Patent Publication Number: US-2009224616-A1

Title: Flat Vibration Motor

Description:
TECHNICAL FIELD 
     The present invention relates to a vibration motor, and more particularly, a flat vibration motor. 
     BACKGROUND ART 
     A flat vibration motor is a miniature motor that can be installed in cellular phones, smart phones, personal digital assistants (PDA), and similar mobile telecommunication terminals and various other electronic devices. When a signal is received from a call center, a flat vibration motor can alert a user of an incoming call through vibrations instead of sound. 
     More specifically, when set in “manner mode”, a mobile telecommunication terminal transmits vibrations through the operating of such a flat vibration motor. 
     A flat vibration motor is coin-sized and generates a strong vibrating force, so that it requires a relatively durable coupling structure. However, its terminals are often deformed due to the strong vibrating force, so that the coupling of the stator portion and the base portion develops problems. 
       FIG. 1  is a perspective view of a flat vibration motor according to the related art. 
     Referring to  FIG. 1 , a flat vibration motor according to the related art includes a stator portion  10 , a rotor portion (inside the stator portion), and a base portion  20 . 
     The stator portion  10  forms a housing within which the rotor portion is rotatably disposed, so that vibrating force imparted by the rotor portion can be transmitted to the outside. Also, the stator portion  10  has a circuit board (not shown) for transmitting electricity to the rotor portion, and allows the rotor portion to rotate. 
     The base portion  20  has a terminal  22  through which electricity is transmitted from an external source, and is coupled to the stator portion  10 . The terminal  22  is connected to the circuit board of the stator portion  10 . 
     Here, the base portion  20  and the stator portion  10  are coupled with an adhesive  30 ; however, such a coupling using the adhesive  30  reduces the service life of the vibration motor. 
     Specifically, depending on the hardened degree of the adhesive  30  or the external environmental conditions (such as a shock from a user dropping the mobile telecommunication terminal), the coupled surfaces of the stator portion  10  and the base portion  20  may develop a gap or completely disengage from each other. 
     When such a problem of coupling the stator portion  10  and the base portion  20  occurs, it can induce a problem in the connection between the terminal  22  and the circuit board, and disrupt the supply of electricity. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     To solve these problems, the present invention provides an improved coupling structure of a flat vibration motor capable of preventing operating failure or irregular operation of the motor as a result of shock incurred thereto. 
     Furthermore, the flat vibration motor according to the present invention uses a physical structure to more firmly couple its stator and base portions, in conjunction with the existing adhesive coupling. 
     Technical Solution 
     To achieve the above objects, there is provided a flat vibration motor including: a rotor portion for generating vibrating force when rotating; a stator portion housing and coupled with the rotor portion to allow the rotor portion to rotate, the stator portion for transmitting electricity; a fixing mount extending from a side of a lower case of the stator portion and including a plurality of fixing arms formed to extend upward therefrom; and a base portion including a terminal for supplying electricity to the stator portion, and a plurality of fixing grooves formed thereon for respectively coupling with the fixing arms. 
     According to another aspect of the present invention, there is provided a flat vibration motor including: a rotor portion for generating vibrating force when rotating; a stator portion housing and coupled with the rotor portion to allow the rotor portion to rotate, the stator portion for transmitting electricity; a fixing mount extending from a side of a lower case of the stator portion and including a plurality of fixing arms formed to extend upward therefrom; and a base portion including a terminal for supplying electricity to the stator portion, and a plurality of fixing grooves formed thereon for respectively coupling with the fixing arms, wherein at least one fixing groove has an angled surface, and a fixing arm that inserts in the fixing groove is altered in shape to press against the angled surface, for coupling the stator portion with the base portion. 
     According to a further aspect of the present invention, there is provided a flat vibration motor including: a rotor portion for generating vibrating force when rotating; a stator portion housing and coupled with the rotor portion to allow the rotor portion to rotate, the stator portion for transmitting electricity; a fixing mount extending from a side of a lower case of the stator portion and including a plurality of fixing arms formed to extend upward therefrom; and a base portion including a terminal for supplying electricity to the stator portion, and a plurality of fixing grooves formed thereon for respectively coupling with the fixing arms, wherein the fixing arms support the base portion in at least two directions. 
     ADVANTAGEOUS EFFECTS 
     An advantage of the flat vibration motor according to the present invention is that it prevents a change in or disengagement of the coupling of the base portion and the stator portion, so that a disruption in the electrical connection between the terminal and the control circuit board can be obviated. 
     Also, the flat vibration motor according to the present invention uses a physical structure to couple the stator portion and the base portion, so that the manufacturing process is more efficient. 
     Furthermore, the flat vibration motor according to the present invention uses a curved elastic portion of the terminal and a coupling of the base portion and stator portion, so that a wide range of shock levels incurred can be absorbed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The spirit of the present invention can be understood more fully with reference to the accompanying drawings. In the drawings: 
         FIG. 1  is a perspective view of a flat vibration motor according to the related art; 
         FIG. 2  is a schematic sectional side view showing the interior configuration of a flat vibration motor according to an embodiment of the present invention; 
         FIG. 3  is perspective view showing a coupling structure of a base portion and a stator portion of a flat vibration motor according to the first embodiment of the present invention; 
         FIG. 4  is a perspective view showing the base portion assembled with the stator portion of the flat vibration motor in  FIG. 3 ; 
         FIG. 5  is a perspective view showing a coupling structure of a base portion and a stator portion of a flat vibration motor according to the second embodiment of the present invention; 
         FIG. 6  is a perspective view showing the base portion assembled with the stator portion of the flat vibration motor in  FIG. 5 ; 
         FIG. 7  is a side view showing the base portion assembled with the stator potion of the flat vibration motor in  FIG. 5 ; 
         FIG. 8  is a perspective view of a base portion of a flat vibration motor according to the third embodiment of the present invention; 
         FIG. 9  is a perspective view showing a base portion coupled with a stator portion of a flat vibration motor according to the third embodiment of the present invention; 
         FIG. 10  is perspective view showing a coupling structure of the base portion and the stator portion of the flat vibration motor according to the fourth embodiment of the present invention; and 
         FIG. 11  is a perspective view showing the base portion coupled with the stator portion of the flat vibration motor in  FIG. 10 . 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, preferred embodiments of a flat vibration motor according to the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 2  is a schematic sectional side view showing the interior configuration of a flat vibration motor according to an embodiment of the present invention. 
     Referring to  FIG. 2 , a flat vibration motor according to one embodiment of the present invention includes a rotor portion  100 , a stator portion  200 , and a base portion  300 . The rotor portion  100  has a coil  130 , a vertical part  140 , and a first circuit board  150 . The stator portion  200  has an upper case  210 , a lower case  220 , a second circuit board  230 , a brush  240 , and a permanent magnet  250 . The base portion  300  has a terminal  310 . 
     The shaft  110  is fixed to the lower case  220  and provides a central axis around which the rotor  100  rotates. A bearing  120  is interposed between the shaft  110  and the rotor  100 . 
     The first circuit board  150  is electrically connected to the coil  130 , contacting the brush  240  through a commutator (not shown) to transmit electricity to the coil  130 . 
     In this structure, the rotor portion  100 , with an eccentric load, rotates within the stator portion  200  to generate vibrating force. To create the eccentric load, the rotor  100  may include an unbalancing member or may be formed to revolve asymmetrically around the rotational axis. 
     The second circuit board  230  is electrically connected to the terminal  310  on the base  300  and the brush  240 . 
     The permanent magnet  250  is donut-shaped and is disposed on the lower case  220  to generate magnetic repulsion with the coil  130 . 
     The base portion  300  includes the terminal  310  and supplies electricity to the flat vibration motor according to embodiments of the present invention. 
     First Embodiment 
     A description of the coupling structure of the base portion  300  and the stator portion  200  according to the first embodiment of the present invention will now be given, with reference to the diagrams. 
       FIG. 3  is perspective view showing a coupling structure of a base portion and a stator portion of a flat vibration motor according to the first embodiment of the present invention, and  FIG. 4  is a perspective view showing the base portion assembled with the stator portion of the flat vibration motor in  FIG. 3 . 
     Referring to  FIGS. 3 and 4 , the stator portion  200  has a fixing mount  410  with a plurality of fixing arms  420  and  430  formed thereon. The base portion  300  has a fixing ledge  450  and a fixing groove  460  formed thereon. The fixing mount  410  extends from a side of the lower case  220  to support the bottom of the base portion  300 , and the fixing arms  420  and  430  are formed on the edges on either side of the fixing mount  410 . 
     In the flat vibration motor according to the first embodiment of the present invention, there are four fixing arms  420  and  430 ; however, their number is not limited thereto and may vary according to requirements. 
     Of the fixing arms, a first fixing arm  420  is formed vertically from the edge of the fixing mount  410  opposite to the stator portion  200 . 
     The second fixing arm  430  is formed vertically from either side edge of the fixing mount  410  that is perpendicular to the direction in which the base portion  300  is supported by the first fixing arm  420 . 
     Here, as shown in  FIG. 3 , the first fixing arm  420  and the second fixing arm  430  may be formed at different heights. 
     The heights of the fixing groove  460  may be formed to correspond in height to the first fixing arm  420  and the second fixing arm  430 . 
     As described below, the base portion  300  and the stator portion  200  are coupled, and the terminal  310  is electrically connected with the second circuit board  230 . 
     As shown in  FIG. 4 , the second fixing arm  430  is inserted into the fixing groove  460  to prevent the base portion  300  from slipping to either side, and the first fixing arm  420  is inserted into the fixing groove of the fixing ledge  450  to mechanically stator portion  200  with the base portion  300 . 
     Also, in the flat vibration motor according to the first embodiment, the fixing arms  420  and  430  may be chemically coupled to the base portion  300  by means of an adhesive (not shown) applied to the coupling surface of the fixing groove  460 . 
     Additionally, the fixing ledge  450 , the fixing groove  460 , the first fixing arm  420 , and the second fixing arm  430  may be formed in a greater number than shown. 
     Furthermore, an adhesive (not shown) may be applied to the coupling surfaces of the base portion  300  and the stator portion  200 . Through this adhesive, the base portion  300  can be more firmly coupled with the stator portion  200 . 
     The coupling surfaces of the base portion  300  and the stator portion  200  may also be chemically, as well as mechanically, coupled by having an adhesive (not shown) applied thereto, to prevent disruptions in the electrical connection of the terminal  310  to the second circuit board  230 . 
     Second Embodiment 
     Below, a description of a coupling structure of the base portion  300  and the stator portion  200  of a flat vibration motor according to the second embodiment of the present invention will be given, with reference to the diagrams. 
       FIG. 5  is a perspective view showing a coupling structure of a base portion  300  and a stator portion  200  of a flat vibration motor according to the second embodiment of the present invention,  FIG. 6  is a perspective view showing the base portion  300  assembled with the stator portion  200  of the flat vibration motor in  FIG. 5 , and  FIG. 7  is a side view showing the base portion  300  assembled with the stator potion  200  of the flat vibration motor in  FIG. 5 . 
     Referring to  FIGS. 5 through 7 , the stator portion  200  has a fixing mount  410  with a plurality of fixing arms  420 ′ and  430  formed thereon. The base portion  300  has a fixing ledge  450  and a fixing groove  460  formed thereon. The fixing mount  410  is formed to extend from a side of the lower case  220  to support the bottom of the base portion  300 , and has the fixing arms  420 ′ and  430  formed on the edges on either side of the fixing mount  410 . 
     Four fixing arms  420 ′ and  430  are provided in the second embodiment; but these are not limited to four, and may be provided in a greater number depending on requirements. 
     The following is an explanation of the fixing arms  420 ′ and  430 . 
     Two first fixing arms  420 ′ are formed vertically from either side of the edge of the fixing mount  410  opposite to the stator portion  200 . The two first fixing arms  420 ′ have end portions  422  (shown in  FIG. 6 ) that are bent to engage with the two fixing ledges  450 , in order to press the base portion  300  towards the stator portion  200  and prevent the base portion  300  from dislodging upward at the same time. 
     For this purpose, the first fixing arm  420 ′ may be formed of a metal material capable of plastic deformation, to be bent after the base portion  300  is seated on the fixing mount  410 . 
     Two second fixing arms  430  are formed vertically from either side edge of the fixing mount  410  perpendicular to the direction in which the base portion  300  is supported by the first fixing arm  420 ′. In the second embodiment, unlike the first fixing arm  420 ′, the second fixing arm  430  does not need to be changed in shape. 
     As shown in  FIGS. 6 and 7 , the second fixing arm  430  is inserted into the fixing groove  460  to prevent the base portion  300  from slipping from either side. 
     Also, as described above, the fixing ledge  450 , the fixing groove  460 , the first fixing arm  420 ′, and the second fixing arm  430  may be formed in a greater number than shown. 
     Additionally, in the flat vibration motor according to the second embodiment, an adhesive (not shown) may be applied to the coupling surfaces of the base portion  300  and the stator portion  200 , in order to provide a firmer coupling between the base portion  300  and the stator portion  200 . 
     Therefore, not only are the base portion  300  and the stator portion  200  coupled mechanically, but they are also coupled chemically, so as to prevent disruptions in the electrical connection between the terminal  310  and the second circuit board  230 . 
     Third Embodiment 
     An explanation of a flat vibration motor according to the third embodiment of the present invention will be given below with reference to the diagrams. 
       FIG. 8  is a perspective view of a base portion  300  of a flat vibration motor according to the third embodiment of the present invention, and  FIG. 9  is a perspective view showing a base portion  300  coupled with a stator portion  200  of a flat vibration motor according to the third embodiment of the present invention. 
     Referring to  FIG. 8 , a fixing shelf  560   a  is formed slanting inward in the fixing groove  560 . Accordingly, as shown in  FIG. 9 , the second fixing arm  430  is inserted in the fixing groove  560 , and then its end part  422   a  bends to angle and engages over the fixing shelf  560   a.    
     The first fixing arm  420 ′ and the second fixing ledge  450  of the third embodiment may be coupled using the same structure as those of the second embodiment. 
     If the vibrating force from the flat vibration motor is excessive or the device is used in an environment that incurs severe shocks, the above-described structure of the third embodiment has all four of the fixing arms formed in a bent shape, so that the stator portion  200  and the base portion  300  can more reliably maintain a coupled state. 
     The number of fixing arms and their opposing shelves/ledges may be increased correspondingly. 
     In the flat vibration motor according to embodiments of the present invention, the fixing groove  460  has a first fixing groove (not shown) formed on a surface of the base portion  300  and a second fixing groove (not shown) formed on an alternate surface of the base portion  300 , so that the fixing groove  460  can support force exerted in at least two directions. 
     The fixing groove  460  has an angled surface, and the fixing arms  420 ′ and  430  that insert into the fixing groove  460  are bent to press against the angled surface, so that force in at least three directions can be supported. 
     Also, the coupling surfaces of the base portion  300  and the stator portion  300  has an adhesive (not shown) applied thereon. This adhesive more firmly couples the base portion  300  with the stator portion  200 . 
     Thus, the base portion  300  and the stator portion  200  are coupled not only mechanically, but also chemically, so that there is no disruption in the electrical connection between the terminal  310  and the second circuit board  230 . 
     Fourth Embodiment 
     Below, an explanation of the flat vibration motor according to the fourth embodiment of the present invention will be given, with reference to the diagrams. 
       FIG. 10  is perspective view showing a coupling structure of the base portion  300  and the stator portion  200  of the flat vibration motor according to the fourth embodiment of the present invention. 
     In a flat vibration motor according to the fourth embodiment of the present invention, the fixing mount  410  is rectangular in shape, and the fixing arm  430  may be formed vertically from the edge of the fixing mount  410  and the fixing groove  560  may be formed on the base portion  300  to couple with the fixing arm  430 . 
     The fixing groove  560  is formed on either side of the base portion  300 , and the fixing arm  430  is formed vertically from either side of the rectangular fixing mount  410  from edges proximal to the stator portion  200  to couple with the fixing grooves  560 . 
     In the fourth embodiment, as described below, the fixing groove  560  forms a fixing shelf  560   a  angled inward, so that the coupling force of the base portion  300  and the stator portion  200  increases. 
       FIG. 11  is a perspective view showing the base portion  300  coupled with the stator portion  200  of the flat vibration motor in  FIG. 10 . 
     Referring to  FIG. 11 , after the fixing arm  430  is inserted into the fixing groove  560 , its end part  422   a  is bent inward to engage with the fixing shelf  560   a.    
     In the flat vibration motor according to the fourth embodiment of the present invention, if the vibrating force from the flat vibration motor is excessive or the device is used in an environment that incurs severe shocks, the fixing arms  430  can be bent to engage with the fixing shelf  560   a , to increase coupling strength so that the stator portion  200  and the base portion  300  can more reliably maintain a coupled state. 
     Also, an adhesive may be applied to the coupling surfaces of the base portion  300  and the stator portion  200 , to more firmly couple the base portion  300  with the stator portion  200 . 
     Thus, the base portion  300  and the stator portion  200  are coupled not only mechanically chemically, so that there is not disruption in the electrical connection between the terminal  310  and the second circuit board  230 . 
     INDUSTRIAL APPLICABILITY 
     While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents.