Patent Publication Number: US-2023138542-A1

Title: Clothes treatment apparatus

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. application Ser. No. 16/957,866, filed Jun. 25, 2020, which is a national stage entry under 35 U.S.C. § 371 based on International Application No. PCT/KR2018/015555, filed Dec. 7, 2018, which claims priority to Korean Patent Application No. 10-2017-0168514, filed Dec. 8, 2017, and Korean Patent Application No. 10-2018-0148692, filed Dec. 8, 2017, the contents of each of the aforementioned applications are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a structure for vibrating clothes in a clothes treatment apparatus. 
     Discussion of the Related Art 
     A clothes treatment apparatus refers to all kinds of apparatuses for maintaining or treating clothes, such washing, drying, and dewrinkling them, at home or at a laundromat. Examples of clothes treatment apparatuses include a washer for washing clothes, a dryer for drying clothes, a washer-dryer which performs both washing and drying functions, a refresher for refreshing clothes, and a steamer for removing unnecessary wrinkles in clothes. 
     More specifically, the refresher is a device used for keeping clothes crisp and fresh, which performs functions like drying clothes, providing fragrance to clothes, preventing static cling on clothes, removing wrinkles from clothes, and so on. The steamer is generally a device that provides steam to clothes to remove wrinkles from them, which can remove wrinkles from clothes in a more delicate way, without the hot plate touching the clothes like in traditional irons. There is a known clothes treatment apparatus equipped with both the refresher and steamer functions, that functions to remove wrinkles and smells from clothes put inside it by using steam and hot air. 
     There is also a known clothes treatment apparatus that functions to smooth out wrinkles in clothes by vibrating (reciprocating) a hanging bar for clothes in a predetermined direction. 
     Technical Problem 
     A problem with the conventional art is that unnecessary vibrations occur in other directions than the direction of vibration when the hanging bar is vibrated. A first aspect of the present disclosure is to minimize unnecessary vibrations by solving this problem. 
     A second aspect of the present disclosure is to minimize unnecessary vibrations and efficiently increase the excitation force in the direction of vibration applied to the hanging bar. 
     Another problem with the conventional art is that amplitude is maintained even if the vibration frequency of the hanging bar is changed, thus putting stress on items. A third aspect of the present disclosure is reduce the stress on items caused by a change of frequency by solving this problem. 
     A fourth aspect of the present disclosure is to allow the hanging bar to move in a vibrating motion by adjusting it to various vibration frequencies and amplitudes when the hanging bar vibrates. 
     SUMMARY OF THE INVENTION 
     In order to address the aforementioned aspects, a clothes treatment apparatus according to an exemplary embodiment of the present disclosure comprises: a frame; 
     a hanger body configured to move with respect to the frame and provided to hang clothes or clothes hangers; a vibrating body configured to move with respect to the frame; a first eccentric portion that is supported by the vibrating body and rotates around a predetermined first rotational axis in such a way that the weight is off-center; a second eccentric portion that is supported by the vibrating body and rotates around a predetermined second rotational axis, which is the same as or parallel to the first rotational axis, in such a way that the weight is off-center; and a hanger driving unit that connects the vibrating body and the hanger body and transmits the vibration of the vibrating body to the hanger body, wherein the first eccentric portion and the second eccentric portion are configured to rotate at the same angular speed but in opposite directions. 
     In order to address the aforementioned aspects, a clothes treatment apparatus according to an exemplary embodiment of the present disclosure comprises: a frame; a hanger body configured to move with respect to the frame in a predetermined vibration direction (+X, −X) and provided to hang clothes or clothes hangers; and a vibration module generating vibrations, wherein the vibration module comprises: a vibrating body configured to move with respect to the frame; a first eccentric portion that is supported by the vibrating body and rotates around a predetermined first rotational axis in such a way that the weight is off-center; a second eccentric portion that is supported by the vibrating body and rotates around a predetermined second rotational axis, which is the same as or parallel to the first rotational axis, in such a way that the weight is off-center; and a hanger driving unit that connects the vibrating body and the hanger body and transmits the vibration of the vibrating body to the hanger body, wherein, when the first eccentric portion generates a centrifugal force toward one side D 1  in the vibration direction (+X, −X) with respect to the first rotational axis, the second eccentric portion generates a centrifugal force toward the one side D 1  with respect to the second rotational axis, and, when the first eccentric portion generates a centrifugal force toward one side D 2  in a direction (+Y, −Y) intersecting the vibration direction (+X, −X) with respect to the first rotational axis, the second eccentric portion generates a centrifugal force toward the opposite side of the one side D 2  with respect to the second rotational axis. 
     In order to address the aforementioned aspects, a clothes treatment apparatus according to an exemplary embodiment of the present disclosure comprises: a frame; a hanger body configured to move with respect to the frame in a predetermined vibration direction (+X, −X) and provided to hang clothes or clothes hangers; and a vibration module generating vibrations, wherein the vibration module comprises: a vibrating body configured to move with respect to the frame; a first eccentric portion that is supported by the vibrating body and rotates around a predetermined first rotational axis in such a way that the weight is off-center; a second eccentric portion that is supported by the vibrating body and rotates around a predetermined second rotational axis, which is the same as or parallel to the first rotational axis, in such a way that the weight is off-center; and a hanger driving unit that connects the vibrating body and the hanger body and transmits the vibration of the vibrating body to the hanger body, wherein, when the weight of the first eccentric portion is off-centered to one side D 1  in the vibration direction (+X, −X) with respect to the first rotational axis, the weight of the second eccentric portion is off-centered to the one side D 1  with respect to the second rotational axis, and, when the weight of the first eccentric portion is off-centered to one side D 2  in a direction (+Y, −Y) intersecting the vibration direction (+X, −X) with respect to the first rotational axis, the weight of the second eccentric portion is off-centered to the opposite side of the one side D 2  with respect to the second rotational axis. 
     In order to address the aforementioned aspects, a vibration module for a clothes treatment apparatus according to an exemplary embodiment of the present disclosure comprises: a vibrating body; a first eccentric portion that is supported by the vibrating body and rotates around a predetermined rotational axis in such a way that the weight is off-center; a second eccentric portion that is supported by the vibrating body and rotates around the rotational axis in such a way that the weight is off-center; and a hanger driving unit configured to connect the vibrating body and an external hanger body. 
     The hanger body may be configured to move with respect to the frame in a predetermined vibration direction (+X, −X), and the centrifugal force of the first eccentric portion with respect to the first rotational axis and the centrifugal force of the second eccentric portion with respect to the second rotational axis may be set to reinforce each other in the vibration direction (+X, −X) and offset each other in a direction (+Y, −Y) intersecting the vibration direction (+X, −X). 
     The centrifugal force of the first eccentric portion and the centrifugal force of the second eccentric portion may be set to completely offset each other in the direction (+Y, −Y) intersecting the vibration direction (+X, −X). 
     The first rotational axis and the second rotational axis may be the same. 
     The vibrating body may be configured to be fixed to the hanger body and move integrally with the hanger body. 
     The clothes treatment apparatus may further comprise a motor disposed on the vibrating body, the first rotational axis and the second rotational axis may be the same, and, when viewed from the direction in which the first rotational axis extends, the hanger driving unit is fixed to the hanger body, in a position between the center of mass of the motor and the first rotational axis. 
     The clothes treatment apparatus may comprise: a frame forming the external appearance and having a treatment space for storing clothes; a hanger module in an upper portion of the treatment space, configured to move with respect to the frame and provided to hang clothes or clothes hangers; a supporting member fixed to the frame and having a center axial portion protruding along a vertically-extending, center axis; and a vibration module rotatably fixed to the center axial portion of the supporting member and generating vibrations on the hanger module, wherein the vibration module comprises: a motor rotating with respect to a motor shaft perpendicular to the center axis; a first eccentric portion rotating in connection with the motor, which rotates around a first rotational axis, spaced apart from and in parallel with the center axis, in such a way that the weight is off-center; a second eccentric portion rotating in connection with the motor, which rotates around the first rotational axis in such a way that the weight is off-center toward the opposite direction of the first eccentric portion; a vibrating body that supports the motor, rotatably supports the first eccentric portion and the second eccentric portion, and moves clockwise or counterclockwise with respect to the center axis, by the centrifugal force of the first eccentric portion with respect to the first rotational axis and the centrifugal force of the second eccentric portion with respect to the second rotational axis; and a hanger driving unit that transmits a force generated by the movement of the vibrating body to the hanger module. 
     Advantageous Effects 
     Through the above means to solve the problems, the centrifugal force F 1  of the first eccentric portion and the centrifugal force F 2  of the second eccentric portion may reinforce each other and apply an excitation force Fo to the hanger body, if they cause a rotation of the vibrating body around the center axis, whereas the centrifugal force F 1  and the centrifugal force F 2  may offset each other and suppress vibrations generated by centrifugal force not related to the generation of excitation force Fo, if they cause no rotation of the vibrating body around the center axis (see  FIGS.  2   a  to  3   d   ). 
     It is possible to further minimize unnecessary vibrations generated in a direction (+Y, −Y) perpendicular to a predetermined vibration direction (+X, −X), because the centrifugal force F 1  and the centrifugal force F 2  are set to “completely offset” each other. 
     The first eccentric portion and the second eccentric portion are configured to rotate at the same angular speed, thereby allowing for periodic reinforcement and offsetting of the centrifugal forces F 1  and F 2  caused by the rotation of the first eccentric portion and second eccentric portion. 
     The angular speed of the first eccentric portion and the angular speed of the second eccentric portion are set equal but in opposite directions, thereby making it easy for the centrifugal force F 1  of the first eccentric portion and the centrifugal force F 2  of the second eccentric portion to reinforce or offset each other repeatedly. 
     The first eccentric portion and the second eccentric portion are configured to rotate around the same axis of rotation. Accordingly, the point of action at which the centrifugal force F 1  of the first eccentric portion and the centrifugal force F 2  of the second eccentric portion are applied can be positioned on a single rotational axis Ow 1  and Ow 2 , the centrifugal force F 1  and the centrifugal force F 2  can efficiently reinforce and offset each other, and it is possible to prevent a local moment load created by the horizontal distance difference between the point of action of the centrifugal force F 1  and the point of action of the centrifugal force F 2 . 
     Since the hanger driving unit is fixed to the hanger body, in a position between the center of mass of the motor and the first rotational axis, this can reduce torsion caused by the center of mass of the motor when an excitation force is transmitted to the hanger body from the vibration module, thereby creating more stable vibrating motion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a clothes treatment apparatus  1  according to an exemplary embodiment of the present disclosure. 
         FIGS.  2   a  to  3   d    are conceptual diagrams showing the operating principle of the vibration module  50  of  FIG.  1   :  FIGS.  2   a  to  2   d    are views showing the operating principle of the vibration module  350  according to a first exemplary embodiment; and  FIGS.  3   a  to  3   d    are views showing the operating principle of the vibration module  450  according to a second exemplary embodiment. 
         FIG.  4    is an exploded perspective view of an operating structure of an exemplary embodiment of the first eccentric portion  55  and second eccentric portion  56  of the vibration module  350  and  450  of  FIGS.  2   a    to  3   d.    
         FIG.  5    is a vertical cross-sectional view of the elements of  FIG.  4    in an assembled state. 
         FIG.  6    is a partial perspective view showing a structural example of the vibration module  350 , elastic member  360 , and supporting member  370  according to a first exemplary embodiment in  FIGS.  2   a  to  2   d   , from which the exterior frame  11   b  is omitted. 
         FIG.  7    is a top elevation view of the structural example of  FIG.  6   . 
         FIG.  8    is a perspective view showing the vibration module  350 , elastic member  360 , supporting member  370 , and hanger module  330  according to the structural example of  FIG.  6    and a partial cross-sectional view of the hanger driving unit  358  and hanger driven unit  331   b , horizontally taken along the line S 4 -S 4 ′. 
         FIG.  9    is a vertical cross-sectional view of the structural example of  FIG.  7   , taken along the line S 3 -S 3 ′. 
         FIG.  10    is a partial perspective view showing a structural example of the vibration module  450 , elastic member  460 , and supporting member  470  according to a second exemplary embodiment in  FIGS.  3   a  to  3   d   , from which the exterior frame  11   b  is omitted. 
         FIG.  11    is a top elevation view of the structural example of  FIG.  10   . 
         FIG.  12    is an elevation view of the vibration module  450 , elastic member  460 , supporting member  470 , and hanger module  430  according to the structural example of  FIG.  11    and a partial cross-sectional view of the hanger driving unit  458  and hanger driven unit  431   b , horizontally taken along the line S 5 -S 5 ′. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     To explain the present disclosure, a description will be made below with respect to a spatial orthogonal coordinate system where X, Y, and Z axes are orthogonal to each other. Each axis direction (X-axis direction, Y-axis direction, and Z-axis direction) refers to two directions in which each axis runs. Each axis direction with a ‘+’ sign in front of it (+X-axis direction, +Y-axis direction, and +Z-axis direction) refers to a positive direction which is one of the two directions in which each axis runs. Each axis direction with a ‘−’ sign in front of it (−X-axis direction, −Y-axis direction, and −Z-axis direction) refers to a negative direction which is the other of the two directions in which each axis runs. 
     The terms mentioned below to indicate directions such as “front(+Y)/back(−Y)/left(+X)/right(−X)/up(+Z)/down(−Z)” are defined by the X, Y, and Z coordinate axes, but they are merely used for a clear understanding of the present disclosure, and it is obvious that the directions may be defined differently depending on where the reference is placed. 
     The terms with ordinal numbers such as “first”, “second”, “third”, etc. added to the front are used to describe constituent elements mentioned below, are intended only to avoid confusion of the constituent elements, and are unrelated to the order, importance, or relationship between the constituent elements. For example, an embodiment including only a second component but lacking a first component is also feasible. 
     Th singular forms used herein are intended to include plural forms as well, unless the context clearly indicates otherwise. 
     Referring to  FIG.  1   , and  FIGS.  6  to  12   , a clothes treatment apparatus  1  according to an exemplary embodiment of the present disclosure comprises a frame  10  placed on a floor on the outside or fixed to a wall on the outside. The frame  10  has a treatment space  10   s  for storing clothes. The clothes treatment apparatus  1  comprises a supply part  20  for supplying at least one among air, steam, a deodorizer, and an anti-static agent to clothes. The clothes treatment apparatus  1  comprise a hanger module  30 ,  330 , and  430  provided to hang clothes or clothes hangers. The hanger module  30 ,  330 , and  430  is supported by the frame  10 . The clothes treatment apparatus  1  comprises a vibration module  50 ,  350 , and  450  for generating vibration. The vibration module  50 ,  350 , and  450  vibrates the hanger module  30 ,  330 , and  430 . The clothes treatment apparatus  1  comprises at least one elastic member  360  and  460  configured to elastically deform or regain its elasticity when the hanger module  30 ,  330 , and  430  moves. The elastic member  360  and  460  is configured to elastically deform or regain its elasticity when the vibration module  50 ,  350 , and  450  moves. The clothes treatment apparatus  1  comprises a supporting member  370  and  470  for supporting one end of the elastic member  360  and  460 . The supporting member  370  and  470  may movably support the vibration module  50 ,  350 , and  450 . The supporting member  370  and  470  may be fixed to the frame  10 . The clothes treatment apparatus  1  may comprise a control part (not shown) for controlling the operation of the supply part  20 . The control part may control whether to operate the vibration module  50 ,  350 , and  450  or not and its operating pattern. The clothes treatment apparatus  1  may further comprise a clothes recognition sensor (not shown) for sensing clothes contained inside the treatment space  10   s.    
     The frame  10  forms the external appearance. The frame  10  forms the treatment space  10   s  in which clothes are stored. The frame  10  comprises a top frame  11  forming the top side, a side frame  12  forming the left and right sides, and a rear frame (not shown) forming the rear side. The frame  10  comprises a base frame (not shown) forming the bottom side. 
     The frame  10  may comprise an interior frame  11   a  forming the inner side and an exterior frame  11   b  forming the outer side. The inner side of the interior frame  11   a  forms the treatment space  10   s . A configuration space  11   s  is formed between the interior frame  11   a  and the exterior frame  11   b . The vibration module  50 ,  350 , and  450  may be disposed within the configuration space  11   s . The elastic member  360  and  460  and the supporting member  370  and  470  may be disposed within the configuration space  11   s.    
     The treatment space  10   s  is a space in which air (for example, hot air), steam, a deodorizer, and/or an anti-static agent is applied to clothes so as to change physical or chemical properties of the clothes. Clothes treatment may be done on the clothes in the treatment space  10   s  by various methods—for example, applying hot air to the clothes in the treatment space  10  to dry the clothes, removing wrinkles on the clothes with steam, spraying a deodorizer to clothes to give them a fragrance, spraying an anti-static agent to clothes to prevent static cling on them. 
     At least part of the hanger module  30 ,  330 , and  430  is disposed within the treatment space  10   s . A hanger body  331  and  431  is disposed within the treatment space  10   s . One side of the treatment space  10   s  is open so that clothes can be taken in and out, and the open side is opened or closed by a door  15 . When the door  15  is closed, the treatment space  10   s  is separated from the outside, and when the door  15  is opened, the treatment space  10   s  is exposed to the outside. 
     The supply part  20  may supply air into the treatment space  10   s . The supply part  20  may circulate the air in the treatment space  10   s  while supplying it. Specifically, the supply part  20  may draw in air from inside the treatment space  10   s  and discharge it into the treatment space  10   s . The supply part  20   s  may supply outside air into the treatment space  10   s.    
     The supply part  20  may supply air that has undergone a predetermined treatment process into the treatment space  10   s . For example, the supply part  20  may supply heated air into the treatment space  10   s . The supply part  20  also may supply cooled air into the treatment space  10   s . Moreover, the supply part  20  may supply untreated air into the treatment space  10   s . Further, the supply part  20  may add steam, a deodorizer, or an anti-static agent to air and supply the air into the treatment space  10   s.    
     The supply part  20  may comprise an air intake opening  20   a  through which air is drawn in from inside the treatment space  10   s . The supply part  20  may comprise an air discharge opening  20   b  through which air is discharged into the treatment space  10   s . The air drawn in through the air intake opening  20   a  may be discharged through the air discharge opening  20   b  after a predetermined treatment. The supply part  20  may comprise a steam spout  20   c  for spraying steam into the treatment space  10   s . The supply part  20  may comprise a heater (not shown) for heating drawn-in air. The supply part  20  may comprise a filter (not shown) for filtering drawn-in air. The supply part  20  may comprise a fan (not shown) for pressurizing air. 
     The air and/or steam supplied by the supply part  20  is applied to the clothes stored in the treatment space  10   s  and affects the physical or chemical properties of the clothes. For example, the tissue structure of the clothes is relaxed by hot air or steam, so that the wrinkles are smoothed out, and an unpleasant odor is removed as odor molecules trapped in the clothes react with steam. In addition, the hot air and/or steam generated by the supply part  20  may sterilize bacteria present in the clothes. 
     Referring to  FIG.  1   ,  FIG.  8   ,  FIG.  9   , and  FIG.  12   , the hanger module  30 ,  330 , and  430  may be disposed above the treatment space  10   s . The hanger module  30 ,  330 , and  430  is provided to hang clothes or clothes hangers. The hanger module  30 ,  330 , and  430  is supported by the frame  10 . The hanger module  30 ,  330 , and  430  is movable. The hanger module  30 ,  330 , and  430  is connected to the vibration module  50 ,  350 , and  450  and receives vibrations from the vibration module  50 ,  350 , and  450 . 
     The hanger module  30 ,  330 , and  430  comprises a hanger body  331  and  431  provided to hang clothes or clothes hangers. In this exemplary embodiment, the hanger body  331  and  431  may be formed with locking grooves  31   a  for hanging clothes hangers, and, in another exemplary embodiment, the hanger body  331  and  431  may be formed with hooks (not shown) or the like so that clothes are hung directly on them. 
     The hanger body  331  and  431  is supported by the frame  10 . The hanger body  331 , and  431  may be connected to the frame  10  through a hanger moving portion  33  and a hanger supporting portion  35 . The hanger body  331  and  431  is configured to move with respect to the frame  10 . The hanger body  331  and  431  is configured to move (vibrate) with respect to the frame  10  in a predetermined vibration direction (+X, −X). The hanger body  331  and  431  may vibrate with respect to the frame  10  in the vibration direction (+X, −X). The hanger body  331  and  431  reciprocates in the vibration direction (+X, −X) by the vibration module  50 ,  350 , and  450 . The hanger module  30 ,  330 , and  430  reciprocates while hanging in an upper portion of the treatment space  10   s.    
     The hanger body  331  and  431  may extend longitudinally in the vibration direction (+X, −X). A plurality of locking grooves  31   a  may be disposed on the upper side of the hanger body  331  and  431 , spaced apart from each other, in the vibration direction (+X, −X). The locking grooves  31   a  may extend in a direction (+Y, −Y) intersecting the vibration direction (+X, −X). 
     The hanger module  30 ,  330 , and  430  may comprise a hanger moving portion  33  which movably supports the hanger body  331  and  431 . The hanger moving portion  33  is movable in the vibration direction (+X, −X). The hanger moving portion  33  may be made of a flexible material so as to make the hanger body  331  and  431  move. The hanger moving portion  33  may comprise an elastic member that is elastically deformable when the hanger body  331  and  431  moves. The upper end of the hanger moving portion  33  is fixed to the frame  10 , and the lower end is fixed to the hanger body  331  and  431 . The hanger moving portion  33  may extend vertically. The upper end of the hanger moving portion  33  rests on a hanger supporting portion  35 . The hanger moving portion  33  connects the hanger supporting portion  35  and the hanger body  331  and  431 . The hanger moving portion  33  is configured to vertically penetrate a hanger guide portion  37 . The length of a horizontal cross-section of the hanger moving portion  33  in the vibration direction (+X, −X) is shorter than its length in the direction (+Y, −Y) perpendicular to the vibration direction (+X, −X). 
     The hanger module  30 ,  330 , and  430  comprises a hanger supporting portion  35  fixed to the frame  10 . The hanger supporting portion  35  secures the hanger moving portion  33  to the frame  10 . The hanger supporting portion  35  may be fixed to the interior frame  11   a . The upper end of the hanger moving portion  33  may be locked and hung on the hanger supporting portion  35 . The hanger supporting portion  35  may be formed in the shape of a horizontal plate, and the hanger moving portion  33  may be configured to penetrate the hanger supporting portion  35 . 
     The hanger module  30 ,  330 , and  430  may further comprise a hanger guide portion  37  for guiding the position of the hanger moving portion  33 . The hanger guide portion  37  is fixed to the frame  10 . The gap between the upper side of the hanger guide portion  37  and the hanger moving portion  33  may be sealed. The lower portion of the hanger guide portion  37  has an upward recess formed in it, and the hanger moving portion  33  may move in the vibration direction (+X, −X) within the upward recess of the hanger guide portion  37 . 
     The vibration module  50 ,  350 , and  450  comprises a hanger driving unit  358  and  458  connected to the hanger module  30 ,  330 , and  430 . The hanger body  331  and  431  comprises a hanger driven unit  331   b  and  431   b  connected to the hanger driving unit  358  and  458 . 
     Referring to  FIGS.  8  and  9   , the hanger driving unit  358  and hanger driven unit  331   b  according to a first exemplary embodiment of the present disclosure will be described below. Either the hanger driving unit  358  or the hanger driven unit  331   b  has a slit that extends in the direction (+Y, −Y) intersecting the vibration direction (+X, −X), and the other has a protruding portion that protrudes in parallel with a center axis Oc to be described later and is inserted into the slit. In this exemplary embodiment, the hanger driven unit  331   b  has a slit  331   bh  that extends in the direction (+Y, −Y), and the hanger driving unit  358  comprises a protruding portion  358   a  that protrudes downward and is inserted into the slit  331   bh . Although not shown, another exemplary embodiment may be given in which the hanger driven unit has a slit that extends in the direction (+Y, −Y) and the hanger driving unit comprises a protruding portion that protrudes upward and is inserted into the slit of the hanger driving unit. 
     In the first exemplary embodiment, the protruding portion  358   a  protrudes in parallel with the center axis Oc. The protruding portion  358   a  extends along a predetermined connection axis Oh to be described later. The protruding portion  358   a  is disposed on the connection axis Oh. The slit  331   bh  is formed longitudinally in the direction (+Y, −Y) perpendicular to the vibration direction (+X, −X) of the hanger module  330 . When the protruding portion  358   a  rotates with respect to the center axis Oc while inserted in the slit  331   bh , the protruding portion  358   a  moves relative to the slit  331   bh  in the perpendicular direction (+Y, −Y), causing the hanger body  331  to reciprocate in the vibration direction (+X, −X). In the partial cross-sectional views of  FIG.  8   , the direction in which the protruding portion  358   a  inserted in the slit  331   bh  moves in an arc (rotates) within a predetermined range is indicated by an arrow, and therefore the range of movement of the hanger driven unit  331   b  vibrating in the left-right direction (+X, −X) is indicated by a dotted line. 
     Referring to  FIG.  12   , the hanger driving unit  458  and hanger driven unit  431   b  according to a second exemplary embodiment will be described below. The hanger driving unit  458  connects and holds together the vibrating body  451  and the hanger body  431 . The hanger driving unit  458  may connect and hold together a lower portion of the vibrating body  451  and the center of the hanger body  431 . Therefore, the vibrating body  451  and the hanger body  431  vibrate as a single unit. 
     In the second exemplary embodiment, the hanger driving unit  458  may extend in parallel with a center axis Oc. The hanger driving unit  458  may be in the shape of a bar. The hanger driving unit  458  may extend along a predetermined connection axis Oh to be described later. The hanger driving unit  458  may be disposed on the connection axis Oh. The hanger driven unit  431   b  may be in the shape of a casing that is open at the top. The hanger driving unit  458  is fixed to the hanger driven unit  431   b . The upper end of the hanger driving unit  458  is fixed to the vibrating body  451 , and the lower end is fixed to the hanger driven unit  431   b . When the hanger driving unit  458 , while fixed to the hanger driven unit  431   b , reciprocates in the vibration direction (+X, −X) of the vibrating body  451 , the hanger body  431  reciprocates in the vibration direction (+X, −X), integrally with the vibrating body  451 . In the partial cross-sectional view of  FIG.  12   , the direction in which the hanger driving unit  458  linearly reciprocates is indicated by an arrow, and therefore the range of movement of the hanger driven unit  431   b  vibrating in the left-right direction (+X, −X) is indicated by a dotted line. 
     Referring to  FIGS.  6  to  12   , the elastic member  360  and  460  is configured to elastically deform or regain its elasticity when the vibration module  50 ,  350 , and  450  vibrates. The elastic member  360  and  460  is configured to elastically deform or regain its elasticity when a vibrating body  351  and  451  vibrates. The elastic member  360  and  460  may restrict the vibration of the vibration module  50 ,  350 , and  450  to a predetermined range. The vibration pattern (amplitude and vibration frequency) of the vibration module  50 ,  350 , and  450  may be determined by putting together the elastic force of the elastic member  360  and  460  and the centrifugal force of the first eccentric portion  55  and second eccentric portion  56 . 
     One end of the elastic member  360  and  460  is fixed to the vibration module  50 ,  350 , and  450 , and the other end is fixed to a supporting member  370  and  470 . The elastic member  360  and  460  may comprise a spring or a mainspring. The supporting member  370  and  470  may comprise a tension spring, a compression spring, or a torsion spring. 
     Referring to  FIGS.  6  to  9   , the elastic member  360  according to the first exemplary embodiment is configured to elastically deform or regain its elasticity when the vibration module  350  rotates around the center axis Oc. The elastic member  360  is configured to elastically deform or regain its elasticity when the vibrating body  351  rotates around the center axis Oc. The elastic member  360  may restrict the vibration of the vibration module  350  to a predetermined angular range. 
     Referring to  FIGS.  10  to  12   , the elastic member  460  according to the second exemplary embodiment is configured to elastically deform or regain its elasticity when the vibration module  450  reciprocates in the vibration direction (+X, −X). The elastic member  460  is configured to elastically deform or regain its elasticity when the vibrating body  451  reciprocates in the vibration direction (+X, −X). The elastic member  460  may restrict the vibration of the vibration module  450  to a predetermined distance range. 
     Referring to  FIGS.  6  to  12   , the supporting member  370  and  470  is fixed to the frame  10 . The supporting member  370  and  470  may be fixed to the interior frame  11   a . The supporting member  370  and  470  may support the elastic member  360  and  460 . 
     Referring to  FIGS.  6  to  9   , the supporting member  370  according to the first exemplary embodiment supports the vibration module  350 . The vibration module  350  may be supported by the interior frame  11   a . The vibration module  350  may be fixed to the frame  10  by the supporting member  370 . The supporting member  370  movably supports the vibration module  350 . The supporting member  370  rotatably supports the vibration module  350 . The supporting member  370  supports the vibration module  350  in such a way as to make it movable around the center axis Oc. The supporting member  370  supports the vibrating body  351 . The vibrating body  351  may be connected to the frame  10  by the supporting member  370 . 
     Referring to  FIGS.  10  to  12   , the supporting member  470  according to the second exemplary embodiment does not need to support the vibration module  450 . The vibration module  450  may be supported by the hanger module  430 . The supporting member  470  may slidably support the vibration module  450 . The supporting member  470  may guide the vibration direction (+X, −X) of the vibration module  450 . The supporting member  470  may function as a guide that restricts the movement of the vibration module  450  in a direction other than a predetermined direction (+X, −X). 
     Referring to  FIGS.  2   a    to  5 , the vibration module  50 ,  350 , and  450  will be briefly described below. The vibration module  50 ,  350 , and  450  moves (vibrates) the hanger body  331  and  431 . The vibration module  50 ,  350 , and  450  is connected to the hanger body  331  and  431 , and transmits vibrations from the vibration module  50 ,  350 , and  450  to the hanger body  331  and  431 . 
     The vibration module  50 ,  350 , and  450  may be disposed between the interior frame  11   a  and the exterior frame  11   b . The interior frame  11   a  on the upper side may be recessed downward to form the configuration space  11   s , and the vibration module  50 ,  350 , and  450  may be disposed in the configuration space  11   s.    
     The vibration module  50 ,  350 , and  450  may be located above the treatment space  10   s . The vibration module  50 ,  350 , and  450  may be disposed above the hanger body  331  and  431 . 
     The vibration module  50 ,  350 , and  450  comprises a vibrating body  351  and  451  configured to move with respect to the frame  10 . The vibrating body  351  and  451  forms the outer appearance of the vibration module  50 ,  350 , and  450 . 
     A predetermined center axis Oc is preset on the vibrating body  351  according to the first exemplary embodiment. The vibrating body  351  is configured in such a way as to rotate around a predetermined center axis Oc where the position relative to the frame  10  is fixed. The supporting member  370  rotatably supports the vibrating body  351 . The vibrating body  351  may be configured to rotate only within a predetermined angular range. For example, the frame  10  or the supporting member  370  may comprise a limit portion that can come into contact with the vibrating body  351 , so as to restrict the range of rotation of the vibrating body  351 . In another example, the elastic force of the elastic member  360  increases as the vibrating body  351  rotates, thus limiting the range of rotation of the vibrating body  351 . 
     The center axis Oc is not preset on the vibrating body  451  according to the second exemplary embodiment. The position of the vibrating body  451  relative to the hanger body  431  is fixed. The hanger driving unit  458  connects and holds the vibrating body  451  and the hanger body  431  together. The vibrating body  451  may be configured to reciprocate only within a predetermined distance range. For example, the frame  10  or the supporting member  470  may comprise a limit portion that can come into contact with the vibrating body  451 , so as to restrict the range of reciprocating motion of the vibrating body  451 . In another example, the elastic force of the elastic member  460  increases as the vibrating body  451  moves, thus limiting the range of movement (vibration) of the vibrating body  451 . 
     The vibrating body  351  and  451  supports the motor  52 . The vibrating body  351  and  451  and the hanger driving unit  358  and  458  are fixed to each other. The vibrating body  351  and  451  supports a weight shaft  54 . The vibrating body  351  and  451  supports a first eccentric portion  55  and a second eccentric portion  56 . The vibrating body  351  and  451  may accommodate the first eccentric portion  55  and the second eccentric portion  56  in it. 
     The vibrating body  351  and  451  may comprise a weight casing  51   b  containing the first eccentric portion  55  and the second eccentric portion  56  in it. The weight casing  51   b  may comprise a first part  51   b   2  forming an upper portion and a second part  51   b   1  forming a lower portion. The second part  51   b   1  may form an inner space forming the bottom surface and peripheral surface, and the first part  51   b   2  may cover the top of the inner space. The first eccentric portion  55  and the second eccentric portion  56  may be disposed vertically in the inner space of the weight casing  51   b . The weight casing  51   b  may be attached to the motor  52 . A hole through which the motor shaft  52   a  is inserted may be formed in one side of the weight casing  51   b.    
     The vibration module  50 ,  350 , and  450  may comprise a motor  52  that generates torque for the first eccentric portion  55  and second eccentric portion  56 . The motor  52  is disposed on the vibrating body  351  and  451 . The motor  52  comprises a rotating motor shaft  52   a . For example, the motor  52  comprises a rotor and a stator, and the motor shaft  52   a  may rotate integrally with the rotor. The motor shaft  52   a  transmits torque to a transmitting portion  53 . The motor shaft  52   a  is inserted and protrudes between the first eccentric portion  55  and the second eccentric portion  56 . The motor shaft  52   a  is connected to the transmitting portion  53 . 
     The vibration module  50 ,  350 , and  450  may comprise a transmitting portion  53  that transmits the torque of the motor  52  to the first eccentric portion  55  and second eccentric portion  56 . The transmitting portion  53  is disposed on the vibrating body  351  and  451 . The transmitting portion  53  may comprise a gear, belt, and/or pulley. 
     The transmitting portion  53  comprises a bevel gear  53   a  that rotates integrally with the motor shaft  52   a . The bevel gear  53   a  has a plurality of gear teeth arranged along the perimeter of the motor shaft  52   a . Assuming that there is an imaginary straight line along the axis of rotation of the motor shaft  52   a , the bevel gear  53   a  has a plurality of gear teeth that slope towards the imaginary straight line in the direction the motor shaft  52   a  protrudes. The bevel gear  53   a  is placed between the first eccentric portion  55  and the second eccentric portion  56 . 
     The transmitting portion  53  may comprise a transmission shaft  53   g  that rotatably supports the bevel gear  53   a . The transmission shaft  53   g  may be supported by the weight shaft  54 . One end of the transmission shaft  53   g  may be fixed to the weight shaft  54 , and the other end may be inserted into the center of the bevel gear  53   a . The transmission shaft  53   g  may be fixed to the center of the weight shaft  54 . The transmission shaft  53   g  may be placed between the first eccentric portion  55  and the second eccentric portion  56 . 
     The vibration module  50 ,  350 , and  450  comprises a first eccentric portion  55  that rotates around a predetermined first rotational axis Ow 1  in such a way that the weight is off-center. The first eccentric portion  55  is configured to rotate around the first rotational axis Ow 1  in such a way that the weight is off-center. The vibration module  50 ,  350 , and  450  comprises a second eccentric portion  56  that rotates around a predetermined second rotational axis Ow 2  in such a way that the weight is off-center. The second eccentric portion  56  is configured to rotate around the second rotational axis Ow 2  in such a way that the weight is off-center. The first rotational axis Ow 1  and the second rotational axis Ow 2  may be the same or different. 
     The second rotational axis Ow 2  is set to be the same as or parallel to the first rotational axis Ow 1 . While the first rotational axis Ow 1  and the second rotational axis Ow 2  in this exemplary embodiment are the same, the first rotational axis Ow 1  and the second rotational axis Ow 2  in other exemplary embodiments may be placed apart in parallel with each other. This makes it easy for the centrifugal force F 1  of the first eccentric portion  55  and the centrifugal force F 2  of the second eccentric portion  56  to reinforce or offset each other repeatedly. 
     In this exemplary embodiment, the first rotational axis Ow 1  and the second rotational axis Ow 2  are the same. Through this, the point of action at which the centrifugal force F 1  of the first eccentric portion  55  and the centrifugal force F 2  of the second eccentric portion  56  are applied can be positioned on a single rotational axis Ow 1 , the centrifugal force F 1  and the centrifugal force F 2  can efficiently reinforce and offset each other, and it is possible to prevent a local moment load created by the horizontal distance difference between the point of action of the centrifugal force F 1  and the point of action of the centrifugal force F 2 . 
     The first rotational axis Ow 1  and the second rotational axis Ow 2  may be disposed in the same direction relative to the motor  52 . 
     The first eccentric portion  55  is supported by the vibrating body  351  and  451 . The first eccentric portion  55  may be rotatably supported by the weight shaft  54  disposed on the vibrating body  351  and  451 . The second eccentric portion  56  is supported by the vibrating body  351  and  451 . The second eccentric portion  56  may be rotatably supported by the weight shaft  54  disposed on the vibrating body  351  and  451 . 
     The first eccentric portion  55  comprises a first rotating portion  55   b  rotating around the first rotational axis Ow 1  in contact with the transmitting portion  53 . The first rotating portion  55   b  receives torque from the transmitting portion  53 . The first rotating portion  55   b  may be formed entirely in the shape of a cylinder around the first rotational axis Ow 1 . 
     The first rotating portion  55   b  may comprise a center portion  55   b   1  that makes rotatable contact with the weight shaft  54 . The weight shaft  54  is placed to penetrate the center portion  55   b   1 . The center portion  55   b   1  extends along the rotational axis Ow 1  and Ow 2 . The center portion  55   b   1  has a center hole along the rotational axis Ow 1  and Ow 2 . The center portion  55   b   1  may be formed in the shape of a pipe. 
     The first rotating portion  55   b  may comprise a peripheral portion  55   b   2  mounted to the center portion  55   b   1 . The center portion  55   b   1  is placed to penetrate the peripheral portion  55   b   2 . The peripheral portion  55   b   2  may be formed entirely in the shape of a cylinder that extends along the rotational axis Ow 1  and Ow 2 . A mounting groove  55   b   3  where the first weight member  55   a  rests may be formed in the peripheral portion  55   b   2 . The mounting groove  55   b   3  may be formed in such a way that its top is open. A centrifugal side of the mounting groove  55   b   3  around the rotational axis Ow 1  and Ow 2  may be blocked. The peripheral portion  55   b   2  and the first weight member  55   a  rotate as a single unit. 
     The first eccentric portion  55  comprises a toothed portion  55   b   4  that receives torque by meshing with the bevel gear  53   a . The toothed portion  55   b   4  is formed on the underside of the peripheral portion  55   b   2 . The toothed portion  55   b   4  is placed on the perimeter around the rotational axis Ow 1  and Ow 2 . The toothed portion  55   b   4  slopes upward from the rotational axis Ow 1  and Ow 2 . 
     The first eccentric portion  55  comprises a first weight member  55   a  fixed to the first rotating portion  55   b . The first weight member  55   a  rotates integrally with the first rotating portion  55   b . The first weight member  55   a  is made of a material with a higher specific gravity than the first rotating portion  55   b.    
     The first weight member  55   a  is placed on one side around the first rotational axis Ow 1 , and causes the weight of the first eccentric portion  55  to be off-centered. The first weight member  55   a  may be formed entirely in the shape of a column whose base is semi-circular. The first weight member  55   a  may be disposed within an angular range of 180 degrees with respect to the first rotational axis Ow 1 , at a certain point in time during rotation of the first eccentric portion  55 . In this exemplary embodiment, the first weight member  55   a  is disposed within the range of 180 degrees with respect to the first rotational axis Ow 1 , at the certain point in time. 
     The second eccentric portion  56  comprises a second rotating portion  56   b  rotating around the second rotational axis Ow 2  in contact with the transmitting portion  53 . The second rotating portion  56   b  receives torque from the transmitting portion  53 . The second rotating portion  56   b  may be formed entirely in the shape of a cylinder around the second rotational axis Ow 2 . 
     The second eccentric portion  56  comprises a center portion  56   b   1  that makes rotatable contact with the weight shaft  54 . The weight shaft  54  is placed to penetrate the center portion  56   b   1 . The center portion  56   b   1  extends along the rotational axis Ow 1  and Ow 2 . The center portion  56   b   1  has a center hole along the rotational axis Ow 1  and Ow 2 . The center portion  56   b   1  may be formed in the shape of a pipe. 
     The second rotating portion  56   b  may comprise a peripheral portion  56   b   2  mounted to the center portion  56   b   1 . The center portion  56   b   1  is placed to penetrate the peripheral portion  56   b   2 . The peripheral portion  56   b   2  may be formed entirely in the shape of a cylinder that extends along the rotational axis Ow 1  and Ow 2 . A mounting groove  56   b   3  where the second weight member  56   a  rests may be formed in the peripheral portion  56   b   2 . The mounting groove  56   b   3  may be formed in such a way that its bottom is open. A centrifugal side of the mounting groove  56   b  around the rotational axis Ow 1  and Ow 2  may be blocked. The peripheral portion  56   b   2  and the second weight member  56   a  rotate as a single unit. 
     The second eccentric portion  56  comprises a toothed portion  56   b   4  that receives torque by meshing with the bevel gear  53   a . The toothed portion  56   b   4  is formed on the topside of the peripheral portion  56   b   2 . The toothed portion  56   b   4  is placed on the perimeter around the rotational axis Ow 1  and Ow 2 . The toothed portion  56   b   4  slopes downward from the rotational axis Ow 1  and Ow 2 . 
     The second eccentric portion  56  comprises a second weight member  56   a  fixed to the second rotating portion  56   b . The second weight member  56   a  rotates integrally with the second rotating portion  56   b . The second weight member  56   a  is made of a material with a higher specific gravity than the second rotating portion  56   b.    
     The second weight member  56   a  is placed on one side with respect to the second rotational axis Ow 2 , and causes the weight of the second eccentric portion  56  to be off-centered. The second weight member  56   a  may be formed entirely in the shape of a column whose base is semi-circular. The second weight member  56   a  may be disposed within an angular range of 180 degrees with respect to the second rotational axis Ow 2 , at a certain point in time during rotation of the second eccentric portion  56 . In this exemplary embodiment, the second weight member  56   a  is disposed within the range of 180 degrees with respect to the second rotational axis Ow 2 , at the certain point in time. 
     The first eccentric portion  55  and the second eccentric portion  56  may be arranged along the center axis Oc, spaced apart from each other. The first eccentric portion  55  and the second eccentric portion  56  may be placed to face each other. The first eccentric portion  55  may be placed above the second eccentric portion  56 . 
     The first rotating portion  55   b  and the second rotating portion  56   b  may be the same weight. The first weight member  55   a  and the second weight member  56   a  may be the same weight. 
     Referring to  FIG.  5   , when the motor shaft  52   a  and the bevel gear  53   a  rotate in one direction, the first eccentric portion  55  rotates counterclockwise and the second eccentric portion  56  rotates clockwise. The first eccentric portion  55  and the second eccentric portion  56  rotate in opposite directions. 
     The vibration module  50 ,  350 , and  450  may comprise a weight shaft  54  that provides function to the first rotational axis Ow 1  and second rotational axis Ow 2 . One weight shaft  54  may provide function to both the first rotational axis Ow 1  and second rotational axis Ow 2 . The weight shaft  54  may be fixed to the vibrating body  351  and  451 . The upper and lower ends of the weight shaft  54  may be fixed to the weight casing  51   b . The weight shaft  54  is disposed on the first rotational axis Ow 1  and the second rotational axis Ow 2 . The weight shaft  54  may be placed to penetrate the first eccentric portion  55  and the second eccentric portion  56 . 
     The vibration module  50 ,  350 , and  450  comprises a hanger driving unit  358  and  458  that connects the vibrating body  351  and  451  and the hanger body  331  and  431 . The hanger driving unit  358  and  458  is configured to connect the vibrating body  351  and  451  and the hanger body  331  and  431  outside the vibration module  50 ,  350  and  450 . The hanger driving unit  358  and  458  transmits the vibration of the vibrating body  351  and  451  to the hanger body  331  and  431 . The hanger driving unit  358  and  458  may transmit the vibration of the vibrating body  351  and  451  to the hanger body  331  and  431 , along the connection axis Oh. 
     The vibration module  50 ,  350 , and  450  comprises an elastic member locking portion  359  and  459  on which one end of the elastic member  360  and  460  is locked. The elastic member locking portion  359  and  459  may be disposed on the vibrating body  351  and  451 . The elastic member locking portion  359  and  459  may apply pressure to the elastic member  360  and  460  or receive elastic force from the elastic member  360  and  460 , when the vibration module  50 ,  350 , and  450  moves. 
     Hereinafter, the operating mechanism of the vibration module  50 ,  350 , and  450  will be described below with reference to  FIGS.  2   a    to  3   d.    
     The vibration direction (+X, −X) refers to a preset direction in which the hanger body  331  and  431  reciprocates. In this exemplary embodiment, the left-right direction is preset as the vibration direction (+X, −X). 
     The “center axis Oc, first rotational axis Ow 1 , second rotational axis Ow 2 , and connection axis Oh mentioned throughout the present disclosure are imaginary axes used to describe the present disclosure, and do not designate actual components of the apparatus. 
     The first rotational axis Ow 1  refers to an imaginary straight line through the center of rotation of the first eccentric portion  55 . The first rotational axis Ow 1  maintains a fixed position relative to the vibrating body  351  and  451 . That is, even when the vibrating body  351  and  451  moves, the first rotational axis Ow 1  moves integrally with the vibrating body  351  and  451  and maintains the position relative to the vibrating body  351  and  451 . The first rotational axis Ow 1  may extend vertically. 
     To provide the function of the first rotational axis Ow 1 , the weight shaft  54  disposed on the first rotational axis Ow 1  may be provided as in this exemplary embodiment. To provide the function of the first rotational axis Ow 1 , in another exemplary embodiment, a projection protruding along the first rotational axis Ow 1  may be formed on either the first eccentric portion  55  or the vibrating body  351  and  451 , and a groove with which the projection rotatably engages may be formed in the other. 
     The second rotational axis Ow 2  refers to an imaginary straight line through the center of rotation of the second eccentric portion  56 . The second rotational axis Ow 2  maintains a fixed position relative to the vibrating body  351  and  451 . That is, even when the vibrating body  351  and  451  moves, the second rotational axis Ow 2  moves integrally with the vibrating body  351  and  451  and maintains the position relative to the vibrating body  351  and  451 . The second rotational axis Ow 2  may extend vertically. 
     To provide the function of the second rotational axis Ow 2 , the weight shaft  54  disposed on the second rotational axis Ow 2  may be provided as in this exemplary embodiment. To provide the function of the second rotational axis Ow 2 , in another exemplary embodiment, a projection protruding along the second rotational axis Ow 2  may be formed on either the second eccentric portion  56  or the vibrating body  351  and  451 , and a groove with which the projection rotatably engages may be formed in the other. 
     The first rotational axis Ow 1  and the second rotational axis Ow 2  may be disposed perpendicular to the vibration direction (+X, −X). In this exemplary embodiment, the first rotational axis Ow 1  and the second rotational axis Ow 2  may extend vertically. 
     The connection axis Oh refers to an imaginary straight line through the point at which excitation force Fo is applied to the hanger body  351  and  451  by the vibration generated by the vibration module  50 ,  350 , and  450 . The connection axis Oh may be defined as a straight line that passes through the point of action of excitation force Fo and extends vertically. The connection axis Oh maintains a fixed position relative to the vibrating body  351  and  451 . That is, even when the vibrating body  351  and  451  moves, the connection axis Oh moves integrally with the vibrating body  351  and  451  and maintains the position relative to the vibrating body  351  and  451 . 
       FIGS.  2   a  to  3   d    illustrate the center m 1  of mass of the first eccentric portion  55 , the center m 2  of mass of the second eccentric portion  56 , the radius r 1  of rotation of the center m 1  of mass with respect to the first rotational axis Ow 1 , the radius r 2  of rotation of the center m 2  of mass with respect to the second rotational axis Ow 2 , the angular speed w of the first eccentric portion  55  around the first rotational axis Ow 1 , the angular speed w of the second eccentric portion  56  around the second rotational axis Ow 2 , the distance A 1  between the center axis Oc and the first rotational axis Ow 1 , the distance A 2  between the center axis Oc and the second rotational axis Ow 2 , and the distance B between the center axis Oc and the connection axis Oh. 
     Also,  FIGS.  2   a  to  3   d    illustrate the direction of the centrifugal force F 1  of the first eccentric portion  55  with respect to the first rotational axis Ow 1  and the direction of the centrifugal force F 2  of the second eccentric portion  56  with respect to the second rotational axis Ow 2 . The sum of the centrifugal force F 1  and centrifugal force F 2  is applied to the vibrating body  351  and  451 . The excitation force Fo refers to a force applied to the hanger body  331  and  431  by the centrifugal forces F 1  and F 2 . 
     The magnitude of the centrifugal force F 1  is m 1 ·r 1 ·w 2 , and the magnitude of the centrifugal force F 2  is m 2 ·r 2 ·w 2 . The centrifugal force F 1  and the centrifugal force F 2  are exerted on the vibrating body  351  and  451 , and the points of action of the centrifugal force F 1  and centrifugal force F 2  are positioned on the first rotational axis Ow 1  and second rotational axis O 2 , respectively. 
     Referring to  FIG.  2   a   ,  FIG.  2   c   ,  FIG.  3   a   , and  FIG.  3   c   , the centrifugal force F 1  and the centrifugal force F 2  are set to reinforce each other in the vibration direction (+X, −X). When the weight of the first eccentric portion  55  is off-centered to one side D 1  in the vibration direction (+X, −X) from the first rotational axis Ow 1 , the weight of the second eccentric portion  56  is off-centered to the one side D 1  with respect to the second rotational axis Ow 2 . When the first eccentric portion  55  generates a centrifugal force F 1  toward one side D 1  in the vibration direction (+X, −X) with respect to the first rotational axis Ow 1 , the second eccentric portion  56  generates a centrifugal force F 2  toward the one side D 1  with respect to the second rotational axis Ow 2 . 
     Referring to  FIG.  2   b   ,  FIG.  2   d   ,  FIG.  3   b   , and  FIG.  3   d   , the centrifugal force F 1  and the centrifugal force F 2  are set to offset each other in a direction (+Y, −Y) intersecting the vibration direction (+X, −X). When the weight of the first eccentric portion  55  is off-centered to one side D 2  in the direction (+Y, −Y) intersecting the vibration direction (+X, −X) with respect to the first rotational axis Ow 1 , the weight of the second eccentric portion  56  is off-centered to the opposite side of the one side D 2  from the second rotational axis Ow 2 . When the first eccentric portion  55  generates a centrifugal force F 1  toward one side D 2  in the direction (+Y, −Y) intersecting the vibration direction (+X, −X) with respect to the first rotational axis Ow 1 , the second eccentric portion  56  generates a centrifugal force F 2  toward the opposite side of the one side D 2  with respect to the second rotational axis Ow 2 . Here, the intersecting direction (+Y, −Y) is a direction perpendicular to the vibration direction (+X, −X) and the rotational axis Ow 1  and Ow 2 . 
     The centrifugal force F 1  and the centrifugal force F 2  are set to offset each other when they generate no excitation force Fo in a predetermined vibration direction (+X, −X). In this case, the centrifugal force F 1  and the centrifugal force F 2  act in opposite directions, and therefore the sum of the centrifugal forces F 1  and F 2  is equal to the difference between the magnitude of the centrifugal force F 1  and the magnitude of the centrifugal force F 2 . Thus, at least one of the centrifugal forces F 1  and F 2  is offset by the other. 
     Preferably, the centrifugal force F 1  and the centrifugal force F 2  are set to “completely offset” each other when they generate no excitation force Fo in a predetermined vibration direction (+X, −X). The centrifugal force of the first eccentric portion and the centrifugal force of the second eccentric portion are set to completely offset each other in the direction (+Y, −Y) intersecting the vibration direction (+X, −X). Here, the expression “completely offset” means that the sum of the centrifugal force F 1  and centrifugal force F 2  is zero. This can minimize unnecessary vibrations generated in a direction (+Y, −Y) perpendicular to a predetermined vibration direction (+X, −X). 
     In order for the centrifugal force F 1  and the centrifugal force F 2  to completely offset each other when they generate no excitation force Fo in the vibration direction (+X, −X), the scalar quantity m 1 ·r 1  and the scalar quantity m 2 ·r 2  may be set equal. 
     i) The radius r 1  of rotation of the center m 1  of mass of the first eccentric portion  55  with respect to the first rotational axis Ow 1 ; and ii) the radius r 2  of rotation of the center m 2  of mass of the second eccentric portion  56  with respect to the second rotational axis Ow 2  may be set equal (r 1 =r 2 ). The mass m 1  of the first eccentric portion  55  and the mass m 2  of the second eccentric portion  56  may be set equal (m 1 =m 2 ). By these two settings (r 1 =r 2 , m 1 =m 2 ), the centrifugal force F 1  and centrifugal force F 2  in the intersecting direction (+Y, −Y) may completely offset each other. Even if the radius r 1  of rotation and the radius r 2  of rotation are different and the mass m 1  and the mass m 2  are different, the settings r 1 =r 2  and m 1 =m 2  allow the centrifugal force F 1  and centrifugal force F 2  in the intersecting direction (+Y, −Y) to completely offset each other. 
     i) the distance A 1  between the first rotational axis Ow 1 ; and ii) the center axis Oc and the distance A 2  between the second rotational axis Ow 2  and the center axis Oc may be set equal. Through this, the centrifugal force F 1  and centrifugal force F 2  contribute to the generation of excitation force Fo in equal proportions, thereby preventing fatigue load from concentrating on either the region supporting the first eccentric portion  55  or the region supporting the second eccentric portion  56 . 
     The first eccentric portion  55  and the second eccentric portion  56  may be configured to rotate at the same angular speed. i) The angular speed w of the first eccentric portion  55  around the first rotational axis Ow 1 ; and ii) the angular speed w of the second eccentric portion  56  around the second rotational axis Ow 2  may be set equal. This allows for periodic reinforcement and offsetting of the centrifugal forces F 1  and F 2  caused by the rotation of the first eccentric portion  55  and second eccentric portion  56 . 
     Here, the angular speed refers to a scalar which only has magnitude but no direction of rotation, which is different from angular velocity which is a vector having both direction of rotation and magnitude. That is, if the angular speed w of the first eccentric portion  55  and the angular speed w of the second eccentric portion  56  are equal, this does not mean that they rotate in the same direction. In this exemplary embodiment, even if the angular speed w of the first eccentric portion  55  and the angular speed w of the second eccentric portion  56  are equal, the first eccentric portion  55  and the second eccentric portion  56  rotate in opposite directions. 
     Hereinafter, the operating mechanism of the vibration module  350  according to the first exemplary embodiment will be described below in more concrete details with reference to  FIGS.  2   a  to  2   d   . The vibrating body  351  is configured to rotate around a predetermined center axis Oc where the position relative to the frame  10  is fixed. 
     In the first exemplary embodiment, the center axis Oc refers to an imaginary straight line through the center of rotation of the vibration module  350 . The center axis Oc is an imaginary straight line that maintains a fixed position relative to the frame  10 . The center axis Oc may extend vertically. 
     To provide the function of the center axis Oc, a center axial portion  375  protruding along the center axis Oc may be formed on the supporting member  370 , and a central groove or hole with which the center axial portion  375  rotatably engages may be formed in the vibrating body  351 , as in the first exemplary embodiment. To provide the function of the center axis Oc, in another exemplary embodiment, a projection protruding along the center axis Oc may be formed on the vibrating body  351 , and a groove with which the projection rotatably engages may be formed in the supporting member  370 . 
     In the first exemplary embodiment, the first rotational axis Ow 1  and the second rotational axis Ow 2  may be spaced apart from the center axis Oc in the same direction. Even if the first rotational axis Ow 1  and the second rotational axis Ow 2  are not the same, the reinforcement and offsetting of the centrifugal force F 1  and the centrifugal force F 2  may be repeated periodically, as long as the first rotational axis Ow 1  and the second rotational axis Ow 2  are placed apart from the center axis Oc in the same direction and the first eccentric portion  55  and the second eccentric portion  56  rotate at the same angular speed in opposite directions around the first rotational axis Ow 1  and second rotational axis Ow 2 , respectively. 
     In the first exemplary embodiment, the center axis Oc, the first rotational axis Ow 1 , and the second rotational axis Ow 2  are disposed to cross one imaginary straight line at a right angle. 
     In the first exemplary embodiment, the circumferential direction DI refers to the direction of a perimeter around the center axis Oc, and encompasses the clockwise direction DI 1  and the counterclockwise direction DI 2 . In the first exemplary embodiment, the clockwise direction DI 1  and the counterclockwise direction DI 2  are defined as viewed from one of the directions (+Z, −Z) in which the center axis Oc extends. 
     When the centrifugal force F 1  with respect to the first rotational axis Ow 1  caused by the rotation of the first eccentric portion is directed in the circumferential direction DI, the centrifugal force F 1  causes a rotation of the vibrating body  351  on the center axis Oc. Likewise, when the centrifugal force F 2  with respect to the second rotational axis Ow 2  caused by the rotation of the second eccentric portion  56  is directed in the circumferential direction DI, the centrifugal force F 2  causes a rotation of the vibrating body  351  on the center axis Oc. 
     In the first exemplary embodiment, the diametrical direction Dr refers to a direction across the center axis Oc, and encompasses the centrifugal direction Dr 1  and the mesial direction Dr 2 . The centrifugal direction Dr 1  refers to a direction away from the center axis Oc, and the mesial direction Dr 2  refers to a direction toward the center axis Oc. 
     When the centrifugal force F 1  with respect to the first rotational axis Ow 1  caused by the rotation of the first eccentric portion  55  is directed in the diametrical direction Dr, the centrifugal force F 1  causes no rotation of the vibrating body  351  on the center axis Oc. Likewise, when the centrifugal force F 2  with respect to the second rotational axis Ow 2  caused by the rotation of the second eccentric portion  56  is directed in the diametrical direction Dr, the centrifugal force F 2  causes no rotation of the vibrating body  351  on the center axis Oc. 
     In the first exemplary embodiment (see  FIG.  7   ), the connection axis Oh and the center axis Oc are placed apart in parallel with each other. A protruding portion  358   a  is formed along the connection axis Oh at a connection point between the vibration module  350  and the hanger body  331  so that the rotating and reciprocating motion (arc motion) of the vibration module  350  is converted into the linear reciprocating motion of the hanger body  331 . 
     In the first exemplary embodiment, since the vibration module  350  rotates around the center axis Oc, the excitation fore Fo can be calculated by converting the sum of the centrifugal force F 1  and centrifugal force F 2  into an external force with a point of action on the connection axis Oh, taking the moment arm lengths A 1 , A 2 , and B into account. 
     Referring to  FIGS.  2   a  and  2   c   , the centrifugal force F 1  and the centrifugal force F 2  are set to reinforce each other when they generate a torque around the center axis Oc of the vibrating body  351 . When the weight of the first eccentric portion  55  is off-centered in one direction D 3 , either clockwise direction DI 1  or counterclockwise direction DI 2  with respect to the center axis Oc, from the first rotational axis Ow 1 , the weight of the second eccentric portion  56  is off-centered in the one direction D 3  from the second rotational axis Ow 2 . When the first eccentric portion  55  generates a centrifugal force in one direction D 3 , either clockwise direction DI 1  or counterclockwise direction DI 2  with respect to the center axis Oc, from the first rotational axis Ow 1 , the second eccentric portion  56  generates a centrifugal force in the one direction D 3  from the second rotational axis Ow 2 . In this case, the moment A 1 ·F 1 +A 2 ·F 2  caused by the centrifugal force F 1  and centrifugal force F 2  is equal to the moment B·Fo caused by the excitation force Fo. Thus, Fo becomes A 1 /B·F 1 +A 2 /B·F 2 . 
     Referring to  FIG.  2   b    and  FIG.  2   d   , the centrifugal force F 1  and the centrifugal force F 2  are set to be directed in opposite directions when they generate no torque around the center axis Oc of the vibrating body  351 . When the weight of the first eccentric portion  55  is off-centered in one direction D 4 , either centrifugal direction Dr 1  or mesial direction Dr 2  with respect to the center axis Oc, from the first rotational axis Ow 1 , the weight of the second eccentric portion  56  is off-centered in the opposite direction of the one direction D 4  from the second rotational axis Ow 2 . When the first eccentric portion  55  generates a centrifugal force in one direction D 4 , centrifugal direction Dr 1  or mesial direction Dr 2  with respect to the center axis Oc, from the first rotational axis Ow 1 , the second eccentric portion  56  generates a centrifugal force in the opposite direction of the one direction D 4  from the second rotational axis Ow 2 . 
     Referring to  FIGS.  2   b  and  2   d   , when the centrifugal force F 1  of the first eccentric portion  55  and the centrifugal force F 2  of the second eccentric portion  56  offset each other, either the direction of action of the centrifugal force F 1  or the direction of action of action of the centrifugal force F 2  is the centrifugal direction Dr 1 , and the other is the mesial direction Dr 2 . 
     In the first exemplary embodiment, the centrifugal force F 1  and the centrifugal force F 2  are set to offset each other when they generate no torque for the vibrating body  351 . In this case, the centrifugal force F 1  and the centrifugal force F 2  act in opposite directions, and therefore the sum of the centrifugal forces F 1  and F 2  is equal to the difference between the magnitude of the centrifugal force F 1  and the magnitude of the centrifugal force F 2 . Thus, at least one of the centrifugal forces F 1  and F 2  is offset by the other. Preferably, the centrifugal force F 1  and the centrifugal force F 2  are set to “completely offset” each other when they generate no torque for the vibrating body  351 . 
       FIGS.  2   a  to  2   d    show the momentum of 90-degree rotation of the first eccentric portion  55  and second eccentric portion  56  rotating at the same angular speed w. 
     Referring to  FIG.  2   a   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the clockwise direction DI 1 , the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the clockwise direction DI 1 . When the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the +X axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the +X axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  reinforce each other, thereby generating a torque for the vibrating body  51  in the clockwise direction DI 1 . The excitation force Fo transmitted to the hanger body  331  along the connection axis Oh acts in the −X axis direction. 
     Referring to  FIG.  2   b   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the centrifugal direction Dr 1 , the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the mesial direction Dr 2 . When the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the −Y axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the +Y axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  generate no torque for the vibrating body  51 . The excitation force Fo transmitted to the hanger body  331  along the connection axis Oh is zero. Also, the centrifugal force F 1  and the centrifugal force F 2  are offset as they act in opposite directions. 
     Referring to  FIG.  2   c   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the counterclockwise direction DI 2 , the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the counterclockwise direction DI 2 . When the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the −X axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the −X axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  reinforce each other, thereby generating a torque for the vibrating body  51  in the counterclockwise direction DI 2 . The excitation force Fo transmitted to the hanger body  331  along the connection axis Oh acts in the +X axis direction. 
     Referring to  FIG.  2   d   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the mesial direction Dr 2 , the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the centrifugal direction Dr 1 . When the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the +Y axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the −Y axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  generate no torque for the vibrating body  51 . The excitation force Fo transmitted to the hanger body  331  along the connection axis Oh is zero. Also, the centrifugal force F 1  and the centrifugal force F 2  are offset as they act in opposite directions. 
     Hereinafter, the operating mechanism of the vibration module  450  according to the second exemplary embodiment will be described below in more concrete details with reference to  FIGS.  3   a  to  3   d   . The vibrating body  451  is configured to be fixed to the hanger body  331  and move integrally with the hanger body  331 . 
     In the second exemplary embodiment (see  FIG.  11   ), when viewed from the direction in which the rotational axis Ow 1  and Ow 2  extends, the connection axis Oh may be disposed between the center Mm of mass of the motor  52  and the rotational axis Ow 1  and Ow 2 . When viewed from the direction (top) in which the first rotational axis Ow 1  extends, the hanger driving unit  458  is fixed to the hanger body  431 , in a position between the center Mm of mass of the motor  52  and the first rotational axis Ow 1 . This can reduce torsion caused by the center Mm of mass of the motor  52  when an excitation force is transmitted to the hanger body  431  from the vibration module  450 , thereby creating more stable vibrating motion. 
     In the second exemplary embodiment, since the vibration module  450  vibrates integrally with the hanger body  431 , the excitation fore Fo can be calculated as the sum of the centrifugal force F 1  and centrifugal force F 2  in the vibration direction (+X, −X). 
     Referring to  FIG.  3   a    and  FIG.  3   c   , the centrifugal force F 1  and the centrifugal force F 2  are set to reinforce each other when exerted on the vibrating body  351  in the vibration direction (+X, −X). In this case, the excitation force Fo in the vibration direction (+X, −X) caused by the centrifugal force F 1  and centrifugal force F 2  is F 1 +F 2 . 
     Referring to  FIG.  3   b    and  FIG.  3   d   , the centrifugal force F 1  and the centrifugal force F 2  are set to be directed in opposite directions when exerted on the vibrating body  351  in the intersecting direction (+Y, −Y). In this case, the excitation force Fo in the vibration direction (+X, −X) caused by the centrifugal force F 1  and centrifugal force F 2  is zero. Also, the excitation force in the intersecting direction (+Y, −Y) caused by the centrifugal force F 1  and centrifugal force F 2  is |F 1 -F 2 |. Preferably, the excitation force in the intersecting direction (+Y, −Y) caused by the centrifugal force F 1  and centrifugal force F 2  is preset to zero. 
       FIGS.  3   a  to  3   d    show the angular momentum of 90-degree rotation of the first eccentric portion  55  and second eccentric portion  56  rotating at the same angular speed w. 
     Referring to  FIG.  3   a   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the +X axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the +X axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  reinforce each other and act on the vibrating body  51  in the +X axis direction. The excitation force Fo transmitted to the hanger body  331  acts in the +X axis direction. 
     Referring to  FIG.  3   b   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the −Y axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the +Y axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  do not act on the vibrating body  51  in the vibration direction (+X, −X). Also, the centrifugal force F 1  and the centrifugal force F 2  in opposite directions offset each other. The excitation force Fo in the vibration direction (+X, −X) transmitted to the hanger body  331  is zero. 
     Referring to  FIG.  3   c   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the −X axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the −X axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  reinforce each other and act on the vibrating body  51  in the −X axis direction. The excitation force Fo transmitted to the hanger body  331  acts in the −X axis direction. 
     Referring to  FIG.  3   d   , when the first eccentric portion  55  generates a centrifugal force F 1  with respect to the first rotational axis Ow 1  in the +Y axis direction, the second eccentric portion  56  generates a centrifugal force F 2  with respect to the second rotational axis Ow 2  in the −Y axis direction. Therefore, the centrifugal force F 1  and the centrifugal force F 2  do not act on the vibrating body  51  in the vibration direction (+X, −X). Also, the centrifugal force F 1  and the centrifugal force F 2  in opposite directions offset each other. The excitation force Fo in the vibration direction (+X, −X) transmitted to the hanger body  331  is zero. 
     Referring to  FIGS.  4  and  5   , a description of the elements common to the first and second exemplary embodiments is the same as what has been described above. Hereinafter, a description will given, focusing on the elements different for the first and second exemplary embodiments. 
     Hereinafter, the configuration of the vibration module  350 , elastic member  360 , and supporting member  370  according to the first exemplary embodiment will be described with reference to  FIGS.  6  to  9   . The vibrating body  351  according to the first exemplary embodiment is configured to be rotatable around the center axis Oc. 
     In the first exemplary embodiment, the weight casing  51   b  is placed apart from the center axis Oc in the centrifugal direction Dr 1 . The weight casing  51   b  and the hanger driving unit  458  may be placed apart from each other, in opposite directions with respect to the center axis Oc. The connection axis Oh and the rotational axis Ow 1  and Ow 2  may be placed apart from each other, in opposite directions with respect to the center axis Oc. The motor  52  may be disposed between the center axis Oc and the rotational axis Ow 1  and Ow 2 . The motor shaft  52   a  may protrude in the centrifugal direction Dr 1 . The motor shaft  52   a  may protrude in the −Y axis direction. 
     The vibrating body  351  may comprise a base casing  351   d  rotatably supported by the center axial portion  375 . The center axial portion  375  is placed to penetrate the base casing  351   d . A bearing B is interposed between the center axial portion  375  and the base casing  351   d . The base casing  351   d  is disposed between the weight casing  51   b  and an elastic member mount  351   c.    
     The vibrating body  351  may comprise a motor supporting portion  351   e  supporting the motor  52 . The motor supporting portion  351   e  may support the bottom end of the motor. The motor supporting portion  351   e  may be disposed between the weight casing  51   b  and the base casing  351   d.    
     The vibrating body  351  may comprise an elastic member mount  351   c  on which one end of the elastic member  360  is locked. When the vibration module  350  rotates and vibrates, the elastic member mount  351   c  applies pressure on the elastic member  360  or receive restoring force from the elastic member  360 . 
     The elastic member mount  351   c  may be disposed on one end of the vibrating body  351  in the centrifugal direction Dr 1 . The elastic member mount  351   c  may connect and extend between the center axis Oc and the connection axis Oh. The elastic member mount  351   c  may extend in the centrifugal direction DO and therefore have a distal end. The elastic member mount  351   c  is disposed on the other side of the first and second rotational axes Ow 1  and Ow 2  with respect to the center axis Oc. The elastic member mount  351   c  may be fixed to the base casing  351   d . The elastic member mount  351   c , base casing  351   d , and motor supporting portion  351   e  may be formed as a single unit. 
     In the first exemplary embodiment, the motor  52  may be placed apart from the center axis Oc. The motor  52  may be disposed between the center axis Oc and the first and second rotational axes Ow 1  and Ow 2 . The motor  52  has a motor shaft  52   a  placed perpendicular to the center axis Oc. The motor shaft  52   a  may protrude from the motor in the centrifugal direction Dr 1 . 
     The hanger driving unit  358  is connected to the hanger body  331 , spaced apart from the center axis Oc. The hanger driving unit  358  may be configured to be connected to the hanger body  331  on the outside, spaced apart from the center axis Oc. 
     The hanger driving unit  358  may comprise a protruding portion  358   a  that protrudes along the connection axis Oh. The protruding portion  358   a  protrudes downward from the hanger driving unit  358 . The protruding portion  358   a  protrudes along the connection axis Oh. The hanger driving unit  358  may comprise a connecting rod  358   a  and  358   b  comprising the protruding portion  358   a . The connecting rod  358   a  and  358   b  may be configured as a separate member. One end  358   a  of the connecting rod  358   a  and  358   b  may be inserted into a slit  331   bh  of the hanger driven unit  331   b . The connecting rod  358   a  and  358   b  converts the rotating motion of the vibration module  350  to reciprocate the hanger body  331 . 
     The connecting rod  358   a  and  358   b  is fixed to the vibrating body  351 . The upper end of the connecting rod  358   a  and  358   b  may be fixed to the vibrating body  351 . The connecting rod  358   a  and  358   b  rotates integrally with the vibrating body  351 . The connecting rod  358   a  and  358   b  may be disposed on the connection axis Oh. The connecting rod  358   a  and  358   b  may transmit the torque of the vibrating body  351  to the hanger body  331 . 
     The connecting rod  358   a  and  358   b  may comprise a vertical extension  358   b  which extends in an up-down direction. The vertical extension  358   b  may extend along the connection axis Oh. The upper end of the vertical extension  358   b  may be fixed to the elastic member mount  351   c . The connecting rod  358   a  and  358   b  comprises the protruding portion  358   a  formed at the distal end of the vertical extension  358   b . The protruding portion  358   a  is disposed on the lower end of the vertical extension  358   b.    
     The vibration module  350  comprises an elastic member locking portion  359  on which one end of the elastic member  360  is locked. When the vibration module  350  rotates around the center axis Oc, the elastic member  360  is elastically deformed by the elastic member locking portion  359 , or the restoring force of the elastic member  360  is transmitted to the elastic member locking portion  359 . The elastic member locking portion  359  is disposed on the elastic member mount  351   c.    
     The elastic member locking portion  359  may comprise a first locking portion  359   a  on which one end of the first elastic member  360   a  is locked. The first locking portion  359   a  may be formed on one side (+X) of the elastic member mount  351   c . The elastic member locking portion  359  may comprise a second locking portion  359   b  on which one end of the second elastic member  360   b  is locked. The second locking portion  359   b  may be formed on the other side (−X) of the elastic member mount  351   c.    
     The elastic member  360  may be disposed between the vibration module  350  and the supporting member  370 . One end of the elastic member  460  is locked on the vibration module  350 , and the other end is locked on an elastic member mounting portion  377  of the supporting member  370 . The elastic member  360  may comprise a tension spring and/or a compression spring. A pair of elastic members  360   a  and  360   b  may be disposed on both sides of the connection axis Oh in the vibration direction (+X, −X). The elastic member  360  may be placed apart from the center axis Oc. 
     A plurality of elastic members  360   a  and  360   b  may be provided. The elastic members  360   a  and  360   b  each may be configured to elastically deform when the vibration module  350  moves in either the clockwise direction DI 1  or the counterclockwise direction DI 2  and regain their elasticity when it moves in the other direction. The elastic members  360   a  and  360   b  may be configured to elastically deform when the hanger body  331  moves to one side in the vibration direction (+X, −X) and regain their elasticity when it moves to the other side. 
     The first elastic member  360   a  is disposed on one side (+X) of the vibrating body  351 . One end of the first elastic member  360   a  may be locked on the first locking portion  359   a , and the other end may be locked on a first mounting portion  377   a  of the supporting member  370 . The first elastic member  360   a  may comprise a spring that elastically deforms in the vibration direction (+X, −X) and regains its elasticity. 
     The second elastic member  360   b  is disposed on the other side (−X) of the vibrating body  351 . The elastic member mount  351   c  is disposed between the first elastic member  360   a  and the second elastic member  360   b . One end of the second elastic member  360   b  may be locked on the second locking portion  359   b , and the other end may be locked on a second mounting portion  377   b  of the supporting member  370 . The second elastic member  360   b  may comprise a spring that elastically deforms in the vibration direction (+X, −X) and regains its elasticity. 
     The supporting member  370  may comprise a center axial portion  375  protruding along the center axis Oc. The center axial portion  375  may protrude upward from a center axis supporting portion  376 . The center axial portion  375  is inserted into a hole formed in the vibrating body  351 . The center axial portion  375  rotatably supports the vibrating body  351  through a bearing B. 
     The supporting member  370  may comprise a center axial supporting portion  376  to which the center axial portion  375  is fixed. The center axial supporting portion  376  may be located a distance below the vibrating body  351 . The center axial supporting portion  376  is fixed to the frame  10 . 
     The supporting member  370  comprises an elastic member mounting portion  377  where one end of the elastic member  360  is fixed. The elastic member mounting portion  377  is fixed to the frame  10 . The elastic member mounting portion  377  may be fixed to the interior frame  11   a . The first mounting portion  377   a  and the second mounting portion  377   b  are placed apart from each other, in opposite directions with respect to the connection axis Oh. 
     Hereinafter, the configuration of the vibration module  450 , elastic member  460 , and supporting member  470  according to the second exemplary embodiment will be described with reference to  FIGS.  10  to  12   . The vibrating body  451  according to the second exemplary embodiment is configured to be fixed to the hanger body  431  and move integrally with the hanger body  431 . 
     The vibrating body  451  comprises a weight casing  51   b . The vibrating body  451  supports the motor  52 . The weight casing  51   b  may be disposed in front of the motor  52 . The motor shaft  52   a  may protrude forward. The connection axis Oh is disposed between the rotational axis Ow 1  and Ow 2  and the center Mm of mass of the motor  52 . 
     The hanger driving unit  458  connects and holds the vibrating body  451  and the hanger body  431  together. The hanger driving unit  458  is fixed to the vibrating body  451 . The hanger driving unit  458  may protrude and extend downward from the vibrating body  451 , so that the lower end is fixed to the hanger body  431 . The lower end of the hanger driving unit  458  is fixed to the hanger driven unit  431   b . The hanger driving unit  458  vibrates integrally with the hanger driven unit  431   b.    
     The hanger driving unit  458  may be disposed on the connection axis Oh. The hanger driving unit  458  may be disposed between the rotational axis Ow 1  and Ow 2  and the center Mm of mass of the motor  52 . When viewed from the direction in which the first rotational axis Ow 1  extends, the hanger driving unit  458  is fixed to the hanger body, in a position between the center Mm of mass of the motor  52  and the first rotational axis Ow 1 . 
     The vibration module  450  comprises an elastic member locking portion  459  on which one end of the elastic member  460  is locked. When the vibration module  450  reciprocates to the left and right, the elastic member  460  is elastically deformed by the elastic member locking portion  459 , or the restoring force of the elastic member  460  is transmitted to the elastic member locking portion  459 . The elastic member locking portion  459  is disposed on the weight casing  51   b.    
     The elastic member locking portion  459  may comprise a first locking portion  459   a  on which one end of the first elastic member  60   a  is locked. The first locking portion  459   a  may be formed on one side (+X) of the weight casing  51   b . The elastic member locking portion  459  may comprise a second locking portion  459   b  on which one end of the second elastic member  460   b  is locked. The second locking portion  459   b  may be formed on the other side (−X) of the weight casing  51   b.    
     The elastic member  460  may be disposed between the vibration module  450  and the supporting member  470 . One end of the elastic member  460  is locked on the vibration module  450 , and the other end is locked on an elastic member mounting portion  477  of the supporting member  470 . The elastic member  460  may comprise a tension spring and/or a compression spring. A pair of elastic members  460   a  and  460   b  may be disposed on both sides of the connection axis Oh in the vibration direction (+X, −X). 
     A plurality of elastic members  460   a  and  460   b  may be provided. The elastic members  460   a  and  460   b  may be configured to elastically deform when the vibration module  450  moves to one side in the vibration direction (+X, −X) and regain their elasticity when it moves to the other side. The elastic members  460   a  and  460   b  may be configured to elastically deform when the hanger body  431  moves to one side in the vibration direction (+X, −X) and regain their elasticity when it moves to the other side. 
     The first elastic member  460   a  is disposed on one side (+X) of the vibrating body  451 . One end of the first elastic member  460   a  may be locked on the first locking portion  459   a , and the other end may be locked on a first mounting portion  477   a  of the supporting member  470 . The first elastic member  460   a  may comprise a spring that elastically deforms in the vibration direction (+X, −x) and regains its elasticity. 
     The second elastic member  460   b  is disposed on the other side (−X) of the vibrating body  451 . One end of the second elastic member  460   b  may be locked on the second locking portion  459   b , and the other end may be locked on a second mounting portion  477   b  of the supporting member  470 . The second elastic member  460   b  may comprise a spring that elastically deforms in the vibration direction (+X, −x) and regains its elasticity. 
     The supporting member  470  comprises an elastic member mounting portion  477  where one end of the elastic member  460  is fixed. The elastic member mounting portion  477  is fixed to the frame  10 . The elastic member mounting portion  477  may be fixed to the interior frame  11   a . The first mounting portion  477   a  and the second mounting portion  477   b  are placed apart from each other, in opposite directions with respect to the connection axis Oh. 
     The supporting member  470  may further comprise a module guide  478  that allows the vibration module  450  to move in the vibration direction (+X, −X) but restricts the movement in a direction (+Y, −Y) intersecting the vibration direction (+X, −X). The module guide  478  may make contact with the hanger driving unit  458  and guide the hanger driving unit  458  in the vibration direction (+X, −X). The module guide  478  may be disposed between the pair of mounting portions  477   a  and  477   b . The module guide  478  may be disposed under the vibrating body  451 . The module guide  478  may be formed in the shape of a horizontal plate. The module guide  478  is fixed to the frame  10 .