a lower magnet  142  and an upper magnet  152  (see  FIG. 3 ) which are disposed below and above the VCM coil  135 , respectively, to face the VCM coil  135 . The lower magnet  142  and the upper magnet  152  are attached to and supported by a lower yoke  143  and an upper yoke  153  (see  FIG. 3 ). The lower magnet  142  and the upper magnet  152  are spaced-apart from each other to accommodate the rear portion of the actuator  120  (i.e., the voice coil  135 ). The lower magnet  142  and the lower yoke  143  constitute a lower VCM block  141 , and the upper magnet  152  and the upper yoke  153  constitute an upper VCM block  150  (see  FIG. 3 ). The lower VCM block  141  and the upper VCM block  150  are assembled with the rear portion  130  of the actuator  120  movably interposed therebetween, thereby forming the VCM  140   
      According to the Flemming&#39;s left hand rule, the actuator  120  pivots with respect to the pivot center  121  by an electromagnetic force generated by an interaction between a current which is input to the VCM coil  135  and a magnetic field formed by the upper and lower magnets  142  and  152 . When the HDD  100  is turned on and the disk  110  starts rotating, the actuator  120  pivots counterclockwise, and the slider  125 , on which the magnetic head is mounted, moves onto a recording surface of the disk  110 . If the HDD  100  is turned off and the disk  110  stops rotating, the actuator  120  pivots clockwise and the slider  125  deviates from surface of the disk  110 . In this case, the slider  125  is parked on a ramp  170  disposed on an outer circumference of the disk  110 . Specifically, an end-tap  127  formed on the front-end of the suspension  123  is lifted on the ramp  170  and parked thereon. It is possible that the slider  125  may rest on a parking zone inside the disk  110  in a parking condition mode.  
      The HDD  100  includes an actuator latch  172 . When the HDD  100  stops operating, and the disk  110  stops rotating and the slider  125  is parked on the ramp  170 , the actuator latch  172  interferes with a hook  132  of the rear portion  130  of the actuator  120  and locks the actuator  120 . Thus, the slider  125  and the disk  110  are prevented from being damaged by an external disturbance. A circulation filter  175  is disposed in one corner of the base member  101  adjacent to an outer circumference of the disk  110 . The circulation filter  175  filters foreign substances such as particles contained in an air flow induced by high-speed rotation of the disk  110 .  
      The HDD  100  includes a crash stopper  160  which restricts a counterclockwise pivot range of the actuator  120 . The actuator  120  that pivots counterclockwise with respect to the pivot center  121  stops moving when a crash stopper collision part  133  formed in the rear portion  130  of the actuator  120  collides with the crash stopper  160 . As such, the actuator  120  and the spindle motor  112  are prevented from colliding with each other because of the external disturbance.  
       FIG. 3  is an exploded perspective view partially illustrating the VCM  140  of the HDD  100  illustrated in  FIG. 2 , and  FIG. 4  is a cross-sectional view illustrating the VCM  140  taken along line IV-IV of  FIG. 3 .  
      Referring to  FIGS. 3 and 4 , the crash stopper  160  includes a pin  161  and a damper  163  which surrounds an outer circumference of the pin  161 . The pin  161  is formed of a metal such as stainless steel, and the damper  163  is formed of a shock-absorbing material, such as a rubber, to absorb a shock when colliding with the crash stopper collision part  133  (see  FIG. 2 ). The crash stopper  160  is inserted and mounted on the base member  101 , and protrudes from the lower VCM block  141  toward the upper VCM block  150 . The crash stopper  160  may have a height higher than a sum of a thickness of the lower yoke  143  of the lower VCM block  140  and a distance between the upper yoke  153  of the upper VCM block  150  and the lower yoke of the lower VCM block  141 , so that an upper end of the crash stopper  160  is inserted into the upper yoke  153  of the upper VCM block  150 . However, the crash stopper  160  of the present embodiment may be formed in one body with the base member  101  or mounted on the lower VCM block  141 .  
      An upper-end of the pin  161  extends toward the upper VCM block  150  and is accommodated in the upper yoke  153 . A through hole  155  is formed in the upper yoke  153  to accommodate the upper-end of the pin  161 . The upper-end of the pin  161  may be formed with a first chamfer  162  having an edge gently processed so that the upper-end of the pin  161  can be easily accommodated in the through hole  155 . The upper yoke  153  of the upper VCM block  150  may include a second chamfer  156  formed at a lower side of the through hole  155  and having an edge gently processed to correspond to the first chamfer  162  of the pin  161 . At least one of the first chamfer  162  and the second chamfer  156  may have a shape of a frustum of a cone of which end area becomes smaller as being closer to the upper VCM block  150 .  
      The HDD  100  has a small size, and the disk  110  has a diameter of equal to or less than 2.5 inch. The HDD  100  is assembled using a top-down method using an automation production facility to increase productivity. In the top-down method, the lower VCM block  141  is disposed on the base member  101 , the actuator  120  is mounted on the base member  101  so that the rear portion  130  of the actuator  120  can be disposed on the lower VCM block  141 , and the upper VCM block  150  is disposed on the lower VCM block  141  and the rear portion  130  of the actuator  120 .  
      In order to arrange the upper VCM block  150  with respect to the lower VCM block  141  in the assembling procedure, the upper VCM block  141  includes at least one guide protrusion  158 , and the lower VCM block  150  includes at least one guide groove  144  to accommodate the corresponding guide protrusion  158 . Another chamfer may also be formed in the guide groove  144  so that the guide protrusion  158  can easily come into the guide groove  144 . The lower VCM block  141  and the upper VCM block  150  do not need to be combined with each other and thus, an adhesive may not be used in the HDD.  
      The lower magnet  142  and the upper magnet  152  of the VCM  140  are separated from each other by a predetermined distance so that the rear portion  130  of the actuator  120  can be interposed therebetween. The upper VCM block  150  includes at least one spacer  157  directly supported on the lower yoke  143  so that the distance can be maintained.  
      To improve productivity, reduce production cost, and reduce the weight of the HDD  100 , the lower VCM block  141  and the upper VCM block  150  may not be combined with each other using a screw. The HDD  100  includes a pressing pad  107  formed of an elastic material attached to an inside of the cover member  105 . The pressing pad  170  may be disposed between an inside surface of the cover member  105  and an upper surface of the yoke  153  of the upper VCM block  150 . When the cover member  105  is combined with the base member  101 , since the pressing pad  107  presses the upper yoke  153  of the upper VCM block  150  toward the base member  101 , the separation of the lower VCM block  141  and the upper VCM block  150  is suppressed.  
      The upper-end of the pin  161  of the crash stopper  160  fixed on the base member  101  is accommodated in the upper VCM block  150 , the guide protrusion  158  of the upper VCM block  150  is accommodated in the guide groove  144  of the lower VCM block  141 , and the upper VCM block  150  is pressed by the pressing pad  107  attached to the cover member  105  so that it cannot be separated from the lower VCM block  141 . Thus, even when a shock is applied to the HDD  100 , the position of the upper VCM block  150  does not change with respect to the base member  101  or the lower VCM block  141 . A length of the damper  163  may be a distance between the base member  101  and a lower surface of the upper yoke  153  of the upper VCM block  150  in a direction of a longitudinal direction of the pin  161 . It is possible that the length may be a distance between an upper surface of the lower yoke of the lower VCM block  141  and the lower surface of the upper yoke of the upper VCM block  150 . It is also possible that the length of the damper  163  is longer than the distance before the cover member  105  is assembled with the base member  101 , but is shortened with respect to the pin  161  by the distance since the damper  163  is an elastic material, when the cover member  105  is assembled with the base member  101 .  
      A method of fabricating the HDD  100  will now be described with reference to  FIGS. 2 through 4 . As described above, the HDD  100  is assembled using the top-down method using an automation productivity facility. First, the spindle motor  112  is mounted on the base member  101  and the disk  110  is fixedly combined with the spindle motor  112 . In addition, the ramp  170  is mounted on the base member  101  and the crash stopper  160  is inserted on the base member  101 . Next, the lower VCM block  141  is disposed on the base member  101 . After that, the actuator  120  is mounted on the base member  101  so that the rear portion  130  of the actuator  120  is located on the lower VCM block  141 , and the actuator latch  172  is installed. Next, the upper VCM block  150  is disposed on the lower VCM block  141  and the rear portion  130  of the actuator  120 .  
      When the guide protrusion  158  of the upper VCM block  150  is disposed on the guide groove  144  of the lower VCM block  141 , and the upper VCM block  150  is disposed on the lower VCM block  141  and the rear portion  130  of the actuator  120 , the guide protrusion  158  is inserted in the guide groove  144 , and at the same time, the pin  161  of the crash stopper  160  protruding in an upward direction toward the upper VCM block  150  is inserted through the through hole  155  of the upper VCM block  150 .  
      Next, the circulation filter  175  is mounted to an outer perimeter of the disk  110 . The cover member  105  is combined with the base member  101 . The pressure pad  107  inside the cover member  105  presses the upper VCM block  150  toward the base member  101  to prevent the separation of the upper VCM block  150  and the lower VCM block  141 .  
      As described above, in the HDD according to the present embodiment, the upper-end of the crash stopper prevents a location change of the upper VCM block caused by an external disturbance such that malfunction and damage of the actuator are prevented.  
      In addition, since an additional fixing unit to fix the upper VCM block with respect to the lower VCM block is not needed, the manufacturing cost of the HDD can be reduced and miniaturization and weight reduction of the hard disk drive are possible.  
      Furthermore, in the method of fabricating the hard disk drive according to the present embodiment, an adhesive may not be used and top-down assembling can be performed using the automation production facility. Thus, assembly productivity can be improved and manufacturing cost can be reduced.  
      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.