Abstract:
Provided herein is an actuator including a housing unit, a drive unit installed in the housing unit, the drive unit having a rotating shaft, a plurality of gears installed in the housing unit and rotated by rotational power of the shaft, the gears being engaged with each other, and a reinforcement part installed in an inside portion of one of the plurality of gears to create reinforcing force. Also, provided herein is an electronic apparatus having the actuator.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2014-0128580 filed on Sep. 25, 2014, and KR Patent Application No. 10-2015-0128389 filed on Sep. 10, 2015, which are hereby incorporated by reference in their entirety into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an actuator and, more particularly, to an actuator capable of preventing generation of an error in actuating angle by preventing declination in the injection and molding operation and an electronic apparatus having the same. 
         [0004]    2. Description of the Related Art 
         [0005]    Various kinds of vehicles including automobiles and trucks are generally equipped with headlamps at the front thereof. The headlamps are turned on to ensure safe driving when a clear view is not secured at night or in a bad weather. 
         [0006]    Conventionally, a headlamp is separately provided with a high beam lamp and a low beam lamp. Thereby, the low beam lamp is usually tuned on during driving. The high beam lamp is turned on when the front view is particularly unclear. 
         [0007]    Accordingly, vertical rotation positions of a vehicular headlamp are set and controlled by operation of a separate actuator. 
         [0008]    In addition, the lamp assembly is connected to a shaft rotatably provided to the actuator, and the rotation position thereof is determined in connection with rotation of the shaft. 
         [0009]    Herein, the rotational power of the shaft is transmitted to multiple gears engaged with each other. 
         [0010]    The gears configured as above are generally fabricated through injection molding. 
         [0011]    When a gear fabricated through injection molding is left in a high-temperature atmosphere, the gear becomes eccentric in the curvature direction and thus comes to have a cumulative pitch error. Thereby, precision of the gear is lowered. 
         [0012]    In addition, when gears having eccentric errors rotate by being engaged with each other, an operating angle error is produced. 
         [0013]    A prior art document related to the present invention is Korean Utility Application Publication No. 20-1999-0015589 (Publication date: May 15, 1999). 
       SUMMARY OF THE INVENTION 
       [0014]    In view of the above, an object of the present invention is to provide an actuator capable of minimizing deviation of the operating angle by preventing deviation of a gear in injection molding and thermal deformation of the gear in a high-temperature atmosphere and an electronic apparatus having the same. 
         [0015]    Another object of the present invention is to provide an actuator capable of enhancing durability of gears and an electronic apparatus having the same. 
         [0016]    Another object of the present invention is to provide an actuator capable of stably supporting a bearing member for guiding rotation of a rotation shaft of a gear and an electronic apparatus having the same. 
         [0017]    According to an aspect of the present, there is provided an actuator including a housing unit, a drive unit installed in the housing unit, the drive unit having a rotating shaft, a plurality of gears installed in the housing unit and rotated by rotational power of the shaft, the gears being engaged with each other, and a reinforcement part installed in an inside portion of one of the plurality of gears to create reinforcing force. 
         [0018]    Preferably, the plurality of gears includes a first gear connected to the shaft arranged along a first axis and configured to rotate, a second gear configured to rotate about a second axis perpendicular to the first axis in connection with the first gear, and a third gear configured to rotate about a third axis perpendicular to the second axis in connection with the second gear, 
         [0019]    Preferably, the second gear is a multi-step gear formed stepwise. 
         [0020]    Preferably, the reinforcement part is inserted into an inside of a lower end of the multi-step gear. 
         [0021]    Preferably, the second gear includes an upper gear and a lower gear, the lower gear being formed at a lower end of the upper gear and having a greater diameter than the upper gear. 
         [0022]    An installation hole is formed at a center of the lower gear. 
         [0023]    The reinforcement part may be fixedly inserted into the installation hole. 
         [0024]    It is better for the reinforcement part to be a reinforcement member made of a metallic material and formed in a ring shape. 
         [0025]    The reinforcement part may be a reinforcement member having two steps. 
         [0026]    The reinforcement part may be a reinforcement member having multiple steps. 
         [0027]    Preferably, a height of the reinforcement part is covered by a length of the rotation shaft penetrating the gears to rotatably support the gears. 
         [0028]    It is better for the reinforcement part to closely contact an outer surface of the rotation shaft. 
         [0029]    Preferably, one region of the reinforcement part is positioned on an axis perpendicular to an axial line of rotation of a counterpart gear part engaged with the reinforcement part. Preferably, a thickness of the reinforcement member in a direction of centripetal force is greater than a thickness of the lower gear. 
         [0030]    Preferably, the reinforcement member is one of a ball bearing and a sleeve bearing. 
         [0031]    Preferably, the reinforcement part is installed at the plurality of gears through one of press fitting, welding, caulking and injection molding. 
         [0032]    One end of the first gear is provided with a bearing, 
         [0033]    Preferably, the housing unit is provided with a bearing accommodation portion, the bearing being accommodated in the bearing accommodation portion. 
         [0034]    Preferably, a bearing cover for covering the bearing is detachably installed at the bearing accommodation portion. 
         [0035]    According to another aspect of the present invention, there is provided an electronic apparatus including the actuator. 
         [0036]    According to embodiments of the present invention, operating angle deviation may be minimized by preventing deviation of a gear in fabricating the gear through injection molding and thermal deformation of the gear in a high-temperature atmosphere. 
         [0037]    According to embodiments of the present invention, durability of gears may be enhanced. 
         [0038]    According to embodiments of the present invention, a bearing member for guiding rotation of a rotation shaft of a gear may be stably supported. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    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: 
           [0040]      FIG. 1  is a perspective view illustrating an actuator according to an embodiment of the present invention; 
           [0041]      FIG. 2  is an exploded perspective view illustrating the actuator according to an embodiment of the present invention; 
           [0042]      FIG. 3  is a perspective view illustrating arrangement of a plurality of gears according to an embodiment of the present invention; 
           [0043]      FIG. 4  is a perspective view illustrating a second gear and a reinforcement part according to an embodiment of the present invention; 
           [0044]      FIG. 5  is a perspective view illustrating a reinforcement part according to another embodiment of the present invention; 
           [0045]      FIG. 6  is a cross-sectional view illustrating coupling of the reinforcement part and the second gear shown in  FIG. 5 ; 
           [0046]      FIG. 7  is a perspective view illustrating a reinforcement part according to another embodiment of the present invention; 
           [0047]      FIG. 8  is an exploded perspective view illustrating coupling of the reinforcement part and the second gear shown in  FIG. 7 ; 
           [0048]      FIG. 9  is a cross-sectional view illustrating coupling of the reinforcement part and the second gear shown in  FIG. 7 ; 
           [0049]      FIG. 10  is a view illustrating connection between the first gear and the second gear; 
           [0050]      FIG. 11  is a view illustrating engagement of the second gear with the third gear; 
           [0051]      FIG. 12  is a perspective view illustrating installation of a bearing cover according to an embodiment of the present invention; and 
           [0052]      FIG. 13  is a graph depicting angular variation of the second gear when a reinforcement member is not applied and when the reinforcement member is applied. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0053]    Hereinafter, an actuator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
         [0054]      FIG. 1  is a perspective view illustrating an actuator according to an embodiment of the present invention, and  FIG. 2  is an exploded perspective view illustrating the actuator according to an embodiment of the present invention. 
         [0055]    Referring to  FIGS. 1 and 2 , the actuator includes a housing unit  100 , a drive unit  200 , a plurality of gears  300 , and a reinforcement part  400 . 
         [0056]    Housing Unit  100   
         [0057]    The housing unit  100  includes a lower housing  110  and an upper housing  120 , which is coupled to the upper end of the lower housing  110 . 
         [0058]    Drive Unit  200   
         [0059]    The drive unit  200  includes a motor  210  and a shaft  220 . 
         [0060]    The shaft  220  is arranged on the central axis of the motor  210  and rotation thereof is actuated by driving the motor  210 . 
         [0061]    Herein, the shaft  220  rotates about a first axis {circle around ( 1 )} extending in a horizontal direction. 
         [0062]    Plurality of Gears  300   
         [0063]      FIG. 3  is a perspective view illustrating arrangement of a plurality of gears according to an embodiment of the present invention. 
         [0064]    Referring to  FIG. 3 , the plurality of gears  300  includes a first gear  310 , a second gear  320  and a third gear  330 . 
         [0065]    The first gear  310  is installed on the shaft  220  and rotated according to rotation of the shaft  220 . 
         [0066]    Accordingly, the first gear  310  rotates about the first axis {circle around ( 1 )}. 
         [0067]    Herein, a first installation area A 1  where the drive unit  200  and the first gear  310  are seated is defined in the lower housing  110 . 
         [0068]    The second gear  320  is vertically disposed to be engaged with the first gear  310 . 
         [0069]    A second installation area A 2  where the second gear  320  is installed is defined in the lower housing  110 . A rotation shaft  111  arranged on a second axis {circle around ( 2 )} perpendicular to the first axis ({circle around ( 1 )}) is disposed in the second installation area A 2 . 
         [0070]    The second gear  320  is fitted onto the rotation shaft  111  and rotatably disposed. 
         [0071]    In addition, the second gear  320  rotates in connection with the first gear  310 . 
         [0072]      FIG. 4  is a perspective view illustrating a second gear and a reinforcement part according to an embodiment of the present invention  FIG. 4 . 
         [0073]    Hereinafter, the second gear  320  according to an embodiment will be described with reference to  FIG. 4 . 
         [0074]    The second gear  320  includes a stepped multi-step gear. 
         [0075]    The second gear  320  includes an upper gear  321  and a lower gear  322  formed at the lower end of the upper gear  321 . 
         [0076]    Preferably, the diameter of the lower gear  322  is greater than that of the upper gear  321 . 
         [0077]    In addition, an installation hole  322   a  is formed at the inner center of the lower end of the lower gear  322 . 
         [0078]    Meanwhile, the third gear  330  is installed to the lower housing  110  such that the third gear  330  is engaged with the upper gear  321  of the second gear  320 . 
         [0079]    Accordingly, the third gear  330  may be rotated in connection with rotation of the second gear  320  and cause other external structures such as a headlamp for a vehicle to rotate within a certain range of angle of rotation in a reciprocating manner. 
         [0080]    Reinforcement Part  400   
         [0081]    Referring to  FIGS. 2 and 3 , the reinforcement part  400  is installed at the inner center of the second gear  320 . 
         [0082]    The reinforcement part  400  includes a ring-shaped reinforcement member  410 . 
         [0083]    Preferably, the reinforcement member  410  is formed of a metallic material. 
         [0084]    The reinforcement member  410  may be installed at the inner center of the second gear  320  through one of press-fit, welding, caulking and insert molding. 
         [0085]    Preferably, the reinforcement member  410  is press-fit into the installation hole  322   a  formed in the lower gear  322  of the second gear  320 . 
         [0086]    Preferably, the thickness of the reinforcement member  410  in the direction of centripetal force is greater than that of the lower gear  322  of the second gear  320 . 
         [0087]    Substantially, the outer circumference of the reinforcement member  410  serves to closely contact the inner circumference of the lower gear  322  of the second gear  320  defining the installation hole  322   a  to support the lower gear  322 . 
         [0088]    The reinforcement member  410  may include either a ball bearing or a sleeve bearing. 
         [0089]    Although not shown in the figure, radially protruding projections may be formed on the outer circumference of the reinforcement member  410 . 
         [0090]    Herein, multiple projection grooves into which the projections are fixedly fitted are preferably formed on the inner circumference of the lower gear  322  defining the installation hole  322   a.    
         [0091]    Accordingly, when the reinforcement member  410  is inserted into the installation hole  322   a , the projections may be fitted into the projection grooves, thereby securing additional fixing force. 
         [0092]    Additionally, the projections may have a curve shape, and the projection grooves may have a curve shape. 
         [0093]    Thereby, even if the lower gear  322  is thermally deformed by contracting and expanding according to the external temperature atmosphere, deforming force according to contraction and expansion maybe deconcentrated through contact between the curved surfaces. Thereby, the amount of deformation of the second gear  320  may be minimized. 
         [0094]    As the reinforcement member, which is a component for compensating for deformation of the injection-molded gear is inserted into the second gear to support the second gear through the configuration and operation described above, precision of the gear may be enhanced. 
         [0095]    Thereby, an improvement related to gear engagement deviation may be obtained, and thus an improvement may be achieved in relation to deviation of operating angle errors affecting the product performance. 
         [0096]    In addition, when the gear is left in a high-temperature environment, thermal deformation may be prevented as the reinforcement member is formed of a metallic material and supports the gear at the inner-diameter portion of the gear. Thereby, degradation of gear precision may be prevented. 
         [0097]    Next, another example of the reinforcement part of the present invention will be described. 
         [0098]      FIG. 5  is a perspective view illustrating a reinforcement part according to another embodiment of the present invention, and  FIG. 6  is a cross-sectional view illustrating coupling of the reinforcement part and the second gear shown in  FIG. 5 . 
         [0099]    Referring to  FIG. 5 , a reinforcement part  600  includes reinforcement members  610  and  620 , which form two steps. 
         [0100]    The two-step reinforcement members  610  and  620  are formed in a stepped ring shape. 
         [0101]    Herein, the second gear  320  is provided with a rotation hole  320   a , through which the rotation shaft  111  passes. The lower end of the second gear  320  is provided with an two-step-shaped installation hole  322   b , into which the reinforcement part  600  is press-fit. 
         [0102]    The reinforcement part  600  is provided with a through hole  600   a , through which the rotation shaft  111  is passed. 
         [0103]    The reinforcement part  600  is installed by being press-fit into the installation hole  322   b  of the second gear  320 . 
         [0104]    The rotation shaft  111  passed through the through hole  600   a  of the reinforcement part  600  may closely contact the inner surface of the through hole  600   a.    
         [0105]    As the length of the reinforcement part  600  press-fit into the second gear  320 , which is an injection-molded gear, increases, clearance of the rotation shaft  111  supporting the second gear  320  is minimized. 
         [0106]    Thereby, movement of the rotation shaft  111  is prevented, and thus the operating angle error resulting from shaking of the gear is lowered. 
         [0107]    Next, a reinforcement part according to another embodiment of the present invention will be described. 
         [0108]      FIG. 7  is a perspective view illustrating a reinforcement part according to another embodiment of the present invention,  FIG. 8  is an exploded perspective view illustrating coupling of the reinforcement part and the second gear shown in  FIG. 7 , and  FIG. 9  is a cross-sectional view illustrating coupling of the reinforcement part and the second gear shown in  FIG. 7 . 
         [0109]    Referring to  FIGS. 7 and 9 , a reinforcement part  700  includes reinforcement members  710 ,  720  and  730 , which form multiple steps. 
         [0110]    The reinforcement members  710 ,  720  and  730  forming three steps are formed in a stepped ring shape. 
         [0111]    Herein, the second gear  320  is provided with the rotation hole  320   a . The lower end of the second gear  320  is provided with an installation hole  322   c  with a three-step shape, into which the reinforcement part  700  is press-fit. 
         [0112]    Among the reinforcement members  710 ,  720  and  730  forming three steps, the uppermost reinforcement member  730  is positioned in the rotation hole  320   a  of the second gear  320 , and closely contacts the inner surface of the rotation hole  320   a.    
         [0113]    The reinforcement part  700  is provided with a through hole  700   a , into which the rotation shaft  111  is fitted. 
         [0114]    The reinforcement part  700  is installed by being press-fit into the installation hole  320 c of the second gear  320 . 
         [0115]    The rotation shaft  111  passing through the through hole  700   a  of the reinforcement part  700  may closely contact the inner surface of the through hole  700   a.    
         [0116]    According to this configuration, the reinforcement part  700  is formed in a three-step shape and is press-fit into the rotation hole  320   a  and the installation hole  322   c  formed in the second gear  320 . 
         [0117]    Additionally, the height of the reinforcement part  700  is covered by the length of the rotation shaft  111 , which is passed through the reinforcement part  700  to rotatably support the second gear  320 . 
         [0118]    Accordingly, the reinforcement part  700  may closely contact the outer surface of the rotation shaft  111 . 
         [0119]    That is, the reinforcement parts  600  and  700  may have a height by which the reinforcement part  600  and  700  can closely contact apart or the entirety of the outer surface of the rotation shaft  111 . 
         [0120]    Accordingly, as the length of the reinforcement part press-fit into the second gear  320 , which is an injection-molded gear, increases, clearance of the rotation shaft  111  supporting the second gear  320  may be minimized. 
         [0121]    Thereby, movement of the rotation shaft  111  is prevented, and thus the operating angle error resulting from shaking of the second gear  320  may be lowered. 
         [0122]      FIG. 10  is a view illustrating connection between a first gear and a second gear, and  FIG. 11  is a view illustrating engagement of the second gear with the third gear. 
         [0123]    Referring to  FIGS. 10 and 11 , a portion of the area of the reinforcement part  600 ,  700  may be positioned on axis C which is perpendicular to the rotation axis of the counterpart gear engaged with the reinforcement part  600 ,  700 . 
         [0124]      FIG. 10  illustrates a case where a portion of the area of the reinforcement part  600  installed on the second gear  320  is on the axial line C of the first gear  310 . 
         [0125]      FIG. 11  illustrates a case where a portion of the area of the reinforcement part  700  installed on the second gear  320  is on the axial line C of the third gear  330 . 
         [0126]    Accordingly, deformation of the second gear  320  may be prevented by disposing the reinforcement part  700  such that the reinforcement part  700  is arranged at a position corresponding to the axial line C of the first gear  310  or the third gear  330 , which is a counterpart gear engaged with the reinforcement part. 
         [0127]      FIG. 12  is a perspective view illustrating installation of a bearing cover according to an embodiment of the present invention. 
         [0128]    The lower housing  110  may be further provided with a bearing accommodation portion  112 . 
         [0129]    Referring to  FIG. 12 , a bearing  311  is installed at an end of the first gear  310 . 
         [0130]    The bearing accommodation portion  112 , which is formed by partitions to define an inner space therein, is formed in the first installation area A 1  in the lower housing  110 . 
         [0131]    The bearing  311  of the first gear  310  is positioned in the inner space of the bearing accommodation portion  112 . 
         [0132]    In addition, a bearing cover  500  is installed at the upper end of the bearing accommodation portion  112 . 
         [0133]    The bearing cover  500  may not only cover the bearing  311  to prevent the bearing  311  from being displaced from the position, but also fix the bearing  311  at the installation position. 
         [0134]    Herein, the bearing cover  500  may be detachable from the upper end of the bearing accommodation portion  112 . 
         [0135]    The bearing cover  500  includes a cover body  510 , which is disposed at the upper end of the bearing accommodation portion  112  and covers the inner space of the bearing accommodation portion  112 , and a catch ring  520 , which is bent downward from a lateral portion of the cover body  510 . 
         [0136]    The catch ring  520  is caught by a catch protrusion (not shown) formed on the outer surface of the partition of the bearing accommodation portion  112 . 
         [0137]    In addition, the cover body  510  may be fixed by being screw-coupled to the bearing accommodation portion  112  by a screw bolt  530 . 
         [0138]    According to an embodiment of the present invention, by covering the bearing installed at an end of the first gear and fixing the installation position of the bearing, stable gear operation may be guided. 
         [0139]      FIG. 13  is a graph depicting angular variation of the second gear when a reinforcement member is not applied and when the reinforcement member is applied. 
         [0140]      FIG. 13  shows the results of vibration according to the rotation angle of the second gear (a) when the reinforcement member is not applied and (b) when the reimbursement member is applied. In case (a), the angular variation changes. In case (b), the angular variation is constant. 
         [0141]    That is, graph (a) implies that the second gear is deformed and is less likely to maintain the original shape thereof. Graph (b) implies that the second gear retains the original shape thereof. 
         [0142]    According to these results, variation of the second gear may be minimized by employing the reinforcement member of the present invention. 
         [0143]    Description has been given above of specific embodiments help an actuator and an electronic apparatus having the same according to the present invention. Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. 
         [0144]    Therefore the scope of the present invention should be defined by the scope of the appended claims and their equivalents, rather than being confined to the embodiments described above. 
         [0145]    That is, the embodiments described above should be construed in all aspects as illustrative and not restrictive. The scope of protection sought by the present invention should be determined by the appended claims and their equivalents, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.