Abstract:
An air conditioner includes: a constituent part in which dusts taken into an indoor device ( 1 ) from the room air are accumulated; and a cleaning device ( 20 ) which sucks in the dusts from the constituent part. The cleaning device ( 20 ) includes: a fan ( 22 ) having a plurality of blades and rotating; a housing ( 21 ) containing the fan ( 22 ) and having an intake opening ( 21   a ) and an exhaust opening ( 21   c ); and an intake channel ( 25 ) having an intake opening facing the constituent part and connected to the intake opening ( 21   a ). An air current is introduced into the housing ( 21 ) from the intake opening ( 21   a ) along the rotation surface of the blades ( 23 ). The blades ( 23 ) have end brims ( 21   b ) of the upstream side of the air current introduced from the intake opening ( 21   a ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an air conditioner equipped with a cleaning apparatus cleaning dust that is stuck and accumulated on a component of an indoor unit by air taken inside. 
       BACKGROUND ART 
       [0002]    A conventional air conditioner is disclosed in Patent Document 1. In this air conditioner, a dust collecting filter is provided at an opening portion that is open in any part of an area expanding from a front surface to a top surface of the indoor unit, and a cleaning apparatus is provided that cleans dust collected by the filter. The cleaning apparatus is equipped with a fan unit that is disposed at a side portion of the indoor unit, and to the fan unit, a suction duct and an air exhaust duct are connected. The suction duct is so disposed as to extend at a front portion of the indoor unit in a traverse direction thereof, and has a nozzle so mounted thereon as to be movable on a surface of the filter. 
         [0003]      FIG. 19  is a sectional view schematically showing the fan unit as seen from a side thereof. In the fan unit  20 , a housing  21  accommodates a fan  22 . The fan  22  has a bottom plate  22   a  connected to a motor shaft  24   a , and is driven to rotate by a fan motor  24 . The fan  22  is formed with a sirocco fan, in which a plurality of blades  23  that extend in a radius direction are arranged annularly on the bottom plate  22   a  at predetermined intervals. 
         [0004]    The housing  21  is formed with a circular air inflow port  21   a  open coaxially with the fan  22 , for which a cover  25   d  covering the air inflow port  21   a  is mounted. With this, an air intake passage  25  is formed that guides a stream of sucked air to the air inflow port  21   a . The blades  23  are arranged outside relative to the air inflow port  21   a , and guide the stream of air flowing through the air inflow port  21   a  in an axial direction of the fan  22 , toward an outer circumferential side, in the radius direction, of the fan  22 . On a circumferential surface of the housing  21 , an air outflow port (unillustrated) is made open and connected to the air exhaust duct. 
         [0005]    When the cleaning apparatus is driven, the fan motor  24  is driven thereby to rotate the fan  22 , and a stream of sucked air is produced accordingly inside the suction passage  25 . Dust stuck on the filter is sucked through the nozzle, made to pass through the suction passage  25  as indicated by arrowed line A 1 , and then enters the housing  21  through the air inflow port  21   a . The stream of air blown inside the housing  21  is then guided in the outer circumferential directions as indicated by arrowed lines A 2  and A 3 , and passes through the air exhaust duct via the air outflow port so as to be expelled together with exhausted air. Thus, the filter is automatically cleaned, with the result that user-friendliness of the air conditioner is increased. 
       LIST OF CITATIONS 
     Patent Literature 
       [0000]    
       
         Patent Document 1: JP-A-2008-75658 (pages 4 to 6, and  FIG. 5 ) 
       
     
       SUMMARY OF THE INVENTION 
     Technical Problem 
       [0007]    With the conventional air conditioner described above, however, the blades  23  are formed such that side edges  23   a  thereof, on an upper stream side, of the stream of air flowing inside the housing  21  extend in the axial direction of the fan  22 . Thus, the stream of air flowing inside the housing  21  and guided in the outer circumferential directions as indicated by arrowed lines A 2  and A 3 , and the side edges  23   a  of the blades  23  form a relationship substantially orthogonal to each other to collide with each other. Thus, dust included in the stream of air is pressed against the side edges  23   a  of the blades  23 , and is likely to be caught by the side edges  23   a  of the blades  23 . Owing to this, dust tends to be accumulated on the side edges  23   a  of the blades  23  and root portions of the blades  23 . 
         [0008]    According to Patent Document 1, a rib is provided for scraping off dust accumulated on the inner circumferential side of the blades  23 . However, provision of such a rib necessitates precisely maintaining an interval between the blades  23  and the rib, and accordingly, increases difficulty in manufacture. Moreover, a gap is formed between the rib and the bottom plate  22   a , preventing the dust accumulated on the root portions of the blades  23  from falling off. Accordingly, an interval in the vicinity of the root portions of the blades  23  is narrowed owing to the presence of dust, and the dust accumulated there fills the spaces between the blades  23  as it gradually grows, with the result that suction power is inconveniently decreased. 
         [0009]    To increase usability, it is desirable that dust removed by the cleaning apparatus be not expelled in any region midway along a passage inside the cleaning apparatus, and that such dust be simply expelled through the air outflow port via the fan  22 . This makes accumulation of dust at the side edges  23   a  and on the root portions of the blades  23  a more significant problem to be overcome. 
         [0010]    Accordingly, the present invention has an object to provide an air conditioner with which the amount of dust accumulated inside a cleaning apparatus is easily reduced. 
       Solution to the Problem 
       [0011]    To achieve the above-described object, according to the present invention, in an air conditioner equipped with a cleaning apparatus with which dust contained in air taken inside an indoor unit and accumulated on a component of the indoor unit is sucked and removed from the component, the cleaning apparatus includes: a fan formed with a plurality of blades, and rotating; a housing accommodating the fan, and formed with an air inflow port thereof and an air outflow port thereof; and a suction passage formed with a suction port thereof facing the component, and connected to the air inflow port, wherein a stream of air is made to flow inside the housing along a rotation plane of the plurality of blades through the air inflow port, and the plurality of blades are formed such that side edges thereof, on an upper stream side, of the stream of air flowing through the air inflow port extend in a radius direction of the fan. 
         [0012]    With this configuration, a stream of air is generated inside the suction passage as the fan is rotated, whereby dust stuck on the component of the indoor unit is made to flow through the suction passage via the suction port. The stream of air flowing through the suction passage then enters the housing through the air inflow port along the rotation plane of the fan. The stream of air thus flowing inside the housing comes into contact with the side edges, extending in the radius direction, of the blades, and is guided thereby toward the outer circumferential side of the fan. The stream of air so guided to the outer circumferential side is exhausted together with the dust through the air outflow port. 
         [0013]    Moreover, according to the present invention, in the air conditioner configured as described above, the fan is formed with a centrifugal fan. With this configuration, the stream of air flowing through the suction passage is made to flow through the air inflow port, which is open in the axial direction of the fan, along the rotation plane of the fan, and is then exhausted in the radius direction of the fan. 
         [0014]    Moreover, according to the present invention, in the air conditioner configured as described above, the side edges of the blades are substantially parallel to the rotation plane of the fan, or descend from the inner circumferential side thereof to the outer circumferential side thereof with an increased distance from the air inflow port as observed in the axial direction of the fan. 
         [0015]    Moreover, according to the present invention, in the air conditioner configured as described above, the fan is formed with a boss around a rotation axis of the fan and in the vicinity of the air inflow port, and the plurality of blades are so formed as to extend from a circumferential surface of the boss to an outer edge of the air inflow port. With this configuration, the stream of air flowing through the air inflow port along the rotation plane of the fan is made to pass through spaces between the side edges, facing the air inflow port, of the blades disposed on the circumferential surface of the boss, and is then guided to pressed surfaces of the blades. 
         [0016]    Moreover, according to the present invention, in the air conditioner configured as described above, the housing is provided with a disk on an axial line of the fan to thereby form the air inflow port in a ring-like shape, and the plurality of blades are so formed as to extend from an inner edge of the air inflow port to an outer edge of the air inflow port. With this configuration, the stream of air flowing through the ring-like-shaped air inflow port along the rotation plane of the fan is made to pass through spaces between the side edges, facing the air inflow port, of the blades, and is then guided to pressed surfaces of the blades. 
         [0017]    Moreover, according to the present invention, in the air conditioner configured as described above, the plurality of blades are interconnected to one another, at side surfaces thereof on a side opposite to a side where the air inflow port is present, by an annular ring. With this configuration, the plurality of blades are reinforced by the ring with no space therebetween blocked on a bottom-surface side of the housing opposite to the air inflow port. 
         [0018]    Moreover, according to the present invention, in the air conditioner configured as described above, the component includes a filter that collects airborne dust taken inside the indoor unit. With this configuration, it is possible to automate cleaning of the filter. 
       Advantageous Effects of the Invention 
       [0019]    With the present invention, the stream of air is made to flow inside the housing through the air inflow port along the rotation plane of the blades, and the blades are formed such that the side edges thereof, on the upper stream side, of the stream of air flowing through the air inflow port extend in the radius direction of the fan. Accordingly, a direction in which the stream of air advances and the side edges, on the upper stream side, of the blades intersect with each other at a small angle. As a result, a pressing force produced when the dust and the side edges of the blades collide with each other is reduced, thereby making it possible to reduce the amount of dust stuck on the blades. Moreover, the dust caught by the side edges of the blades are pushed toward the outer circumferential side by the stream of air and centrifugal force, thereby making it possible to further reduce the amount of dust stuck on the blades. Thus, it is possible to easily reduce the amount of dust accumulated at the side edges of the blades and between the blades inside the cleaning apparatus. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0020]      FIG. 1  A perspective view of an interior of an air conditioner according to a first embodiment of the present invention. 
           [0021]      FIG. 2  A perspective view of an interior of the air conditioner according to the first embodiment of the present invention. 
           [0022]      FIG. 3  A perspective view of a fan unit of a cleaning apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0023]      FIG. 4  A perspective view of the fan unit of the cleaning apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0024]      FIG. 5  A perspective view of a fan of the cleaning apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0025]      FIG. 6  A plan view of the fan of the cleaning apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0026]      FIG. 7  A side sectional view schematically showing the fan unit of the cleaning apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0027]      FIG. 8  A side sectional view schematically showing a fan unit of a cleaning apparatus of an air conditioner according to a second embodiment of the present invention. 
           [0028]      FIG. 9  A side sectional view schematically showing a fan unit of a cleaning apparatus of an air conditioner according to a third embodiment of the present invention. 
           [0029]      FIG. 10  A perspective view of a fan of a cleaning apparatus of an air conditioner according to a fourth embodiment of the present invention. 
           [0030]      FIG. 11  A side view of the fan of the cleaning apparatus of the air conditioner according to the fourth embodiment of the present invention. 
           [0031]      FIG. 12  A side view showing another shape of the fan of the cleaning apparatus of the air conditioner according to the fourth embodiment of the present invention. 
           [0032]      FIG. 13  A side view showing yet another shape of the fan of the cleaning apparatus of the air conditioner according to the fourth embodiment of the present invention. 
           [0033]      FIG. 14  A side view showing yet another shape of the fan of the cleaning apparatus of the air conditioner according to the fourth embodiment of the present invention. 
           [0034]      FIG. 15  A sectional view illustrating an arrangement of a blade inside the cleaning apparatus of the air conditioner embodying the present invention. 
           [0035]      FIG. 16  A sectional view illustrating another arrangement of the blade inside the cleaning apparatus of the air conditioner embodying the present invention. 
           [0036]      FIG. 17  A sectional view illustrating another arrangement of a blade inside a cleaning apparatus of an air conditioner presented as a comparative example. 
           [0037]      FIG. 18  A sectional view illustrating another arrangement of the blade inside the cleaning apparatus of the air conditioner presented as a comparative example. 
           [0038]      FIG. 19  A side sectional view schematically showing a fan unit of a cleaning apparatus of a conventional air conditioner. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0039]    Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, for convenience of explanation, the same parts as in the conventional example shown in  FIG. 19  will be identified by the same reference signs.  FIG. 1  is a perspective view of an interior of an indoor unit of an air conditioner according to a first embodiment with an exterior panel removed therefrom. An indoor unit  1  has a heat exchanger  3  so disposed as to face opening portions (unillustrated) formed at front and top surfaces of the exterior panel and through which air in a room is taken in. In a lower portion of the indoor unit  1 , a blowout port  5  is provided through which conditioned air from which heat has been rejected by the heat exchanger  3  is sent out. The blowout port  5  is formed with a louver (unillustrated) with which a direction in which wind is blown out can be changed. 
         [0040]    In front of and above the heat exchanger  3 , a filter rail  2   a  is provided on which a filter  2  (see  FIG. 2 ) is mounted. In a left-side portion of the indoor unit  1 , a fan unit  20  is so provided as to form the cleaning apparatus  10 , and to remove dust collected by the filter  2  (see  FIG. 2 ). The cleaning apparatus  10  is equipped with a suction passage  25  and an air exhaust passage  28 . The suction passage  25  has a front surface portion  25   a  thereof disposed at a front portion of the indoor unit  1  and extending in a traverse direction of the indoor unit  1 , and a side surface portion  25   b  thereof disposed at a side surface of the indoor unit  1 . The front surface portion  25   a  is covered by a cylindrical duct  25   c , and the side surface portion  25   b  is covered by a cover  25   d.    
         [0041]      FIG. 2  shows the duct  25   c  of the front surface portion  25   a  and the cover  25   d  (see  FIG. 3 ) of the side surface portion  25   b  are removed to expose the suction passage  25 . Between the opening portions (unillustrated) of the exterior panel and the heat exchanger  3 , the filter  2  is disposed that collects dust. The filter  2  is made movable on the filter rail  2   a  in up and down directions by a filter driving motor  4  that is provided at the left-side portion of the indoor unit  1 . 
         [0042]    The duct  25   c  (see  FIG. 1 ) of the front surface portion  25   a  of the suction passage  25  is formed with a suction port (unillustrated) facing the filter  2 , and inside the duct  25   c , a rotary brush  27  is so disposed as to extend in the traverse direction. The rotary brush  27  is driven to rotate by a brush motor  26  provided at a right-side portion of the indoor unit  1 , and thereby beats out dust collected by the filter  2 . 
         [0043]      FIG. 3  is a perspective view of the fan unit  20  of the cleaning apparatus  10 , and  FIG. 4  shows the fan unit  20  with the cover  25   d  removed therefrom. In the fan unit  20 , the housing  21  accommodating the fan  22  is formed with an air inflow port  21   a  circularly open in a vertical plane of the housing  21 . The housing  21  is so formed in a cylindrical manner as to surround the fan  22 , and is provided with an air outflow port  21   c  (see  FIG. 5 ) open from a circumferential surface of the fan  22  in a tangential direction. To the air outflow port  21   c , a duct  28   a  is so connected as to form the air exhaust passage  28 . 
         [0044]    The housing  21  is formed integrally with a communication port  25   e  for communication between the front surface portion  25   a  (see  FIG. 1 ) and the side surface portion  25   b  of the suction passage  25 . The front surface portion  25   a  is formed by the duct  25   c  (see  FIG. 1 ) that is fitted into the communication port  25   e , and the side surface portion  25   b  is formed by the cover  25   d  covering the air inflow port  21   a.    
         [0045]      FIGS. 5 and 6  are a perspective view and a plan view of the fan  22 , respectively. 
         [0046]    The fan  22  is driven to rotate by a fan motor  24  (see  FIG. 7 ) mounted on a rear surface of a bottom plate  21   b  of the housing  21  (see  FIG. 3 ). The fan  22  is formed with a turbo fan in which a number of blades  23  are arranged in a radial manner on a circumferential surface of a boss  22   b  disposed at a center portion. An axial direction of rotation of the fan  22  is arranged in the traverse direction of the indoor unit  1 , thereby reducing an increase in width in the traverse direction of the indoor unit  1 . 
         [0047]    The boss  22   b  is so disposed as to support a motor shaft  24   a  (see  FIG. 7 ) of the fan motor  24 , with a side surface thereof on an upper stream side arranged in the vicinity of the air inflow port  21   a  (see  FIG. 4 ). The blades  23  extend from the circumferential surface of the boss  22   b  outward relative to an outer edge of the air inflow port  21   a , and each have a pressed surface  23   c  thereof formed into a curved surface perpendicular to a rotation plane. The blades  23  may be formed with planar surfaces. Moreover, side edges  23   b , on an air-inflow-port  21   a  side, of the blades  23  are each formed substantially parallel to the rotation plane of the fan  22  and, on a bottom-plate  21   b  side, the blades  23  are interconnected to one another by an annular ring  22   c  so as to be reinforced. 
         [0048]      FIG. 7  is a side sectional view schematically showing the fan unit  20 . The side surface portion  25   b  of the suction passage  25  is so formed as to have a width W in an axial direction of the fan  22  sufficiently small compared with a diameter of the air inflow port  21   a , along an opening surface of the air inflow port  21   a  of the housing  21 . The side edges  23   b , on the air-inflow-port  21   a  side, of the blades  23  are disposed in the vicinity of the air inflow port  21   a  along the air inflow port  21   a.    
         [0049]    In the air conditioner configured as described above, from room air taken inside the indoor unit  1  through the opening portions of the exterior panel, dust included therein is collected by the filter  2 . The air from which dust has been removed then passes through the heat exchanger  3 , where heat is rejected from the air, and resulting air is sent out to the room through the blowout port  5 . In this way, conditioning of room air is performed. 
         [0050]    When an instruction is issued to drive the cleaning apparatus  10 , the filter driving motor  4 , the brush motor  26 , and the fan motor  24  are driven accordingly. By driving the filter driving motor  4 , the filter  2  is moved in the up and down directions on the filter rail  2   a . By driving the brush motor  26 , the rotary brush  27  is rotated, and thereby dust collected by the filter  2  moving up and down is beat out. By driving the fan motor  24 , the fan  22  is rotated, and thereby a sucked air stream is produced inside the suction passage  25 . 
         [0051]    Thus, dust stuck on the filter  2  is taken in together with the air stream through the suction port of the duct  25   c , and is made to pass through the front surface portion  25   a  of the suction passage  25  as indicated by arrowed line B 1  (see  FIG. 1 ). The air stream passing through the front surface portion  25   a  is made to further pass through the side surface portion  25   b  whose width W is small, as indicated by arrowed line B 2  (see  FIG. 7 ), and then flows inside the housing  21  along the rotation plane of the fan  22  through the air inflow port  21   a  as indicated by arrowed line B 3 . Moreover, part of the air stream is bent in the vicinity of the air inflow port  21   a , and reverses its traveling direction so as to flow inside the housing  21  as indicated by arrowed line B 4 . 
         [0052]    The blades  23  are formed such that the side edges  23   b  thereof, on the upper stream side, of the air stream flowing through the air inflow port  21   a  as indicated by arrowed line B 3  are arranged in parallel to the rotation plane and extend in the radius direction of the fan  22 . This permits the air stream flowing inside the housing  21  to come into contact with the blades  23  at a small intersecting angle. Thus, it is possible to reduce a pressing force produced when the dust included in the air stream and the side edges  23   b  of the blades  23  collide with each other, and hence to reduce the amount of dust stuck on the blades  23 . 
         [0053]    Moreover, dust caught by the side edges  23   b  of the blades  23  is pushed toward the outer circumferential side of the blades  23  with the air stream advancing in the radius direction of the fan  22 . In addition, the dust caught by the side edges  23   b  is pushed toward the outer circumferential side of the blades  23  with a centrifugal force of the blades  23 . Thus, it is possible to further reduce the amount of dust stuck on the blades  23 . 
         [0054]    The air stream flowing inside the housing  21  is thus guided in an outer circumferential direction of the fan  22 , and is then made to pass through the air exhaust passage  28  via the air outflow port  21   c  so as to be exhausted to outdoor together with the dust. Thus, cleaning of the filter  2  is automated. 
         [0055]    According to this embodiment, the air stream flows inside the housing  21  along the rotation plane of the fan  22  through the air inflow port  21   a , and the blades  23  are formed such that the side edges  23   b  thereof, on the upper stream side, of the air stream flowing through the air inflow port  21   a  extend in the radius direction of the fan  22 ; this makes the intersecting angle formed by the advancing direction of the air stream and the side edges  23   b  of the blades  23  small. Thus, it is possible to reduce a pressing force produced when the dust and the side edges  23   b  of the blades  23  collide with each other, and hence to reduce the amount of dust stuck on the blades  23 . In addition, the dust caught by the side edges  23   b  of the blades  23  is pushed toward the outer circumferential side of the blades  23  thanks to the air stream and centrifugal force, thereby making it possible to further reduce the amount of dust stuck on the blades  23 . Thus, it is possible to easily reduce the amount of dust accumulated at the side edges  23   b  of the blades  23  and between the blades  23  inside the cleaning apparatus  10 . 
         [0056]    Moreover, the fan  2  is formed with a turbo fan. This makes it possible to easily make the air stream inside the housing  21  flow in the outer circumferential direction along which the air outflow port  21   c  is formed. Accordingly, it is possible to easily reduce the amount of dust accumulated. Here, the fan  2  is not limited to a turbo fan; the same effect can be offered by a centrifugal fan such as a radial fan. However, forming of the fan  2  using a turbo fan, owing to its high static pressure, leads to a reduced number of blades  23 . This makes it possible to further reduce the amount of dust accumulated between the blades  23 . Moreover, with the turbo fan, a speed of rotation is increased compared with a sirocco fan for blowing out the same amount of wind. Thus, it is possible to increase the centrifugal force, and hence to reduce the amount of dust stuck on the blades  23 . 
         [0057]    Moreover, the fan  22  is provided with the boss  22   b  around its rotation center in the vicinity of the air inflow port  21   a , and the blades  23  are so formed as to extend from the circumferential surface of the boss  22   b  outward relative to the outer edge of the air inflow port  21   a ; accordingly, the blades  23  are formed such that the side edges  23   b  thereof substantially parallel to the rotation plane of the fan  22  are arranged on the upper stream side of the air stream flowing through the air inflow port  21   a . Thus, it is possible to easily make the intersecting angle formed by the air stream and side edges (side edges  23   b ), on the upper stream side, of the blades  23  small. Here, the blades  23  have simply to extend at least to the outer edge of the air inflow port  21   a.    
         [0058]    Moreover, the blades  23  on the bottom-plate  21   b  side opposite to a side on which the air inflow port  21   a  is present are interconnected to one another by the annular ring  22   c  so as to be reinforced. The blades  23  may be reinforced with the blades  23  on the bottom-plate  21   b  side interconnected to one another by a supporting member such as a plate-shaped disk. However, use of a plate-shaped supporting member leads to an interior of the housing  21  separated into an air-inflow-port  21   a  side and a bottom-plate  21   b  side. Accordingly, when the fan motor  24  having much play in an axial direction of the motor shaft  24   a  is used, a difference between a static pressure on the air-inflow-port  21   a  side and a static pressure on the bottom-plate  21   b  side is produced, causing the fan  22  to be pushed toward the air-inflow-port  21   a  side. As a result, the side edges  23   b , on the upper stream side, of the blades  23  may rub against the housing  21 . 
         [0059]    Thus, with the blades  23  on the bottom-plate  21   b  side interconnected to one another by the ring  22   c , it is possible to form, on a side opposite to the air inflow port  21   a , an opening portion having a large open area, with no gap between the blades blocked. This makes it possible to prevent the blades  23  and the housing  21  from being displaced in a sliding manner. In addition, this makes dust accumulated between the blades  23  easily drop off through the opening portion, and thereby avoides blocking the gaps between the blades  23  with dust. 
         [0060]    The configuration of this embodiment is summarized as noted below: 
         [0000]    (1) The air stream passing through the air inflow port  21   a  flows along the rotation plane of the fan  22 , and its inflow direction and the rotation axis of the fan  22  are substantially perpendicular to each other.
 
(2) The side edges  23   b , on the upper stream side, of the blades  23  and the rotation axis of the fan  22  are substantially perpendicular to each other as seen from the side.
 
(3) The inflow direction in which the air stream flows through the air inflow port  21   a  and the side edges  23   b  of the blades  23  are substantially parallel to each other as seen from the side.
 
(4) The blades  23  are so disposed as to be perpendicular to the rotation plane of the fan  22 , and the end portions on the upper stream side are not inclined forward in the rotation direction of the fan  22 .
 
         [0061]    Next, an air conditioner according to a second embodiment will be described. 
         [0062]      FIG. 8  is a side sectional view schematically showing a fan unit  20  of a cleaning apparatus  10  of an air conditioner according to this embodiment. For convenience of explanation, the same parts as in the first embodiment described above with reference to  FIGS. 1 to 7  will be identified by the same reference signs. The air conditioner of this embodiment differs from that of the first embodiment in shape of the blades  23  of the cleaning apparatus  10 . The other parts are the same as in the first embodiment. 
         [0063]    The blades  23  of the fan  22  are so formed as to extend from the circumferential surface of the boss  22   b  outward relative to the outer edge of the air inflow port  21   a , and each have a pressed surface  23   c  formed into a curved surface perpendicular to the rotation plane of the fan  22 . The blades  23  have simply to be formed up to the outer edge of the air inflow port  21   a , and may be formed with planar surfaces. Moreover, the blades  23  are formed such that the side edges  23   b  thereof on the air-inflow-port  21   a  side are arranged on the upper stream side of the air stream flowing through the air inflow port  21   a , and that the side edges  23   b  descend from the inner circumferential side thereof to the outer circumferential side thereof with an increased distance from the air inflow port  21   a  as observed in the axial direction of the fan  22 . 
         [0064]    With respect to the air stream flowing through the air inflow port  21   a  as indicated by arrowed line B 3 , the side edges  23   b , on the upper stream side, of the blades  23  are so formed as to descend in the radius direction of the fan  22  toward the circumferential side thereof with an increased distance from the rotation plane of the fan  22 . Accordingly, the air stream flowing inside the housing  21  comes into contact with the blades  23  at a further smaller intersecting angle as compared with the first embodiment. Thus, it is possible to further reduce the amount of dust accumulated on the blades  23 . 
         [0065]    The side edges  23   b  of the blades  23  may be so formed as to ascend from the inner circumferential side thereof to the outer circumferential side thereof as observed in the axial direction, with a decreased distance from the air inflow port  21   a . Thus, the side edges  23   b  are so made to extend in the radius direction, with the result that an angle formed by intersecting with the air stream is large compared with those in the first and second embodiments but small compared with the conventional art, thereby making it possible to reduce the amount of dust accumulated. 
         [0066]    The configuration of this embodiment is summarized as noted below: 
         [0000]    (1) The air stream flowing through the air inflow port  21   a  passes along the rotation plane of the fan  22 , and its inflow direction and the rotational axis are substantially perpendicular to each other.
 
(2) The side edges  23   b , on the upper stream side, of the blades  23  are made in a descending manner with respect to the rotation axis so that part, on the outer circumferential side, of the side edges  23   b  are away from the air inflow port  21   a  as observed in the axial direction from the side.
 
(3) The air stream flowing through the air inflow port  21   a  is made to pass along the side edges  23   b  of the blades  23 .
 
(4) The blades  23  are provided perpendicularly to the rotation plane, and the end portions, on the upper stream side, of the blades  23  are not inclined forward in the rotation direction of the fan  22 .
 
         [0067]    Next, an air conditioner according to a third embodiment will be described.  FIG. 9  is a side sectional view schematically showing a fan unit  20  of a cleaning apparatus  10  of an air conditioner according to this embodiment. For convenience of explanation, the same parts as in the first embodiment described above with reference to  FIGS. 1 to 7  will be identified by the same reference signs. The air conditioner of this embodiment differs from that of the first embodiment in shape of the fan  22  and shape of the air inflow port  21   a  inside the cleaning apparatus  10 . The other parts are the same as in the first embodiment. 
         [0068]    In the fan unit  20  of this embodiment, the housing  21  is provided with a disk  21   d  coaxially with the fan  22  to thereby form the air inflow port  21   a  in a ring-like shape. Moreover, the fan  22  is formed with a centrifugal fan, in which the blades  23  are provided perpendicularly to the rotation plane on the bottom plate  22   a . The side edges  23   a , on the inner circumferential side, of the blades  23  are arranged inward relative to an inner edge of the air inflow port  21   a , so that the side edges  23   a  do not come into contact with the air stream from the air inflow port  21   a.    
         [0069]    Of the blades  23 , the side edges  23   b  facing the air inflow port  21   a  are so formed as to extend in the radius direction substantially parallel to the rotation plane of the fan  22 . Thus, the side edges  23   b  are so formed as to extend from the inner edge of the air inflow port  21   a  to the outer edge of the air inflow port  21   a . As a result, the side edges  23   b  of the blades  23  are arranged on the upper stream side of the air stream flowing through the air inflow port  21   a.    
         [0070]    According to this embodiment, as in the first embodiment, a direction in which the air stream advances and the side edges  23   b , on the upper stream side, of the blades  23  intersect with each other at a small angle. Thus, it is possible to easily reduce the amount of dust accumulated at the side edges  23   b  of the blades  23  and between the blades  23  inside the cleaning apparatus  10 . Here, the side edges  23   b  of the blades  23  may be made in a descending manner as in the second embodiment. 
         [0071]    The configuration of this embodiment is summarized as noted below: 
         [0000]    (1) The air stream flowing through the air inflow port  21   a  passes along the rotation plane of the fan  22 , and its inflow direction and the rotation axis of the fan  22  are substantially perpendicular to each other.
 
(2) The side edges  23   b , on the upper stream side, of the blades  23  and the rotation axis of the fan  22  are substantially perpendicular to each other as seen from the side.
 
(3) The inflow direction in which the air stream flows through the air inflow port  21   a  and the side edges  23   b  of the blades  23  are substantially parallel to each other as seen from the side.
 
(4) The blades  23  are provided perpendicularly to the rotation plane of the fan  22 , and end portions, on the upper stream side, of the blades  23  are not inclined forward in the rotation direction of the fan  22 .
 
         [0072]    Next, an air conditioner according to a fourth embodiment will be described.  FIGS. 10 and 11  are a perspective view and a side view, respectively, schematically showing the fan  22  of the cleaning apparatus  10  inside the air conditioner according to this embodiment. For convenience of explanation, the same parts as in the first embodiment described above with reference to  FIGS. 1 to 7  will be identified by the same reference signs. In  FIGS. 10 and 11 , only one blade  23  is drawn for the purpose of clarifying the shape of the blades  23 , and the other plurality of blades  23  are omitted from the drawings. The air conditioner of this embodiment differs from that of the first embodiment in shape of the blades  23  inside the cleaning apparatus  10 . The other parts are the same as in the first embodiment. 
         [0073]    The blades  23  of the fan  22  are so formed as to extend outward from the circumferential surface of the boss  22   b , and are formed into a curved surface inclined relative to the rotation plane of the fan  22 . The blades  23  are inclined, on an air-inflow-port  21   a  side thereof, backward in the rotation direction R of the fan  22  and, on a bottom-plate  21   b  side thereof, forward in the rotation direction R of the fan  22 . Accordingly, as shown in  FIG. 11 , an angle α formed by an inclination direction D in which the end portion, on the air-inflow-port  21   a  side, of the blade  23  is inclined and the rotation direction R of the blade  23  results in an obtuse angle. With this, the inclination direction D of the end portion, on the air-inflow-port  21   a  side, of the blade  23  is, with respect to the rotation direction R, a direction permitting dust, which is being carried by the air stream, to be released when hitting the side edge  23   b . Thus, dust is not pressed against the side edge  23   b.    
         [0074]    Thus, according to this embodiment, it is possible to offer the same effect as in the first embodiment, and to reduce a pressing force produced, owing to the rotation of the fan  22 , when dust and the side edges  23   b  of the blades  23  collide with each other. Thus, it is possible to further reduce the amount of dust stuck on the blades  23 . 
         [0075]    The shape of the blades of this embodiment is not limited to that shown in  FIGS. 10 and 11 . For example, as shown in  FIG. 12 , the planar blades  23  may be inclined, on the air-inflow-port  21   a  side thereof, backward in the rotation direction R and, on the bottom-plate  21   b  side, forward in the rotation direction R. Moreover, as shown in  FIG. 13 , the blades  23  may be formed with only the vicinity of the side edge  23   b  inclined. Further, as shown in  FIG. 14 , the side edge  23   b  may be provided with an incline by forming a chamfered portion  23   d  on the pressed surface  23   c  on a side of the side edge  23   b.    
         [0076]    The configuration of this embodiment is summarized as noted below: 
         [0000]    (1) The air stream flowing through the air inflow port  21   a  passes along the rotation plane of the fan  22 , and its inflow direction and the rotation axis of the fan  22  are substantially perpendicular to each other.
 
(2) The side edges  23   b , on the upper stream side, of the blades  23  and the rotation axis of the fan  22  are substantially perpendicular to each other.
 
(3) The inflow direction in which the air stream flows through the air inflow port  21   a  and the side edges  23   b  of the blades  23  are substantially parallel to each other as seen from the side.
 
(4) The end portions, on the upper stream side, of the blades  23  are inclined backward in the rotation direction.
 
         [0077]    Although the first to fourth embodiments deal with arrangements in which a place to which dust is expelled is outdoor, it is not specifically limited to this. For example, in a case where the indoor unit  1  is placed inside a room having no wall facing the outdoor, it may be difficult to lead the air exhaust passage  28  to outside of the room. Accordingly, dust may be expelled in a dust box disposed inside the room via the air outflow port  21   c . This makes it possible to reduce the trouble of cleaning the filter  2  regularly. From the viewpoint of satisfactory aesthetic appearance and installation space, it is more desirable that the dust box be disposed inside the indoor unit  1 . 
         [0078]    Moreover, although the cleaning apparatus  10  is aimed at removing dust collected by the filter  2  and accumulated thereon, it is not specifically limited to this. The cleaning apparatus  10  may clean the exterior panel, the heat exchanger  3 , a blower fan sending out conditioned air, and components, such as a louver, composing the air passages through which conditioned air passes. Dust stuck on the filter  2  and the exterior panel adsorbs a lot of oil present inside a room, dust stuck on the heat exchanger  3 , the blower fan, the louver and the like contains a lot of moisture produced by condensation in particular during air cooling. Either type of dust tends to be stuck on the blades  23  of the fan  22  inside the cleaning apparatus  10 . In either case, with the cleaning apparatus  10  as in any one of the embodiments described above, it is possible to reduce the amount of dust stuck on the blades  23 . 
         [0079]    Moreover, examples of the fan  22  may include not only a centrifugal fan, but also an axial-flow fan or a diagonal fan. In either case, as described above, the side edges, on the upper stream side, of the blades  23  with which the air stream flowing through the air inflow port  21   a  makes contact are so formed as to extend in the radius direction, thereby making it possible to reduce the amount of dust accumulated. 
         [0080]    As will be described below, regardless of a direction in which the air stream flows through the air inflow port  21   a , it is possible to reduce the amount of dust accumulated depending on an arrangement of the blades  23 .  FIG. 15  is a sectional view of the blade  23 , covering the same arrangements as in the first to third embodiments.  FIG. 16  is a sectional view of the blade  23 , covering the same arrangement as in the fourth embodiment ( FIG. 12 ). Examples covered by these figures include not only arrangements of the blades  23  in the centrifugal fan but also the arrangements of the blades  23  in an axial-flow fan and a diagonal fan. Moreover,  FIGS. 17 and 18  are sectional views each showing an arrangement of the blades  23  as a comparative example. 
         [0081]    In  FIG. 15 , an angle θ formed by a direction in which a resultant force F obtained by combining a ram pressure received by the pressed surface  23   c  as the blades  23  are rotated with a centrifugal force imposed on the blades  23  acts, and a direction E in which the pressed surface  23   c  extends from a side edge  23   e  (corresponding to  23   b  in  FIGS. 7 to 9 ), on the upper stream side, of the blade  23  is 90°. In  FIG. 16 , the angle θ formed by the direction of the resultant force F and the direction E in which the side edge  23   e  (corresponding to  23   b  in  FIG. 12 ), on the upper stream side, of the blade  23  extends is obtuse. 
         [0082]      FIG. 17  covers the same configuration of the blade  23  as that of the conventional example shown in  FIG. 19 , where the side edge  23   e , on the upper stream side, of the blade  23  corresponds to  23   a  in  FIG. 19 , and the angle θ is sharp. Also in  FIG. 18 , the angle θ is sharp. 
         [0083]    As indicated by the comparative examples, when the angle θ is sharp, the ram pressure received by the side edge  23   e  and the centrifugal force are positive pressures (forces acting in a direction in which dust is pressed against the side edge  23   e ); accordingly, dust tends to be accumulated on the side edge  23   e . In contrast, by making the angle θ equal to or more than 90° ( FIGS. 15 and 16 ), the ram pressure received by the side edge  23   e , on the upper stream side, of the blade  23  and the centrifugal force are zero or negative pressures (forces acting in a direction in which dust is scraped off from the side edge  23   e ). Thus, it is possible to reduce the amount of dust accumulated on the side edges  23   e  even if a pressing force is imposed on the side edges  23   e  according to a velocity of the air stream. 
         [0084]    When the velocity of the air stream is taken into account, so long as the fan  22  is formed with a centrifugal fan, it is advantageous that the air stream flows through the air inflow port  21   a  at an angle as close to the right angle as possible with respect to the rotation axis of the fan  22 . In other words, it is preferable that the inflow direction form an angle as small as possible with respect to the rotation plane of the blades  23 . For that, it is necessary to reduce height of an air stream flowing through the duct (side surface portion  25   d ) in the axial direction of the fan  22 . Moreover, in a case where the fan  22  is formed with a diagonal fan or an axial-flow fan, it is possible to eliminate a restriction like that. 
       INDUSTRIAL APPLICABILITY 
       [0085]    Any one of the embodiments described herein is applicable to an air conditioner equipped with a cleaning apparatus cleaning a filter thereof. 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
         
           
               1  Indoor unit 
               2  Filter 
               3  Heat exchanger 
               4  Filter driving motor 
               5  Blowout port 
               6  Louver 
               10  Cleaning apparatus 
               20  Fan unit 
               21  Housing 
               21   a  Air inflow port 
               21   b  Bottom plate 
               21   c  Air outflow port 
               22  Fan 
               22   b  Boss 
               23  Blades 
               23   a ,  23   b ,  23   e  Side edges 
               23   c  Pressed surface 
               24  Fan motor 
               25  Suction passage 
               25   a  Front surface portion 
               25   b  Side surface portion 
               26  Brush motor 
               27  Rotary brush 
               28  Air exhaust passage