Abstract:
Disclosed is a sealing structure for a motor using a kinetic pressure bearing, capable of improving productivity by reducing assembling time through modification in the sealing structure of the bearing, and of extending life of a motor, improving performance of a motor by more effectively preventing leakage of an oil in the interior of the bearing, to the outside.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a motor using a kinetic pressure bearing, and more particularly to a sealing structure for a motor using a kinetic pressure bearing, capable of improving quality and productivity by more completely preventing an oil provided for kinetic pressure generation and lubrication, from leaking out.  
           [0003]    2. Description of the Related Art  
           [0004]    In general, a small precision motor currently used, adopts a fluid kinetic pressure bearing for generating kinetic pressure by torque due to rotation of a motor in the inside of a bearing so that a rotor floats above a stator and rotates, and for heat-resisting and abrasion-resisting properties.  
           [0005]    [0005]FIG. 1 is a cross-sectional view of a motor using a kinetic pressure bearing of the related art, and FIG. 2 is an exploded, cross-sectional view of a sealing structure for a motor using a kinetic pressure bearing of the related art.  
           [0006]    The motor of the related art, consists of: a cylinder shaped bearing  104  fixed on a base plate  102 ; a stator  106  fixed on the outer peripheral surface of the bearing  104 , and to which power supply is applied; a magnet  108  arranged, with a constant interval, above the outer peripheral surface of the stator  106 , for being rotated by interaction with the stator  106 ; a rotor  110  on which the magnet  108  is fixed and positioned on the upper side of the bearing; a shaft  112  inserted into the bearing  104  and fixed on the rotor  110  in its upper end, for supporting the rotor  110  so that the rotor is rotatable, and for generating kinetic pressure while being rotated in the interior of the bearing  104 ; a sealing unit  120  mounted on the lower end of the bearing, for preventing an oil provided to the interior of the bearing  104 , from leaking out.  
           [0007]    The sealing unit  120  is fixed on the lower end of the bearing  104  by caulking process, and consists of: a cover plate  114  having an air exhausting hole  116  for discharging an air of the interior of the bearing  104 , to the outside; a bending member  118  adhered to the back side of the cover plate  114 , for preventing leakage of an oil by sealing the air exhausting hole  116 .  
           [0008]    Assembling process for the sealing unit of the related art having the foregoing construction, will be descried with reference to FIG. 2.  
           [0009]    A cover plate  114  is fit into the bearing  104  and fixed by caulking process. After sufficient amount of oil is provided to the interior of the bearing  104 , a shaft  112  fixed on the rotor  110  is inserted into the interior of the bearing  104 . At the moment, oil except the oil necessary for lubrication and kinetic pressure generation in the interior of the bearing  104 , is exhausted together with the air in the interior of the bearing  104 , to the outside through the air exhausting hole  116 .  
           [0010]    After that, the oil exhausted through the air exhausting hole  116  and stuck on the cover plate  114 , is wiped away, and the bending member  118  is processed by heat fusion in order to seal the air exhausting hole  116 , so that leakage of the oil in the interior of the bearing  104  to the outside, is prevented and at the same time, inflow of external air is prevented.  
           [0011]    But, in the sealing structure for the motor using the kinetic pressure bearing of the related art as descried above, as the air exhausting hole remains exposed to the outside, there may exist a danger of incomplete hardening of the bending member due to mixture of the oil and the bending member upon heat fusion of the bending member. Additionally, due to such incomplete hardening, problems that adhesive force of the bending member is deteriorated and the oil in the interior of the bearing leaks out to the outside, or external air penetrates into the interior of the bearing, seriously spoiling the bearing, deteriorating performance of the motor, are generated.  
           [0012]    Also, a problem that the bending member flows into the interior of the bearing through the air exhausting hole, upon heat fusion of the bending member, and is mixed with the oil, deteriorating lubrication performance, thereby shorting life of the motor due to abrasion, is generated.  
         SUMMARY OF THE INVENTION  
         [0013]    To solve the above-indicated problems, it is, therefore, an object of the present invention to provide a sealing structure for a motor using a kinetic pressure bearing, capable of improving productivity through reduction in assembling time by modifying a sealing structure of a bearing, and of improving life and performance of a motor by more effectively preventing oil in the interior of the bearing from leaking out to the outside.  
           [0014]    The foregoing and other objects and advantages are realized by providing a sealing structure for a motor using a kinetic pressure bearing including: a bearing fixed on a base plate; a stator arranged on an outer peripheral surface of the bearing; a rotor arranged, with constant interval, on an outer peripheral surface of the stator; a shaft inserted into the bearing, and fixed in the rotor; a cover plate fixed on a lower end of the bearing, and having an air exhausting hole for discharging an air in an interior of the bearing to an outside; a first plate fit into a back side of the cover plate, for sealing the air exhausting hole; a packing member stuck on a back side of the first plate, for preventing leakage of an oil; a second plate fixed on a back side of the packing member, for protecting the packing member.  
           [0015]    It is a preferable aspect of the present invention that a sealing is fit between a back side of the bearing and the cover plate, for preventing oil from leaking out to a gap between the bearing and the cover plate.  
           [0016]    It is another preferable aspect of the present invention that the cover plate has a fitting portion so that the first plate, the packing member and the second plate are sequentially fit, respectively, in a back side of a cylindrical shape.  
           [0017]    It is yet another preferable aspect of the present invention that the fitting portion is of a cylindrical shape having a predetermined length and is fixed by heat fusion after the first plate, the packing member and the second plate are fitted.  
           [0018]    It is another preferable aspect of the present invention that the cover plate is manufactured by metal or synthetic resin.  
           [0019]    It is another preferable aspect of the present invention that the first and the second plates are manufactured in form of a cylindrical shape having a predetermined thickness and made of metal or synthetic member.  
           [0020]    It is another preferable aspect of the present invention that the packing member is manufactured by rubber material having a predetermined elasticity. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    The above objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:  
         [0022]    [0022]FIG. 1 is a cross-sectional view of a motor using a kinetic pressure bearing of the related art;  
         [0023]    [0023]FIG. 2 is an exploded, cross-sectional view of a motor using a kinetic pressure bearing of the related art;  
         [0024]    [0024]FIG. 3 is a cross-sectional view illustrating an oil sealing structure of a motor using a kinetic pressure bearing according to the present invention;  
         [0025]    [0025]FIG. 4 is an exploded, cross-sectional view illustrating an oil sealing structure of a motor using a kinetic pressure bearing according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    A preferred embodiment of the present invention will now be described with reference to the accompanying drawings. In the following description, same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description such as a detailed construction and elements of the invention are nothing but the ones provided to assist in a comprehensive understanding of the invention. Thus, it is apparent that the present invention can be carried out without those defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.  
         [0027]    [0027]FIG. 3 is a cross-sectional view of a motor using a kinetic pressure bearing according to the present invention.  
         [0028]    Referring to FIG. 3, the motor using a kinetic pressure bearing of the present invention includes: a cylinder shaped bearing  4  fixed on a base plate  2 ; a stator  6  fixed on the outer peripheral surface of the bearing  4 ; a magnet  8  arranged, with a constant interval, above the outer peripheral surface of the stator  6 , for being rotated by interaction with the stator  6 ; a rotor  10  on which the magnet  8  is fixed and positioned on the upper side of the bearing, for being rotated together with the magnet  8 ; a shaft  12  inserted into the bearing  4  and fixed on the rotor  10  in its upper end, for supporting the rotor  10  so that the rotor is rotatable, and for generating kinetic pressure while being rotated in the interior of the bearing  4 ; a sealing unit  16  mounted on the lower end of the bearing, for preventing an oil supplied to the interior of the bearing  4 , from leaking out.  
         [0029]    Here, the oil supplied to the interior of the bearing  4  plays a role of making the rotor  10  rotated with being floated above by generating kinetic pressure, floating the shaft  12  upon rotation of the shaft  12 , and at the same time, plays a role of performing lubrication and heat-resisting operations between the bearing  4  and the shaft  12 .  
         [0030]    The sealing unit  16  is fixed on the lower end of the bearing  4  by caulking process, and includes: a cover plate  20  having an air exhausting hole  22  for discharging an air in the interior of the bearing  4 , to the outside; a first plate  24  fit into the back side of the cover plate  20 , for sealing the air exhausting hole  22 ; a packing member  26  stuck on the back side of the first plate  24 , for preventing an oil from leaking out to a gap between the first plate  24  and the cover plate  20 ; and a second plate  28  stuck on the back side of the packing member  26 , for protecting the packing member  26 .  
         [0031]    Here, the bearing  4  has, in its back side, a groove  36  formed in the peripheral direction and a sealing  30  is fit into the groove  36 , whereby leakage of an oil, to a gap between the cover plate  20  and the back side of the bearing  4 , is prevented.  
         [0032]    The cover plate  20  is manufactured by metal or plastics resin, and has a fitting portion  32  of a cylindrical shape so that the first plate  24 , the packing member  26 , and the second plate  28  are sequentially fit in its back side of a circular plate.  
         [0033]    Also, the first and the second plates  24  and  28  are manufactured in form of circular plate having a predetermined thickness, and the packing member  26  is made of rubber material having a predetermined elasticity and is fit in the inner peripheral surface of the fitting portion  32  in the cover plate, so that leakage of the oil is prevented.  
         [0034]    Assembling process for the sealing unit according to the present invention having the foregoing construction, will be described in detail with reference to FIG. 4.  
         [0035]    The sealing  30  is fit into the groove  36  formed on the back side of the bearing  4 . After that, the cover plate  20  is stuck on and fixed in the back side of the bearing  4  by caulking process or heat fusion, and sufficient amount of oil is supplied to the interior of the bearing  4 . Additionally, the shaft  12  fixed on the rotor  10  is inserted into the interior of the bearing  4 . At the moment, oil except the oil necessary for lubrication and kinetic pressure generation, is discharged together with air of the interior in the bearing  4 , to the outside through the air exhausting hole  22  formed on the cover plate.  
         [0036]    After that, the first plate  24  is fit into the fitting portion  32  of the cover plate, so that the air exhausting hole  22  is sealed, and the packing member  26  is fit in the inner peripheral surface of the fitting portion in a sealing manner, whereby leakage of the oil flowing into the gap between the first plate  24  and the cover plate  20  through the air exhausting hole  22 , to the outside, is prevented.  
         [0037]    Also, the second plate  28  is stuck on the back side of the packing member  26  and the outer peripheral surface of the cover plate  20  is processed by heat fusion, so that assembling process is completed.  
         [0038]    Therefore, the sealing structure for the motor using the kinetic pressure bearing according to the present invention having the foregoing construction, has the first plate, the packing member, and the second plate sequentially fit in its back side of the cover plate, and then assembled in a manner of heat fusion, thereby effectively preventing the oil of the interior in the bearing, from leaking out and having strong points of improving reliability as well as extending life of the motor.  
         [0039]    Additionally, as assembling process is completed when the first plate, the packing member and the second plate are sequentially fit in the back side of the cover plate, assembling time is possibly reduced, so that productivity is improved and production costs is lowered.  
         [0040]    While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.