Patent Publication Number: US-11655826-B2

Title: Blower

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 to Korean Application Nos. 10-2020-0057726 filed on May 14, 2020, 10-2020-0066278 filed on Jun. 2, 2020, 10-2020-0066279 filed on Jun. 2, 2020, 10-2020-0066280 filed on Jun. 2, 2020, and 10-2020-0139361 filed on Oct. 26, 2020, whose entire disclosures are hereby incorporated by reference. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to a blower. 
     2. Background 
     A blower may create a flow of air to circulate air in an indoor space, or to guide an air flow toward a user. When the blower is provided with a filter, the blower may improve indoor air quality by purifying contaminated air in a room. To adjust a flow direction of the air discharged from the blower, a main body of the blower may be rotated, and the blower may be provided with a bearing that supports a rotation of the main body. 
     However, when structures for improving a air blowing or discharging performance and filtering performance are additionally provided in the main body, there may be no durable bearing structure capable of supporting an increased load. In addition, a position of the motor that rotates the main body may be limited to avoid interference with a rotating plate. 
     Korean Patent Registration No. 10-1814574 discloses a bearing structure that supports a rotation of the blower and a motor that is provided on the base to provide rotational force. Because the bearing is provided in the center of the main body, a load of the body distributed outward may not be evenly supported in a radial direction evenly. In addition, an inner space of an annular bearing may be wasted, and space efficiency may be compromised or reduced because the motor may have to be installed on the base to avoid interference with the bearing and the rotating plate. In addition, a use life of the bearing and the main body may be reduced due to friction between the structures during rotation because a spacing between the non-rotating structure and the rotating structure may not be sufficient or secured. 
     Korean Patent Registration 10-1370267 discloses a bearing structure that supports the shaft to rotate smoothly within the sleeve, however the entire load of the body is not supported. 
     The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
         FIG.  1    is a perspective view of a blower or air purifier according to an embodiment. 
         FIG.  2    is a vertical cross-sectional perspective view of the blower shown in  FIG.  1    on a P-P′ line. 
         FIG.  3    is a vertical cross-sectional perspective view of the blower shown in  FIG.  1    on a Q-Q′ line. 
         FIG.  4    is a top view of a blower according to an embodiment. 
         FIG.  5    is a horizontal cross-sectional perspective view of the blower shown in  FIG.  1    on a R-R′ line. 
         FIG.  6    is an exemplary view of an airflow converter according to an embodiment. 
         FIG.  7    is a structural diagram of an airflow converter according to an embodiment. 
         FIG.  8    is a longitudinal sectional view of a lower portion of a blower according to an embodiment. 
         FIG.  9    is a view of a lower structure of a blower according to an embodiment. 
         FIG.  10    is a perspective view of a driving unit according to an embodiment. 
         FIG.  11    is an exploded perspective view of a driving unit according to an embodiment. 
         FIG.  12    is a top view of a base according to an embodiment. 
         FIG.  13    is an exploded view of a driving unit according to an embodiment and viewed from below. 
         FIG.  14    is a bottom view of a rotating plate according to an embodiment. 
         FIG.  15    is a longitudinal sectional view of a driving unit according to an embodiment. 
         FIG.  16    is an exploded perspective view of a driving unit according to a second embodiment. 
         FIG.  17    is a top view of a base according to the second embodiment. 
         FIG.  18    is an exploded view of a driving unit according to the second embodiment. 
         FIG.  19    is a bottom view of a rotating plate according to the second embodiment. 
         FIG.  20    is a longitudinal sectional view of a driving unit according to the second embodiment. 
         FIG.  21    is a perspective view of a part of a driving unit according to a third embodiment. 
         FIG.  22    is a top view of the structure shown in  FIG.  21   . 
         FIG.  23    is a longitudinal sectional view of a driving unit according to the third embodiment. 
         FIG.  24    is a longitudinal sectional view of the structure shown in  FIG.  21   . 
         FIG.  25    is a diagram illustrating an internal structure of a part of a driving unit according to the third embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , the blower  1  may alternatively be referred to or implemented as an air conditioner, an air clean fan, or an air purifier where air is suctioned and the suctioned air is circulated. 
     The blower  1  according to embodiments herein may include a suction module or assembly  100  through which air is suctioned and a blowing module or assembly  200  through which the suctioned air is discharged. The blower  1  may have a column or cone shape whose diameter decreases upward or toward the blowing module  200 , and the blower  1  may have a shape of a cone or truncated cone as a whole. As a cross-section and/or weight increases toward a bottom, a center of gravity may be lowered, reducing a risk of tipping. However, configuring the cross section to narrow toward the top is not necessary. 
     The suction module  100  may have a cross-sectional arear or diameter that gradually decreases the top. The blowing module  200  may also have a cross-sectional area or diameter that gradually decreases toward the top. The blowing module  200  may be provided above the suction module  100 , and diameters of the suction module  100  and blowing module  200  may be configured such that a transition appears smooth or seamless. 
     The suction module  100  may include a driving unit or drive  500 , a lower case  120  provided above a driving unit  500 , and a filter  130  provided inside the lower case  120 . 
     The driving unit  500  may be seated on a ground, floor, or other surface and may support a weight of the rest of the blower  1 . The lower case  120  and the filter  130  may be placed in the upper side of the driving unit  500 . The driving unit  500  may rotate the blower  1  by rotating the lower case  120 . Such rotation may adjust a position or orientation of the blowing assembly  200  to control a direction of air flow. For example, the driving unit  500  may be used to oscillate the blower  1  back and forth between two positions. 
     An outer shape of the lower case  120  may be conical (or alternatively cylindrical), and a space in which the filter  130  is provided may be formed inside the lower case  120 . The lower case  120  may have a suction port  121  opened to an inside of the lower case  120 . A plurality of suction ports  121  may be formed along a circumferential surface of the lower case  120 . 
     An outer shape of the filter  130  may be cylindrical (or alternatively, conical). Foreign matter contained in the air introduced through the suction port  121  may be filtered by the filter  130 . 
     The blowing module  200  may have a slot or opening penetrating a middle portion so as to appear to be separated and having two columns extending vertically. The slot or opening may define a blowing space S described in more detail later. The blowing module  200  may include a first tower or extension  220  and a second tower or extension  230  spaced apart from each other. The blowing module  200  may include a tower base or connector  210  connecting the first tower  220  and the second tower  230  to the suction module  100 . The tower base  210  may be above an upper side of the suction module  100  and may be provided at a lower side of the first and second tower  220  and  230 . 
     An outer shape of the tower base  210  may be conical (or alternatively, cylindrical), and the tower base  210  may be provided on an upper surface of the suction module  100  to form an outer circumferential surface continuous with the suction module  100 . 
     An upper surface  211  of the tower base  210 , hereinafter called the tower base upper surface  211 , may be concaved downward to form a recess or groove extending forward and backward. The first tower  220  may extend upward from a first side  211   a  (e.g., a left side) of the tower base upper surface  211 , and the second tower  230  may extend upward from the a second side  211   b  (e.g., a right side) of the tower base upper surface  211 . 
     The tower base  210  may distribute filtered air supplied from an inside of the suction module  100  and provide the distributed air to the first tower  220  and the second tower  230 . 
     The tower base  210 , the first tower  220 , and the second tower  230  may be manufactured as separate components, or alternatively may be manufactured integrally. The tower base  210  and the first tower  220  may form a first continuous outer circumferential surface of the blower  1 , and the tower base  210  and the second tower  230  may form a second continuous outer circumferential surface of the blower  1 . 
     As an alternative to the embodiment shown in  FIG.  1   , the first tower  220  and the second tower  230  may be directly assembled to the suction module  100  without the tower base  210  or may be manufactured integrally with the suction module  100 . 
     The first tower  220  and the second tower  230  may be spaced apart from each other, and a blowing space S may be formed between the first tower  220  and the second tower  230 . 
     The blowing space S may be understood as a space between the first and second towers  220  and  230  which has open front, rear, and upper sides. 
     The outer shape of the blowing module  200  including the first tower  220 , the second tower  230 , and the blowing space S may be a conical (or alternatively, cylindrical) shape. 
     First and second discharge ports  222  and  232  respectively formed in the first tower  220  and the second tower  230  may discharge air toward the blowing space S. 
     The first tower  220  and the second tower  230  may be provided symmetrically with respect to the blowing space S so that an air flow is uniformly distributed in the blowing space S, facilitating control of a horizontal airflow and a rising airflow. 
     The first tower  220  may include a first tower case  221  forming an outer shape of the first tower  220 , and the second tower  230  may include a second tower case  231  forming an outer shape of the second tower  230 . The tower base  210 , the first tower case  221 , and the second tower case  231  may be referred to as an upper case which is provided above the lower case  120  and has first and second discharge ports  222  and  232  through which air is discharged. The lower case  120  and the upper case defined by the tower base  210 , first tower case  221 , and second tower  231  may collectively be referred to as a “case.” 
     The first discharge port  222  may be formed in the first tower  220  to extend vertically, and the second discharge port  232  may be formed in the second tower  230  to extend vertically. 
     A flow direction of the air discharged from the first tower  220  and the second tower  230  may be formed in the front and rear direction. 
     A width of the blowing space S, which may be defined by a distance between the first tower  220  and the second tower  230 , may be constant in the vertical direction. Alternatively, the width of the blowing space S may increase or decrease in the vertical direction. 
     Air flowing to a front of the blowing space S may be evenly distributed in the vertical direction by making the width of the blowing space S constant along the vertical direction. 
     If a width of an upper side of the blowing space S differs from the width of a lower side of the blowing space S, a flow speed at the wider side may be lower than at the narrower side, and a deviation of speed may occur in the vertical direction. When a deviation of air flow speed occurs in the vertical direction, an amount of clean air supplied may vary according to a vertical position from which the air is discharged. 
     Air discharged from each of the first discharge port  222  and the second discharge port  232  may be supplied to a user after being joined in the blowing space S. 
     The air discharged from the first discharge port  222  and the air discharged from the second discharge port  232  may not flow individually to the user, but may be supplied to the user after combining or mixing in the blowing space S. 
     An indirect airflow may be formed in the air around the blower  1  due to air discharged to the blowing space S such that the air around the blower  1  may also flow toward the blowing space S. 
     Since the discharged air of the first discharge port  222  and the discharged air of the second discharge port  232  are joined in the blowing space S, a straightness or steadiness of the joined discharged air may be improved. By joining the discharged air in the blowing space S, the air around the first tower  220  and the second tower  230  may also be induced to flow forward along an outer circumferential surface of the blowing module  200 . 
     The first tower case  221  may include a first tower upper end  221   a  forming an upper surface of the first tower  220 , a first tower front end  221   b  forming a front surface of the first tower  220 , a first tower rear end  221   c  forming a rear surface of the first tower  220 , a first outer wall  221   d  forming an outer circumferential surface of the first tower  220 , and a first inner wall  221   e  forming an inner surface of the first tower  220  facing the blowing space S. 
     Similarly, the second tower case  231  may include a second tower upper end  231   a  forming an upper surface of the second tower  230 , a second tower front end  231   b  forming a front surface of the second tower  230 , a second tower rear end  231   c  forming a rear surface of the second tower  230 , a second outer wall  231   d  forming an outer circumferential surface of the second tower  230 , and a second inner wall  231   e  forming an inner surface of the second tower  230  facing the blowing space S. 
     The first outer wall  221   d  and the second outer wall  231   d  may be formed to curve convexly outward in to radial direction so that outer circumferential surfaces of each of the first tower  220  and the second tower  230  are curved. 
     The first inner wall  221   e  and the second inner wall  231   e  may be formed to curve convex inward toward the blowing space S in the radial direction so inner circumferential surfaces of each of the first tower  220  and the second tower  230  are curved. 
     The first discharge port  222  may be formed in the first inner wall  221   e  and extend in the vertical direction. The first discharge port  222  may be opened inward in the radial direction. The second discharge port  232  may be formed in the second inner wall  231   e  and extend in the vertical direction. The second discharge port  232  may be opened inward in the radial direction. 
     The first discharge port  222  may be positioned closer to the first tower rear end  221   c  than the first tower front end  221   b . The second discharge port  232  may be positioned closer to the second tower rear end  231   c  than the second tower front end  231   b.    
     A first board slit  223  may be formed in the first inner wall  221   e  to extend vertically. A second board slit  233  may be formed in the second inner wall  231   e  to extend vertically. The first board slit  223  and the second board slit  233  may be formed to be opened inward in the radial direction. A first airflow converter  401  ( FIG.  6   ) described later may pass through the first board slit  223  and a second airflow converter  402  ( FIG.  6   ) described later may pass through the second board slit  233 . 
     The first board slit  223  may be positioned closer to the first tower front end  221   b  than the first tower rear end  221   c . The second board slit  233  may be positioned closer to the second tower front end  231   b  than the second tower rear end  231   c . The first board slit  223  and the second board slit  233  may face each other. 
     Hereinafter, an internal structure of the blower  1  will be described with reference to  FIGS.  2  and  3   .  FIG.  2    is a cross-sectional view of the blower  1  cut along the line P-P′ shown in  FIG.  1   , and  FIG.  3    is a cross-sectional view showing the blower  1  along the line Q-Q′ shown in  FIG.  1   . 
     Referring to  FIG.  2   , a substrate assembly or controller  150  (e.g., printed circuit board or PCB assembly) to control an operation of a fan assembly  300  and a heater  240  may be provided in an upper side of the driving unit  500 . A control space  150 S in which the substrate assembly  150  is provided may be formed in the upper side of the driving unit  500 . 
     The filter  130  may be provided above the control space  150 S. The filter  130  may have a hollow cylindrical shape, and a cylindrical filter hole  131  or hollow opening may be formed inside the filter  130 . 
     Air introduced through the suction port  121  may pass through the filter  130  and flow to the filter hole  131 . 
     A suction grill  140  may be provided above the filter  130 . Air flowing upward through the filter  130  may pass through the suction grill  140 . The suction grill  140  may be provided between the fan assembly  300  and the filter  130 . When the lower case  210  is removed and the filter  130  is separated from the blower  1 , the suction grill  140  may prevent a user&#39;s hand from contacting the fan assembly  300 . 
     The fan assembly  300  may be provided in the upper side of the filter  130  and may generate a suction force for air outside the blower  1 . 
     By driving the fan assembly  300 , ambient air outside the blower  1  may be suctioned through the suction port  121  and the filter hole  131  sequentially to flow to the first tower  220  and the second tower  230 . 
     A pressurizing space  300   s  in which the fan assembly  300  is provided may be formed between the filter  130  and the blowing module  200 . 
     A first distribution space  220   s  may be formed inside the first tower  220 , and a second distribution space  230   s  may be formed inside the second tower  230 . Air that passes through the pressurizing space  300   s  may flow upward through the first or second distribution spaces  220   s  or  230   s . The tower base  210  may distribute the air that passed through the pressurizing space  300   s  into the first distribution space  220   s  and the second distribution space  230   s . The tower base  210  may form a channel connecting the first and second towers  220  and  230  and the fan assembly  300 . 
     The first distribution space  220   s  may be formed between the first outer wall  221   d  and the first inner wall  221   e . The second distribution space  230   s  may be formed between the second outer wall  231   d  and the second inner wall  231   e.    
     The first tower  220  may include a first flow guide or air guide  224  that guides a flow direction of the air inside the first distribution space  220   s . A plurality of first flow guides  224  may be provided to be spaced apart from each other vertically. 
     The first flow guide  224  may be formed to protrude from the first tower rear end  221   c  toward the first tower front end  221   b . The first flow guide  224  may be spaced apart from the first tower front end  221   b  in the front-rear direction. The first flow guide  224  may extend obliquely downward while progressing toward the front. An angle at which each of the plurality of first flow guides  224  is inclined downward may decrease as the first flow guide  224  progresses upward. 
     The second tower  230  may include a second flow guide or air guide  234  that guides a flow direction of the air inside the second distribution space  230   s . A plurality of second flow guides  234  may be provided to be spaced apart from each other vertically. 
     The second flow guide  234  may be formed to protrude from the second tower rear end  231   c  toward the second tower front end  231   b . The second flow guide  234  may be spaced apart from the second tower front end  231   b  in the front-rear direction. The second flow guide  234  may extend obliquely downward while progressing toward the front. An angle at which each of the plurality of second flow guides  234  is inclined downward may decrease as the second flow guide  234  progresses upward. 
     The first flow guide  224  may guide the air discharged from the fan assembly  300  to flow toward the first discharge port  222 . The second flow guide  234  may guide the air discharged from the fan assembly  300  to flow toward the second discharge port  232 . 
     Referring to  FIG.  3   , the fan assembly  300  may include a fan motor  310  which generates power, a motor housing  330  which receives the fan motor  310 , a fan  320  which is rotated by receiving power from the fan motor  310 , and a diffuser  340  which guides the flow direction of the air pressurized by the fan  320 . 
     The fan motor  310  may be provided at an upper side of the fan  320  and may be connected to the fan  320  through a motor shaft  311  extending downward from the fan motor  310 . 
     The motor housing  330  may include a first or upper motor housing  331  covering an upper portion of the fan motor  310  and a second or lower motor housing  332  covering a lower portion of the fan motor  310 . 
     The first discharge port  222  may be provided in the upper side of the tower base  210 . A first discharge port lower end  222   d  may join with or be provided in the upper side of the tower base upper surface  211 . 
     The first discharge port  222  may be spaced apart from the lower side of the first tower upper end  221   a . A first discharge port upper end  222   c  may be formed to be spaced apart from the lower side of the first tower upper end  221   a.    
     The first discharge port  222  may obliquely extend in the vertical direction to be inclined. The first discharge port  222  may be inclined forward while progressing upward. The first discharge port  222  may obliquely extend rearward with respect to a vertical axis Z extending in the vertical direction. 
     A first discharge port front end  222   a  and a first discharge port rear end  222   b  may extend obliquely in the vertical direction, and may extend parallel to each other. The first discharge port front end  222   a  and the first discharge port rear end  222   b  may be inclined rearward with respect to the vertical axis Z extending in the vertical direction. 
     The first tower  220  may include a first discharge guide  225  to guide the air inside the first distribution space  220   s  to the first discharge port  222 . 
     The first tower  220  may be symmetrical with the second tower  230  with respect to the blowing space S, and may have the same shape and structure as the second tower  230 . The description of the first tower  220  described above may be identically applied to the second tower  230 . 
     The blower  1  may include a heater  240  provided inside the upper case. A plurality of heaters  240  may be provided to correspond to the first discharge port  222  and the second discharge port  232 , respectively. The heater  240  may include a first heater  241  provided in the first tower  220  and a second heater  242  provided in the second tower  230 . The first heater  241  may be provided obliquely or at an angle in the vertical direction to correspond to or align with the first discharge port  222 , and the second heater  242  may be provided obliquely or at an angle in the vertical direction to correspond to or align with the second discharge port  232 . 
     The heater  240  may be supplied with power by a power supply device based on a switched mode power supply (SMPS) method. The heater  240  may receive power from an external power source and heat the air discharged to the blowing space S through the discharge port  222 ,  232 . 
     Hereinafter, an air discharge structure of the blower  1  for inducing a Coanda effect will be described with reference to  FIGS.  4  and  5   .  FIG.  4    shows a form in which the blower  1  is viewed from the top to the bottom, and  FIG.  5    shows a form in which the blower  1  is cut along the R-R′ diagram shown in  FIG.  1    and viewed upward. 
     Referring to  FIG.  4   , due to the convex curvatures of the first and second inner walls  221   e  and  231 , a distance between the first inner wall  221   e  and the second inner wall  231   e  may decrease while approaching a closer of the blowing space S. 
     The first inner wall  221   e  and the second inner wall  231   e  may be formed to be convex toward the radial inner side, and a shortest or center distance D 0  may be formed between the vertices or centers of the first inner wall  221   e  and the second inner wall  231   e . The shortest distance D 0  may be formed in the center of the blowing space S. 
     The first and second discharge ports  222  and  232  may be formed behind a position where the shortest distance D 0  is formed. 
     The first tower front end  221   b  and the second tower front end  231   b  may be spaced apart by a first or front distance D 1 . The first tower rear end  221   c  and the second tower rear end  231   c  may be spaced apart by a second or rear distance D 2 . 
     The first distance D 1  and the second distance D 2  may be the same, but embodiments disclosed herein are not limited. The first distance D 1  may be greater than the shortest distance D 0 , and the second distance D 2  may be greater than the shortest distance D 0 . 
     The distance between the first inner wall  221   e  and the second inner wall  231   e  may be decreased from the rear ends  221   c ,  231   c  to a position where the shortest distance D 0  is formed, and may be increased from a position where the shortest distance D 0  is formed to the front ends  221   b ,  231   b.    
     The first tower front end  221   b  and the second tower front end  231   b  may be formed to be inclined or curved with respect to a front-rear axis X. 
     Tangent lines drawn at each of the first and second tower front ends  221   b  and  231   b  may have a certain inclination angle A with respect to the front-rear axis X. 
     Some of the air discharged forward through the blowing space S may flow with the inclination angle A with respect to the front-rear axis X. 
     Due to this curved structure of the first and second inner walls  221   e  and  231   e , the diffusion angle of the air discharged forward through the blowing space S may be increased. 
     A first airflow converter  401  described later may be brought into the first board slit  223  when air is discharged forward through the blowing space S. 
     A second airflow converter  402  described later may be brought into the second board slit  233  when air is discharged forward through the blowing space S. 
     Referring to  FIG.  5   , air discharged toward the blowing space S may be guided in a flow direction by the first discharge guide  225  and the second discharge guide  235 . 
     The first discharge guide  225  may include a first inner guide  225   a  connected to the first inner wall  221   e  and a first outer guide  225   b  connected to the first outer wall  221   d.    
     The first inner guide  225   a  may be manufactured integrally with the first inner wall  221   e , or alternatively may be manufactured separately and later combined. 
     The first outer guide  225   b  may be manufactured integrally with the first outer wall  221   d , or alternatively may be manufactured separately and later combined. 
     The first inner guide  225   a  may be formed to protrude from the first inner wall  221   e  toward the first distribution space  220   s.    
     The first outer guide  225   b  may be formed to protrude from the first outer wall  221   d  toward the first distribution space  220   s . The first outer guide  225   b  may be formed to be spaced apart from the first inner guide  225   a  and may form the first discharge port  222  between the first inner guide  225   a  and the first outer guide  225   b.    
     A radius of curvature of the first inner guide  225   a  may be less than a radius of curvature of the first outer guide  225   b.    
     The air in the first distribution space  220   s  may flow between the first inner guide  225   a  and the first outer guide  225   b , and may flow into the blowing space S through the first discharge port  222 . 
     The second discharge guide  235  may include a second inner guide  235   a  connected to the second inner wall  231   e  and a second outer guide  235   b  connected to the second outer wall  231   d.    
     The second inner guide  235   a  may be manufactured integrally with the second inner wall  231   e , or alternatively may be manufactured separately and later combined. 
     The second outer guide  235   b  may be manufactured integrally with the second outer wall  231   d , or alternatively may be manufactured separately and later combined. 
     The second inner guide  235   a  may be formed to protrude from the second inner wall  231   e  toward the second distribution space  230   s.    
     The second outer guide  235   b  may be formed to protrude from the second outer wall  231   d  toward the second distribution space  230   s . The second outer guide  235   b  may be formed to be spaced apart from the second inner guide  235   a  and may form a second discharge port  232  between the second inner guide  235   a  and the second outer guide  235   b.    
     A radius of curvature of the second inner guide  235   a  may be smaller than a radius of curvature of the second outer guide  235   b.    
     The air in the second distribution space  230   s  may flow between the second inner guide  235   a  and the second outer guide  235   b  and flow into the blowing space S through the second discharge port  232 . 
     A width of the first discharge port  222  may be formed to gradually decrease and then increase as it progresses from an inlet of the first discharge guide  225 , which may be an inlet  222   i  of the first discharge port  222 , toward an outlet of the first discharge guide  226 , which may be an outlet  222   o  of the first discharge port  222 . 
     An inlet width w 1  of the inlet  222   i  may be larger than an outlet width w 3  of the outlet  222   o.    
     The inlet width w 1  may be defined as a distance between an outer end of the first inner guide  225   a  and an outer end of the first outer guide  225   b . The outlet width w 3  may be defined as a distance between the first discharge port front end  222   a , which is an inner end of the first inner guide  225   a , and the first discharge port rear end  222   b , which is an inner end of the first outer guide  225   b.    
     The inlet width w 1  and the outlet width w 3  may each be larger than a shortest or inner width w 2  of the first discharge port  222 . 
     The shortest width w 2  may be defined as the shortest distance between the first discharge port rear end  222   b  and the first inner guide  225   a.    
     The width of the first discharge port  222  may gradually decrease from the inlet of the first discharge guide  225  to a position where the shortest width w 2  is formed, and may gradually increase from a position where the shortest width w 2  is formed to the outlet of the first discharge guide  225 . 
     Similar to the first discharge guide  225 , the second discharge guide  235  may have a second discharge port front end  232   a  and a second discharge port rear end  232   b . The second discharge guide  235  may have a same width distribution or configuration as the first discharge guide  225 . 
     The air discharged to the blowing space S through the first discharge port  222  may flow forward along an inner surface of the first inner wall  221   e  due to the Coanda effect. The air discharged to the blowing space S through the second discharge port  232  may flow forward along an inner surface of the second inner wall  231   e  due to the Coanda effect. 
     Hereinafter, a wind direction change by an air flow converter  400  will be described with reference to  FIGS.  6  and  7   .  FIG.  6    is a diagram illustrating a form in which the airflow converter  400  protrudes into the blowing space S so that the blower  1  forms an upward airflow, and  FIG.  7    is a diagram illustrating the operating principle of the airflow converter  400 . 
     Referring to  FIG.  6   , the airflow converter  400  may protrude toward the blowing space S and may convert the flow of air discharged forward through the blowing space S into a rising wind. 
     The airflow converter  400  may include a first airflow converter  401  provided at the first tower case  221  and a second airflow converter  402  provided at the second tower case  231 . 
     The first airflow converter  401  and the second airflow converter  402  be coupled to (e.g., inserted in) and protrude from each of the first tower  220  and the second tower  230  toward the blowing space S to block a front of the blowing space S. 
     When the first airflow converter  401  and the second airflow converter  402  protrude to block the front of the blowing space S, the air discharged through the first discharge port  222  and the second discharge port  232  may flow upward in the Z direction. 
     The first and second airflow converters  401  and  402  may be configured be inserted or pulled to an inside of the first and second towers  220  and  230 , respectively, via the first and second board slits  223  and  233 . When the first airflow converter  401  and the second airflow converter  402  are respectively brought or pulled into the first tower  220  and the second tower  230  to open the front of the blowing space S, the air discharged through the first discharge port  222  and the second discharge port  232  may flow forward X through the blowing space S. As an alternative, the first and second airflow converts  401  and  402  may be configured to be removable from the first and second board slits  223  and  233  (e.g., by lifting or pulling). As another alternative, the first and second air flow converters  401  and  402  may be removably coupled to the inner walls  221   e  and  231   e  of the first and second tower cases  221  and  231 . 
     Referring to  FIG.  7   , the first and second airflow converters  401  and  402  may each include a board  410  protruding toward the blowing space S, a motor  420  providing driving force to the board  410  to move the board  410 , a board guide  430  to guide a moving direction of the board  410 , and a cover  440  to support the motor  410  and the board guide  430 . 
     Hereinafter, the first airflow converter  401  will be described as an example, but the description of the first airflow converter  401  described below may be identically applied to the second airflow converter  402 . 
     The board  410  may be brought into the first board slit  223  as shown in  FIGS.  4  and  5   . When the motor  420  is driven, the board  410  may protrude into the blowing space S through the first board slit  223 . The board  410  may be curved to have an arc shape. When the motor  420  is driven, the board  410  may be moved in a curved or circumferential direction to protrude into the blowing space S. 
     The motor  420  may be connected to a pinion gear  421  to rotate the pinion gear  421 . The motor  420  may rotate the pinion gear  421  clockwise or counterclockwise. 
     The board guide  430  may have a plate shape extending vertically. The board guide  430  may include a guide slit  450  which is inclined upward in a rightward direction (or alternatively, leftward direction), based on  FIG.  7   . The board guide may include a rack  431  formed to protrude toward and engage with the pinion gear  421 . 
     When the motor  420  is driven and the pinion gear  421  is rotated, the rack  431  engaged with the pinion gear  421  may be moved vertically. 
     A guide protrusion or knob  411  may be formed in the board  410  to protrude toward the board guide  430 . The guide protrusion  411  may be inserted into the guide slit  450 . 
     When the board guide  430  is moved vertically according to the vertical movement of the rack  431 , the guide protrusion  411  may be moved by an edge of the board guide  430  defining the guide slit  450  pressing against the guide protrusion  411 . According to the vertical movement of the board guide  430 , the guide protrusion  411  may be moved diagonally within the guide slit  450 . 
     When the rack  431  is moved upward, the guide protrusion  411  may be moved along the guide slit  450  to be positioned in a lowermost end (also a leftmost end in  FIG.  7   ) of the guide slit  450 . When the guide protrusion  411  is positioned in the lowermost end of the guide slit  450 , the board  410  may be completely concealed within the first tower  220  as shown in  FIGS.  4  and  5   . When the rack  431  is moved upward, the guide slit  450  is also moved upward. Accordingly, the guide protrusion  411  may be moved in the circumferential direction on a same horizontal plane along the guide slit  450 . 
     When the rack  431  is moved downward, the guide protrusion  411  may be moved along the guide slit  450  to be positioned in an uppermost end (also a rightmost end in  FIG.  7   ) of the guide slit  450 . When the guide protrusion  411  is positioned in the uppermost end of the guide slit  450 , the board  410  may protrude from the first tower  220  toward the blowing space S as shown in  FIG.  6   . When the rack  431  is moved downward, the guide slit  450  is also moved downward. Accordingly, the guide protrusion  411  may be moved in the circumferential direction on the same horizontal plane along the guide slit  450 . 
     The cover  440  may include a first cover  441  provided outside the board guide  430 , a second cover  442  provided inside the board guide  430  and contacting the first inner surface  221   e , a motor support plate  443  extended upward from the first cover  441  and connected to the motor  420 , and a stopper  444  to limit the vertical movement of the board guide  430 . 
     The first cover  441  may cover an outside of the board guide  430 , and the second cover  442  may cover an inside of the board guide  430 . The first cover  441  may separate a space in which the board guide  430  is provided from the first distribution space  220   s . The second cover  442  may prevent the board guide  430  from contacting the first inner wall  221   e.    
     The motor support plate  443  may extend upward from the first cover  441  to support the load of the motor  420 . 
     The stopper  444  may be formed to protrude toward the board guide  430  from the first cover  441 . A locking protrusion may be formed on a surface of the board guide  430 , and the locking protrusion may be configured to be caught by the stopper  444  according to the vertical movement of the board guide  430 . When the board guide  430  is moved vertically, the locking protrusion may be caught by the stopper  444  so that a vertical movement of the board guide  430  may be restricted. 
     Hereinafter, the internal structure of the suction module  100  will be described with reference to  FIGS.  8  and  9   . Referring to  FIGS.  8 - 9   , the fan assembly  300  may include a fan housing  350  in which the fan  320  is received. 
     The fan housing  350  may include a bell mouth or air guide  141  that guides the air passing through the filter  130  to the fan  320 . The bell mouth  141  may be provided above the filter  130 , and the suction grill  140  may be provided between the filter  130  and the bell mouth  141 . 
     The bell mouth  141  may have a ring shape having a predetermined inner diameter BD, and an inside may be opened in a vertical direction. The inner diameter BD may be understood as a diameter of an inner circumferential surface  141   a  of the bell mouth  141 , and an air flow path toward the fan  320  may be formed inside the bell mouth  141 . 
     The fan  320  connected to the motor shaft  311  may generate a suction force to suction the air in the filter hole  131  by rotation, and the air in the filter hole  131  may flow into the fan housing  350  through the suction grill  140  and the bell mouth  141 . The filter  130  may have a cylindrical shape in which the filter hole  131  is formed, and the air introduced into the lower case  120  through the suction hole  121  may flow into the filter hole  131  by passing between the outer circumferential  130   a  and inner circumferential surface  130   b  of the filter  130 . The air introduced into the lower case  120  may flow into the filter hole  131  via the filter  130  while foreign substances are removed by a pre-filter, hepa filter, or deodorizing filter provided between the outer circumferential surface  130   a  and the inner circumferential surface  130   b  of the filter  130 . 
     The filter  130  may be supported by a filter frame  132  that limits movement of the filter  130  in a radially outward direction. The filter frame  132  may extend in the vertical direction and may contact the outer circumferential surface  130   a  of the filter  130 . A plurality of filter frames  132  (e.g., three) may be provided to be spaced apart in a circumferential direction. The filter  130  may enter or exit through an area in which the filter frame  132  is not provided. The lower case  120  may be provided to be detachably attached to the driving unit  500 , and the user may remove the lower case  120  and then pull out the filter  130  to clean the filter  130 . 
     The filter frame  132  may be connected to the substrate housing  160  provided under the filter  130 . The substrate housing  160  may be in contact with the lower surface of the filter  130  to support the filter  130 . The substrate housing  160  may include a housing outer wall  161  extending in the circumferential direction and supported by driving unit  500 ,  600  ( FIG.  16   ), and/or  700  ( FIG.  21   ). 
     The housing outer wall  161  may include an upper surface of the outer housing wall  161   a  extending in the circumferential direction, a frame connection portion or tab  161   b  protruding upward from the upper surface of the housing outer wall  161   a , and a frame fastening hole  161   c  formed in the frame connection portion  161   b . The filter frame  132  may be connected to the housing outer wall  161  through a predetermined fastening member (e.g., a bolt or screw) penetrating the frame fastening hole  161   c  and may be fixed to the substrate housing  160 . 
     The driving unit  500 ,  600 ,  700  to rotate the blower  1  may be provided under the substrate housing  160 . The driving unit  500 ,  600 ,  700  may include a base  510 ,  610  ( FIG.  16   ), and  760  ( FIG.  21   ) in contact with the ground and a rotating plate  520  and  620  ( FIG.  16   ) that is rotatably provided on the upper side of the base  510 ,  610 , and  760 . 
     The substrate housing  160  may be provided above the rotating plate  520  and  620 , and the rotating plate  520  and  620  may be rotated while supporting the load of the substrate housing  160  and all the structures provided on an upper side of the substrate housing  160 . 
     Hereinafter, an external structure of the driving unit  500  according to a first embodiment will be described with reference to  FIG.  10   . Referring to  FIG.  10   , the driving unit  500  may include a base  510 , a rotating plate  520  connected to the lower case  120  and rotatably provided on an upper side of the base  510 , and a motor  530  that generates power to rotate the rotating plate  520 . 
     The base  510  may be in contact with the ground and may be fixedly provided on the ground, and may have a shape of a bowl. The rotating plate  520  may be provided so as to be rotatable above the base  510  and supported by the base  510 . The base  510 , when the rotating plate  520  is rotated, may support the normal stress and shear stress generated by all the structures provided on an upper side of the base  510  including the rotating plate  520 . 
     The rotating plate  520  may be provided to cover an upper portion of the base  510  and may include a first seating portion  521  on which the substrate housing  160  is seated and a second seating portion  522  on which the lower case  120  is seated. The first seating portion  521  and the second seating portion  522  may be integrally formed, and the first seating portion  521  and the second seating portion  522  can be distinguished from each other by a first stepped portion  520   d  formed between the first seating portion  521  and the second seating portion  522 . The first seating portion  521  may be formed to protrude upwardly than the second seating portion  522 , and the first stepped portion  520   d  may be formed to have a height in the vertical direction and extend in the circumferential direction. 
     The first seating portion  521  may include a central portion  520   a  in which a shaft through hole  520   s   1  is formed, a first rim  520   b  formed to surround the central portion  520   a , a second rim  520   c  formed to surround the first rim  520   b , and the first stepped portion  520   d  protruding downward from the second rim  520   c . An overall outer shape of the central portion  520   a  may be a disk shape, and a shaft through hole  520   s   1  opened in the vertical direction may be formed in the central portion  520   a . The shaft through hole  520   s   1  may be a space into which a shaft body  570  ( FIG.  11   ) described later is inserted. A pair of crests or curved portions  520   a   1  formed to face each other may be formed in the shaft through hole  520   s   1 . The crest  520   a   1  may be a region formed by partially submerging the central portion  520   a  into the shaft through hole  520   s   1 , and the shaft through hole  520   s   1  may have a portion protruding radially inward by the crest  520   a   1 . 
     An overall outer shape of the first rim  520   b  may be annular, and the first rim  520   b  may be connected to the central portion  520   a  along an outer circumference of the central portion  520   a . An upper surface of the first rim  520   b  may be formed to be bent or recessed downward from an upper surface of the central portion  520   a.    
     An overall outer shape of the second rim  520   c  may be annular, and the second rim  520   c  may be connected to the first rim  520   b  along an outer circumference of the first rim  520   b . An upper surface of the second rim  520   c  may be formed to be bent or stepped upward from an upper surface of the first rim  520   b . The first rim  520   b  may be understood as a region recessed downward between the central portion  520   a  and the second rim  520   c.    
     An overall outer shape of the first stepped portion  520   d  may be cylindrical, and a shape of the cross-section may be annular. The first stepped portion  520   d  may be formed to protrude or be bent downward along an outer circumference of the second rim  520   c , and may extend in a circumferential direction. The first seating portion  521  may be vertically spaced apart from the second seating portion  522  by the first stepped portion  520   d.    
     The second seating portion  522  may include a third rim  520   e  connected to the first stepped portion  520   d , a second step portion  520   f  protruding downward from the third rim  520   e , a bent portion  520   g  connected to the second stepped portion  520   f , and an edge  520   h  connected to the bent portion  520   g . An overall external shape of the third rim  520   e  may be annular and may be connected to the first stepped portion  520   d  along an outer circumference of the first stepped portion  520   d . The third rim  520   e  may protrude in a radially outward direction from a lower end of the first stepped portion  520   d  and may extend in a circumferential direction. The third rim  520   e  may be located below the second rim  520   c.    
     The second stepped portion  520   f  may be formed to protrude downward from an outer circumference of the third rim  520   e  and may extend in the circumferential direction. The third rim  520   e  may be vertically spaced apart from the bent portion  520   g  by the second stepped portion  520   f.    
     The first stepped portion  520   d  and the second stepped portion  520   f  may be referred to as “stepped portions” formed to be bent from an upper surface of the rotating plate  520 . The bent portion  520   g  may be formed to protrude in a radially outward direction from an outer circumference of the second stepped portion  520   f  and may extend in a circumferential direction. The bent portion  520   g  may be bent downward at least once in a radially outward direction. The bent portion  520   g  may be defined as an area between the second stepped portion  520   f  and the edge  520   h.    
     The edge  520   h  may form the outermost side of the rotating plate  520 . The edge  520   h  may be formed to protrude in a radially outward direction from an outer circumference of the bent portion  520   g  and may extend in a circumferential direction. A lower surface of the edge  520   h  may be in contact with an upper surface of the base  510  and supported by the base  510 . 
     An upper boss  529  may be formed to protrude upward from an upper surface of the rotating plate  520 . A plurality of upper bosses  529  may be formed to be spaced apart in the circumferential direction and may protrude upward from an upper surface of the second rim  520   c . The upper boss  529  may be connected to the substrate housing  160  to fix the substrate housing  160  to the rotating plate  520 . The substrate housing  160  may be fixed to the rotating plate  520  through a predetermined fastening member (e.g., bolt) penetrating the upper boss  529  and is integrally rotated with the rotating plate  520  by the rotation of the rotating plate  520 . 
     The motor  530  may be provided above the rotating plate  520 . At the rotating plate  520 , a motor insertion groove  520   s   2  opened in the vertical direction may be formed. The motor  530  may be supported by the rotating plate  520  by a part of a lower area of the motor  530  being inserted inserted into the motor insertion groove  520   s   2 . The motor insertion groove  520   s   2  may be formed at the second rim  520   c  and may be formed between the plurality of upper bosses  529 . The motor  530  may be rotated integrally with the rotating plate  520  while being inserted into the motor insertion groove  520   s   2 . As the motor  530  is provided above the rotating plate  520  and rotated together, the vertical height of the driving unit  500  can be reduced so that the driving unit  500  can be manufactured more compactly. 
     An overall external shape of the motor  530  may be cylindrical. The motor  530  may include a wire connection part or connector  531  formed to protrude to an outside of the motor  530  and electrically connected to the wire  590 . When the motor  530  is integrally rotated with rotating plate  520 , to prevent the wire connection part  531  from being removed, any one of the plurality of upper bosses  529  may be a stopper boss  529   a . The stopper boss  529   a  may have the same shape as the upper boss  529 , and can be defined as an upper boss positioned adjacent to the wire connection part  531 . The stopper boss  529   a  may be located within a radius of rotation of the wire connection part  531 , and the wire connection part  531  may be caught by the stopper boss  529   a  while being rotated. 
     A case fastening hole  520   e   2  may be formed at the rotating plate  520 . A predetermined fastening member (e.g., bolt) connected to the lower case  120  may penetrate the case fastening hole  520   e   2 . The case fastening hole  520   e   2  may be formed to be vertically opened in the third rim  520   e . A plurality of case fastening holes  520   e   2  may be formed to be spaced apart in a circumferential direction. The case fastening hole  520   e   2  may be formed at the lower boss  528  ( FIG.  13   ) to be described later, and a predetermined fastening member may pass through the case fastening hole  520   e   2  to connect the lower case  120  to the rotating plate  520 . The lower case  120  may be connected to the rotating plate  520  and may be rotated integrally with the rotating plate  520  by the rotation of the rotating plate  520 . 
     The first stepped portion  520   d  may extend in a circumferential direction, and at least a portion may be formed to be bent in a radially inward direction. The first stepped portion  520   d  may be formed to be bent in a radially inward direction to form a valley  520   d   1 . The valley  520   d   1  may form a groove  520   e   1  that is vertically opened between the first stepped portion  520   d  and the third rim  520   e . At the lower case  210 , a protrusion to facilitate connection with the rotating plate  520  may be formed, and the protrusion may be inserted into the groove  520   e   1  so that the lower case  120  may be fixed to the rotating plate  520 . However, the lower case  120  may be connected to the rotating plate  520  through the case fastening hole  520   e   2 , and the valley  520   d   1  and the groove  520   e   1  may alternatively be omitted. 
     The first stepped portion  520   d  and the second stepped portion  520   f  may provide a height distribution of the rotating plate  520  extending in the radial direction, so that the first stepped portion  520   d  and the second stepped portion  520   f  may provide a space for a bearing  580  ( FIG.  13   ) to be described later to be placed inside the rotating plate  520 . 
     Hereinafter, a structure of the base  510  according to the first embodiment will be described with reference to  FIG.  11   . Referring to  FIG.  11   , the base  510  includes a stem or side wall  511  that forms a space at an inner side and is in contact with a ground, table, or floor surface, and a roof or upper portion  512  covering an inner space of the stem  511  and provided on an upper side of the stem  511 . The roof  512  may alternatively be referred to as a cap. 
     An overall appearance of the stem  511  may be a bowl type, and the space may be formed inside. An overall external shape of the roof  512  may be a disk shape and may be seated on an upper surface of the stem  511 . 
     The roof  512  may include a first support  512   a  seated on the stem  511 , a second support  512   b  connected to the first support  512   a , a third support  512   d  connected to the second support  512   b , and a mount  512   e  protruding upward from the third support  512   d . The supports  512   a ,  512   b , and  512   d  and the mount  512   e  may be integrally formed. 
     An overall outer shape of the first support  512   a  may be annular and may form an edge of the roof  512 . A lower surface of the first support  512   a  may contact an upper surface of the stem  511 . The roof  512  may be supported by the stem  511 . 
     An overall outer shape of the second support  512   b  may be annular, may be formed to protrude in a radially inward direction from an inner circumference of the first support  512   a , and may extend in a circumferential direction. The first support  512   a  and the second support  512   b  may be distinguished by a rail  513  described later. 
     An overall external shape of the third support  512   d  may be annular and may be formed to protrude radially inward from an inner circumference of the second support  512   b . The third support  512   d  may extend in the circumferential direction. The third support  512   d  may be defined as an inner region of the boundary wall  514  to be described later. 
     An overall external shape of the mount  512   e  may be cylindrical and may be formed to protrude upward from an upper surface of the third support  512   d . The shaft body  570  may pass through a central portion of the mount  512   e , and the shaft body  570  may be rotatably provided in a central portion of the mount  512   e.    
     The base  510  may have a rail or ridge  513  protruding upward from the base  510 . The rail  513  may extend in a circumferential direction to form a circular closed loop. 
     An overall outer shape of the rail  513  may be a ring shape, and the bearing  580  ( FIG.  13   ) and/or  680  ( FIG.  18   ) to be described later may move along a movement path formed by the rail  513 . In addition, since the rotation of the bearing  580  and  680  may be supported by the rail  513 , removal of the bearing  580  and/or  680  from the movement path may be prevented. 
     The base  510  may include a boundary wall or flange  514  formed to protrude upward from an upper surface of the base  510 . An overall outer shape of the boundary wall  514  may be cylindrical and may extend in a circumferential direction to form a space  514   s  inside. The boundary wall  514  may be formed to protrude upward from an upper surface of the roof  512 , and the second support  512   b  and the third support  512   d  may be distinguished based on the boundary wall  514 . The boundary wall  514  may be formed radially inside the rail  513  and may be formed radially outside the rotating shaft housing  515  to be described later. 
     The driving unit  500  may include a first gear  540  connected to the motor  530  and a second gear  550  engaged with the first gear  540 . The motor  530  may be provided above the rotating plate  520 , and the first gear  540  may be provided below the rotating plate  520 . The first gear  540  may be a spur gear or a pinion gear. 
     The second gear  550  may be seated on the base  510  and may be provided radially inside the first gear  540 . The first gear  540  may be rotated in engagement with the second gear  550  at an outer radial side of the second gear  550 . The second gear  550  may be a ring gear and may extend along a circumferential direction. 
     The second gear  550  may be connected to the boundary wall  514 . The second gear  550  may contact and be attached to an outer circumferential surface of the boundary wall  514 . The second gear  550  may be in a fixed state, and when the first gear  540  engages with the second gear  550  and rotates, the first gear  540  and the motor  530  connected to the first gear  540  may be integrally rotated with the rotating plate  520 . 
     The second gear  550  may be provided between the rail  513  and the shaft body  570 . The second gear  550  may be provided between the rail  513  and the boundary wall  514 . Due to this arrangement structure, an inner space  514   s  of the boundary wall  514  can be used compactly as a space to arrange and support the shaft body  570 . 
     The base  510  may include a rotating shaft housing  515  protruding toward the rotating plate  520 . An overall external shape of the rotating shaft housing  515  may be cylindrical, and the rotating shaft housing  515  may provide a space in which the shaft body  570  may be inserted. The rotating shaft housing  515  may be formed to protrude upward from an upper surface of the mount  512   e  and may be formed to face an inner circumferential surface of the boundary wall  514 . 
     A shaft bearing  560  ( FIG.  13   ) to be described later may be provided inside the rotating shaft housing  515 . The rotating shaft housing  515  may support the shaft bearing  560  to prevent the shaft bearing  560  and the shaft body  570  from being removed from the center of rotation. 
     Hereinafter, a detailed structure of the shaft body  570  and a relative positional relationship between the rail  513  and the second gear  550  and the shaft body  570  will be described with reference to  FIG.  12   . Referring to  FIG.  12   , a shaft insertion hole  510   s   1  may be formed inside the rotating shaft housing  515  through which the shaft body  570  penetrates, and into which a shaft holder  526  described later may be inserted. The shaft insertion hole  510   s   1  may be defined a space that penetrates rotation shaft housing  515  in a vertical direction. The shaft insertion hole  510   s   1  may correspond to a cylindrical space inside the rotating shaft housing  515 . 
     The shaft body  570  may penetrate upward through the shaft insertion hole  510   s   1 . The shaft body  570  may be provided such that a lower portion is provided inside the base  510  and an upper portion passes through the shaft insertion hole  510   s   1 . 
     The shaft body  570  may include a first body  571  extending to be bent, a second body  572  provided to be spaced apart from the first body  571 , and a third body  573  provided to be spaced apart from the first body  571  and the second body  572  respectively. The first body  571 , the second body  572 , and the third body  573  may be provided to be spaced apart from each other in the shaft insertion hole  510   s   1 . 
     Based on  FIG.  12   , the first body  571  may be provided in front of the second body  572  and the third body  573 , and the first body  571  may be extended longer than the second body  572  and the third body  573 . The second body  572  and the third body  573  may be provided to face the first body  571  in a forward direction, and the second body  572  and the third body  573  may face each other in the left and right directions. The second body  572  may be provided on the left side and the third body  573  may be provided on the right side, but the second body  572  and the third body  573  may have the same shape. 
     The second body  572  and the third body  573  may be connected to each other to have the same shape as the first body  571 . The shaft body  570  may include two first bodies  571  having the same shape, and the two first bodies  571  may be spaced apart so as to face each other in the front-rear direction. 
     The first body  571  may extend to be bent in a horizontal direction and may be bent 3 times along an extending direction. The first body  571  may include a left end portion  571   a  that is obliquely extended rearward, a right end portion  571   c  extending obliquely to the rear, and a core portion  571   b  that extends forward to be bent from each of the left end portion  571   a  and the right end portion  571   c.    
     The second body  572  may extend to be bent in a horizontal direction and may be bent once along the extending direction. The second body  572  may include one (i.e., a first) end portion  572   a  extending obliquely forward and another (i.e., a second) end portion  572   b  extended to be bent from the one end portion  572   a.    
     The third body  573  may extend to be bent in a horizontal direction and may be bent once along the extending direction. The third body  573  may include one (i.e., a first) end portion  573   a  extending obliquely forward, and another (i.e., a second) end portion  573   b  extended to be bent from the one end portion  573   a . The second body  572  and the third body  573  may have the same shape and structure. 
     A wire through portion  570   s  may be formed between the first body  571  and the second body  572  and between the first body  571  and the third body  573 . A wire  590  ( FIG.  15   ) may be inserted into the shaft body  570  through a reel  574  ( FIG.  15   ), which will be described later. The wire  590  may pass through the wire through portion  570   s  and extend upward to be electrically connected to the motor  530 . The wire through portion  570   s  may be defined as an inner space of the shaft body  570  including the rotation center O of the rotating plate  520 . Since the wire  590  may extend upward along the rotation center O and to be connected to the motor  530 , while the rotating plate  520  is rotated, the wire  590  may not be twisted, and an electrical connection between the motor  530  and the wire  590  may be maintained. 
     As an upper side of the base  510  moves radially outward from the rotation center O, the rotation shaft housing  515 , the boundary wall  514 , the second gear  550 , and the rail  513  may be sequentially arranged. Since the rail  513  may be provided radially outside the second gear  550 , during a movement of the bearing  580 , the rail  513  and/or bearing  580  may not interfere with the second gear  550 . As the second gear  550  engages with the first gear  540  at an inner side of the rail  513 , the second gear  550  may secure a sufficient distance from the bearing  580  and a distance of a power transmission path between the first gear  540  and the second gear  550  may be reduced, thereby minimizing power loss. 
     The rail  513 , the second gear  550 , and the shaft body  570  may be provided on the same horizontal plane. The rail  513 , second gear  550 , and shaft body  570  may be provided to vertically penetrate a predetermined horizontal plane including an upper surface of the base  510  and which is perpendicular to the vertical axis. Such horizontal plane may include an upper surface of the roof  512 . 
     Due to this structure, a space between the rail  513  and the boundary wall  514  may receive the second gear  550 , and a space inside the boundary wall  514  may receive the shaft body  570 . All of the rail  513 , the second gear  550 , and the shaft body  570  may be provided on a single horizontal plane. A height occupied by the driving unit  500  in the vertical direction may be reduced so that a height of the lower case  120  spaced upward from the ground may be reduced. As a position of the suction hole  121  may be lowered, dust accumulated on the ground may be effectively suctioned through the suction hole  121 . 
     Hereinafter, a detailed configuration of the rotating plate  520  according to the first embodiment will be described with reference to  FIG.  13    Referring to  FIG.  13   , the stem  511  may include a lower plate  511   a  which contacts a ground, a stem outer wall  511   b  extending obliquely upward from an edge of the lower plate  511   a , and a stem seating portion or rim  511   c  extending radially outward from an upper end of the stem outer wall  511   b.    
     An overall outer shape of the lower plate  511   a  may be a disk shape, and a plurality of holes  511   s  into which fastening members (e.g., bolts or screws) in the base  510  may be inserted may be formed to be spaced apart in a circumferential direction. 
     The stem outer wall  511   b  may extend in a circumferential direction and may be formed to be inclined outward in the radial direction. The stem seating portion  511   c  may extend in a circumferential direction and may be formed to face the edge  520   h  of the rotating plate  520  at an upper side. When the rotating plate  520  is seated on the base  510 , the edge  520   h  may be seated and supported on an upper surface of the stem seating portion  511   c.    
     The rotating plate  520  may include a first circumferential wall  523  extending in a circumferential direction, a second circumferential wall  524  extending in a circumferential direction at an inner side of the first circumferential wall  523 , and a third circumferential wall  525  extending in a circumferential direction at an inner side of the second circumferential wall  524 . The first circumferential wall  523 , the second circumferential wall  524 , and the third circumferential wall  525  may be concentric, and their diameters may increase in a radially outward direction. 
     The first circumferential wall  523 , the second circumferential wall  524 , and the third circumferential wall  525  may be formed by cutting. The first gear  540  may be provided at an area where the circumferential wall  523 ,  524  and  525  ends or is otherwise cut off. 
     The first gear  540  may be connected to the motor  530  through the driving motor shaft  532 , and the driving motor shaft  532  and the first gear  540  may be provided under the motor insertion groove  520   s   2 . The rotating plate  520  may include a shaft holder  526  protruding downward from the center portion  520   a  and providing a space into which the shaft body  570  is inserted. An overall external shape of the shaft holder  526  may be cylindrical, and a shaft insertion groove  520   s   1  may be formed inside the shaft holder  526 . 
     The shaft holder  526  includes a holder outer wall  526   a  forming an outer shape of the shaft holder  526 , a crest  526   b  protruding radially inward from the holder outer wall  526   a , and a body fastening member  526   c  (e.g., screw) that is inserted into the crest  526   b . The body fastening member  526   c  may be inserted into a body fastening hole formed at the crest  526   b  and opened in a vertical direction. 
     The shaft body  570  may be inserted into the shaft holder  526  and fixed to the shaft holder  526 , and a curvature of the crest  526   b  may be formed to match the first body  571 , the second body  572 , and the third body  573 , respectively. The shaft body  570  may be fixed to the rotating plate  520  by penetrating the body fastening member  526   c  through the shaft body  570  and the crest  526   b  while the shaft body  570  is inserted into the shaft holder  526 . The shaft body  570  may be rotated integrally with the rotating plate  520 , a structure of the shaft body  570  may be simplified, and a structure of the shaft body  570  may reduce or minimize interference between the shaft body  570  and the base  510 . 
     The driving unit  500  may include a shaft bearing  560  provided to surround the shaft body  570 . An overall external shape of the shaft bearing  560  may be cylindrical, and the shaft body  570  may penetrate inside the shaft bearing  560 . 
     The shaft bearing  560  may include a first layer  561  provided so as to be rotatable integrally with the shaft holder  526 , and a second layer  562  provided to surround the first layer  561 . The first layer  561  may be provided radially inside the second layer  562 , and an outer circumferential surface of the first layer  561  may contact an inner circumferential surface of the second layer  562 . 
     The second layer  562  may be provided at an inner side of the rotating shaft housing  515 , and an outer circumferential surface of the second layer  562  may contact an inner circumferential surface of the rotating shaft housing  515 . The first layer  561  may be rotatably connected to the second layer  562 , and the rotating plate  520  may be rotated together with the shaft holder  526 . The second layer  562  may be fixedly provided at the rotating shaft housing  515  and may not be rotated even if the rotating plate  520  is rotated. The first layer  561  may support the rotation of the shaft holder  526 , and the second layer  562  may support the rotation of the first layer  561 . Lubricant oil may be injected between the first layer  561  and the second layer  562 . 
     The shaft bearing  560  may be provided at the rotating plate  520  to surround the holder outer wall  526   a  of the shaft holder  526 , or alternatively may be provided at the base  510  to be fixed to an inner surface of the rotating shaft housing  515 . The rotating plate  520  may include a lower boss  528  protruding downward from the second seating portion  522 . A plurality of lower bosses  528  may be formed to be spaced apart in a circumferential direction, and a case fastening hole  520   e   2  may be formed in the lower boss  528  to extend vertically. 
     The rotating plate  520  may include a plurality of ribs  527  extending in the radial direction. A plurality of ribs  527  may be formed to be spaced apart in a circumferential direction. The plurality of ribs  527  may include a first rib  527   a  extending from the edge  520   h  toward a first circumferential wall  523 , a second rib  527   b  extending from the first circumferential wall  523  toward a second circumferential wall  524 , and a third rib  527   c  extending from the second circumferential wall  524  toward a third circumferential wall  525 . The plurality of ribs  527  may include a first boundary rib  527   d  provided at a cut portion of the circumferential walls  523 ,  524 , and  525  and extending in a radial direction and a second boundary rib  527   e  provided at a cut portion of the circumferential walls  523 ,  524 ,  525  and spaced apart from the first boundary rib  527   d  in a circumferential direction. 
     The first boundary rib  527   d  may be a single rib  527   d  in which the second rib  527   b  and the third rib  527   c  are connected to each other to form a continuous surface. The first boundary rib  527   d  may extend in a radial direction and may be provided adjacent to one side (e.g., a first side) of the first gear  540 . The second boundary rib  527   e  may be a single rib  527   e  in which the second rib  527   b  and the third rib  527   c  are connected to each other to form a continuous surface, and the second boundary rib  527   e  may be spaced apart from the first boundary rib  527   d  in a circumferential direction and provided adjacent to the other (e.g., a second) side of the first gear  540 . 
     The first gear  540  may be provided and rotated between the first boundary rib  527   d  and the second boundary rib  527   e . The ribs  527  may include a fourth rib  527   f  extending radially from the inside of the third circumferential wall  525 . The fourth rib  527   f  may be located between a fourth circumferential wall  521   a  and a fifth circumferential wall  521   b . The fourth circumferential wall  521   a  may be protruded from a lower surface of the first seating portion  521 . The fifth circumferential wall  521   b  may be protruded from a lower surface of the first seating portion  521  and spaced apart from the fourth circumferential wall  521   a . The fourth circumferential wall  521   a  and the fifth circumferential wall  521   b  may have an annular shape, and a plurality of fourth ribs  527   f  may be formed to be spaced apart along a circumferential direction. 
     The rotating plate  520  may include a plurality of bearings  580  arranged to be spaced apart from each other along a circumferential direction of the rotating plate  520  and supported to be rotatable on the base  510 . Rollers may be used as a type of the bearing  580 . 
     The bearing  580  may be provided between ribs among a plurality of ribs  527  spaced apart in a circumferential direction. For example, the bearing  580  may be provided between a plurality of first ribs  527   a . The bearing  580  may be provided between the edge  520   h  and the first circumferential wall  523  spaced apart from each other in a radial direction. 
     The bearing  580  may include a support protrusion  581  formed to protrude downward from the rotating plate  520 , a support shaft  582  connected to the support protrusion  581 , and a wheel  583  through which the support shaft  582  passes. The support protrusion  581  may have an insertion hole into which the support shaft  582  may be inserted, and the support shaft  582  may be inserted upward to the support protrusion  581 . 
     The support shaft  582  may support the wheel  583 . Screws, pins, etc. may be used as a type of the support shaft  582 . The support shaft  582  may be inserted into and fixed to the support protrusion  581  and may support the wheel  583  so that the wheel  583  is not removed downward. 
     The wheel  583  may be provided to be rotatable between the support protrusion  581  and the support shaft  582 . A ball bearing or roller may be used as the wheel  583 . The wheel  583  may be rotated using the support shaft  582  as a rotation axis. 
     When the rotating plate  520  is rotated, the wheel  583  may be rotated using the support shaft  582  as a rotation axis, and may be moved in a circumferential direction based on the rotation center O to revolve around the rotation center O. The shaft body  570  may provide a revolution axis P extending in the vertical direction and passing through the rotation center O, and the support shaft  582  may provide a rotational axis Q extending in the vertical direction. The revolution axis P and the rotational axis Q may be formed side by side. When the rotating plate  520  is rotated, the bearing  580  may be rotated about the rotational axis Q and at the same time move in a circumferential direction about the revolution axis P. The wheel  583  may be loosely coupled around the support shaft  582  to facilitate rotation. 
     Hereinafter, a detailed structure and arrangement position of the bearing  580  according to the first embodiment will be described with reference to  FIG.  14   . Referring to  FIG.  14   , a cutout portion  520   s   3  to receive the first gear  540  may be formed between the first boundary rib  527   d  and the second boundary rib  527   e . The cutout portion  520   s   3  may be understood as a portion in which the circumferential walls  523 ,  524 , and  525  are cut off or ended. 
     The first gear  540  may be provided so as to be rotatable inside the cutout portion  520   s   3 , and reinforcing ribs  527   a   1 ,  527   a   2  and  527   a   3  extending from the edge  520   h  toward the first gear  540  may be formed at the cutout portion  520   s   3 . Each of the reinforcing ribs  527   a   1 ,  527   a   2 , and  527   a   3  may have a same shape as the first rib  527   a . A boss support portion  529   b  connected to the stopper boss  529   a  and extending downward may be formed at the cutout portion  520   s   3 . 
     A plurality of bearings  580  may be provided to be spaced apart from each other in a circumferential direction. As an example, five bearings  580  may be provided to be spaced apart from each other. However, a number of bearings  580  is not limited to five. 
     The plurality of bearings  580  may include a first bearing  580   a  provided opposite to the driving motor shaft  532  based on the rotation center O, a second bearing  580   b  provided between the driving motor shaft  532  and the first bearing  580   a , and a third bearing  580   c  provided between the first bearing  580   a  and the second bearing  580 . The first bearing  580   a , the second bearing  580   b , and the third bearing  580   c  may be different in an arrangement position. The shape and structure of each bearings  580   a ,  580   b ,  580   c  may be similar or identical. 
     The first bearing  580   a  may be provided opposite to the driving motor shaft  532  based on the rotation center O. The support shaft  582  of the first bearing  580 , the driving motor shaft  532 , and the rotation center O may be located on a center line CL. However, the first bearing  580   a  does not necessarily have to be provided on the center line CL. Due to this arrangement of the first bearing  580   a , a region of the rotating plate  520  where support is weak due to being farthest from the driving shaft  532  may be stably supported by the first bearing  580   a.    
     A separation angle θ between the second bearing  580   b  and the first gear  540  centered on the rotation center O may be an acute angle. The separation angle θ between the driving motor shaft  532  and the support shaft  582  centered on the rotation center O may be an acute angle. The second bearing  580   b  may include one side or a first bearing  580   b   1  provided adjacent to the first boundary rib  527   d  and the other or a second bearing  580   b   2  provided adjacent to the second boundary rib  527   e , and the one side bearing  580   b   1  and the other side bearing  580   b   2  may be symmetrically provided with respect to the driving motor shaft  532 . 
     Due to this arrangement of the second bearing  580   b , a weak rigidity of the cutout portion  520   s   3  in which the circumferential walls  523 ,  524 , and  525  are not formed may be reinforced or supplemented. By placing the second bearing  580   b  adjacent to the cutout portion  520   s   3 , vibration generated by rotation of the first gear  540  provided in the cutout portion  520   s   3  and engaged with the second gear  550  may be reduced or suppressed as much as possible. 
     The third bearing  580   c  may include one (or a first) side bearing  580   c   1  spaced apart from one side of the first bearing  580   a , and the other (or a second) side bearing  580   c   2  spaced apart from the other side of the first bearing  580   a . The one side bearing  580   c   1  and the other side bearing  580   c   2  may be symmetrically provided with respect to the driving motor shaft  532 . 
     The first gear  540  may rotate by being engaged with the second gear  550  at a radially inner side of the bearing  580 . A first distance R 1  from the rotation center O to the driving motor shaft  532  may be less than a second distance R 2  from the rotation center O to the support shaft  582 . 
     Due to this structure, a distance of the power transmission path from the driving motor shaft  532  to the rotational center O may be reduced, improving power or energy efficiency. By arranging the bearing  580  outside the first gear  540 , vibration generated by the rotation of the first gear  540  may be effectively reduced. By arranging the bearing  580  as close to the edge  520   h  as possible, a load of heavy structures rotating on an upper side of the rotating plate  520  may be evenly distributed in a radial direction. 
     The rotating plate  520  may include an upper mount  520   i  connected to the substrate housing  160 . The upper mount  520   i  may be formed to protrude downward from a lower surface of the rotating plate  520 . The upper mount  520   i  may include a mount body  520   i   1  extending between the ribs  527  and a mount hole  520   i   2  formed to be opened vertically at the mount body  520   i   1 . The rotating plate  520  may be connected to the substrate housing  160  through a predetermined fastening member (e.g., bolt or screw) penetrating through the mount hole  520   i   2 . 
     Hereinafter, an internal structure of the base  510  and a connection relationship between the base  510  and the rotating plate  520  and the substrate housing  160  and the lower case  120  according to the first embodiment will be described with reference to  FIG.  15   . Referring to  FIG.  15   , a control space  150   s  to receive substrates  152  and  153  (e.g., printed circuit boards or PCBs) may be formed inside the substrate housing  160 . The substrate  152  and  153  may include a first substrate  152  and a second substrate  153  ( FIG.  20   ). The first substrate  152  may control the driving unit  500 , the airflow converter  400 , and the fan assembly  300 . The second substrate  153  may control the driving of the heater  240 . 
     At least a portion of the motor  530  may be provided in the control space  150   s  of the substrate housing  160 . The motor  530  may be rotated inside of the substrate housing  160 . The substrates  152  and  153  and the motor  530  are provided together in the control space  150   s  of the substrate housing  160 , integrated management of electric components can be achieved. 
     The substrate housing  160  may include a first magnetic member  169  protruding radially outward from the housing outer wall  161 . The lower case  120  may include a second magnetic member  129  having a polarity opposite to that of the first magnetic member  169 . The lower case  120  may be detached from the substrate housing  160  by the magnetic force of the first magnetic member  169  and the second magnetic member  129 . 
     The housing outer wall  161  may include a fastening portion  161   d  extending radially outward from a lower end of the housing outer wall  161 , and a support portion  161   e  extending downward from an outer end of the fastening portion  161   d . The fastening portion  161   d  may be mounted on the third rim  520   e  and fixed to the rotating plate  520  by a fastening member passing through the case fastening hole  520   e   1 . The support portion  161   e  may be seated on the edge  520   h  and supported by the edge  520   h . Alternatively, a fastening member penetrating through the case fastening hole  520   e   1  may be directly connected to the lower case  120  rather than the substrate housing  160 , so that the lower case  120  is connected to the rotating plate  520  and fixed to the rotating plate  520 . 
     A space  510   s   2  may be formed inside the stem  511  of the base  510 . The shaft body  570  may be inserted into the space  510   s   2 . The shaft body  570  may include a first body  571  provided in the rotating shaft housing  515 , a reel  574  connected to the first body  571 , provided under the first body  571 , and received in the base  510 , and a fastening plate  576  protruding in a radial direction and connected to the shaft holder  526 . 
     The reel  574  may be provided under the rotating shaft housing  515  and may have a cylindrical shape in which the wire through portion  570   s  is formed. The fastening plate  576  may extend radially inward from an upper portion of the reel  574 , and the body fastening member  526   c  may penetrate the fastening plate  576  and the crest  526   b  to fix the shaft body  570  to the rotating plate  520 . 
     The wire  590  may receive power from an external or commercial power source. The wire  590  may be wound a predetermined number of times along an outer circumferential surface of the reel  574 . The wire  590  may be electrically connected to the motor  530  through the wire through portion  570   s  formed inside the reel  574 . A reel bearing  575  to support a winding of the wire  590  may be provided inside the base  510 . 
     A vertical or first gap G 1  may be formed between the base  510  and the rotating plate  520 . The gap G 1  may be understood as a space between the first line L 1  extending along a lower surface of the rotating plate  520  and the second line L 2  extending along an upper surface of the base  510 . 
     A vertical or second gap G 2  may be formed between the base  510  and the bearing  580 . The gap G 2  may be understood as a space between the second line L 2  extending along an upper surface of the base  510  and the third line L 3  extending along a lower surface of the bearing  580 . A part of the bearing  580  may be in contact with the base  510 , and the rest of the bearing  580  may be spaced apart from an upper surface of the base  510  to form the gap G 2 . 
     The gaps G 1  and G 2  may be formed by the base  510  directly supporting the bearing  580 . An outer side (e.g. at the wheel  583  and/or a bushing) of the bearing  580  may be seated on an upper side of the rail  513  and may be moved in a circumferential direction along the rail  513 . A lower surface of the rotating plate  520  may be spaced apart from and not in contact with an upper surface of the base  510 , and the rotating plate  520  may be rotatably supported by the base  510  by the bearing  580  seated on the rail  513 . 
     As the bearing  580  is rotated while seated on the rail  513  protruding upward, the rotating plate  520  and the bearing  580  may be rotated while maintaining the gaps G 1  and G 2 . Accordingly, abrasion of the driving unit  500  due to friction generated by the rotation may be reduced or prevented. 
     The support shaft  582  of the bearing  580  may be provided outside the rail  513  in a radial direction. An inner part or section of the bearing  580  may be supported by the rail  513 . As the support shaft  582  of the bearing  580  is provided outside the rail  513 , a load of the blower  1  may be evenly distributed in a radial direction. 
     Hereinafter, an operation motion of the driving unit  500  according to the first embodiment will be described with reference to  FIGS.  10  to  15   . Referring to  FIGS.  10  to  15   , when the motor  530  makes the driving motor shaft  532  rotate with power supplied through the wire  590 , the first gear  540  connected to the driving motor shaft  532  may be rotated. The second gear  550  may be fixed to the boundary wall  514 , and the first gear  540  may be rotated along an outer circumference of the second gear  550  extending in a circumferential direction. As the first gear  540  is rotated, the rotating plate  520  may be rotated in a circumferential direction with the shaft body  570  as a rotating shaft. While the rotating plate  520  is rotated, the rotation of the rotating plate  520  may be supported by a shaft bearing  560  in which at least a portion is rotated together with the shaft holder  526 . When the rotating plate  520  is rotated, the bearing  580  may be rotated about the rotation axis Q and, at the same time, may be moved in a circumferential direction around the revolution axis P. The bearing  580  may be moved in a circumferential direction while seated on and supported by the rail  513 . 
     By this structure, the plurality of bearings  580  that are spaced apart from each other in a circumferential direction and directly supported by the base  510  may evenly distribute the heavy load of the blower  1  to the base  510 , and a rotation of the blower  1  may be stably supported. As the bearing  580  is rotated about the rotation axis Q and supports the load of the blower  1  body, abrasion caused by friction between the bearing  580  and the base  510  surface may be reduced or prevented, and a use life of the bearing  580  may be extended. 
     Hereinafter, a structure of a base  610  according to a second embodiment will be described with reference to  FIG.  16   . Features of the base  610  may be similar to the base  510  described with reference to the first embodiment, and similar features may be omitted in the following explanation. 
     The base  610  may include a stem  611  having an inner space and configured to contact the ground, floor surface, tabletop, etc. The base  610  may include a roof  612  provided on an upper side of the stem  611  and covering the inner space of the stem  611 . Since the stem  611  and the roof  612  may be the same as or similar to the stem  511  and the roof  512  according to the first embodiment, detailed descriptions will be omitted. 
     The base  610  may have a rail  613  protruding upward from the base  610 . The rail  613  may include a first rail  613   a  formed to protrude upward from an upper surface of the roof  612  and a second rail  613   b  formed at an inner side of the first rail  613   a  and facing the first rail  613   a . The first rail  613   a  and the second rail  613   b  may have a ring shape, and the first rail  613   a  and the second rail  613   b  may be concentric. The bearing  680  ( FIG.  18   ) described later may be rolled in a circumferential direction between the first rail  613   a  and the second rail  613   b , and the first rail  613   a  and the second rail  613   b  may prevent the bearing  680  from deviating from a rotating path. 
     The base  610  may include a plurality of boundary walls  614  protruding upward from an upper surface of the base  610 . An overall outer shape of the boundary wall  614  may be cylindrical and may extend in a circumferential direction to form a space  614   s  inside. The boundary wall  614  may be formed to protrude upward from an upper surface of the roof  612 , may be formed at an inner side of the rail  613 , and may be formed at an outer side of the rotating shaft housing  615  to be described later. 
     The driving unit  600  may include a first gear  640  connected to the motor  630  and a second gear  650  engaged with the first gear  640 . The motor  630  may be provided above the rotating plate  620 , and the first gear  640  may be provided below the rotating plate  620 . The first gear  640  may be a spur gear or a pinion gear. 
     The second gear  650  may be seated on the base  610  and provided at an inner side of the first gear  640 . The first gear  640  may be rotated by engaging the second gear  650  at an outer side of the second gear  650 . The second gear  650  may be a ring gear and may extend along a circumferential direction. 
     The second gear  650  may be connected to the boundary wall  614 . The second gear  650  may contact and attached to an outer circumferential surface of the boundary wall  614 . The second gear  650  may be in a fixed state, and when the first gear  640  rotates, the first gear  640  and the motor  630  may be rotated integrally. 
     The second gear  650  may be provided between the rail  613  and the shaft body  670 . The second gear  650  may be provided between the rail  613  and the boundary wall  614 . Due to this structure, a space  614   s  formed inside the boundary wall  614  may be used compactly as a space in which a structure supporting the shaft body  670  is arranged. 
     The base  610  may include a rotating shaft housing  615  protruding toward the rotating plate  620 . An overall external shape of the rotating shaft housing  615  may be cylindrical, and the rotating shaft housing  615  may provide a space in which the shaft body  670  may be inserted. The rotating shaft housing  615  may be formed to face an inner circumferential surface of the boundary wall  614 . 
     The driving unit  600  may include a shaft bearing  660  provided to surround the shaft body  670  inserted into the shaft through hole  620   s   1 . An overall external shape of the shaft bearing  660  may be cylindrical, and the shaft body  670  may pass through an inner side of the shaft bearing  660 . 
     The shaft bearing  660  may include a first layer  661  provided to be rotatable integrally with a shaft holder  626  ( FIG.  18   ) and a second layer  662  provided to surround the first layer  661 . The first layer  661  may be provided at an inner side of the second layer  662 , and an outer circumferential surface of the first layer  661  may contact an inner circumferential surface of the second layer  662 . 
     The second layer  662  may be provided at an inner side of the rotating shaft housing  615 . An outer circumferential surface of the second layer  662  may contact an inner circumferential surface of the rotating shaft housing  615 . 
     The first layer  661  may be rotatably connected to the second layer  662 , and the rotating plate  620  may be rotated together with the shaft holder  626 . The second layer  662  may be fixedly provided at the rotating shaft housing  615  and may not be rotated even if the rotating plate  620  is rotated. The first layer  661  may support the rotation of the shaft holder  626 , and the second layer  662  may support the rotation of the first layer  661 . Lubricant oil may be injected between the first layer  661  and the second layer  662 . 
     Hereinafter, referring to  FIG.  17   , a detailed structure of the shaft body  670  according to the second embodiment and the relative positional relationship between the rail  613 , the second gear  650 , and the shaft body  670  are described. Referring to  FIG.  17   , a shaft insertion hole  610   s   1  through which the shaft body  670  is penetrated and the shaft holder  626  to be described later is inserted may be formed at an inner side of the first layer  661 . The shaft insertion hole  610   s   1  may define a space that vertically penetrates the base  610 . The space defined by the shaft insertion hole  610   s   1  may be a cylindrical space inside the first layer  661 . 
     The shaft body  670  may penetrate upward through the shaft insertion hole  610   s   1 . The shaft body  670  may be provided so that a lower part or portion is provided inside the base  610  and an upper part or portion passes through the shaft insertion hole  610   s   1 . 
     The shaft body  670  may include a first body  671  extending to be bent, a second body  672  provided to be spaced apart from the first body  671 , and a third body  673  provided to be spaced apart from the first body  671  and the second body  672 . The first body  671 , the second body  672 , and the third body  673  may be provided to be spaced apart from each other in the shaft insertion port  610   s   1 . Since the shaft body  670  may be the same as or similar to the shaft body  570  according to the first embodiment, a detailed description thereof will be omitted. 
     A wire through portion  670   s  may be provided between the first body  671  and the second body  672  and between the first body  671  and the third body  673 . A wire  690  ( FIG.  20   ) to be described later may pass through the wire through portion  670   s  and extend upward to be electrically connected to the motor  630 . The wire through portion  670   s  may be defined as an inner space of the shaft body  670  including the rotation center O of the rotating plate  620 . Since the wire  690  extends upward along the rotation center O and is connected to the motor  630 , even if the rotating plate  620  is rotated, the wire  690  may not be twisted, and a connection of the wire  690  and the motor  630  may be maintained. 
     The shaft bearing  660 , the rotating shaft housing  615 , the boundary wall  614 , the second gear  650 , and the rail  613  may be sequentially arranged in that order in a radial direction from the rotation center O. 
     The rail  613 , the second gear  650 , and the shaft body  670  may be provided on a same or predetermined horizontal plane that is perpendicular to a vertical line and includes an upper surface of the base  610 . Since a description thereof is the same as or similar to that of the first embodiment, a detailed description will be omitted. 
     Hereinafter, a detailed configuration of a rotating plate  620  according to the second embodiment will be described with reference to  FIG.  18   . Referring to  FIG.  18   , the stem  611  may include a lower plate  611   a  in contact with the ground, floor, or other support surface, a stem outer wall  611   b  extending obliquely upward from an edge of the lower plate  611   a , and a stem seating portion or rim  611   c  extending radially outward from an upper end of the stem outer wall  611   b.    
     An overall outer shape of the lower plate  611   a  may be a disk shape, and a plurality of holes  611   s  into which fastening members in the base  610  may be inserted may be formed to be spaced apart in a circumferential direction. The stem outer wall  611   b  may extend in a circumferential direction and may be formed to be inclined outward in the radial direction. 
     The stem seating portion  611   c  may extend in a circumferential direction and may be formed to face the edge  620   h  of the rotating plate  620 . When the rotating plate  620  is seated on the base  610 , the edge  620   h  may be seated and supported on an upper surface of the stem seating portion  611   c.    
     The rotating plate  620  may include a first circumferential wall  623  extending in a circumferential direction, a second circumferential wall  624  extending in a circumferential direction at an inner side of the first circumferential wall  623 , and a third circumferential wall  625  extending in a circumferential direction at an inner side of the second circumferential wall  624 . The first circumferential wall  623 , the second circumferential wall  624 , and the third circumferential wall  625  may be concentric, and a diameter may increase as they are positioned in a radially outward direction. 
     The first circumferential wall  623 , the second circumferential wall  624 , and the third circumferential wall  625  may be formed by cutting. The first gear  640  may be provided at a cut portion of the circumferential walls  623 ,  624  and  625 . The first gear  640  may be connected to the motor  630  through the motor shaft  632 , and the motor shaft  632  and the first gear  640  may be provided under a motor insertion groove  620   s   2 . 
     The rotating plate  620  may include a shaft holder  626  that provides a space into which the shaft body  670  is inserted. An overall external shape of the shaft holder  626  may be cylindrical, and a shaft insertion groove  620   s   1  may be formed inside the shaft holder  626 . 
     The shaft holder  626  may include a holder outer wall  626   a  forming an outer shape of the shaft holder  626 , a crest  626   b  protruding radially inward from the holder outer wall  626   a , and a body fastening hole  626   c  formed to be opened in the vertical direction on the crest  626   b . The shaft body  670  may be inserted into the shaft holder  626  and fixed to the shaft holder  626 , and the radius of curvature of the crest  626   b  may be formed to match to a shape of the bodies  671 ,  672  and  673 . When the shaft body  670  is inserted into the shaft holder  626 , a predetermined fastening member may pass through the body fastening hole  626   c  to fix the shaft body  670  to the rotating plate  620 . The shaft body  670  may be rotated integrally with the rotating plate  620 . The shaft body  670  may simplify a structure of a rotating shaft of the rotating plate  620  and minimize interference between the rotating shaft and the base  610 . 
     The rotating plate  620  may include a lower boss  628  formed to protrude downward. A plurality of lower bosses  628  may be formed to be spaced apart in a circumferential direction, and the lower boss  628  may be connected to the case  100 . 
     The rotating plate  620  may include a plurality of ribs  627  extending in a radial direction and spaced apart in a circumferential direction. The plurality of ribs  627  may include a first rib  627   a  extending from the edge  620   h  toward the first circumferential wall  623 , a second rib  627   b  extending from the first circumferential wall  623  toward the second circumferential wall  624 , and a third rib  627   c  extending from the second circumferential wall  624  toward the third circumferential wall  625 . Each of the ribs  627   a ,  627   b , and  627   c  may be provided on the same straight line extending in a radial direction. 
     The plurality of ribs  627  may also include a first boundary rib  627   d  and a second boundary rib  627   e . The first boundary rib  627   d  may be provided at a cut-off portion of the circumferential walls  623 ,  624 ,  625  and extend in a radial direction. The second boundary rib  627   e  may be provided at the cut-off portion of the circumferential walls  623 ,  624 , and  625  and spaced apart from the first boundary rib  627   d  in a circumferential direction. 
     The first boundary rib  627   d  may be a single rib  627   d  in which the first rib  627   a , the second rib  627   b , and the third rib  627   c  are connected to each other to form a continuous surface. The first boundary rib  627   d  may extend in a radial direction and may be provided adjacent to one (or a first) side of the first gear  640 . 
     The second boundary rib  627   e  may be a single rib  627   e  in which the first rib  627   a , the second rib  627   b , and the third rib  627   c  are connected to each other to form a continuous surface. The second boundary rib  627   e  may be spaced apart from the first boundary rib  627   d  in a circumferential direction and provided adjacent to the other (or a second) side of the first gear  640 . 
     The first gear  640  may be provided and rotated between the first boundary rib  627   d  and the second boundary rib  627   e . The rotating plate  620  may comprise a plurality of bearings  680  arranged to be spaced apart from each other along a circumferential direction of the rotating plate  620  and supported to be rotatable on the base  610 . A roller may be used as a type of bearing  680 . 
     The bearings  680  may be provided between the ribs of the plurality of ribs  627 . For example, the bearings  680  may be provided between a plurality of second ribs  627   b . The bearing  680  may be provided between the circumferential walls  623 ,  624 , and  625  spaced apart in a radial direction and may also be provided between the first circumferential wall  623  and the second circumferential wall  624 . 
     When the rotating plate  620  is rotated, the bearing  680  may be rotated about a support shaft  683  ( FIG.  19   ) described later and may be moved in a circumferential direction about the rotation center O to revolve around the rotation center O. The shaft body  670  may extend in a vertical direction and may provide a revolution axis P′ passing through the rotation center O, and the support shaft  683  may provide a rotational axis Q′ extending in a radial direction. The revolution axis P′ and the rotation axis Q′ may be extended perpendicular to each other. When the rotating plate  620  is rotated, the bearing  680  may be rotated about the rotation axis Q′ and at the same time move in a circumferential direction about the revolution axis P′. 
     The rotating plate  620  may include a protrusion receiving portion  620   i  formed to protrude downward. The protrusion receiving portion  620   i  may form a lower boundary of the groove  520   e   1  into which a protrusion protruding from the lower case  120  is inserted. The protrusion receiving portion  620   i  may be provided between ribs among the plurality of ribs  627 . The protrusion receiving part  620   i  may fix the protrusion of the lower case  120  to fix the lower case  120  to the rotating plate  620 . Alternatively, it is also possible to fix the lower case  120  only with the lower protrusion  628  without the protrusion receiving portion  620   i.    
     Hereinafter, a detailed structure and arrangement position of the bearing  680  according to a second embodiment will be described with reference to  FIG.  19   . Referring to  FIG.  19   , a cutout portion  620   s   3  to receive the first gear  640  may be formed between the first boundary rib  627   d  and the second boundary rib  627   e . The cutout portion  620   s   3  may be a portion in which the circumferential walls  623 ,  624 , and  625  are cut or ended. 
     The first gear  640  may be arranged to be rotatable at the cutout portion  620   s   3 , and a reinforcing rib  627   a   1  extending from the edge  620   h  toward the first gear  640  may be formed at the cutout portion  620   s   3 . A boss support portion  629   b  connected to the stopper boss  529   a  and extending downward may be formed at the cutout portion  620   s   3 . 
     A holder protrusion  626   d  protruding radially outward from the holder outer wall  626   a  may be formed at the shaft holder  626 . A plurality of holder protrusions  626   d  may be formed to be spaced apart in a circumferential direction. 
     The bearing  680  may include a first support protrusion  681  connected to the first circumferential wall  623 , a second support protrusion  682  connected to the second circumferential wall  624 , a wheel  684  provided between the first support protrusion  681  and the second support protrusion  682 , and a support shaft  683  extending from the first support protrusion  681  toward the second support protrusion  682 , penetrating the wheel  684 , and extending to face an upper surface of the base  610 . The first support protrusion  681  may be fixed on the first circumferential wall  623 , and the second support protrusion  682  may be fixed on the second circumferential wall  624 . 
     The support shaft  683  may be connected to the first support protrusion  681  and the second support protrusion  682  and may support a rotation of the wheel  684 . The rotation of the wheel  684  may be supported by the support shaft  683 , and the wheel  684  may be rotated about a rotation axis extending in a radial direction. The wheel  684  may be rotatably connected to the support shaft  683 . 
     A plurality of bearings  680  (e.g., six bearings  680 ) may be provided to be spaced apart in a circumferential direction. Embodiments disclosed herein are not limited to a number of bearings  680 . The plurality of bearings  680  may include a first bearing  680   a  provided between the plurality of ribs  627 , a second bearing  680   b  provided adjacent to the boundary ribs  627   d  and  627   e , and a third bearing  680   c  provided adjacent to the protrusion receiving portion  620   i . The first bearing  680   a , the second bearing  680   b , and the third bearing  680   c  may be distinguished according to an arrangement position, but each bearing  680   a ,  680   b ,  680   c  may have the same or similar structure. The first bearing  680   a  may mean all bearings other than the second bearing  680   b  and the third bearing  680   c.    
     The second bearing  680   b  may include one side bearing  680   b   1  provided adjacent to the first boundary rib  627   d , and the other side bearing  680   b   2  provided adjacent to the second boundary rib  627   e . Here, “being provided adjacent” may mean that the second bearing  680   b  is provided between the boundary ribs  627   d  and  627   e  and the rib  627  provided nearest to the boundary ribs  627   d  and  627   e . One side bearing  680   b   1  may be provided between the first boundary rib  627   d  and the rib  627  provided nearest to the first boundary rib  627   d , and the other side bearing  680   b   2  may be provided between the second boundary rib  627   e  and the rib  627  provided nearest to the second boundary rib  627   e.    
     Due to this arrangement of the second bearing  680   b , a weak rigidity of the cutout portion  620   s   3  in which the circumferential walls  623 ,  624 , and  625  are not formed be supplemented or reinforced. Vibration generated as the first gear  640  provided in the cutout portion  620   s   3  is rotated in engagement with the second gear  650  may be suppressed or reduced due to placing the second bearing  680   b  adjacent to the cutout  620   s   3 . 
     The third bearing  680   c  may include one (or a first) side bearing  680   c   1  spaced apart from one side of the protrusion receiving portion  620   i , and the other (or a second) side bearing  680   c   2  spaced apart from the other side of the protrusion receiving portion  620   i . The third bearing  680   c  may be provided adjacent to the protrusion accommodating portion  620   i . Here, “being provided adjacent to the protrusion receiving portion  620   i ” may mean that the third bearing  680   c  is provided between the two ribs  627  arranged closest to the protrusion receiving portion  620   i . Due to this arrangement of the third bearing  680   c , a weak stiffness or rigidity of the adjacent region in which the protrusion receiving portion  620   i  is formed may be reinforced or supplemented. 
     The first gear  640  may be rotated by engaging the second gear  650  at an inner side of the bearing  680 . A third distance R 3  from the rotation center O to the motor shaft  632  may be less than a fourth distance R 4  from the rotation center O to the support shaft  683  of the bearing  680 . Due to this structure, a length of a power transmission path from the rotational shaft  632  of the first gear  640  to the rotational center O may be reduced or minimized, thereby improving power or energy efficiency. By placing the bearing  680  at an outer side of the first gear  640 , vibrations generated by the rotation of the first gear  640  may be effectively reduced. By arranging the bearing  680  as close to the edge  620   h  as possible, the load of heavy structures rotating on an upper side of the rotating plate  620  may be evenly distributed in the radial direction. 
     Hereinafter, referring to  FIG.  20   , an internal structure of the base  610  according to the second embodiment and the connection relationship between the base  610  and the rotating plate  620 , the substrate housing  160 , and the lower case  120  will be described. Referring to  FIG.  20   , a control space  150   s  configured to receive substrates  152  and  153  may be formed inside the substrate housing  160 . The substrates  152  and  153  may include a first substrate  152  and a second substrate  153 . The first substrate  152  may be configured to control the driving unit  600 , the airflow converter  400 , and the fan assembly  300 . The second substrate  153  may be configured to control a driving of the heater  240 . 
     At least a portion of the motor  630  may be provided in the control space  150   s  of the substrate housing  160 . The motor  630  may be rotated inside of the substrate housing  160 . The connection structure between the rotating plate  620 , the substrate housing  160 , and the lower case  120  may be the same as or similar to that of the first embodiment, and thus a detailed description thereof will be omitted. 
     A space  610   s   2  may be formed inside the stem  611  of the base  610  The shaft body  670  may be inserted in the space  610   s   2 . The shaft body  670  may include a first body  671  provided in the rotating shaft housing  615  and a reel  674  connected to the first body  671 , provided under the first body  671 , and received inside the base  610 . 
     The reel  674  may be provided under the rotating shaft housing  615  and may have a cylindrical shape in which a wire through portion  670   s  is formed. At the reel  674 , a fastening boss  675  protruding upward may be formed, and the fastening boss  675  may be inserted into the crest  626   b  of the shaft holder  626  so as to fix the shaft body  670  to the rotating plate  620 . 
     The wire  690  may receive power from an external or commercial power source or supply. The wire  690  may be wound a predetermined number of times along an outer circumferential surface of the reel  674  and may be electrically connected to the motor  630  by passing through the wire through portion  670   s  formed in the reel  674 . Due to the structure of the reel  674  and the wire through portion  670   s , twisting of the wire  690  caused by the rotation of the rotating plate  620  may be reduced or prevented, and electrical connection between the wire  690  and the motor  630  may be maintained. 
     The rotating plate  620  may be connected to the substrate housing  160  by an upper boss  629  protruding upward of the rotating plate  620 . A vertical gap G between the base  610  and the rotating plate  620  may be formed. The gap G may be understood as a space between the first line L 1  extending along a lower surface of the rotating plate  620  and the second line L 2  extending along an upper surface of the base  610 . 
     The gap G may be formed by arranging the bearing  680  to protrude from the rotating plate  620  toward the base  610 . The bearing  680  may be provided to protrude downward from a lower surface of the rotating plate  620  toward the base  610  by the gap G. The lower surface of the rotating plate  620  may be spaced apart from and not in contact with an upper surface of the base  610 , and the rotating plate  620  may be supported so as to be rotatable to the base  610  only by the bearing  680 . Due to this structure, the rotating plate  620  may be rotated while maintaining the gap G formed between the base  610 . Abrasion of the driving unit  600  due to friction generated between the rotating plate  620  and the base  610  may be reduced or prevented. 
     Hereinafter, an operating motion of the driving unit  600  according to the second embodiment will be described with reference to  FIGS.  16  to  20   . Referring to  FIGS.  16  to  20   , when the motor  630  rotates the motor shaft  632  with power supplied through the wire  690 , the first gear  640  connected to the motor shaft  632  may be rotated. The second gear  650  may be fixed to the boundary wall  614 , and the first gear  640  may be rotated along an outer circumference of the second gear  650  extending in a circumferential direction. 
     As the first gear  640  is rotated, the rotating plate  620  may be rotated about the shaft body  670 . While the rotating plate  620  is rotated, the rotation of the rotating plate  620  may be supported by a shaft bearing  660  in which at least a portion is rotated together with the shaft holder  626 . 
     When the rotating plate  620  is rotated, the bearing  680  may be rolled on an upper surface of the base  610 . The bearing  680  may be rolled between a pair of rails  613 , and a load of the bearing  680  may be supported by the base  610 . When the rotating plate  620  is rotated, the bearing  680  may be rotated about rotation axis Q′ and moved in a circumferential direction around the revolution axis P′. 
     By the above-described support structure, a plurality of bearings  680  provided to be spaced apart in a circumferential direction and directly supported by the base  610  may distribute the heavy load of the blower  1  body to the base  610  uniformly. Accordingly, the bearing  680  may support the rotation of the blower  1  stably. As the bearing  680  supports the load of the blower  1  body while rolling an upper surface of the base  610 , abrasion caused by friction between the bearing  680  and a surface of the base  610  may be reduced or prevented. 
     The bearing  580  according to the first embodiment of the present invention and the bearing  680  according to the second embodiment may have different structures and operating motions. However, the driving unit  500  according to the first embodiment and the driving unit  600  according to the second embodiment may otherwise have the same structure except for the bearings  580  and  680 . 
     Hereinafter, a driving unit  700  according to a third embodiment will be described with reference to  FIGS.  21  to  25   . Referring to  FIGS.  21  and  22   , the driving unit  700  may be provided under the lower case  120  and may support the load of the blower  1 . The driving unit  700  may make the blower  1  main body rotate. 
     The driving unit  700  may include a base  760 , a motor  710  provided above the base  760  and configured to provide power, and a bearing  730  provided above the base  760  and supported by the base  760 . The base  760  may be fixed to the ground, floor, or other supporting surface and not move. The motor  710  may be provided above the base  760 . 
     A bearing installation part or support  731  protruding upward of the base  760  may be formed at the base  760 . The bearing installation support  731  may have a hollow cylindrical shape. The bearing  730  may have an annular shape and may be seated on an upper side of the bearing installation support  731 . The bearing  730  may be rotated on an upper side of the bearing installation support  731 . 
     A rotation shaft installation part or support  713  may be provided inside the bearing installation support  731 . The rotation shaft installation support  713  may protrude upward from the base  760 . The rotation shaft installation support  713  may be provided at the center of the base  760  and may be integrally formed with the base  760 . 
     The rotation shaft  711  extending vertically may be provided so as to be rotatable at the rotation shaft installation support  713 . The rotation shaft  711  may be rotated while being inserted into the rotation shaft installation support  713 . The rotation shaft installation support  713  may distribute the load of the blower  1  concentrated on the rotation shaft  711  to the base  760 . 
     The shaft coupling member  712  to which the rotation shaft  711  is connected may be provided so as to be rotatable above the rotation shaft installation support  713 . The shaft coupling member  712  may be rotated about a vertical axis together with the rotation shaft  711 . 
     The power transmitted from the motor  710  may rotate the rotation shaft  711  and the shaft coupling member  712 . The blower  1  may be rotated by the rotation of the rotation shaft  711  and the shaft coupling member  712 , and the rotation shaft installation support  713  and the bearing  730  may support the load of the blower  1 . 
     The driving motor shaft  715  connected to the motor  710  may extend in a radial direction and may be provided horizontally. The driving motor shaft  715  rotated by the driving of the motor  710  may transmit power to a power transmission member  740  ( FIG.  23   ) described later. The motor  710  may be fixed to the base  760 . 
     Referring to  FIGS.  23  to  25   , the lower case  120  may be rotated by the driving unit  700 . The lower case  120  may include an outer case  123  in which a suction hole  121  is formed and an inner case  124  provided inside the outer case  123 . The outer case  123  and the inner case  124  may be integrally formed. 
     The outer case  123  may be formed in a cylindrical shape, and the cross-sectional area may be narrower toward the upper side. The outer case  123  may form an outer shape of the lower case  120 . The inner case  124  may have a cylindrical shape in which a space is formed inside. A substrate housing  160  may be provided above the inner case  124 . The inner case  124  may perform a same or similar function as the rotating plates  520  and  620  in the first and second embodiments. The inner case  160  may support the entire load of the blower  1  except for the driving unit  700 . The inner case  160  may rotate all structures of the blower  1  provided on an upper side of the driving unit  700 . 
     The inner case  124  may include an upper wall  124   a  to which the rotation shaft  711  is assembled and a side wall  124   b  protruding downward from the upper wall  124   a . The upper wall  124   a  may have a disk shape. The substrate housing  160  may be mounted on an upper side of the upper wall  124   a . The rotation shaft  711  may be directly inserted into the upper wall  124   a  and rotated together with the upper wall  124   a . The shaft coupling member  712  may be connected to the upper wall  124   a  to rotate the upper wall  124   a.    
     The side wall  124   b  may extend in a circumferential direction of the lower case  120  and may be cylindrical to form a space inside. The side wall  124   b  may be connected to the outer case  123  and transmit rotational power to the outer case  123 . 
     The power transmission member  740  may be configured to transmit power generated from the motor  710  to the inner case  124 . The power transmission member  740  may include a drive gear  741  connected to the motor  710  by the drive motor shaft  715  and a rack gear  742  engaging with the drive gear  741 . 
     The drive gear  741  may be directly connected to the motor  710  by the drive motor shaft  715  and may transmit power generated from the motor  710  to the rack gear  742 . The rack gear  742  may protrude radially inward from the side wall  124   b  of the inner case  124 . The rack gear  742  may extend in a circumferential direction, and a gear tooth protruding downward may be formed. The rack gear  742  may be formed in a ring shape or an arc shape. 
     The rack gear  742  may be moved in a circumferential direction by being engaged with the drive gear  741 . When the rack gear  742  is moved in the circumferential direction, structures provided on an upper side of the inner case  124  may be rotated. 
     The bearing  730  may be provided under the inner case  124  to support the inner case. The bearing  730  may be rotated according to the rotation of the inner case  124 . Thrust bearing can be used as a type of the bearing  730 . 
     A light emitting assembly  750  providing an identification mark for rotational drive of the blower  1  will be described with reference to  FIGS.  21  to  25   . The light emitting assembly  750  may include a light emitting member or device  751  (e.g., a light emitting diode or an LED lamp) that emits light by receiving power, a circuit board  752  on which the light emitting member  751  is installed, and a light transmitting member or guide  753  to guide the light generated from the light emitting member  751  to an outside of the blower  1 . 
     The circuit board  752  may be provided above the base  760  and may be formed in a ring shape or an arc shape. The circuit board  752  may be provided under the drive gear  741 . The circuit board  752  may be provided between the base  760  and the lower case  120 . 
     A substrate support rib  752   a  protruding upward from the base  760  may be formed at the base  760 . A plurality of substrate support ribs  752   a  may be formed to be spaced apart from each other in a circumferential direction. The substrate support rib  752   a  may support the circuit board  752 . 
     The light emitting member  751  may be installed on a lower surface of the circuit board  752  and may irradiate light toward a lower side of the circuit board  752 . A plurality of light emitting members  751  may be provided to be spaced apart from each other in a circumferential direction. 
     The light transmitting member  753  may be provided below the lower case  120  and may be provided above the base  760 . The light transmitting member  753  may be provided between the lower case  120  and the base  760 . 
     The light transmitting member  753  may be formed in a ring shape or an arc shape. The light transmitting member  753  may be provided under the light emitting member  751 . 
     The light transmitting member  753  may include a first surface  753   a  and a second surface  753 . Light irradiated from the light emitting member  751  may be projected through the first surface  753   a  and the second surface  753   b  to ultimately be propagated to an outside of the blower  1 . 
     Light projected on the first surface  753   a  may be refracted inside the light transmitting member  753  and proceed toward the second surface  753   b . The shape of a longitudinal section of the light transmitting member  753  may be formed to be bent toward an outer side in the radial direction. The second surface  753   b  may extend in a circumferential direction and may form a surface continuous with an outer circumferential surface  761  of the base  760 . 
     When power is applied to the motor  710  and the blower  1  is rotated, power may be applied to the light emitting members  751  corresponding to the range in which the blower  1  is rotated. The plurality of light emitting members  751  may be lightened simultaneously or sequentially according to the rotation of the blower  1 . 
     This application is related to co-pending U.S. application Ser. No. 17/190,692 filed Mar. 3, 2021, U.S. application Ser. No. 17/191,873 filed Mar. 4, 2021, U.S. application Ser. No. 17/197,918 filed Mar. 10, 2021, U.S. application Ser. No. 17/332,681 filed May 27, 2021, U.S. application Ser. No. 17/318,242 filed May 12, 2021, and U.S. application Ser. No. 17/318,274 filed May 12, 2021, whose entire disclosures are incorporated by reference herein. 
     Embodiments disclosed herein may provide a bearing provided on a rotating plate that rotates while being supported by a base. A rotation of a blower may be stably supported by the base and the bearing. A plurality of bearings may be arranged to be spaced apart in a circumferential direction. A load of a body of the blower may be evenly distributed among the plurality of bearings, thereby improving the life of the bearing. 
     A frictional resistance generated between the rotating plate and the base may be reduced or eliminated by maintaining a vertical gap between the rotating plate and the base by the bearing. A rotational support structure may be compact by utilizing an empty space formed at an inner side of the bearing as a space in which the first gear and the second gear are arranged. Since a first gear and a second gear may be provided at an inner side of the bearing, the power transmission path may be shortened, thereby reducing the power required for rotation. 
     The bearing may be prevented from being separated from a rotation path during rotation by a rail structure guiding a rotation path of the bearing. By passing a wire through a center of the rotation shaft, the wire may not be twisted during rotation. A substrate and the motor may be collectively arranged on an upper side of the rotating plate so that integrated management of electrical components is possible. 
     The effects of the embodiments disclosed herein are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the description of the claims. Although the embodiments have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, the scope of the present disclosure is not construed as being limited to the described embodiments but is defined by the appended claims as well as equivalents thereto. 
     Embodiments disclosed herein may provide a blower in which a rotational drive is stably supported. Embodiments disclosed herein may provide a blower having a support structure with improved durability. Frictional resistance due to rotation may be reduced or minimized. 
     Embodiments disclosed herein may provide a blower in which a structure supporting rotational drive is compacted. The blower may reduce or minimize the power required for rotation. 
     Embodiments disclosed herein may provide a blower in which removal of a structure by rotation may be prevented. Embodiments disclosed herein may provide a blower that is prevented from twisting the wire due to rotation. Embodiments disclosed herein may provide a blower capable of integrated management of electric parts. 
     The problems of the present invention are not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the description. 
     Embodiments disclosed herein may provide a blower including a base, a case provided above the base and having an air inlet and an air outlet, and a fan provided inside the case. The blower may include a rotating plate connected to the case and rotatably provided on an upper side of the base, a motor generating power to rotate the rotating plate, and a bearing provided between the rotating plate and the base, fixed to the rotating plate, and movably supported on the base, so that a separate housing to receive the bearing is not required and the rotating plate can be rotated stably because the bearing may be directly supported on the base. 
     The motor may be supported by the rotating plate so that N arrangement position of the motor may not be limited to a specific area. The motor may be fixed to the upper side of the rotating plate so as to rotate together with the rotating plate, thereby increasing a utilization of a space formed under the rotating plate. 
     At least a part of the motor may be inserted into the motor insertion groove that is opened in the vertical direction on the rotating plate so that a phenomenon that the motor is removed during rotation may be prevented. The blower may further include a rail provided on the upper side of the base and extending along the rotational direction of the rotating plate. 
     The bearing may be provided on the upper side of the rail and may be moved along the extending direction of the rail so that the bearing&#39;s rotation path can be guided by rail. The blower may include a first gear connected to the motor and fixed to the rotating plate and a second gear engaged with the first gear and fixed to the base. The first gear may be moved along the circumference of the second gear. 
     The bearing may be provided farther from the rotation center of the rotating plate than the first gear so that a position where the gear is engaged is formed close to the rotation center, thereby reducing or minimizing a power transmission path transmitted through the gear. The first gear, the second gear, and the rail may be arranged side by side in a horizontal direction so that a height of the driving unit may be reduced. 
     The blower may further include a shaft bearing, at least a part of which is rotated together with the rotating plate, thereby preventing or reducing abrasion of the rotating plate. The shaft bearing may be provided so as to surround the shaft holder so that vibration of the rotating plate may be prevented through double support by the shaft holder and the shaft bearing. 
     The blower may further include a shaft body rotatably coupled to the base. The blower may further include a shaft holder protruding toward the base from the rotation center of the rotating plate. The shaft body may be inserted into the shaft holder and fixed to the rotating plate. 
     The rotating plate may include a stem forming a space inside and a roof having a shaft insertion hole through which the shaft body passes and covering the space at the top of the shaft. At least a part of the shaft body may pass through the shaft insertion hole and may be located inside the space, thereby preventing the shaft body from being separated from the rotation center. 
     The shaft body may penetrate the shaft holder. The shaft holder may include a crest protruding radially inward and a body fastening hole opened in the vertical direction at the crest, and it may be possible to improve the compatibility of the shaft holder and the shaft body. 
     The rail may protrude upward from an upper surface of the base and may form a gap between the rotating plate and the base so that the gap between the rotating plate and the base may be maintained. The rotating plate may include a first seating portion on which the motor is seated, a second seating portion provided outside the first seating portion and on which the case is seated, and a stepped portion connecting the first seating portion and the second seating portion so that the case can be stably fixed to the rotating plate. The bearing may include a wheel rotatably supported on the base and a support shaft penetrating the wheel and fixed to the rotating plate. The motor may be spaced apart from the outside of the rotation center of the rotating plate. 
     At least one of the plurality of bearings may be provided at a position opposite to the motor based on the rotation center of the rotating plate, thereby preventing a phenomenon in which a center of gravity is concentrated on a specific portion. 
     When the rotating plate is rotated, the bearing may be moved along the rotational direction of the rotating plate while being rotated around the support shaft so that wear of the bearing due to friction can be reduced or minimized through rotational motion by two rotating shafts. The support shaft may extend in the vertical direction. 
     A part of the lower surface of the bearing may be in contact with the base, and the rest may be spaced upward from the base, thereby reducing or minimizing abrasion of the bearing due to rotation. The support shaft may extend in a radial direction of the rotating plate. 
     The bearing may be moved along the rotational direction of the rotating plate while the circumferential surface is in contact with the base so that wear of the bearing due to friction may be reduced or minimized through rolling motion. 
     It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers. In contrast, when an element is referred to as being “directly on” another element or layer, there are no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. 
     Spatially relative terms, such as “lower”, “upper” and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented “upper” relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Embodiments of the disclosure are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.