Patent Publication Number: US-2019184324-A1

Title: Air cleaner

Description:
TECHNICAL FIELD 
     Embodiments of the present disclosure relate to an air cleaner having an improved structure. 
     BACKGROUND ART 
     An air cleaner is a device to remove contaminants in the air. The air cleaner may remove bacteria, viruses, mold, fine dust, and chemical substances causing foul odors from suctioned air. 
     The air cleaner may include a filter to purify polluted indoor air. The air suctioned into the air cleaner may pass through the filter such that contaminants are removed from the suctioned air, thus producing purified air. The purified air may be discharged outside from the air cleaner. 
     The air cleaner may be used in various spaces having different air-contamination levels. When the air cleaner is used in a high-air-contamination space, the air cleaner may operate at a high speed to more quickly purify indoor air. The air cleaner may operate at a low speed in an indoor space in which air contamination level is low and indoor quietness is needed. 
     The air cleaner may include different kinds of filters to remove various contaminants from the air. A pre-filter configured to filter out relatively large-sized dust in the air may be located at the foremost position of one or more filters. 
     Dust or contaminants in the air may be collected in each filter provided in the air cleaner. In order to efficiently perform air purification, there is a need to remove the dust or contaminants collected in the filter or replace the filter with a new filter. 
     DISCLOSURE 
     Technical Problem 
     It is an object of the present disclosure to provide an air cleaner for changing an operation mode thereof according to the degree of indoor air contamination and an indoor space condition. 
     It is another object of the present disclosure to provide an air cleaner for easily cleaning a filter. 
     Technical Solutions 
     The objects of the present disclosure can be achieved by an air cleaner including a housing, an inlet located at a lower part of the housing, a filter assembly located above the inlet, a diameter of which is gradually shortened in a direction from an upper part of the filter assembly to a lower part of the filter assembly, an outlet located above the second filter assembly, and a brush unit configured to remove or separate contaminants attached to an outer surface of the filter assembly from the filter assembly. 
     The filter assembly may include a first filter assembly and a second filter assembly located above the first filter assembly. 
     The air cleaner may further include a discharge member located above the filter assembly, and formed to have the outlet while movable in a vertical direction. 
     The discharge member may include a first outlet formed at a side surface of the discharge member, and a second outlet formed at a top surface of the discharge member. 
     The discharge member may operate in any one of a first discharge mode and a second discharge mode. In the first discharge mode, the first outlet may be inserted into the housing, and air may be discharged outside only through the second outlet. In the second discharge mode, the first outlet may be exposed outside the housing, and air may be discharged outside through the first outlet and the second outlet. 
     The air cleaner may further include a notification means contained in the housing, and configured to indicate whether air is currently discharged outside through the outlet. 
     The notification means may be implemented as a light or lamp configured to be movable. 
     The brush unit may be in contact with an outer surface of the filter assembly, and may be movable along the outer surface of the filter assembly. 
     The brush unit may include a brush part configured to be in contact with the outer surface of the filter assembly, and a coupling part connected to a driving source. 
     The air cleaner may further include a propeller rotatably mounted to one end of the filter assembly. The brush unit is connected to the propeller. 
     A blowing fan may be mounted to one side of the filter assembly so as to suction air, and the propeller may rotate by air current generated by rotation of the blowing fan. 
     A dust collection space may be formed in a portion of the housing. The filter assembly may be contained in the dust collection space. A portion of the housing in which the dust collection space is formed may be detachably coupled to the remaining portions of the housing. 
     The filter assembly may include a flow passage, one end of which is formed to communicate with an external part of the filter assembly. 
     When the filter assembly is contained in the dust collection space, the flow passage may be formed to communicate with the dust collection space, and another end of the flow passage may be configured to be opened or closed by a cap. 
     The filter assembly may be formed in a manner that a diameter of the filter assembly is gradually shortened in a direction from an upper part of the filter assembly to a lower part of the filter assembly. 
     In accordance with another aspect of the present disclosure, the air cleaner includes a case, a filter assembly, a second filter assembly, and a vibration generator. An inlet may be located at a lower part of the case, and an outlet may be located at an upper part of the case. The first filter assembly may be contained in the case, and may filter out contaminants from the suctioned air. The second filter assembly may be located above the first filter assembly, and may filter out contaminants from the air having passed through the first filter assembly. The vibration generator may vibrate any one of the first filter assembly and the second filter assembly. 
     The vibration generator may include a cam. At least a portion of an outer surface of the cam may be formed to protrude, and the cam may be movable. 
     The first filter assembly or the second filter assembly may include a bearing configured to be in contact with the cam. 
     A diameter of at least one of the first filter assembly and the second filter assembly may be gradually shortened in a downward direction. 
     In accordance with another aspect of the present disclosure, the air cleaner includes an inlet and an outlet. The inlet may be located at a lower part of the air cleaner, and the outlet may be located at an upper part of the air cleaner. The air cleaner includes a housing, a filter assembly, a brush unit, and a discharge member. A diameter of the filter assembly may be gradually shortened in a downward direction. The brush unit rotates at the outside of the filter assembly, and at the same time removes contaminants from the outer circumference of the filter assembly. The outlet may be formed in the discharge member. The discharge member may be located at an upper part of the housing, and may be movable in a vertical direction. The outlet may include a first outlet formed at a side surface of the discharge member so as to omnidirectinally discharge the air, and a second outlet formed at a top surface of the discharge member. 
     Advantageous Effects 
     As is apparent from the above description, the air cleaner according to the embodiments of the present disclosure may operate at a proper operation mode according to surroundings of an indoor space and the degree of indoor air contamination, such that the air cleaner can be easily used by users, resulting in greater convenience of use. 
     In addition, one or more filters can be easily and conveniently cleaned, such that efficiency deterioration of the air cleaner is prevented. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating an air cleaner according to an embodiment of the present disclosure. 
         FIG. 2  is an elevation view illustrating a discharge member of an air cleaner according to an embodiment of the present disclosure. 
         FIG. 3  is a view illustrating internal constituent elements of an air cleaner according to an embodiment of the present disclosure. 
         FIG. 4  is an exploded perspective view illustrating an air cleaner according to an embodiment of the present disclosure. 
         FIG. 5  is a view illustrating some portions of an air cleaner according to an embodiment of the present disclosure. 
         FIG. 6  is a view illustrating a first filter assembly provided with a brush unit according to an embodiment of the present disclosure.   “ ” ,   “  brush part” , ‘brush unit’  “brush unit”   ,  . 
         FIG. 7  is an exploded perspective view illustrating a first filter assembly provided with a brush unit according to an embodiment of the present disclosure. 
         FIG. 8  is a view illustrating some portions of a first filter assembly provided with a brush unit according to an embodiment of the present disclosure. 
         FIGS. 9A and 9B  are views illustrating some portions of a first filter assembly provided with a brush unit according to another embodiment of the present disclosure. 
         FIGS. 10 and 11  are views illustrating a first filter assembly according to another embodiment of the present disclosure. 
         FIG. 12  is a view illustrating a first filter assembly according to an embodiment of the present disclosure. 
         FIG. 13  is a view illustrating a second filter assembly according to an embodiment of the present disclosure. 
     
    
    
     BEST MODE 
     Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. An air cleaner according to the following embodiments of the present disclosure will hereinafter be described with reference to the attached drawings. 
       FIG. 1  is a perspective view illustrating an air cleaner according to an embodiment of the present disclosure.  FIG. 2  is an elevation view illustrating a discharge member of the air cleaner.  FIG. 3  is a view illustrating internal constituent elements of the air cleaner.  FIG. 4  is an exploded perspective view illustrating the air cleaner. 
     Referring to  FIGS. 1 to 4 , the air cleaner  1  may be formed in a substantial cylindrical shape. The air cleaner  1  may include housings  10   a  and  10   b  forming the appearance thereof, and a plurality of assemblies  2  and  5 . An exemplary embodiment in which two filter assemblies  2  and  5  are arranged in a vertical direction will hereinafter be described with reference to the attached drawings. 
     The filter assemblies  2  and  5  may include a first filter assembly  2  and a second filter assembly  5  located above the first filter assembly  2 . The first filter assembly  2  may filter out relatively heavy contaminants in the air. The second filter assembly  5  may filter out relatively light contaminants in the air. For example, air including dust having a diameter of about 10 μm may pass through the filter assembly  2 , such that the first filter assembly  2  may filter out the dust having a diameter of about 10  82  m. In addition, the air including dust having a diameter of about 2.5 μm may pass through the second filter assembly  5  such that the second filter assembly  5  may filter out the dust having a diameter of about 2.5 μm. 
     Each housing  10   a  or  10   b  may be formed in a substantially cylindrical shape. The housings  10   a  and  10   b  may include the first housing  10   a  to surround the first filter assembly  2  and a blowing fan  6 , and the second housing  10   b  located above the first housing  10   a.  The first housing  10   a  may include a lower housing  102  and an upper housing  103  located over the lower housing  102 . The lower housing  102  may include the first filter assembly  2 , and the upper housing  103  may include the first blowing fan  6 . The lower housing  102  including the first filter assembly  2  may be detachably coupled to the air cleaner  1 . The user may separate the lower housing  102  from the air cleaner  1 , such that the user may replace the first filter assembly  2  contained in the lower housing  102  with another filter assembly or may clean the first filter assembly  2 . 
     A grille member  8  may be disposed between the first housing  10   a  and the second housing  10   b.  Outdoor air may be introduced into the air cleaner  1  through the grille member  8 , such that relatively large dust or contaminants in the air may be filtered out. The air introduced into the air cleaner  1  through the grille member  7  may pass through the second filter assembly  5 . 
     The air cleaner  1  may further include a base  11  seated on the ground. The first filter assembly  2  may be disposed over the base  11 . An inlet  110  may be formed in the base  11 . The air introduced into the air cleaner  1  through the inlet  110  may pass through the first filter assembly  2  so that contaminants in the introduced air can be filtered out. 
     The first blowing fan  6  may be disposed over the first filter assembly  2 . The second filter assembly  5  may be disposed over the first blowing fan  6 . A second blowing fan  7  may be disposed over the second filter assembly  5 . 
     By rotation of the first blowing fan  6 , the air may be introduced into the first filter assembly  2  through the inlet  110 . By rotation of the second blowing fan  7 , the air having passed through the first filter assembly  2  may be introduced into the second filter assembly  5 , and may also be introduced into the second filter assembly  5  through the grille member  8 . The first blowing fan  6  and the second blowing fan  7  may simultaneously operate, or only one of the first blowing fan  6  and the second blowing fan  7  may operate as necessary. 
     A discharge member  9  provided with outlets  900  and  910  may be disposed over the second housing  10   b  in a manner that purified air having no contaminants can be discharged outside through the outlets  900  and  910 . The discharge member  9  may include a body  90 , a first outlet  900  formed at a side surface of the body  90 , and a second outlet  910  formed at a top surface  91  of the body  90 . 
     The discharge member  9  may be formed in a shape corresponding to the shape of an inner surface of the second housing  10   b.  The first outlet  900  may be formed along a side surface of the discharge member  9  such that the air is discharged outside in a lateral or side direction. The air discharged through the first outlet  900  may form a distributed air flow of 360°. 
     The discharge member  9  may move upward and downward. When the discharge member  9  moves down, the first outlet  900  formed at the side surface of the body  90  may be inserted into the second housing  10   b,  and the air may be discharged outside through the second outlet  910  formed at the top surface  91 . When the discharge member  9  moves upward, the first outlet  900  may be exposed outside, and the air may be discharged outside through the first outlet  900  and the second outlet  910 . 
     When the contamination level of indoor air is low or the air cleaner  1  is set to a sleep mode, the discharge member  9  may be inserted into the second housing  10   b  and the air may be discharged outside only through the second outlet  910 . When the air is discharged outside only through the second outlet  910 , the speed of air purification may be reduced, resulting in reduction in noise caused by air discharge. 
     In this case, the first blowing fan  6  may not operate, and the second blowing fan  7  may operate. When the first blowing fan  6  operates, most indoor air may be introduced into the second filter assembly  5  through the grille member  8 , such that the indoor air may be purified by the second filter assembly  5  and the purified air may be discharged outside through the second outlet  910 . When necessary, the first blowing fan  6  may operate, and the second blowing fan  7  may not operate. In addition, the first blowing fan  6  and the second blowing fan  7  may simultaneously operate, and the air purified by the filter assemblies  2  and  5  may be intensively discharged in a vertical direction through the second outlet  910 . 
     If the air cleaner  1  is set to a strong mode because the contamination level of indoor air is high or the indoor air needs to be quickly purified, the discharge member  9  may protrude from the second housing  10   b,  and the air may be rapidly discharged through the first outlet  900  and the second outlet  910 . In this case, since the air is discharged through the first outlet  900  and the second outlet  910 , noise caused by air discharge may unavoidably increase, but the air can be quickly purified within a short period of time. 
     In this case, the first blowing fan  6  and the second blowing fan  7  may simultaneously operate. The indoor air may be introduced into the air cleaner through the inlet  110  and the grille member  8 , and may be purified by the first filter assembly  2  and the second filter assembly  5 , such that the purified air may be discharged outside through the first outlet  900  and the second outlet  910 . When necessary, it may also be possible to operate only one of the first blowing fan  6  and the second blowing fan  7 . 
     The air cleaner  1  may operate in a plurality of operation modes. The operation mode of the air cleaner  1  may be automatically changed according to the contamination level of indoor air or the like, and the air cleaner  1  may also operate in a specific mode according to user setting information. Various embodiments of the operation modes of the air cleaner  1  will hereinafter be described in detail. 
     For example, the air cleaner  1  may operate in a first mode in which the second blowing fan  7  located at a higher position may operate at a low speed. The second blowing fan  7  may operate at a constant low speed. In this case, the discharge member  9  may be inserted into the second housing  10   b,  such that the purified air may be discharged only through the second outlet  910 . The air may be discharged outside at a low speed through the second outlet  910 , such that gentle flow of air having less noise may be discharged outside. The first mode may be mainly used at night or during bedtime. 
     The air cleaner  1  may operate in a second mode in which the second blowing fan  7  is automatically driven according to the contamination level of indoor air. When the second blowing fan  7  rotates at a low speed, the discharge member  9  may remain inserted into the second housing  10   b,  and the purified air may be discharged outside through the second outlet  910 . When the rotation speed of the second blowing fan  7  gradually increases, the discharge member  9  may protrude outward from the second housing  10   b,  such that the purified air may be rapidly discharged through the first outlet  900  and the second outlet  910 . In order to discharge the purified air through the second outlet  910  irrespective of the operation speed of the second blowing fan  7 , the discharge member  9  may also remain inserted into the second housing  10   b.    
     For example, the air cleaner  1  may mainly operate in the second mode in daytime in which most people are actively moving. 
     In order to rapidly purify the indoor air using the air cleaner  1 , the air cleaner  1  may operate in a third mode in which the first blowing fan  6  and the second blowing fan  7  are simultaneously driven. In this case, the discharge member  9  may protrude outward from the second housing  10   b,  and the purified air may be rapidly discharged outside through the first outlet  900  and the second outlet  910 . When the contamination level of indoor air is very high or when many people are present in a limited-sized space, the air cleaner  1  may operate in the third mode. In the third mode, the air cleaner  1  may rapidly purify the indoor air at a maximum air speed and a maximum air volume. 
     The air cleaner  1  may operate in a fourth mode in which the first blowing fan  6  and the second blowing fan  7  operate at different speeds. For example, the first blowing fan  6  may rotate at a higher speed, and the second blowing fan  7  may rotate at a lower speed than the first blowing fan  6 . The discharge member  9  may remain inserted into the second housing  10   b,  and the purified air may be discharged outside through the second outlet  910 . In the fourth mode, the air cleaner  1  may mainly operate for circulation or deodorization of the indoor air. 
     The scope or spirit of the operation mode of the air cleaner  1  is not limited to the above-mentioned first to fourth modes. 
       FIG. 5  is a view illustrating some portions of the air cleaner according to an embodiment of the present disclosure. 
     The air cleaner  1  shown in  FIG. 5  may include a notification means capable of intuitively informing the user of the operation states of the air cleaner  1 . The notification means may be implemented as a light or lamp. For example, in order to indicate that the air is omnidirectionally discharged through the second outlet  910  under the condition that the air is discharged outside through the first outlet  900  and the second outlet  910  by upward movement of the discharge member  9 , the light may rotate at 360° in the vicinity of the second outlet  910 , such that the light may emit light in sequence. 
     In addition, the rotation speed of the light may be changeable with the rotation speed of each blowing fan  6  or  7 . When each of the blowing fans  6  and  7  rotates at a low speed, the light may rotate at a low speed. When each of the blowing fans  6  and  7  rotates at a high speed, the light may also rotate at a high speed. 
     In addition, color of the light may also be changed according to the contamination level of indoor air. The contamination level of indoor air may be measured by a sensor located in the air cleaner  1 . When the contamination level of indoor air is very high, the light blinks in red. As the contamination level of indoor air is gradually reduced, the light sequentially blinks in the order of orange • yellow • green • blue • purple. 
       FIG. 6  is a view illustrating a first filter assembly provided with a brush unit.  FIG. 7  is an exploded perspective view illustrating the first filter assembly provided with the brush unit.  FIG. 8  is a view illustrating some portions of the first filter assembly provided with the brush unit. 
     Referring to  FIGS. 6 to 8 , a diameter of the first filter assembly  2  may be gradually shortened in a downward direction of the first filter assembly  2 . For example, the first filter assembly  2  may be formed to have a substantially conical shape or a substantially circular truncated conical shape. When the first filter assembly  2  is formed to have a circular truncated conical shape, a diameter D 1  of one end of the first filter assembly  2  may be longer than a diameter D 2  of the other end of the first filter assembly  2 . One end of the first filter assembly  2  may be disposed at an upper part of the first filter assembly  2 , and the other end of the first filter assembly  2  may be disposed at a lower part of the first filter assembly  2 . In the first filter assembly  2 , one end having a longer diameter D 1  may be located at a higher position than the other end having a shorter diameter D 2 . 
     As described above, the first filter assembly  2  is formed to have a conical shape or a circular truncated conical shape, such that the first filter assembly  2  formed either in the conical shape or in the circular truncated conical shape may have a larger surface area than the other filter assembly formed in a cylindrical shape on the assumption that the first filter assembly  2  and the other first filter assembly are formed to have the same diameter. Therefore, the air suctioned through the inlet  110  may more easily pass through the first filter assembly  2  having a larger surface area, resulting in improved air purification efficiency. 
     In comparison with the other filter assembly formed in a plate shape on the assumption that the same diameter is used, the first filter assembly  2  formed either in a conical shape or in a circular truncated conical shape may have a larger surface area. As described above, the first filter assembly  2  may be formed to have a larger surface area, resulting in higher air purification efficiency. 
     The first filter assembly  2  may include a pre-filter  21  and a High Efficiency Particulate Air (HEPA) filter  22 . The pre-filter  21  may be formed in conical shape or in a circular truncated conical shape. The HEPA filter  22  may be formed in a shape corresponding to the inner surface of the pre-filter  21 , and may be included in the pre-filter  21 . 
     A brush unit  3  may be provided at the side of the first filter assembly  2 . The brush unit  3  may be in contact with the outer surface of the pre-filter  21 . The brush unit  3  may rotate around the pre-filter  21  such that contaminants attached to the surface of the pre-filter  21  can be separated from the pre-filter  21 . 
     The brush unit  3  may include a brush part  30  and a coupling part  31 . The brush part  30  may be in contact with the outer surface of the pre-filter  21  so that contaminants attached to the surface of the pre-filter  21  can be dropped or separated from the pre-filter  21 . The coupling part  31  may be connected to the brush part  30  such that the coupling part  31  may receive driving power from a driver  33 . In this case, the driver  33  may be implemented as a motor. 
     The brush part  30  may rotate while in contact with the surface of the pre-filter  21 , such that contaminants attached to the surface of the pre-filter  21  can be dropped or separated. The coupling part  31  may rotate the brush part  30  upon receiving driving power from the driver  33 . One end of the coupling part  31  may be connected to the brush part  30 , and the other end of the coupling part  31  may be connected to the driver  33 . 
     The coupling part  31  may be connected to the driver  33  through a transfer member  34 . The transfer member  34  may include a rotation plate  340  connected to a rotation shaft  33  contained in the driver  33 , and a first interference protrusion  341  protruding from one surface of the rotation plate  340 . The first interference protrusion  341  may be located to be eccentric from the rotation shaft  330  such that the first interference protrusion  341  is not located at the same shaft as the rotation shaft  330 . A second interference protrusion  32  interfered with by the first interference protrusion  341  may be provided to one side of the coupling part  31 . The second interference protrusion  32  may not be located at the same shaft as the rotation shaft  330 . 
     If the rotation plate  340  is rotated by the driver  33 , the first interference protrusion  341  may rotate around the rotation shaft  330 . When the first interference protrusion  341  touches the second interference protrusion  32 , the first interference protrusion  341  may rotate together with the second interference protrusion  32 . As a result, the coupling part  31  and the brush part  30  connected to the coupling part  31  may simultaneously rotate. 
     An outer side of the first filter assembly  2  may be surrounded by an inner wall  100 . A dust collection space  101  formed by the inner wall  100  may be formed in the lower housing  102 , and the first filter assembly  2  may be included in the dust collection space  101 . The inner wall  100  may be integrally formed with the lower housing  102 . The inner wall  100  may be formed in a cylindrical shape. Therefore, a diameter D 3  between the first filter assembly  2  and the inner wall  100  may gradually increase in length in a downward direction of the first filter assembly  2 . 
     The dust collection space  101  may be disposed between the inner wall  100  and the first filter assembly  2 , such that dust or contaminants filtered out by the pre-filter  21  may drop from the surface of the pre-filter  21  and be collected in the dust collection space  101 . The dust or contaminants separated from the surface of the pre-filter  21  may be collected in the dust collection space  101  by the brush part  30 . 
     The brush unit  3  may be controlled to periodically clean the pre-filter  21 . For example, when the air cleaner  1  is turned on, the air cleaner  1  may perform air purification after removing contaminants from the pre-filter  21  via the brush unit  3 . Even in the air purification operation, when the amount of contaminants filtered out by the pre-filter  21  is equal to or larger than a preset reference amount of contaminants, or whenever a predetermined time elapses after starting the air cleaner  1 , contaminants attached to the pre-filter  21  may be removed from the pre-filter  21  by the brush unit  3 . 
     Contaminants may be removed from the pre-filter  21  by the brush unit  3 , such that suction force of the air can be prevented from being reduced. In addition, air purification efficiency of indoor air can also be prevented from being degraded. 
     The lower housing  102  may be detachably coupled to the first filter assembly  2 , such that the lower housing  102  may be separated from the first filter assembly  2  as necessary. As a result, the user may separate the lower housing  102  from the first filter assembly  2 , and may then discard the dust or contaminants collected in the dust collection space  101 , such that the air cleaner  1  can be sanitarily managed by the user. 
       FIGS. 9A and 9B  are views illustrating some portions of a first filter assembly provided with a brush unit according to another embodiment of the present disclosure. 
     Referring to  FIGS. 9A and 9B , a brush unit  3   a  according to another embodiment may be connected to a propeller  35  uncoupled from a driving source. The propeller  35  may rotate without power. The propeller  35  may be disposed between the first filter assembly  2  and the first blowing fan  6 . By rotation of the first blowing fan  6 , the propeller  35  may rotate by air suctioned through an inlet  110 . 
     As illustrated in  FIG. 9A , an upper end of the brush unit  3   a  may be connected to the propeller  35 . As illustrated in  FIG. 9B , the brush unit  3   a  may be connected to the propeller  35 . 
     The brush unit  3   a  may include a brush part  30   a  connected to the propeller  35 . The brush part  30   a  may remain in contact with the outer wall of the first filter assembly  2  (i.e., the outer wall of the pre-filter  21 ). One end of the brush unit  3   a  may be connected to the propeller  35 . The brush unit  3   a  may rotate together with the propeller  35 . By rotation of the brush unit  3   a,  contaminants attached to the outer wall of the pre-filter  21  may be removed by the brush part  30   a.  Contaminants removed from the pre-filter  21  by the brush part  30   a  may be collected in the dust collection space  101  shown in  FIG. 6 . 
     The propeller  35  may be installed to rotate only when the first blowing fan  6  rotates at a preset rotation speed or higher. Therefore, the propeller  35  rotates such that contaminants attached to the pre-filter  21  can be removed by the brush part  30   a  only when the first blowing fan  6  rotates at a high speed (for example, when indoor air needs to be rapidly purified or when the contamination level of indoor air is very high). 
     If the rotation speed of the first blowing fan  6  is high, it is expected that the amount of air, that is scheduled to pass through the pre-filter  21  per unit time, increases and the amount of contaminants filtered out by the pre-filter  21  also increases in proportion to the amount of air. The air cleaner  1  according to this embodiment is configured to remove contaminants attached to the pre-filter  21  using the brush part  30   a,  such that the air cleaner  1  can be easily and efficiently managed by the user. 
     In addition, when the brush unit  3   a  is installed to rotate together with the propeller  35 , the brush unit  3   a  can rotate without power such that the amount of power consumed by the air cleaner  1  can be greatly reduced. 
     Although the above-mentioned embodiment has disclosed the exemplary case in which the brush unit  3   a  is mounted to the propeller  35  that is capable of rotating without power for convenience of description and better understanding of the present disclosure, the scope or spirit of the present disclosure is not limited thereto, and it should be noted that the brush unit  3   a  may also rotate while coupled to the first blowing fan  6  as necessary. In this case, a gear ratio of a gear by which the brush unit  3   a  is connected to the first blowing fan  6  may be controlled or adjusted in a manner that the brush unit  3   a  rotates at a lower speed than the first blowing fan  6 . In addition, the brush unit  3   a  may also be connected to a torque limiter in a manner that the brush unit  3   a  can be prevented from rotating at a predetermined speed or higher. The scope or spirit of such connection between the brush unit  3   a  and the first blowing fan  6  is not limited to the above-mentioned structure. 
       FIGS. 10 and 11  are views illustrating a first filter assembly according to another embodiment of the present disclosure. 
     Referring to  FIGS. 10 and 11 , the first filter assembly  2  according to another embodiment may vibrate upon receiving driving power. when the first filter assembly  2  vibrates, contaminants attached to the pre-filter  21  may be dropped or separated from the pre-filter  21 . Contaminants separated from the pre-filter  21  may be collected in the dust reception space  101 . 
     A shaft  23  extended downward may be provided to the first filter assembly  2 , and a ring-shaped bearing  37  may be mounted to the shaft  23 . The bearing  37  may be in contact with a cam  36  connected to the driving source  33   a.  The cam  36  may be connected to the driving source  33   a through the rotation shaft  31 .    
     Uneven parts may be formed in at least a portion of the outer surface of the cam  36 . At least a portion of the outer surface of the cam  36  may be formed in an irregular shape, or a cross-sectional view of the cam  36  may not be formed in a smooth circular shape. For example, the cross-sectional view of the cam  36  may be formed in an oval shape. The scope or spirit of the shape of the cam  36  is not limited thereto, and the cam  36  may also be formed in an irregular shape. 
     If the cam  36  rotates by driving power of the driving source  33   a,  the bearing  37  is pushed laterally and then moves back to an original position thereof due to the shape of the cam  36 . In this case, the first filter assembly  2  may move together with the bearing  37 . When the cam  36  continues to rotate, the bearing  37  and the first filter assembly  2  are pushed laterally and then move back to original positions thereof such that such pushing and backward movement of the first filter assembly  2  may be repeatedly performed, resulting in vibration of the first filter assembly  2 . When the first filter assembly  2  vibrates, contaminants attached to the pre-filter  21  may be dropped or removed from the pre-filter  21 . The contaminants removed from the pre-filter  21  may be collected in the dust collection space  101 . 
     The cam  36  may be installed to periodically rotate. After the air cleaner  1  is turned on, when the amount of contaminants filtered out by the pre-filter  21  is equal to or larger than a preset reference amount of contaminants, or whenever a predetermined time elapses during operation of the air cleaner  1 , the cam  36  may rotate for a predetermined time. Contaminants attached to the pre-filter  21  may be periodically removed by periodic rotation of the cam  37 , such that air suction force can be prevented from being deteriorated. 
       FIG. 12  is a view illustrating a first filter assembly according to an embodiment of the present disclosure. 
     Referring to  FIG. 12 , the first filter assembly  2  may include a flow passage  24  formed to communicate with an external part of the first filter assembly  2 , and a cap  25  formed to open or close the flow passage  24 . When the first filter assembly  2  is included in the lower housing  102 , the flow passage  24  may be formed to communicate with the dust reception space  101 . 
     The flow passage  24  may be formed in a pipe shape having a predetermined length, such that the flow passage  24  may be extended in a vertical direction within the inner space of the first filter assembly  2 . One end of the flow passage  24  may be located in the first filter assembly  2 , and the other end of the flow passage  24  may communicate with the dust collection space  101  indicating the outer space of the first filter assembly  2 . During operation of the air cleaner  1 , the end part of the flow passage  24  may be blocked by the cap  25  in a manner that the air suctioned into the first filter assembly  2  is prevented from flowing through an inner space  240  of the flow passage  24 . 
     When contaminants collected in the dust collection space  101  are removed, the user may open the cap  25  and may connect a connection pipe P of a vacuum cleaner (not shown) to the flow passage  24 . When the vacuum cleaner is driven on the condition that the connection pipe P is connected to the flow passage  24 , contaminants collected in the dust collection space  101  may be suctioned into the vacuum cleaner. As a result, the user may easily and conveniently remove contaminants collected in the dust collection space  101 . 
       FIG. 13  is a view illustrating a second filter assembly according to an embodiment of the present disclosure. 
     Referring to  FIG. 13 , a diameter of the second filter assembly  5  may be gradually shortened in a downward direction of the second filter assembly  5  in a similar way to the first filter assembly  2 . For example, the second filter assembly  5  may be formed to have a substantially conical shape or a substantially circular truncated conical shape. The second filter assembly  5  may be located in the grille member  8 . The second filter assembly  5  may include a filter frame  51  and a HEPA filter  52  contained in the filter frame  51 . The HEPA filter  52  may be formed in a conical shape or in a circular truncated conical shape. The filter frame  51  may also be formed in a conical shape or in a circular truncated conical shape. 
     The filter frame  51  and the HEPA filter  52  may be installed in a manner that the diameters of the filter frame  51  and the HEPA filter  52  are located at an upper part of the second filter assembly  5 . A carbon filter  53  may be located over the HEPA filter  52 . The carbon filter  53  may be formed to have a flat surface, such that the carbon filter  53  may be seated on the filter frame  51 . 
     The air suctioned through the inlet  110  may pass through the first filter assembly  2 , and may then pass through the second filter assembly  5 . In addition, the air introduced through the grille member  8  may also pass through the second filter assembly  5 . In this case, the grille member  8  may be used as a pre-filter. That is, the air from which relatively large dust or contaminants are filtered out by the grille member  8  may pass through the second filter assembly  5 . Contaminants are removed from the air having passed through the second filter assembly  5 , such that purified air having no contaminants may be discharged through the outlets  900  and  910 . 
     Although the above-mentioned example has disclosed the embodiment in which the first filter assembly and the second filter assembly are different in structure from each other for convenience of description and better understanding of the present disclosure, the scope or spirit of the present disclosure is not limited thereto, and the second filter assembly may also be formed to have the same structure as the first filter assembly. In addition, the second filter assembly may also include a brush unit or a structure for vibrating the second filter assembly as necessary.