Patent Publication Number: US-7909572-B2

Title: Shroud and rotary vane wheel of propeller fan and propeller fan

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 11/363,535, filed on Feb. 28, 2006 which is based upon and claims the benefit of priority from Japanese Patent Application Nos. 2005-225856, 2005-225858 and 2005-225859 filed Aug. 3, 2005, the entire contents of all of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a shroud and a rotary vane wheel of a propeller fan and the propeller fan. 
     2. Description of the Related Art 
     A vehicle is provided with a propeller fan for cooling heat exchangers such as a radiator and a condenser of an air conditioner. Japanese Patent Application Laid-Open No. 2002-47937 discloses a stay for supporting a boss of the fan to a shroud. To achieve high fan efficiency and low noise when running at low speed, this stay is of an aspect ratio &gt;1, has a longitudinal direction of its section oriented toward a direction of an airflow generated by driving the fan and also has a cavity provided on a side of a negative pressure of the stay generated by the airflow when the vehicle is running at high speed. 
     An engine room of the vehicle hardly has space because it has not only an engine as a power source of the vehicle but also its accessories mounted therein. For this reason, the propeller fan for cooling the radiator and condenser is limited as to its dimension in the airflow direction. Consequently, the space between the fan and the stay becomes small, and noise when operating the propeller fan becomes high. The stay is required to have strength for supporting the fan and driving means (an electric motor for instance) of the fan. This strength cannot be secured, however, if the stay is rendered thin in an attempt to reduce the noise when operating the propeller fan. Such a problem is not considered in Japanese Patent Application Laid-Open No. 2002-47937. Therefore, there is room for improvement in a conventional technology disclosed in Japanese Patent Application Laid-Open No. 2002-47937 as to reducing the noise while limiting the dimension in the airflow direction and further securing support strength of the stay (first problem). 
     As for the propeller fan for cooling the radiator and condenser for the vehicle, it is placed in a narrow engine room and required to be further lightweight, and so there is a strong request for compactification regarding a depth dimension in a flow direction of cooling wind. If the depth dimension is thus reduced, however, a cross-section of a cooling wind channel of the shroud of the propeller fan changes drastically because the radiator on an upstream side is rectangular while an air sucking path of the propeller fan is round. For this reason, there is a problem that an uneven drift is formed in a circumferential direction of the propeller fan (rotary vane wheel) to generate unpleasant BPF (Blade Passing Frequency) noise. 
     The radiator and condenser as cooling subjects are small-size and require high heat exchange performance so that ventilation resistance thereof is high. For this reason, the propeller fan is driven under a condition of a high static pressure difference reverse to an adverse wind direction. In this case, there is a problem that the flow on a propeller plane of the rotary vane wheel breaks away so as to increase input and the noise under the same air volume condition. 
     As for these problems, there is a known technology described in Japanese Patent Application Laid-Open No. 7-167095 regarding a conventional propeller fan. The conventional propeller fan (electric fan) is the electric fan rotatively driven by the electric motor, which comprises a boss portion for rotating by receiving a driving force of the electric motor and 9 to 13 blades (blade portion) placed around the boss portion circumferentially apart from the boss portion. The blade is characterized by being a forward swept vane of which angle of advance overlooking a vane edge from a vane root is 35 to 45 degrees. 
     However, the propeller fan described in Japanese Patent Application Laid-Open No. 7-167095 is not sufficient as to noise reduction performance (second problem). 
     As the rotary vane wheel provided to the conventional propeller fan has multiple blades in general, the multiple blades rotate on rotating the rotary vane wheel by the driving means such as the electric motor so as to let the air flow by means of these blades. Thus, these blades for blowing air by letting the air flow are fixed on a hub of the rotary vane wheel. The hub is provided to connect the blades to an axis of the driving means and transfer rotation of the axis of the driving means to the blades. For that reason, the hub does not contribute to air blowing so much. Therefore, there is a conventional rotary vane wheel wherein occupancy of the blades in the rotary vane wheel is enlarged to increase a sent air volume so as to improve air blowing performance. In Japanese Patent Application Laid-Open No. 2004-218513 for instance, a joint of the blades and the hub is extended inward in a radial direction centering on a rotation axis of the hub to increase length of the blades in the radial direction. It is thereby possible to improve the occupancy of the blades in the case of axially viewing the rotary vane wheel so as to increase the sent air volume and improve the air blowing performance. 
     In the case of the above-mentioned rotary vane wheel, however, there is little difference in that the hub does not contribute to improvement in the air blowing performance so much because the hub is basically in a cylindrical shape. As with the above-mentioned rotary vane wheel, the blades are extended inward in the radial direction centering on a rotation axis of the hub so that a radial step is generated on an end of the upstream side of the hub in the circumferential direction of the rotation axis. Therefore, there is a possibility that the airflow may be disturbed in this part. In the case where the airflow is thus disturbed, the efficiency lowers and so there is a possibility that the air blowing performance may lower and the noise may be easily generated (third problem). 
     SUMMARY OF THE INVENTION 
     Objects of the present invention are at least to solve the above-mentioned problems. 
     According to one aspect of the present invention, a shroud of a propeller fan includes a body portion for accommodating a rotary vane wheel of the propeller fan; a mount positioned at a center of the body portion for supporting rotary vane wheel driving means for driving the rotary vane wheel; and multiple support beams radially extending from the mount for joining the mount and the body portion, wherein each of the support beams becomes thicker from an upstream side of a flow direction of air discharged by the rotary vane wheel toward a downstream side thereof, an edge portion of each of the support beams on the downstream side of the flow direction of the air discharged by the rotary vane wheel is oriented in a direction parallel to a rotation axis of the rotary vane wheel, and the edge portion of each of the support beams on the upstream side of the flow direction of the air discharged by the rotary vane wheel is oriented in a direction opposite to a rotation direction of the rotary vane wheel. 
     According to another aspect of the present invention, a propeller fan includes the shroud of the propeller fan; rotary vane wheel driving means attached on a mount; and a rotary vane wheel driven by the rotary vane wheel driving means. 
     According to still another aspect of the present invention, a propeller fan includes a rotary vane wheel having multiple blade portions arranged on a hub portion which is a rotor; a motor for rotating the rotary vane wheel; and a shroud having a motor holding portion for holding the motor, wherein, a ratio H/D F  between an axial width H and a diameter D F  at an end of the rotary vane wheel is in a range of H/D F ≦0.12, a ratio D m /D F  between a diameter D m  of the hub portion and the diameter D F  at the end of the blade portion is in the range of D m /D F ≦0.50, a ratio P/C between a circumferential pitch P and a chord length C of the blade portion is in the range of 1.0&lt;P/C&lt;1.2, and an outer circumferential side of the blade portion is swept forward in a rotation direction of the rotary vane wheel. 
     According to still another aspect of the present invention, a rotary vane wheel includes multiple blade portions; and a hub having the multiple blade portions provided on its outer circumferential surface, wherein, in the case where, of both edges of the outer circumferential surface in an axial direction of a rotation axis of the hub, one edge is an upstream side end portion and the other edge is a downstream side end portion, the outer circumferential surface has an inclined portion inclined against the rotation axis in a direction to be further away from the rotation axis as directed from the upstream side end portion to the downstream side end portion and a parallel portion formed along the rotation axis, the parallel portion is formed between a connecting portion connecting the blade portion to the outer circumferential surface and the downstream side end portion, and positioned more inward in a radial direction of the rotation axis than an extended inclined portion which is a virtual extended portion of the inclined portion continued from the inclined portion between the connecting portion and the downstream side end portion. 
     According to still another aspect of the present invention, a propeller fan includes the rotary vane wheel; driving means for supporting the rotary vane wheel rotatably centering on the rotation axis; and a shroud for placing the rotary vane wheel therein and fixing the driving means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view showing an example of a propeller fan according to a first embodiment of the present invention mounted on a heat exchanger for a vehicle; 
         FIG. 2  is a front view showing a state of the propeller fan according to the first embodiment of the present invention viewed from a vehicle front side; 
         FIG. 3  is an A to A arrow view of  FIG. 2 ; 
         FIG. 4  is a front view showing a rotary vane wheel provided to the propeller fan according to the first embodiment of the present invention; 
         FIG. 5  is a plan view showing support beam provided to a shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 6  is a sectional view of the support beam provided to the shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 7  is a sectional view of the support beam provided to the shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 8A  is a B to B sectional view of  FIG. 5 ; 
         FIG. 8B  is a C to C sectional view of  FIG. 5 ; 
         FIG. 8C  is a D to D sectional view of  FIG. 5 ; 
         FIG. 9  is a partial sectional view showing the propeller fan according to the first embodiment of the present invention; 
         FIG. 10  is a schematic diagram of a ventilation range of the propeller fan; 
         FIG. 11  is a schematic diagram showing a relation of a discharge flow of the rotary vane wheel, a specific sound level K PWL-BPF  relating to acoustic power based on a discrete frequency BPF and a flow concentration coefficient value R against a distance between a blade portion of the rotary vane wheel and the heat exchanger; 
         FIG. 12A  is a schematic diagram showing a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 12B  is a schematic showing a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 12C  is a schematic showing a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 13  is a schematic diagram showing a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment of the present invention; 
         FIG. 14  is a front view showing the propeller fan according to a second embodiment of the present invention; 
         FIG. 15  is a rear view showing the propeller fan according to the second embodiment of the present invention; 
         FIG. 16  is a side sectional view showing the propeller fan according to the second embodiment of the present invention; 
         FIG. 17  is a front side perspective view showing the rotary vane wheel of the propeller fan described in  FIGS. 14 to 16 ; 
         FIG. 18  is an A to A sectional view showing the blade portion of the rotary vane wheel described in  FIG. 17 ; 
         FIG. 19  is a plan view showing the blade portion of the rotary vane wheel described in  FIG. 17 ; 
         FIG. 20  is a plan view showing the blade portion of the rotary vane wheel described in  FIG. 17 ; 
         FIG. 21  is a schematic diagram showing the action of the propeller fan described in  FIGS. 14 to 16 ; 
         FIG. 22  is a schematic diagram showing the action of the propeller fan described in  FIGS. 14 to 16 ; 
         FIG. 23  is a schematic diagram showing the action of the propeller fan described in  FIGS. 14 to 16 ; 
         FIG. 24  is a schematic diagram showing the action of the propeller fan described in  FIGS. 14 to 16 ; 
         FIG. 25  is a front view of the propeller fan according to a third embodiment of the present invention; 
         FIG. 26  is an A to A sectional view of  FIG. 25 ; 
         FIG. 27  is a B to B arrow view of  FIG. 26 ; 
         FIG. 28  is an external view of the rotary vane wheel viewed from a direction of  FIG. 25 ; 
         FIG. 29  is a perspective view of the rotary vane wheel viewed from a front end side of a hub; 
         FIG. 30  is a perspective view of the rotary vane wheel viewed from an opposite direction to the rotary vane wheel of  FIG. 29 ; 
         FIG. 31  is a D to D sectional view of  FIG. 28 ; 
         FIG. 32  is an E to E sectional view of  FIG. 31 ; 
         FIG. 33  is an F to F sectional view of  FIG. 31 ; 
         FIG. 34  is a C to C arrow view of  FIG. 26 , which is a relevant part detail view of the rotary vane wheel; and 
         FIG. 35  is a detail view of a G portion of  FIG. 28 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereunder, the present invention will be described in detail by referring to the attached drawings. The present invention will not be limited by embodiments described below. Components of the following embodiments include the ones easily assumable by those in the art or the ones which are substantially the same. 
     First Embodiment 
     While a propeller fan according to a first embodiment is not limited as to its application, it is suitable in particular to the propeller fan which is limited as to a dimension in a rotation axis direction of a rotary vane wheel provided to the propeller fan. Such a propeller fan can be exemplified by the one used for cooling of a heat exchanger mounted on a vehicle, such as a passenger car or a truck. 
       FIG. 1  is a plan view showing an example of the propeller fan according to the first embodiment mounted on the heat exchanger for a vehicle. A description will be given by using  FIG. 1  as to an example of mounting a propeller fan  1  according to the first embodiment. The propeller fan  1  is used for cooling of the heat exchanger such as a radiator  2  or a condenser  3 . In general, a vehicle such as a passenger car or a truck has the radiator  2  for cooling engine coolant or the condenser  3  of an air conditioner mounted at a front of the vehicle (hereafter, vehicle front) L in its traveling direction, and leads a driving wind thereto so as to cool the coolant and condense a refrigerant. 
     In the example shown in  FIG. 1 , the condenser  3  and the radiator  2  are united by fasteners  4 . The propeller fan  1  according to the first embodiment is mounted on the radiator  2 , and its position is at a rear of the vehicle (hereafter, vehicle rear) T side in its traveling direction. Thus, this example has the condenser  3 , radiator  2  and propeller fan  1  configured as one and mounted in an engine room of the vehicle on the vehicle front L side. 
       FIG. 2  is a front view showing a state of the propeller fan according to the first embodiment viewed from the vehicle front side.  FIG. 3  is an A to A arrow view of  FIG. 2 .  FIG. 4  is a front view showing the rotary vane wheel provided to the propeller fan according to the first embodiment. The rotary vane wheel is omitted in  FIG. 2 . As shown in  FIG. 3 , the propeller fan according to the first embodiment comprises a rotary vane wheel  8  shown in  FIG. 4 , a shroud  5  shown in  FIG. 2  and an electric motor (rotary vane wheel driving means)  6  shown in  FIGS. 2 and 3 . 
     The rotary vane wheel  8  shown in  FIG. 4  is configured by a hub  8 H and multiple blade portions  8 W mounted on an outer circumferential portion thereof. The rotary vane wheel  8  comprises 7 blade portions  8 W. However, the number of the blade portions  8 W is not limited thereto. As shown in  FIG. 3 , the hub  8 H of the rotary vane wheel  8  is mounted on a rotation axis  6 S of the electric motor  6 . The electric motor  6  rotates the rotary vane wheel  8  centering on a rotation axis Zf, and lefts air W flow from the vehicle front L side to the vehicle rear T. In that process, the air W exchanges heat with the coolant and refrigerant flowing inside the radiator  2  and the condenser  3 . Here, a rotation direction of the rotary vane wheel  8  is a direction Fr in  FIGS. 2 and 4 . And the rotation axis Zf is the rotation axis of the electric motor  6  and the rotary vane wheel  8 . 
     The shroud  5  comprises a mount pedestal  7  for mounting the electric motor  6  as the rotary vane wheel driving means. As shown in  FIG. 2 , the mount  7  is supported on a body portion  5 B of the shroud  5  by multiple support beams  10  radially extending from the rotation axis Zf. A ventilation flue  9  is formed between the mount  7  and the body portion  5 B. As shown in  FIG. 2 , the ventilation flue  9  is divided off by the support beams  10 . Here, the number of the support beams  10  is  11  in the first embodiment. However, the number of the support beams  10  is not limited thereto. 
     The engine room of the vehicle hardly has space because it has not only an engine as a power source of the vehicle but also its accessories mounted therein. In particular, it is necessary in recent years to secure a crushable zone for the traveling direction of the vehicle for the sake of improving collision safety so that devices mounted in the engine room are limited as to a dimension in the traveling direction of the vehicle. For this reason, the propeller fan  1  for cooling the condenser  3  and radiator  2  is also limited as to the dimension in a flow direction of the air W, that is, the direction parallel with the rotation axis Zf of the rotary vane wheel  8  of the propeller fan  1 . 
     Because of this limitation of the dimension, space between the support beams  10  and the blade portions  8 W of the rotary vane wheel  8  is also limited so that a sufficient dimension cannot be secured. Here, during operation of the propeller fan  1 , the rotary vane wheel  8  rotates at high speed and so the support beams  10  on a stationary side and the blade portions  8 W of the rotary vane wheel  8  perform relative movement at high speed. In the case where the space between the support beams  10  and the blade portions  8 W of the rotary vane wheel  8  cannot be secured sufficiently, it furthers pressure interference generated by the relative movement between the support beams  10  and the blade portions  8 W and generates harsh noise called discrete frequency noise. Thus, the propeller fan  1  according to the first embodiment has the following configuration of the support beams  10  provided to the shroud  5  in order to cope with this problem. 
       FIG. 5  is a plan view showing the support beam provided to the shroud of the propeller fan according to the first embodiment.  FIG. 5  shows a state of one of the support beams provided to the shroud viewed from the vehicle front side.  FIGS. 6 and 7  are sectional views of the support beam provided to the shroud of the propeller fan according to the first embodiment.  FIG. 8A  is a B to B sectional view of  FIG. 5 ,  FIG. 8B  is a C to C sectional view of  FIG. 5 , and  FIG. 8C  is a D to D sectional view of  FIG. 5 . Here, a section of the support beam means a longitudinal direction of the support beam, that is, the section orthogonal to the radial direction of the rotary vane wheel. 
     The support beams  10  provided to the shroud  5  of the propeller fan  1  according to the first embodiment are configured so that thickness h of the support beams  10  becomes larger from an upstream side (IN side of  FIG. 6 ) of the flow direction of the air discharged by the rotary vane wheel  8  toward a downstream side (OUT side of  FIG. 6 ) of the flow direction of the air discharged by the rotary vane wheel  8 . And an edge (hereafter, a downstream side edge)  10   to  of the support beams  10  on the downstream side of the flow direction of the air discharged by the rotary vane wheel  8  is inclined to be oriented toward a direction parallel with the rotation axis Zf of the rotary vane wheel  8 , and an edge (hereafter, an upstream side edge)  10   ti  of the support beams  10  on the upstream side of the flow direction of the air discharged by the rotary vane wheel  8  is inclined to be oriented toward a direction opposite to the rotation direction Fr of the rotary vane wheel  8 . Here, the thickness of the support beam  10  means the dimension in a direction orthogonal to a center line S of the support beam  10  in a cross-section of the support beam  10 . 
     In such a configuration, when the air discharged by the rotary vane wheel  8  passes through the support beams  10 , the flow of the air discharged from the rotary vane wheel  8  (arrows Wi of  FIG. 6 ) is changed to the direction of the rotation axis Zf of the rotary vane wheel  8  (arrows Wo of  FIG. 6 ) by the support beams  10 . To be more specific, the support beams  10  rectify the flow of the air discharged by the rotary vane wheel  8  to reduce circling components thereof. As an upstream side  10   i  of the support beams  10  is inclined toward the direction opposite to the rotation direction Fr of the rotary vane wheel  8 , the air discharged by the rotary vane wheel  8  flows smoothly along the upstream side  10   i  of the support beams  10  and the direction of the flow is gradually changed. It is possible, by these actions, to reduce pressure interference between the rotary vane wheel  8  and the support beams  10  so as to prevent generation of the noise of discrete frequency components as a noise source. 
     The thickness h of the support beams  10  becomes gradually larger from the upstream side edge portion  10   ti  toward the downstream side edge portion  10   to , and the downstream side edge portion  10   to  faces the direction parallel with the rotation axis Zf of the rotary vane wheel  8 . To be more specific, as shown in  FIG. 6 , the thickness of the support beams  10  becomes gradually larger from the upstream side edge portion  10   ti  toward the downstream side edge portion  10   to  in order of hi, hm and ho. As the support beams  10  have such a cross-section, it is possible to increase geometric moment of inertia and secure a cross section on the downstream side  10   o  of the support beams  10  so as to secure sufficient strength of the rotary vane wheel  8  in the rotation axis Zf direction. It is thereby possible to secure sufficient strength to bear a road surface vibrational acceleration when mounted on the vehicle in addition to a static load and a vibrational load of the electric motor  6  and the rotary vane wheel  8 . 
     Here, the upstream side  10   i  of the support beams  10  refers to the range further on the blade portion  8 W side of the rotary vane wheel  8  than an approximate center M of a length H of the support beams  10  in the rotation axis Zf direction of the rotary vane wheel  8 . The downstream side  10   o  of the support beams  10  refers to the range further on the downstream side (OUT side of  FIG. 6 ) of the flow direction of the air discharged by the rotary vane wheel  8  than the approximate center M of the length H of the support beams  10  in the rotation axis Zf direction of the rotary vane wheel  8 . 
     The cross-section of the support beam  10  can be configured as shown in  FIG. 7  for instance. Reference character S refers to the center line in the cross section orthogonal to the longitudinal direction of the support beams  10 . The center line S is rendered as an arc of ¼ or less centering on a virtual center point P, and the center of a first circle C 1  configuring the downstream side edge portion  10   to  is placed on the center line S. And, as well as the first circle C 1 , a second circle C 2 , a third circle C 3  and so on having their centers on the center line S are placed by rendering their radiuses smaller gradually toward the upstream side edge portion  10   ti  according to a distance from the downstream side edge portion  10   to  to the upstream side edge portion  10   ti . The center of an n-th circle C n  configuring the upstream side edge portion  10   ti  is placed on the most upstream position on the center line S, that is, the position opposed to the rotary vane wheel  8 . Here, if the radius of the first circle C 1  is r 1 , the radius of the second circle C 2  is r 2 , . . . and the radius of the n-th circle C n  is r n , it is r 1 &gt;r 2 &gt;r n . 
     Thus, after placing the first circle C 1  configuring the downstream side edge portion  10   to  to the n-th circle C n  configuring the upstream side edge portion  10   ti  in sequence, they are connected by an envelope including parts on circumferences of the first circle C 1 , second circle C 2 , third circle C 3  to n-th circle C n  irrespectively. The cross-section of the support beam  10  according to the first embodiment is composed of a contour configured by two envelopes SC 1  and SC 2 , the arc of the first circle C 1  on the downstream side in the airflow direction and the arc of the n-th circle C n  on the upstream side in the airflow direction. A technique for deciding the cross-section of the support beam  10  according to the first embodiment is not limited to this. 
     The support beams  10  provided to the shroud  5  according to the first embodiment has the inclination of the upstream side edge portion  10   ti  varied toward the outside of the longitudinal direction of the support beams  10  (arrow Do direction of  FIG. 5 ), that is, as directed from the mount  7  side to the body portion  5 B of the shroud  5 . As shown in  FIG. 7 , reference character l 1  denotes a tangent of the upstream side edge portion  10   ti  at an intersecting point j between the upstream side edge portion  10   ti  configured by the arc and the center line S of the support beam  10  on the cross section orthogonal to the longitudinal direction of the support beams  10 . And reference character l 2  denotes a straight line orthogonal to the tangent l 1  while reference character θ denotes an angle of gradient made by the straight line  12  and a plane including the rotation axis Zf of the rotary vane wheel  8 . To be more specific, the angle of gradient θ indicates the inclination of the upstream side edge portion  10   ti  (inclination to the plane including the rotation axis Zf of the rotary vane wheel  8 ). 
     As shown in  FIGS. 8A to 8C , the angle of gradient θ becomes larger as directed toward the outside of the longitudinal direction of the support beams  10 . To be more specific, it is θ 3 &gt;θ 2 &gt;θ 1 . To be more specific, as directed from the inside of the longitudinal direction (the mount  7  side) of the support beams  10  toward the outside of the longitudinal direction (the body portion  5 B of the shroud  5 ), an opening becomes larger between the plane including the rotation axis Zf of the rotary vane wheel  8  and the upstream side edge portion  10   ti . A circumferential velocity of the rotary vane wheel  8  becomes higher from the inside toward the outside of the rotary vane wheel  8 , and the circling components of the air discharged by the rotary vane wheel  8  become stronger accordingly. To be more specific, the flows of the air discharged by the rotary vane wheel  8  become those denoted by reference characters Wi, Wm and Wo as directed toward the outside of the radial direction of the rotary vane wheel  8  respectively. However, the components in the rotation direction Fr of the rotary vane wheel  8  become larger as the flows of the air discharged by the rotary vane wheel  8  are directed toward the outside of the radial direction of the rotary vane wheel  8 . 
     The support beams  10  provided to the shroud  5  according to the first embodiment enlarges the opening between the plane including the rotation axis Zf of the rotary vane wheel  8  and the upstream side edge portion  10   ti . It is thereby possible to reduce the pressure interference between the rotary vane wheel  8  and the support beams  10  all over the longitudinal direction of the support beams  10  so as to prevent generation of the noise of the discrete frequency components more effectively. As the downstream side edge portion  10   to  is directed toward the rotation axis Zf of the rotary vane wheel  8 , it is also possible to increase geometric moment of inertia and secure sufficient strength. 
       FIG. 9  is a partial sectional view showing the propeller fan according to the first embodiment.  FIG. 10  is a schematic diagram of a ventilation range of the propeller fan.  FIG. 11  is a schematic diagram showing a relation of a discharge flow of the rotary vane wheel, a specific sound level K PWL-BPF  relating to acoustic power based on a discrete frequency BPF and a flow concentration coefficient value R against a distance between the blade portion of the rotary vane wheel and the heat exchanger. Here, a distance t shown in  FIG. 9  indicates the distance between the blade portion  8 W of the rotary vane wheel  8  and the heat exchanger. 
     The value R shown in  FIG. 11  will be described by using  FIG. 10 .  FIG. 10  shows on its left side a ventilation range A ∞ of the propeller fan  1  in the case where the distance t is infinite, that is, the distance between the blade portion  8 W of the rotary vane wheel  8  and the heat exchanger is infinitely apart. The value R in this case is 0 so that the air flows from the heat exchanger to the propeller fan with complete uniformity.  FIG. 10  shows on its right side a ventilation range A 0  of the propeller fan  1  in the case where the distance t is 0, that is, there is no distance between the blade portion  8 W of the rotary vane wheel  8  and the heat exchanger. The value R in this case is approximately 2.5 so that the air flows from the heat exchanger through the portion of the blade portion  8 W of the rotary vane wheel  8 . Here, the value R is represented by a formula (1).
 
 R =√((1 /A )×∫ A ( u ( a ))− u   —   av ) 2   da )  (1)
 
Here, A denotes area of the entire region, u (a) denotes dimensionless velocity in a miniregion a. And u_av is an average of the velocity in the entire region rendered dimensionless, which is 1.
 
     As shown in  FIG. 11 , a discharge flow Q of the rotary vane wheel  8  increases as the distance t is rendered larger, that is, as the distance between the heat exchanger and the blade portion  8 W of the rotary vane wheel  8  is rendered larger. If the value R is rendered larger than t 2 , the value R becomes asymptotic to an approximately fixed value. Therefore, it is desirable to render the distance t between the blade portion  8 W of the rotary vane wheel  8  and the heat exchanger as large as possible, that is, at least larger than t 2 . 
     If the t is rendered larger, however, the distance between the blade portion  8 W of the rotary vane wheel  8  and the support beams  10  becomes closer so that noise components based on the discrete frequency BPF (Blade Passing Frequency) (that is, the specific sound level relating to the acoustic power based on the BPF of  FIG. 11 ) become larger. Here, BPF_SQ of  FIG. 11  is the noise component based on the BPF having a rectangular cross section of the support beam, and BPF_W is the noise component based on the BPF of the support beam  10  according to the first embodiment. In the case where the distance t between the blade portion  8 W of the rotary vane wheel  8  and the heat exchanger is the same, the support beam  10  according to the first embodiment can render the noise component based on the BPF smaller compared to the support beam of the rectangular cross section. To be more specific, the support beam  10  according to the first embodiment can render the distance t between the blade portion  8 W of the rotary vane wheel  8  and the heat exchanger larger while suppressing the noise component based on the BPF. Consequently, it is possible to render the discharge flow Q of the rotary vane wheel  8  larger while suppressing the noise component based on the BPF. Next, a description will be given as to a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment. 
       FIGS. 12A to 12C  are schematic diagrams showing a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment.  FIG. 13  shows a modified example of the support beam provided to the shroud of the propeller fan according to the first embodiment. It is possible to configure a center line Sa by combining two straight lines as with a support beam  10   a  shown in  FIG. 12A . It is also possible to configure a center line Sb by combining three straight lines as with a support beam  10   b  shown in  FIG. 12B . 
     It is also possible to render an upstream side edge  10   cti  in a sharp-edge shape rather than the arc as with a support beam  10   c  shown in  FIG. 12C . It is thereby possible to further reduce resistance of the air discharged by the rotary vane wheel  8 . Here, sharp-edge refers to the case where the upstream side edge  10   cti  is an arc, the radius of the arc being 0.5 mm or less. 
     Furthermore, it is also possible to form a groove  10   ds  on a downstream side  10   do  as with a support beam  10   d  shown in  FIG. 13 . It is thereby possible, for instance, to house electric wire for supplying power to the electric motor  6  in the groove  10   ds  so as to exploit the space effectively. It is possible, as a part of the support beam  10   d  is eliminated, to render the support beam  10   d  further lightweight. It is also possible to render the support beam as a hollow structure. It is also possible, in this case, to place the electric wire, signal line and the like in the hollow portion and render it further lightweight by providing the hollow portion. 
     As described above, the first embodiment and modified example thereof have the upstream side of the support beam inclined toward the direction opposite to the rotation direction of the rotary vane wheel, and so the air discharged by the rotary vane wheel flows smoothly along the upstream side of the support beams and the direction of the flow is gradually changed. The downstream side edge of the support beam is oriented toward the direction parallel to the rotation axis of the rotary vane wheel. It is thereby possible to rectify the circling components of the flow of the air discharged by the rotary vane wheel to reduce them so as to reduce the pressure interference between the rotary vane wheel and the support beams and prevent generation of the noise of discrete frequency components as a noise source. 
     The support beams become gradually thicker from the upstream side edge toward the downstream side edge, and the downstream side edge faces the direction parallel with the rotation axis of the rotary vane wheel. As the support beams have such a cross-section, it is possible to increase geometric moment of inertia of the support beams. It is possible to secure a sufficient cross section on the downstream side of the support beams. It is possible, by these actions, to secure sufficient strength in the rotation axis direction of the rotary vane wheel in particular. It is consequently possible, even in the case of limiting the dimension in the airflow direction, to reduce the noise and secure the strength of the support beams supporting the rotary vane wheel and rotary vane wheel driving means. It is thereby possible to reduce the number of the support beams and further reduce an aerodynamic drag and the noise. 
     Second Embodiment 
       FIGS. 14 to 16  are a front view ( FIG. 14 ), a rear view ( FIG. 15 ) and a side sectional view ( FIG. 16 ) showing the propeller fan according to a second embodiment of the present invention.  FIG. 17  is a front side perspective view showing the rotary vane wheel of the propeller fan described in  FIGS. 14 to 16 .  FIGS. 18 to 20  are an A to A sectional view ( FIG. 18 ) and plan views ( FIGS. 19 and 20 ) showing the blade portion of the rotary vane wheel described in  FIG. 17 .  FIGS. 21 to 24  are schematic diagrams showing the action of the propeller fan described in  FIGS. 14 to 16 . 
     This propeller fan  11  is placed in the downstream of the radiator for cooling the vehicle and the condenser for air conditioning and in proximity to the engine (not shown), and has a function of air-cooling the radiator and the condenser for air conditioning. The propeller fan  11  comprises a shroud  12 , a rotary vane wheel  13  and a motor  14  (refer to  FIGS. 14 to 16 ). 
     The shroud  12  is composed of a resin material, and includes a body portion  21 , a motor holding portion  22  and a rib portion  23  (refer to  FIG. 16 ). The body portion  21  is a frame-like member having an opening for introducing air at its center. The body portion  21  has the rotary vane wheel  13  and motor  14  accommodated therein. The motor holding portion  22  is a member for holding the motor  14 , and is placed at the center of the opening of the body portion  21  while supported by the rib portion  23 . The rotary vane wheel  13  is an axial fan having a hub portion  31  and a blade portion  32  composed of the resin material, and is configured by having multiple blade portions  32  annularly arranged on the hub portion  31  as a rotor (refer to  FIG. 14 ). The motor  14  is a power source for rotating the rotary vane wheel  13 . The motor  14  is coupled to the rotary vane wheel  13  on its output side (front side) and screwed and fixed on the motor holding portion  22  of the body portion  21  on its opposite output side (backside). 
     If the rotary vane wheel  13  is rotated by driving of the motor  14 , the propeller fan  11  has the air introduced from the front (the side of the radiator for cooling and condenser for air conditioning) to the opening of the body portion  21  to be sent backward. Thus, the radiator and condenser are cooled. 
     [Noise Reduction Structure of the Rotary Vane Wheel] 
     Here, as regards the propeller fan  11 , (1) flatness H/D F  of the rotary vane wheel  13  is H/D F ≦0.12 (refer to  FIGS. 16 and 17 ). The flatness H/D F  is defined by the ratio between an axial width H of the blade portion  32  and a diameter D F  at an end of the blade portion  32 . (2) A ratio D m /D F  between a diameter D m  of the hub portion  31  and the diameter D F  at the end of the blade portion  32  is D m /D F ≦0.50. To be more specific, annular channel area of cooling wind is defined by the ratio D m /D F . (3) A pitch chord ratio P/C of the blade portion  32  is 1.0≦P/C≦1.2. The pitch chord ratio P/C is defined by the ratio between a circumferential pitch P and a chord length C of the blade portion  32  on an arbitrary cylindrical section A to A (refer to  FIG. 18 ) in an annular radial dimension range in which a radius ratio (vane radius ratio) of the blade portion  32  is 10(%) to 95(%). (4) The outer circumferential side of the blade portion  32  is swept forward in the rotation direction of the rotary vane wheel  13  (forward swept vane). 
     In such a configuration, the diameter ratio D m /D F  between the hub portion  31  and the blade portion  32  and the pitch chord ratio P/C of the blade portion  32  are rendered appropriate on the rotary vane wheel  13  having a low degree of flatness H/D F  while the blade portion  32  is the forward swept vane so as to prevent the rotation of the rotary vane wheel  13  from stalling. Thus, the air blowing performance (aerodynamic performance) in the sound operational area is improved so that the operation of the rotary vane wheel  13  becomes stable. This has an advantage of improving the noise performance, air blowing performance and air blowing efficiency of the propeller fan  11 . 
     For instance, if the pitch chord ratio P/C of the blade portion  32  becomes smaller, a stall point pressure (pressure whereby a differential pressure hardly increases even if an air volume φ is reduced) of the rotary vane wheel  13  increases (refer to  FIG. 21 ). If the pitch chord ratio P/C is P/C&lt;1.0, however, the adjacent blade portion  32  overlaps so that molding and manufacturing of the rotary vane wheel  13  made of a resin become difficult (refer to  FIG. 22 ). 
     MODIFIED EXAMPLE 1 
     As for the propeller fan  11 , it is desirable that, when a straight line m is drawn from a point S at which a chord ratio c/C at a radial outer edge of the blade portion  32  is 50(%) to the rotation center of the rotary vane wheel  13 , the chord ratio c/C of an intersecting point T of the straight line m and a radial inner edge (the hub portion  31 ) of the blade portion  32  is in the range of 0.10≦c/C≦0.30 (refer to  FIG. 19 ). This renders a degree of forward sweeping of the rotary vane wheel  13  appropriate. Therefore, there is an advantage of further improving the noise performance, air blowing performance and air blowing efficiency of the propeller fan  11 . 
     The chord ratio c/C is the ratio of a distance c from an front edge (edge of an rotation advance side) of the blade portion  32  to the chord length C of the blade portion  32  in a cylindrical sectional view (refer to  FIG. 19 ) centering on the rotation center of the rotary vane wheel  13 . 
     MODIFIED EXAMPLE 2 
     As for the propeller fan  11 , it is desirable that a curve l on the blade portion  32  of which chord ratio c/C is 50(%) is an approximately arc of a radius R, and a ratio R/D F  between the radius R of the curve l and the diameter D F  of the rotary vane wheel  13  is in the range of 0.2≦R/D F ≦0.5 (refer to  FIG. 20 ). It is more desirable that the ratio R/D F  is 0.3≦R/D F ≦0.4 (R/D F ≈0.36). This renders the degree of forward sweeping of the rotary vane wheel  13  appropriate. Therefore, there is an advantage of further improving the noise performance, air blowing performance and air blowing efficiency of the propeller fan  11 . 
     For instance, if the degree of forward sweeping of the rotary vane wheel  13  is too low or too high, the noise performance (K PWL ) of the propeller fan  11  is degraded by the breakaway of the flow on a propeller vane plane (refer to  FIG. 23 ). 
     MODIFIED EXAMPLE 3 
     As for the propeller fan  11 , a curve l on the blade portion  32  of which chord ratio c/C is 50(%) is drawn first. Next, a circle is drawn, which has a radius r with a ratio r/D F  to the diameter D F  of the rotary vane wheel  13  at 0.35≦r/D F ≦0.5 and is centering on the rotation center of the rotary vane wheel (refer to  FIG. 20 ). An intersecting point of the circle and the curve l is an origin (blade portion center origin) O. A straight line passing through the origin O and the rotation center of the rotary vane wheel  13  is an axis Y. A straight line passing through the origin O and orthogonal to the axis Y is an axis X. 
     In this case, the curve l should desirably become an arc having its center on the axis X. To be more specific, the curve l is represented as (X+R) 2 +Y 2 =R 2  (R: radius of the curve l) in an X-Y coordinate system. This renders the degree of forward sweeping of the rotary vane wheel  13  appropriate. Therefore, there is an advantage of further improving the noise performance, air blowing performance and air blowing efficiency of the propeller fan  11 . 
     MODIFIED EXAMPLE 4 
     As for the propeller fan  11 , it is desirable that the number Z of the blade portions  32  formed on the rotary vane wheel  13  is 6 to 9. It is also desirable that the number Z of the blade portions  32  is an odd number (7 or 9). Such a configuration reduces the acoustic power of BPF noise in particular out of generated noise components. Thus, there is an advantage of further improving the noise performance of the propeller fan  11 . 
     As for the relation between the number Z of the blade portions  32  and the noise performance of the propeller fan  11 , the generated noise (K PWL ) is rendered less and the rotary vane wheel  13  is less likely to stall as a ratio C H /D F  between a chord length C H  of the blade portion  32  and the diameter D F  of the rotary vane wheel  13  becomes larger at the hub portion  31 , which is desirable (refer to  FIG. 24 ). It is also desirable that the generated noise (K PWL ) is rendered less as the pitch chord ratio P/C becomes smaller. If the pitch chord ratio P/C is less than a predetermined value (P/C&lt;1.0), however, the molding and manufacturing of the rotary vane wheel  13  become difficult. Therefore, the number Z of the blade portions  32  formed on the rotary vane wheel  13  is prescribed by considering these. 
     MODIFIED EXAMPLE 5 
     As for the propeller fan  11 , it is possible to adopt a configuration of having a plurality of the blade portions  32  placed on the rotary vane wheel  13  at uneven pitches P. In this case, it is desirable to have the pitch chord ratio P/C prescribed based on an average of the pitches P of the blade portions  32 . Such a configuration reduces the acoustic power of BPF noise in particular out of generated noise components by having the pitch chord ratio P/C appropriately prescribed. Thus, there is an advantage of further improving the noise performance of the propeller fan  11 . 
     Third Embodiment 
       FIG. 35  is a detail view of a G portion of  FIG. 28 . The acting face  136  and the negative pressure face  137  have guide fences  140  as wall portions provided thereon. The guide fences  140  include an inner circumferential guide fence  141  and an outer circumferential guide fence  142 . Of these, the inner circumferential guide fence  141  is provided in a part in proximity to the connecting portion  132  of the blade portion  131  and closer to the blade portion outer end portion  133  than the connecting portion  132  is to the blade portion outer end portion  133 . The outer circumferential guide fence  142  is provided in a part in proximity to the blade portion outer end portion  133  and closer to the connecting portion  132  than the blade portion outer end portion  133  is to the connecting portion  132 . Furthermore, the inner circumferential guide fences  141  are provided on both the surfaces of the acting face  136  and negative pressure face  137  while the outer circumferential guide fence  142  is provided only on the negative pressure face  137 . The guide fences  140  are in the shape along the circumferential direction centering on the rotation axis  125 , and are projecting from the surfaces of the blade portions  131 . To be more specific, each of the guide fences  140  is formed in the shape of a plate bending along the circumferential direction centering on the rotation axis  125  from the proximity of the front edge  134  to the rear edge  135 . As for height from the surfaces of the blade portions  131 , it becomes higher as directed from the front edge  134  to the rear edge  135 . 
     To describe them in detail, the hub  111  has a front edge  112  formed like an approximately circular disk, and also has a connection hole  120  axially penetrating the circle of the front edge  112  at the center of the circle which is the shape of the front edge  112 . The motor  150  rotatably supports the hub  111  by inserting a motor axis  151  as an axis rotating on driving the motor  150  into the connection hole  120  to connect it therewith. To be more specific, the rotary vane wheel  110  has a rotation axis  125  of the hub  111  as a central axis of the connection hole  120 , and is rotatably supported by the motor  150  by centering on the rotation axis  125 . The shroud  103  has multiple motor supporting portions  106  provided on one of both the edges in the axial direction of the cylinder portion  105 . All the multiple motor supporting portions  106  are formed inward in the radial direction of the cylinder portion  105  from the cylinder portion  105 . The motor  150  is fixed on the motor supporting portions  106  and thereby fixed on the shroud  103 . The motor  150  has an electric cord  152  for conveying electricity from a power supply (not shown) connected thereto, and the electric cord  152  further has a connector  153  for connecting to another electric cord  152  provided on the edge of the opposite side to the edge on the motor  150  side thereof. 
     The multiple blade portions  131  provided on the hub  111  of the rotary vane wheel  110  are formed outward from the radial direction centering on the rotation axis  125 . The cylinder portion  105  of the shroud  103  is formed with a radius slightly larger than the distance between an outer edge of the blade portions  131  of the rotary vane wheel  110  and the rotation axis  125 . And the rotary vane wheel  110  is provided inside the cylinder portion  105  in the orientation in which a cylindrical axis (not shown) as the shape of the cylinder portion  105  and the rotation axis  125  overlap. The channel forming surface  104  is connected to the edge of the opposite side to the edge having the motor supporting portions  106  provided thereon of both the edges in the axial direction of the cylinder portion  105 . As for the shape thereof, it is formed in a rectangular shape at the position apart from the cylinder portion  105  in the axial direction of the rotation axis  125  and in forms closer to circular as directed toward the cylinder portion  105 . 
     The rotary vane wheel  110  placed in the cylinder portion  105  of the shroud  103  is in the orientation in which the front edge  112  of the hub  111  is located on the channel forming surface  104  side and the motor  150  is located on the motor supporting portion  106  side. Furthermore, a heat shield plate  107  is provided at the position further apart from the channel forming surface  104  than the motor  150  in the direction opposite to the direction in which the channel forming surface  104  is formed, that is, the direction in which the motor supporting portions  106  are provided in the axial direction of the rotation axis  125 . The heat shield plate  107  is formed by a thin plate and fixed on the motor supporting portions  106 . 
       FIG. 28  is an external view of the rotary vane wheel viewed from the direction of  FIG. 25 .  FIG. 29  is a perspective view of the rotary vane wheel viewed from the front end side of the hub.  FIG. 30  is a perspective view of the rotary vane wheel viewed from the opposite direction to the rotary vane wheel of  FIG. 29 . The hub  111  of the rotary vane wheel  110  has an outer circumferential surface  113  provided over the entire circumference surrounding the front edge  112 . The outer circumferential surface  113  is provided in one direction in the axial direction of the rotation axis  125  from the front edge  112 . Of both the edges in the axial direction of the rotation axis  125  of the outer circumferential surface  113 , the edge of the front edge  112  side is an upstream side end portion  114  while the edge of the opposite side to the edge of the front edge  112  side is a downstream side end portion  115 . The multiple blade portions  131  are connected to the outer circumferential surface  113  by a connecting portion  132 . All the blade portions  131  are formed in the same shape. 
     As for the multiple blade portions  131  thus formed in the same shape, the outermost edge in the radial direction centering on the rotation axis  125  is provided as a blade portion outer end portion  133 . As directed from the connecting portion  132  to the blade portion outer end portion  133 , the width becomes larger in the circumferential direction of the rotation axis  125  or the circumferential direction of the circle which is the shape of the front edge  112 . Of both the edges of each of the blade portions  131  in the circumferential direction, one edge is a front edge  134  of the blade portion  131  while the other edge is a rear edge  135  of the blade portion  131 . Of these, the front edge  134  is bending to be convex in the direction of the rear edge  135  while the rear edge  135  is bending to be convex in the direction to be apart from the front edge  134 . Furthermore, the rear edge  135  is formed zigzag to be concavo-convex in the circumferential direction centering on the rotation axis  125 . 
     The blade portions  131  are formed in the shape of plates which is the above shape if viewed in the axial direction of the rotation axis  125 . And the blade portion  131  formed in the shape of a plate has two surfaces mutually oriented toward the opposite directions. Of the two surfaces, the surface positioned on the downstream side end portion  115  side of the hub  111  is an acting face  136 , and the surface positioned on the upstream side end portion  114  side and on the opposite side to the acting face  136  is a negative pressure face  137 . 
       FIG. 31  is a D to D sectional view of  FIG. 28 . Each of the blade portions  131  is inclined toward the circumferential direction centering on the rotation axis  125 . As for the direction of the inclination, the front edge  134  is positioned close to the upstream side end portion  114 , and the rear edge  135  is positioned close to the downstream side end portion  115 . For this reason, each of the blade portions  131  is inclined toward the circumferential direction to shift from the upstream side end portion  114  side to the downstream side end portion  115  side as directed from the front edge  134  to the rear edge  135 . Thus, the acting face  136  faces another blade portion  131  on the front edge  134  side while the negative pressure face  137  faces another blade portion  131  on the rear edge  135  side. 
     The outer circumferential surface  113  of the hub  111  has an inclined portion  116  and a parallel portion  117 . Of these, the parallel portion  117  is formed between the connecting portion  132  of the blade portion  131  and the downstream side end portion  115 . As for the end portion of the front edge  134  side of the blade portion  131  of the parallel portion  117 , the position in the circumferential direction centering on the rotation axis  125  is almost at the same position as the position of the front edge  134 . To be more specific, the end portion of the front edge  134  side of the parallel portion  117  is formed toward the direction of the downstream side end portion  115  from the front edge  134  along the axial direction of the rotation axis  125 . The rear edge  135  side of the blade portion  131  of the parallel portion  117  is formed from the rear edge  135  to the downstream side end portion  115  almost at the same angle as the angle of gradient of the connecting portion  132  of the blade portion  131  inclined toward the circumferential direction centering on the rotation axis  125 . To be more specific, the parallel portion  117  is formed in a shape of an approximately right triangle where the downstream side end portion  115  and the end portion of the front edge  134  side are orthogonal and a portion continuously formed from the front edge  134  to the downstream side end portion  115  through the rear edge  135  is a hypotenuse. The inclined portion  116  is formed around the parallel portion  117 . 
       FIG. 32  is an E to E sectional view of  FIG. 31 .  FIG. 33  is an F to F sectional view of  FIG. 31 . The inclined portion  116  as a part of the outer circumferential surface  113  of the hub  111  is inclined toward the rotation axis  125  in the direction to be apart from the rotation axis  125  as directed from the upstream side end portion  114  to the downstream side end portion  115 . To be more specific, the inclined portion  116  is in the shape of a part of a cone. The parallel portion  117  is formed from the connecting portion  132  as a part connecting the blade portion  131  with the outer circumferential surface  113  of the hub  111  to the downstream side end portion  115  so as to be a plane formed along the rotation axis  125 . The parallel portion  117  is located more inward in the radial direction of the rotation axis  125  than an extended inclined portion  126  which is a virtual extended portion of the inclined portion  116  continued from the inclined portion  116 . To be more specific, the extended inclined portion  126  is a virtual portion in the case of having the inclined portion  116  provided in the part where the parallel portion  117  is provided. The parallel portion  117  is formed more inward in the radial direction of the rotation axis  125  than the extended inclined portion  126  which is the virtual inclined portion  116 . 
     The parallel portion  117  is formed further on the downstream side end portion  115  side than the connecting portion  132  of the blade portion  131 , that is, on the acting face  136  side. And the inclined portion  116  is formed further on the upstream side end portion  114  side than the connecting portion  132  so that the inclined portion  116  is formed on the negative pressure face  137  side. For this reason, the shape of the connecting portion  132  on the acting face  136  side is the shape along the parallel portion  117 , and its shape on the negative pressure face  137  side is the shape along the inclined portion  116 . Here, the blade portion  131  is inclined from the upstream side end portion  114  side toward the downstream side end portion  115  side as directed from the front edge  134  to the rear edge  135 . And the inclined portion  116  is inclined toward the rotation axis  125  in the direction to be apart from the rotation axis  125  as directed from the upstream side end portion  114  toward the direction of the downstream side end portion  115 . Furthermore, the shape of the negative pressure face  137  side is the shape along the inclined portion  116 , and so the connecting portion  132  is apart from the rotation axis  125  as directed from the front edge  134  to the rear edge  135 . For this reason, the length of the negative pressure face  137  in the radial direction centering on the rotation axis  125  becomes shorter as directed from the front edge  134  to the rear edge  135 . 
       FIG. 34  is a C to C arrow view of  FIG. 26 , which is a relevant part detail view of the rotary vane wheel. As for the parallel portion  117 , the end portion of the side having the front edge  134  located thereon of the blade portion  131  and the inclined portion  116  adjacent thereto further in the circumferential direction centering on the rotation axis  125  than the end portion are at different positions in the radial direction centering on the rotation axis  125 , where there is a step between the parallel portion  117  and the inclined portion  116  in this part. For this reason, the parallel portion  117  and the inclined portion  116  in this part are connected by a step portion  118  formed along the radial direction of the rotation axis  125 . As for the parallel portion  117 , at the position of the downstream side end portion  115 , the end portion other than that of the step portion  118  in the circumferential direction is almost at the same position in the radial direction centering on the rotation axis  125  as the position of the inclined portion  116  in the radial direction. The step portion  118  connects this end portion with the adjacent parallel portion  117 . For this reason, at the position of the downstream side end portion  115 , the parallel portion  117  has the end portion of the step portion  118  side positioned innermost in the radial direction. It is positioned more outward from the radial direction as directed apart from the step portion  118 , and is connected to the adjacent parallel portion  117  by another step portion  118  at the position most distant from the step portion  118 . Thus, each of the parallel portions  117  is connected to the adjacent parallel portion  117  by the step portion  118  so that the shape of the outer circumferential surface  113  is the shape like a ratchet gear when viewing the downstream side end portion  115  in the axial direction of the rotation axis  125 . The hub  111  thus formed in the shape like a ratchet gear has a fixed radial thickness. Inside the hub  111 , there are multiple ribs  119  shaped like plates provided. 
       FIG. 35  is a detail view of a G portion of  FIG. 28 . The acting face  136  and the negative pressure face  137  have guide fences  140  as wall portions provided thereon. The guide fences  140  include an inner circumferential guide fence  141  and an outer circumferential guide fence  142 . Of these, the inner circumferential guide fence  141  is provided in a part in proximity to the connecting portion  132  of the blade portion  131  and closer to the blade portion outer end portion  133  than the connecting portion  132 . The outer circumferential guide fence  142  is provided in a part in proximity to the blade portion outer end portion  133  and closer to the connecting portion  132  than the blade portion outer end portion  133 . Furthermore, the inner circumferential guide fences  141  are provided on both the surfaces of the acting face  136  and negative pressure face  137  while the outer circumferential guide fence  142  is provided only on the negative pressure face  137 . The guide fences  140  are in the shape along the circumferential direction centering on the rotation axis  125 , and are projecting from the surfaces of the blade portions  131 . To be more specific, each of the guide fences  140  is formed in the shape of a plate bending along the circumferential direction centering on the rotation axis  125  from the proximity of the front edge  134  to the rear edge  135 . As for height from the surfaces of the blade portions  131 , it becomes higher as directed from the front edge  134  to the rear edge  135 . 
     The inner circumferential guide fences  141  are provided on both the acting face  136  and negative pressure face  137 , where the inner circumferential guide fences  141  of both the faces are almost at the same position in the radial direction centering on the rotation axis  125 . If a distance J from the connecting portion  132  of the blade portion  131  to the blade portion outer end portion  133  in the radial direction centering on the rotation axis  125  is 100%, both the inner circumferential guide fence  141  on the acting face  136  side and inner circumferential guide fence  141  on the negative pressure face  137  side should desirably be provided at the positions where a distance K from the connecting portion  132  to the outward in the radial direction is in the range of 5 to 45%. 
     Next, a manufacturing method of the rotary vane wheel  110  will be described. The rotary vane wheel  110  is shaped by the resin, and so it is formed by injection molding or the like. To be more specific, it is formed by pouring a liquid resin into a mold (not shown) having space in the shape of the rotary vane wheel  110 , filling the space with the resin and hardening the resin. This mold consists of a mold for forming the portion of the upstream side end portion  114  side in the axial direction of the rotation axis  125  and a mold for forming the portion of the downstream side end portion  115 . The negative pressure face  137  side of the blade portion  131  and the inclined portion  116  of the hub  111  are formed by the mold for the upstream side end portion  114  side, and the acting face  136  side of the blade portion  131  and the parallel portion  117  of the hub  111  are formed by the mold for the downstream side end portion  115  side. When manufacturing the rotary vane wheel  110 , these molds are combined, the resin is poured into the space in the shape of the rotary vane wheel  110  shaped in these molds, and these molds are removed in the axial direction if the resin gets hardened. Thus, the rotary vane wheel  110  can be taken out of the molds so as to have the rotary vane wheel  110  formed in the above-mentioned shape. 
     The propeller fan  101  according to the third embodiment has the above configuration. Hereunder, the actions thereof will be described. The connector  153  of the electric cord  152  connected to the motor  150  provided on the propeller fan  101  is connected to another electric cord  152  connected to the power supply so as to electrically connect the motor  150  to the power supply. And if electricity is sent to the motor  150 , the motor axis  151  of the motor  150  rotates. If the motor axis  151  rotates, the hub  111  of the rotary vane wheel  110  having the connection hole  120  connected to the motor axis  151  rotates centering on the rotation axis  125 . Thus, the entire rotary vane wheel  110  rotates centering on the rotation axis  125 . As for the rotation direction thereof, each of the blade portions  131  of the rotary vane wheel  110  rotates in the direction toward the front edge  134  of the blade portion  131 . To be more specific, the rotary vane wheel  110  rotates in the direction where the front edge  134  is located in a traveling direction of each of the blade portions  131 . 
     If the rotary vane wheel  110  is rotated in this direction, the air hits the acting face  136  side because the blade portion  131  is inclined in such a way that the acting face  136  side faces another blade portion  131  on the front edge  134  side. Each of the blade portions  131  is inclined toward the circumferential direction to shift from the upstream side end portion  114  side to the downstream side end portion  115  side of the hub  111  as directed from the front edge  134  to the rear edge  135 . Therefore, if the air hits the acting face  136  side, the air flows in the direction of the downstream side end portion  115  side of the hub  111 . To be more specific, as the rotary vane wheel  110  rotates, the air flows from the front edge  134  side to the rear edge  135  side along the acting face  136  on the acting face  136  side. The air flows to the direction from the upstream side end portion  114  side to the downstream side end portion  115  side in addition to flowing from the front edge  134  side to the rear edge  135  side. If the rotary vane wheel  110  rotates, the air continuously flows as above. Therefore, on operation of the propeller fan  101 , the air flows along the axial direction of the rotation axis  125  from the channel forming surface  104  side of the shroud  103  toward the direction in which the motor supporting portions  106  are provided. 
     As described above, the acting face  136  side of the blade portion  131  is hit by the air so that air pressure becomes high. As opposed to the acting face  136  side where air pressure becomes high, the negative pressure face  137  side has the air pressure thereon reduced because the air is pushed away by the blade portions  131  when the blade portions  131  moves in conjunction with the rotation of the rotary vane wheel  110 . To be more specific, as the rotary vane wheel  110  rotates, the air flows along the negative pressure face  137  side from the front edge  134  side to the rear edge  135  side on the negative pressure face  137  side. As the negative pressure face  137  is a gently convex portion in the flow direction, a flow rate for going round the convex portion becomes faster so that the air pressure on the negative pressure face  137  side becomes lower than the air pressure on the acting face  136  side. To be more specific, the air on the negative pressure face  137  side becomes a negative pressure to the air on the acting face  136  side. 
     Therefore, in the case where the rotary vane wheel  110  rotates at high speed and the blade portions  131  move at high speed, it is possible to let more air flow toward the direction along the rotation axis  125  from the direction of the channel forming surface  104  to the direction of the motor supporting portions  106 . In this case, however, the air pressure on the acting face  136  side becomes higher, and the air pressure on the negative pressure face  137  side becomes lower. Here, the hub  111  having the blade portions  131  connected thereto has the inclined portion  116 . The air flowing along the rotation axis  125  from the upstream side end portion  114  toward the direction of the downstream side end portion  115  also flows along the inclined portion  116 . However, the inclined portion  116  is inclined toward the direction to be apart from the rotation axis  125  as directed from the upstream side end portion  114  to the downstream side end portion  115 . For this reason, the width of the channel of the air around the hub  111  becomes narrower as directed from the upstream side to the downstream side of the airflow. To be more specific, the channel of the air is a contracted flow channel which becomes narrower as directed from the upstream side to the downstream side. 
     As for the connecting portion  132  of the blade portion  131 , the shape of the negative pressure face  137  side is the shape along the inclined portion  116 . Furthermore, on the negative pressure face  137 , channel intervals in the radial direction centering on the rotation axis  125  become narrower as directed from the front edge  134  to the rear edge  135 . For this reason, the air flowing along the negative pressure face  137  has its air pressure increased while remaining attached to a vane surface as directed from the front edge  134  to the rear edge  135  so that the breakaway due to excessively lowered air pressure is prevented. 
     In comparison, the parallel portions  117  are formed on the acting face  136  side of the connecting portion  132  of the blade portion  131 . The parallel portions  117  are located more inward in the radial direction than the extended inclined portion  126 . The connecting portion  132  on the acting face  136  side is in the shape along the parallel portions  117 . Therefore, the connecting portion  132  on the acting face  136  side is located more inward in the radial direction than the connecting portion  132  on the negative pressure face  137  side, and the area of the acting face  136  is larger by just that much. For this reason, it is possible to receive a larger amount of air on the acting face  136  so as to let it flow from the upstream side end portion  114  side to the downstream side end portion  115  side. 
     When letting the air flow from the front edge  134  to the rear edge  135  along the negative pressure face  137 , the air flowing around the rear edge  135  which is formed zigzag gets disturbed a little due to the zigzag shape. To be more specific, an eddy of the air generated on the rear edge  135  is further rendered finer. 
     The air thus flowing along the acting face  136  and the negative pressure face  137  is rectified by the inner circumferential guide fences  141  and outer circumferential guide fences  142  formed on the surfaces thereof. To be more specific, for instance, the air flowing between the inner circumferential guide fence  141  and the connecting portion  132  keeps flowing between them from the front edge  134  to the rear edge  135 . 
     The above propeller fan  101  has the hub  111  formed in an approximately conical shape, that is, basically as a cone, in which many portions other than the parallel portions  117  are the inclined portion  116 . It is thereby possible, when letting the air flow from the upstream side end portion  114  toward the direction of the downstream side end portion  115 , to form the contracted flow channel so as to prevent the air pressure from becoming too low on the negative pressure face  137  on rotation of the rotary vane wheel  110 . Therefore, even in the case where the air flows at low pressure from the front edge  134  to the rear edge  135  of the negative pressure face  137 , it is possible to prevent the air from breaking away due to the low pressure and also prevent the air blowing efficiency from being reduced due to occurrence of the breakaway or the noise from being generated on occurrence of the breakaway. As the parallel portion  117  is located more inward in the radial direction of the rotation axis  125  than the extended inclined portion  126 , the area of the acting face  136  which is the surface of the blade portion  131  on the parallel portion  117  side is larger. Therefore, it is possible to increase the amount of air flowing on the blade portion  131 . Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise. 
     As the rear edge  135  of the blade portion  131  is zigzag, the eddy of the air generated on the rear edge  135  is further rendered finer so as to prevent the air from breaking away significantly. Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise more securely. 
     As the guide fences  140  as the wall portions are provided on the surfaces of the blade portions  131 , it is possible to rectify the air flowing on the surface of the blade portions  131  so as to let the air flow efficiently. The outer circumferential surface  113  is shaped by the inclined portion  116  and parallel portions  117 , and so the air flowing along the outer circumferential surface  113  is apt to be disturbed. Even in the case where the airflow is disturbed, however, the disturbance of the air is blocked by the guide fences  140 . To be more specific, even in the case where the disturbance of the air occurs on the outer circumferential surface  113  and this air reaches the surface of the blade portion  131  from around the connecting portion  132  of the blade portion  131  connected to the outer circumferential surface  113 , the air having its flow disturbed can only flow between the guide fences  140  and the connecting portion  132  on the surface of the blade portion  131 . Furthermore, as the parallel portions  117  are formed on the acting face  136  side of the blade portion  131 , the air flowing along the outer circumferential surface  113  of the hub  111  is apt to be disturbed on the acting face  136  side of the blade portion  131 . The guide fences  140  are also provided on the acting face  136  side of the blade portion  131 . It is thereby possible to prevent the disturbed air from flowing in a wide range on the acting face  136  where the disturbed air is apt to flow. Therefore, it is possible to more securely prevent a problem such as the breakaway of the air from occurring on the entire acting face  136  where such a problem is apt to occur due to the flow of the disturbed air. Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise more securely. 
     As the guide fences  140  are provided on the surfaces of both the acting face  136  and the negative pressure face  137 , it is possible to more securely rectify the air flowing on the surface of the blade portions  131  so as to let the air flow efficiently. There are the cases where, as the air pressure on the acting face  136  side is higher than that on the negative pressure face  137  side of the blade portion  131 , the air on the acting face  136  side flows into the negative pressure face  137  side from the rear edge  135  of the blade portion  131 . Even in this case, it is possible, as the guide fences  140  are provided on the surface of the negative pressure face  137 , to keep the air flown in from the acting face  136  side within the range where the guide fences  140  are provided so as to prevent a disturbed flow of this air. Consequently, it is possible to improve the air blowing performance and efficiency more securely. 
     In the case where the air flows into the negative pressure face  137  side from the acting face  136  side, it often flows in from the rear edge  135  side so that disturbance of the air often occurs from the rear edge  135  side. However, the guide fences  140  become higher from the surface as directed from the front edge  134  to the rear edge  135 . It is thereby possible, even in the case where the disturbance of the air occurs around the rear edge  135 , to keep the disturbance more securely within the range where the guide fences  140  are provided so as to prevent the disturbance of the air more securely from influencing the entire blade portion  131  and causing the problem such as the breakaway of the air to the entire blade portion  131 . Consequently, it is possible to improve the air blowing performance and efficiency more securely. 
     In the case where the distance J from the connecting portion  132  of the blade portion  131  to the blade portion outer end portion  133  in the radial direction centering on the rotation axis  125  is 100%, it is possible to provide the inner circumferential guide fences  141  to the position where the distance K from the connecting portion  132  to the outward in the radial direction is in the range of 5 to 45% so as to prevent the disturbance of the air around the connecting portion  132  from influencing the entire surface of the blade portion  131 . To be more specific, it is possible to set the distance K from the connecting portion  132  to the inner circumferential guide fences  141  in the radial direction to 5% or more of the distance J from the connecting portion  132  to the blade portion outer end portion  133  so as to keep the disturbance of the air in the portion closer to the connecting portion  132  from the inner circumferential guide fences  141  more securely in the case where the air gets disturbed around the connecting portion  132 . It is thereby possible to prevent the disturbance of the air having occurred around the connecting portion  132  from influencing the entire surface of the blade portion  131 . 
     It is also possible to set the distance K from the connecting portion  132  to the inner circumferential guide fences  141  in the radial direction to 45% or less of the distance J from the connecting portion  132  to the blade portion outer end portion  133  so as to prevent the disturbance of the air from reaching the portion close to the blade portion outer end portion  133  in the case where the air gets disturbed around the connecting portion  132 . It is thereby possible to prevent the range influenced by the disturbance of the air from becoming too wide and also prevent the air blowing efficiency from being reduced on the entire rotary vane wheel  110  as in the case where the range influenced by the disturbance of the air is too wide. Thus, it is possible to prevent the disturbance of the air having occurred around the connecting portion  132  from influencing the entire surface of the blade portion  131  and causing the problem such as the breakaway of the air to the entire blade portion  131 . In particular, it is possible to set the range influenced by the disturbance of the air only to the portion close to the connecting portion  132 . As for the blade portion  131  of the rotary vane wheel  110 , the circumferential velocity is faster in the portion close to the blade portion outer end portion  133  than in the portion close to the connecting portion  132  and so air blowing action is more significant in the portion close to the blade portion outer end portion  133 . However, it is possible to blow air in the portion close to the blade portion outer end portion  133  more securely by setting the range influenced by the disturbance of the air only to the portion close to the connecting portion  132 . Consequently, it is possible to improve the air blowing performance and efficiency more securely. 
     The hub  111  of the rotary vane wheel  110  is formed basically as the cone of which diameter is larger on the downstream side end portion  115  than on the upstream side end portion  114 . The parallel portion  117  parallel with the rotation axis  125  is formed from the connecting portion  132  of the blade portion  131  to the downstream side end portion  115  of the hub  111 . It is thereby possible to eliminate an undercut part such as the part from the blade portion  131  to the downstream side end portion  115  in the case where the hub  111  is formed basically as the cone. To be more specific, in the case of forming the hub  111  basically as the cone and providing the blade portions  131  to the hub  111  as an integrated body and in the case of manufacturing it by resin molding, it is not possible, of the molds for shaping the rotary vane wheel  110 , to remove the mold for shaping the part from the blade portions  131  to the downstream side end portion  115  in the axial direction of the rotation axis  125  after shaping the rotary vane wheel  110  because the diameter on the blade portion  131  side is smaller than that of the downstream side end portion  115 . As opposed to this, the rotary vane wheel  110  has the parallel portion  117  parallel with the rotation axis  125  formed from the blade portion  131  to the downstream side end portion  115 . Therefore, it is possible, after pouring the resin into the mold and having the resin hardened, to remove the mold in the direction of the rotation axis  125  easily and pull out the shaped rotary vane wheel  110  easily. Consequently, it is possible to manufacture the above-mentioned rotary vane wheel  110  with the resin easily so as to reduce cost of manufacturing. 
     Furthermore, the hub  111  has the fixed radial thickness. Therefore, even in the case of manufacturing the rotary vane wheel  110  by resin molding, it is possible to change the dimension on hardening the resin at a fixed ratio. Thus, a strain on hardening the resin is reduced so that accuracy can be more easily achieved. Consequently, it is possible to improve the accuracy of the rotary vane wheel  110 . 
     As the above propeller fan  101  is provided with the above-mentioned rotary vane wheel  110 , the propeller fan  101  can have the above-mentioned effects by having the rotary vane wheel  110  rotated by the motor  150  as the driving means. Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise so as to obtain the propeller fan  101  of high quality. 
     As mentioned above, when the air discharged by the rotary vane wheel passes the support beams, the shroud of the propeller fan has a flow of the air discharged by the rotary vane wheel changed to the direction of the rotation axis of the rotary vane wheel by the support beams. To be more specific, the support beams rectify it to reduce circling components of the flow of the air discharged by the rotary vane wheel. As the upstream side of the support beams is inclined toward the direction opposite to the rotation direction of the rotary vane wheel, the air discharged by the rotary vane wheel flows smoothly along the upstream side of the support beams and the direction of the flow is gradually changed. It is possible, by these actions, to reduce pressure interference between the rotary vane wheel and the support beams so as to prevent generation of the noise of discrete frequency components as a noise source. 
     The support beams become gradually thicker from the edge of the upstream side toward the edge of the downstream side, and the edge of the downstream side faces the direction parallel with the rotation axis of the rotary vane wheel. As the support beams have such a cross-section, it is possible to increase geometric moment of inertia of the support beams. It is possible to secure a sufficient cross section on the downstream side of the support beams. It is possible, by these actions, to secure sufficient strength of the rotary vane wheel in the rotation axis direction of the rotary vane wheel in particular. It is consequently possible to reduce the noise and secure the strength of the support beams supporting the rotary vane wheel and rotary vane wheel driving means even in the case of limiting the dimension in the airflow direction. 
     Furthermore, the support beams provided to the shroud of the propeller fan have increased inclination on the upstream side of the support beams for the plane including the rotation axis of the rotary vane wheel from the mount side toward the body portion of the shroud, that is, toward outside of a longitudinal direction of the support beams. It is thereby possible to reduce the pressure interference between the rotary vane wheel and the support beams all over the longitudinal direction of the support beams so as to prevent generation of the noise of the discrete frequency components more effectively. 
     The propeller fan has the diameter ratio D m /D F  between the hub portion and the blade portion and a pitch chord ratio P/C of the blade portion rendered appropriate on the rotary vane wheel having a low degree of flatness H/D F  while the blade portion is a forward swept vane so as to prevent the flow on a propeller plane of the rotary vane wheel from breaking away. Thus, air blowing performance (aerodynamic performance) in a sound operational area is improved so that operation of the rotary vane wheel becomes stable. This has an advantage of improving noise performance of the propeller fan. 
     The propeller fan has a chord ratio c/C of the intersecting point T of the straight line m and the radial inner edge of the blade portion (hub portion) rendered appropriate when the straight line m is drawn from the point S at which the chord ratio c/C at the radial outer edge of the blade portion is 50(%) to the rotation center of the rotary vane wheel so as to render a degree of forward sweeping of the rotary vane wheel appropriate. Therefore, there is an advantage of further improving the noise performance of the propeller fan. 
     The propeller fan has the curve l on the blade portion of which chord ratio c/C is 50(%) as the approximate arc of a radius R, where the ratio R/D F  (degree of forward sweeping) between the radius R of the curve l and the diameter D F  of a rotary vane wheel  3  is rendered appropriate. Therefore, there is an advantage of further improving the noise performance of the propeller fan. 
     The propeller fan has the curve l as the arc having its center on the axis X, and so the degree of forward sweeping of the rotary vane wheel  3  is rendered appropriate. Therefore, there is an advantage of further improving the noise performance of the propeller fan. 
     The propeller fan has the number Z of the blade portions formed on the rotary vane wheel rendered appropriate, and so acoustic power of BPF noise is reduced in particular out of the generated noise components. Thus, there is an advantage of further improving the noise performance of the propeller fan. 
     The propeller fan has the pitch chord ratio P/C prescribed properly, and so the acoustic power of the BPF noise is reduced in particular out of the generated noise. Thus, there is an advantage of further improving the noise performance of the propeller fan. 
     The propeller fan has the diameter ratio D H /D F  between the hub portion and the blade portion and the pitch chord ratio P/C of the blade portion rendered appropriate on the rotary vane wheel having a low degree of flatness H/D F  while the blade portion is the forward swept vane so as to prevent the flow on the propeller plane of the rotary vane wheel from breaking away. Thus, air blowing performance (aerodynamic performance) in a sound operational area is improved so that operation of the rotary vane wheel becomes stable. This has an advantage of improving the noise performance, air blowing performance and air blowing efficiency of the propeller fan. 
     As for the rotary vane wheel of this invention, the outer circumferential surface of the hub has the inclined portion inclined against the rotation axis of the hub in a direction to be further away from the rotation axis as directed from the upstream side edge to the downstream side edge and the parallel portion formed along the rotation axis, where the parallel portion is formed in the area from the connecting portion to the downstream side edge. To be more specific, the hub is formed in an approximately conical shape, and has the parallel portion formed only in the area from the connecting portion to the downstream side edge. It is thereby possible, when rotating the rotary vane wheel centering on the rotation axis and letting the air flow from the upstream side edge to the downstream side edge, to render width of the channel narrower as directed from the upstream side of the airflow to the downstream side. To be more specific, it is possible to form a contracted flow channel as directed from the upstream side to the downstream side so as to prevent a pressure of a negative pressure portion on the surface of the blade portion from becoming too low on rotation of the rotary vane wheel. Therefore, it is possible to prevent the air from breaking away in the negative pressure portion and also prevent the air blowing efficiency from being reduced due to breakaway or the noise from being generated on breakaway. As the parallel portion is positioned more inward in the radial direction of the rotation axis than the extended inclined portion which is the virtual extended portion of the inclined portion, it is possible to increase the area of the blade portion on the parallel portion side. It is thereby possible to increase the air volume flowing in the blade portion. Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise. 
     As for the rotary vane wheel, it is possible, as its rear edge is formed zigzag, to disturb the airflow slightly around the rear edge so as to prevent the air from significantly breaking away. Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise more securely. 
     The rotary vane wheel has the wall portion provided on the surface of the blade portion, and so it is possible to rectify the air flowing on the surface of the blade portion so as to let the air flow efficiently. Consequently, it is possible to improve the air blowing performance and efficiency more securely. 
     The rotary vane wheel has the wall portion provided on the surfaces of both the acting face and negative pressure face, and so it is possible to rectify the air flowing on the surface of the blade portion more securely so as to let the air flow efficiently. Consequently, it is possible to improve the air blowing performance and efficiency more securely. 
     The rotary vane wheel can prevent disturbance of the air around the connecting portion from exerting influence on the entire surface of the blade portion by providing the wall portion in the range. To be more specific, in the case where the distance from the connecting portion to the direction of the blade portion outer edge of the wall portion is smaller than 5% of the distance from the connecting portion to the blade portion outer edge, it is difficult to bring the disturbance of the air around the connecting portion within a portion closer to the connecting portion than the wall portion. Therefore, there is a possibility that the disturbance of the air around the connecting portion may reach the portion closer to the blade portion outer edge than the wall portion. In the case where the distance from the connecting portion to the direction of the blade portion outer edge of the wall portion is larger than 45% of the distance from the connecting portion to the blade portion outer edge, the range over which the disturbance of the air around the connecting portion exerts influence is so wide that the air blowing efficiency of the entire rotary vane wheel may be reduced and the air blowing performance may be reduced. Thus, it is possible to prevent the disturbance of the air around the connecting portion from exerting influence on the entire surface of the blade portion by setting the distance from the connecting portion to the direction of the blade portion outer edge of the wall portion within 5 to 45% of the distance from the connecting portion to the blade portion outer edge. Consequently, it is possible to improve the air blowing performance and efficiency more securely. 
     The propeller fan has the rotary vane wheel provided thereto, and so the propeller fan can have the above-mentioned effects by having the rotary vane wheel rotated by the driving means. Consequently, it is possible to improve the air blowing performance and efficiency and reduce the noise. 
     The above-mentioned rotary vane wheel has the effects of improving the air blowing performance and efficiency and reducing the noise. The above-mentioned propeller fan has the effects of improving the air blowing performance and efficiency and reducing the noise. 
     The embodiments of the present invention are as described above. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.