Abstract:
There is provided a motor device. A motor device according to an aspect of the invention may include: a stator including a core having a coil wound therearound; a rotor having a magnet facing the core to thereby generate an electromagnetic force involved in interactions therebetween, the rotor rotating a shaft; a sleeve supporting the shaft; and a sleeve housing having a mounting surface to support the core and a protrusion protruding from the mounting surface to prevent a rotation of the core.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of Korean Patent Application No. 10-2009-0132233 filed on Dec. 28, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a motor device and a method of manufacturing the same, and more particularly, to a motor device enhancing economic efficiency by reducing the number of components used therein and a method of manufacturing the same. 
     2. Description of the Related Art 
     In general, a spindle motor, installed inside an optical disc drive, rotates a disk so that an optical pickup can read data recorded on the disk. 
     Small, lightweight, and thin hard disk drivers are now required. In particular, as for ultra-thin, slim spindle motors, used in laptop computers, magnetic circuits have also been reduced in size. Thus, various designs thereof have been developed in order to generate torque high enough to rotate an optical disc and ensure a stable rotation of the optical disc. 
     A motor device may include a shaft supporting a rotary body while the rotary body is rotating, a sleeve receiving the shaft therein, and a holder fixing these components to the inside thereof. 
     Here, cores may be mounted on the upper side of the holder such that the cores face a magnet in order to generate an electromagnetic force. Here, however, the cores may also be rotated by a rotary force exerted by the generated electromagnetic force. 
     Furthermore, since a motor device is manufactured by assembling a plurality of components, a large number of components make it difficult to manufacture a motor device and serve to increase manufacturing costs. Therefore, there is a need for techniques to solve these problems. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a motor device that can reduce the number of components used therein and prevent a rotation of a core and a method of manufacturing the same. 
     According to an aspect of the present invention, there is provided a motor device including: a stator including a core having a coil wound therearound; a rotor having a magnet facing the core to thereby generate an electromagnetic force involved in interactions therebetween, the rotor rotating a shaft; a sleeve supporting the shaft; and a sleeve housing having a mounting surface to support the core and a protrusion protruding from the mounting surface to prevent a rotation of the core. 
     The sleeve housing may be formed integrally with a base plate supporting the stator. 
     The sleeve housing and the base plate may each have a plate-like shape. 
     The protrusion may include a plurality of protrusions provided on the mounting surface. 
     A recess may be formed in the core so that the protrusion is received within the recess. 
     According to another aspect of the present invention, there is provided a method of manufacturing a motor device, the method including: arranging a plate having a plate-like shape under a press jig; and forming a mounting surface to support a core and a protrusion protruding from the mounting surface at the same time by pressing the plate down. 
     The forming of the protrusion may include forming a plurality of protrusions on the mounting surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a partially cut-away perspective view illustrating a motor device according to an exemplary embodiment of the present invention; 
         FIG. 2  is a cross-sectional view illustrating a motor device according to an exemplary embodiment of the present invention; 
         FIG. 3  is a perspective view illustrating a base plate according to an exemplary embodiment of the present invention; 
         FIG. 4  is a partially sectional perspective view illustrating the base plate of  FIG. 3 ; 
         FIGS. 5 and 6  are cross-sectional views illustrating a method of manufacturing a base plate of a motor device according to an exemplary embodiment of the present invention; and 
         FIG. 7  is a partially cross-sectional view illustrating a sleeve housing and a base plate of a motor device according to another exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A motor device and a method of manufacturing the same will be described in more detail with reference to  FIGS. 1 through 6 . Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
     The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. While those skilled in the art could readily devise many other varied embodiments that incorporate the teachings of the present invention through the addition, modification or deletion of elements, such embodiments may fall within the scope of the present invention. 
     In the drawings, the same or like reference numerals will be used throughout to designate the same or like components. 
       FIG. 1  is a partially cut-away perspective view illustrating a motor device according to an exemplary embodiment of the invention.  FIG. 2  is a cross-sectional view illustrating a motor device according to an exemplary embodiment of the invention. 
     Referring to  FIGS. 1 and 2 , a motor device  100  may include a stator  110 , a rotor  120 , a sleeve  130 , and a base plate  150 . 
     The stator  110  is a stationary part that has winding coils  112  generating an electromagnetic force having a predetermined magnitude when power is applied thereto, and a plurality of cores  114  around which the winding coils  114  are wound in a radial manner on the basis of at least one pole. 
     The rotor  120  is a rotating part which is rotatable relative to the stator  110 . Further, the rotor  120  has a rotor case  160 , which is shaped like a cup and has a magnet  122  with an annular shape formed along an outer circumferential surface thereof. The magnet  122  corresponds to the cores  114  at a predetermined interval therebetween. The magnet  122  may be a permanent magnet having magnetic north and south poles magnetized alternately in the circumferential direction to thereby generate a magnetic force having a predetermined magnitude. 
     As shown in  FIG. 1 , the sleeve  130  may be assembled in such a manner that a lower body of the sleeve  130  is pressed and inserted into a sleeve housing  152  of the base plate  150 . Here, the sleeve  130  may refer to a rotation support member that corresponds to the rotor  120  at a predetermined interval therebetween to produce a sliding surface therebetween. 
     A shaft hole  132  may be formed in the sleeve  130  so that the shaft  140  is bound to the sleeve  130  through the shaft hole  132 . A plurality of radial dynamic pressure recesses may be formed into the shaft hole  132 . 
     The shaft  140  is inserted into the shaft hole  132  of the sleeve  130  so that the shaft  140  rotates together with the rotor case  160 . The rotor case  160  is mounted on the upper surface of the shaft  140 . 
     Here, the shaft  140  may extend in the direction of the axis of rotation, and a thrust plate  142  is formed on a bottom surface of the shaft  140  to thereby reduce a frictional force relative to the shaft  140  during rotation. 
     The base plate  150  may have a cavity therein such that the shaft  140  and the sleeve  130  are pressed and inserted in the cavity. Further, the base plate  150  may have a mounting surface  154  such that the cores  114  are mounted on an upper side thereof. 
     A protrusion  156  protrudes upwardly from the mounting surface  154 . The protrusion  156  is located between the cores  114  to thereby prevent the cores  114  from rotating due to electromagnetic force. 
       FIG. 3  is a perspective view illustrating a base plate according to an exemplary embodiment of the invention.  FIG. 4  is a partially sectional perspective view illustrating the base plate of  FIG. 4 . 
     Referring to  FIGS. 3 and 4 , the base plate  150  may be composed of a piece of metal plate that is formed integrally with the sleeve housing  152  formed by pressing such that the sleeve housing  152  protrudes on the basis of the cavity in which the shaft  140  and the sleeve  130  are received. Here, the protrusion  156  is pressed at the same time as the mounting surface  154  is compressed, so that the sleeve housing  152  is formed integrally with the base plate  150  (in the direction of the arrow depicted in  FIG. 4 ). 
     Therefore, since the base plate  150  is manufactured using a piece of metal plate, it is easy to form the base plate  150 . Furthermore, the sleeve housing  152  is formed integrally with the base plate  150  without using a separate holder, thereby reducing the number of components thereof. 
     Here, the number of protrusions  156  is not limited to one, and a plurality of protrusions may be provided according to the designers&#39; intentions. 
     Hereinafter, the components, illustrated in  FIGS. 1 and 2 , will be described in more detail. 
     The rotor case  160  may include a hub  162 , a horizontal portion  164 , and a vertical portion  166 . The hub  162  comes into contact with and extends along the side surface of the shaft  140 . The horizontal portion  164  is formed integrally with the hub  162  while a disk D is mounted on the horizontal portion  164 . The vertical portion  166  is bent perpendicularly downward from the horizontal portion  164 . 
     Here, the horizontal portion  164  forming an upper surface of the rotor case  160  may be level to thereby prevent the disk D from being inclined when the disk D is mounted. A buffer portion  158  may be formed on the horizontal portion  164  such that the buffer portion  158  comes into contact with a bottom surface of the disk D. The buffer portion  158  may be formed of rubber. 
     Therefore, the motor device according to this embodiment is engaged with the shaft  140  and rotates together with the shaft  140 , and also includes the rotor case  160  to support a disk to be mounted thereon. Thus, as compared with a structure having a holder assembled to a shaft and a case mounted on the holder, the motor device according to this embodiment can achieve further reduction in the thickness thereof. 
     Furthermore, a disk chucking device  170  may include a chuck housing  172 , springs  174 , and chuck chips formed of chip members  176 . 
     The chuck housing  172  is mounted on the upper side of the rotor case  160 . The chuck housing  172  may have a receiving space therein such that the chip members  176  are received therein while being exposed to the outside. Therefore, openings are formed in the receiving space so that the chip members  176  are mounted while being partially exposed to the outside. 
     The springs  174  are received in the chuck housing  172  such that one set of ends of the springs  174  come into contact with the chip members  176 . When the chip members  176  are moved inwards by the disk, the elastic force exerted by the springs  171  is applied so that the chip members  176  return to their original positions. 
     The chip members  176  are mounted on the chuck housing  172  such that one set of ends of the chip members  176 , located inside the chuck housing  172 , are exposed to the outside. When the disk is mounted, the chip members  176  come into contact with a hole in the disk and are pushed into the inside of the chuck housing  172 . Once the disk is located at its mounting position, the chip members  176  return to their original positions by the springs  174  to thereby secure the disk. 
       FIGS. 5 and 6  are cross-sectional views illustrating a method of manufacturing a base plate of a motor device according to an exemplary embodiment of the invention. 
     Referring to  FIGS. 5 and 6 , first, according to a method of manufacturing a motor device, a plate  10  having a plate-like shape is disposed under a press jig  20 . 
     Here, the press jig  20  presses the plate  10  downwards on the basis of a hole in the plate  10 . Further, the press jig  20  may have an outer surface being bent so that the mounting surface  154  and the protrusion  156  are simultaneously formed on the plate  10 . However, the shape of the press jig  20  is not limited thereto, and the press jig  20  may be formed in various shapes according to the designers&#39; intentions. 
     In this embodiment, according to the manufacturing method, the plate  10  may be pressed down to form the mounting surface  154  in order to support cores and the protrusion  156  protruding from the mounting surface  154  at the same time. 
     Here, a base jig  30  is located at a corresponding position to the press jig  20 , and the base jig  30  is bent according to the shape of the press jig  20  so that the base jig  30  comes into tight contact with the press jig  20 . 
     When the press jig  20  is moved (in the direction of the arrow) so that the press jig  20  and the base jig  30  come into close contact with each other, the mounting surface  154  and the protrusion  156  are formed on the plate  10 , and the sleeve housing  152  is formed integrally with the plate  10 . 
     Here, a plurality of protrusions  156  may be formed in the mounting surface  154 . In the case that the press jig  20  has a shape corresponding to the plurality of protrusions, it is easy to realize the mounting surface  154  with the plurality of protrusions. 
     Therefore, since the base plate  150  is formed of a piece of metal plate, it is easy to manufacture the base plate  150  by using a one-time pressing process. Plus, the sleeve housing  152  is formed integrally with the base plate  150  to thereby reduce the number of components, so that economic efficiency is realized. 
       FIG. 7  is a partially sectional view illustrating a sleeve housing and a base plate of a motor device according to another exemplary embodiment of the invention. 
     Referring to  FIG. 7 , a sleeve housing  252  and a base plate  254  may be formed separately, and a base plate  254  is mounted on a lower surface of the sleeve housing  252 . 
     Here, the sleeve housing  252  has a mounting portion so that the cores  114  are mounted thereon. A protrusion  256  may protrude upwardly from the mounting portion so that the protrusion  256  is inserted into the core  114 . 
     A recess is formed in the core  114  so that the protrusion  256  is received within the recess. 
     Therefore, the motor device according to this embodiment includes the sleeve housing  252  having the mounting portion in order to support the core  114  and the protrusion  256  in order to the rotation of the core  114 , so that the protrusion  256  prevents the rotation of the core  114  to thereby increase the rotation resistance of the core  114 . 
     As set forth above, according to exemplary embodiments of the invention, according to a motor device and a method of manufacturing the same provides a sleeve housing having a mounting surface in order to support a core and a protrusion in order to prevent the rotation of the core, so that the protrusion prevents the rotation of the core to thereby increase the rotation resistance of the core. 
     While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.