JP2010216361A - Axial fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that in a conventional axial fan, as air separates from a pressure surface to flow downstream and not along blades at the inner peripheral part of the fan, energy is hardly transmitted from the blades, and when the air does not flow along blade surfaces, blown-out flow is easily directed in the revolving direction of the fan, so that air flow is disturbed by a crosspiece and a rib of a protective grille installed at downstream of the fan and noise becomes large. <P>SOLUTION: The axial fan 101 includes a plurality of blades on the circumferential face of a hub 1 mounted on a rotary shaft, and blows air in the axial direction through the rotation of the rotary shaft. In the axial fan 101, the main blade 5 and an auxiliary blade 6 are disposed at positions shifted from each other in the axial direction. The auxiliary blade 6 is disposed further on the axial downstream side than the main blade 5 and covers the rear edge 52 of the main blade 5. The fan diameter of the auxiliary blade 6 is smaller than that of the main blade 5. In the axial fan 101, the air flow on the inner peripheral side is made to flow along the main blade 5, activating energy transmission, and noise occurring in a fan grille can be reduced by directing the blown-out air flow in the axial direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an axial fan and an outdoor unit of an air conditioner using the same.

  FIG. 13 is a configuration diagram of a conventional axial fan. A plurality of blades 2 are attached around a boss 1 (sometimes referred to as a hub), and a shaft attached to the boss 1 rotates to generate wind in the blowing direction 3. A blower using an axial fan is often provided with a fan grill or a protection net composed of a plurality of crosspieces and ribs 4 on the blowout side so as not to injure hands and the like with rotating blades.

  In order to realize energy saving (lower input) of the blower, it is necessary to increase the efficiency of the blower. If a lot of energy is given while the air flows between the blades, the efficiency of the fan can be improved. In an example of a conventional axial fan, an auxiliary wing is sandwiched between main wings to prevent an increase in the angle of attack of the wing, thereby suppressing separation (Patent Document 1), and a plurality of sets of wings. Is provided at a position shifted in the axial direction and is provided at a predetermined angle in the rotational direction, and high efficiency can be expected with a multistage blade row (Patent Document 2).

JP-A-8-177772 JP-A-5-248395

  In order to increase the efficiency of an axial fan used for a blower or an air conditioner, it is necessary that air flows along the blade surface (pressure surface) and receives a large amount of energy transfer from the blade. At the outer periphery of a conventional fan, air flows along the blade surface, so that energy is easily transferred from the blade to the air. However, in the inner periphery of the fan, air hardly follows the blades, and the air immediately leaves the pressure surface and flows downstream, so that energy is not easily transmitted from the blades. Also, if the air does not flow along the blade surface, the blowout flow tends to turn in the direction of rotation of the fan, and there is a risk that the airflow will be disturbed by the bars and ribs of the protective grill (fan grill) installed downstream of the fan, resulting in increased noise. is there.

  As described in Patent Document 1, when an auxiliary wing is provided between main wings, the effect of suppressing the flow to the pressure surface is obtained at the trailing edge of the main wing. The energy transfer from the wing to the air and the control of the direction of the blowout airflow are insufficient. In addition, since the space between the main wings on the inner peripheral side is closed with auxiliary wings, there is a risk of a reduction in air volume.

  In the arrangement of the main wing and the small wing as disclosed in Patent Document 2, there is nothing that presses the air flowing through the inner peripheral portion of the pressure surface against the surface, and thus a great effect cannot be expected. Moreover, since it becomes the structure which closes between the blade | wings of an inner peripheral side, there exists a possibility of an air volume fall.

  An object of the present invention is to provide an axial fan that is energy efficient and low in noise.

The axial fan of this invention is
In an axial fan that is attached to a rotating shaft and blows gas in the axial direction of the rotating shaft by rotation of the rotating shaft,
A hub attached to the rotating shaft;
A plurality of main wings installed in the hub;
The main wings of the plurality of main wings are provided with the same number of auxiliary wings as the main wings installed on the hub in a one-to-one correspondence,
The auxiliary wing is
The rear edge of the auxiliary wing is located at a position shifted to the downstream side in the axial direction from the corresponding main wing and projected onto a plane having the rotation axis as a normal along with the corresponding main wing. It overlaps with the trailing edge of the main wing or is positioned in the reverse rotation direction with respect to the trailing edge of the main wing, and the fan diameter of the auxiliary wing is smaller than the fan diameter of the main wing.

  According to the present invention, the air entering the pressure surface of the inner peripheral portion of the blade (smaller fan diameter side) flows in the space surrounded by the main wing and the auxiliary wing, and does not leave the pressure surface. As a result, since the energy transmission becomes active on the inner peripheral side of the main wing, the efficiency of the inner peripheral wing is improved. In addition, since the flow follows the blades, the blow-out flow can easily be directed in the axial direction of the rotating shaft, so that the airflow smoothly passes between the crosspieces of the fan grill, and noise generation can be suppressed.

FIG. 3 shows an axial fan 101 according to the first embodiment. FIG. 3 is a flowchart around a blade of a conventional axial fan for comparison with the axial fan 101 of the first embodiment. Explanatory drawing of the blowing flow direction of the conventional fan demonstrated in Embodiment 1. FIG. FIG. 3 is a flowchart around a blade of an axial fan 101 according to the first embodiment. FIG. 6 shows an axial fan 102 according to the second embodiment. FIG. 10 is a velocity vector diagram of the axial fan 102 according to the second embodiment. FIG. 10 shows a projection of a line 19 of an axial fan 103 in the third embodiment. FIG. 10 is a diagram illustrating a forward tilt angle of a blade of an axial fan 103 according to the third embodiment. FIG. 9 is a flowchart of a blade outer peripheral portion of an axial fan 103 according to the third embodiment. FIG. 10 shows an axial fan 104 in the fourth embodiment. FIG. 10 shows an axial fan 105 according to the fifth embodiment. FIG. 10 shows an axial fan 106 according to the sixth embodiment. The figure which shows the conventional axial fan.

Embodiment 1 FIG.
The axial fan 101 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view (a), a front view (b), and a side view (c) between blades of an axial fan 101 according to the first embodiment (a cross section when a blade is cut by a cylindrical side surface having a predetermined radius). Show). In order to make the figure easy to understand, one wing (one main wing 5 and one auxiliary wing 6 corresponding to the main wing 5) is shown. A main wing 5 and an auxiliary wing 6 are attached to a peripheral surface of a boss 1 (also referred to as a hub) to which a rotating shaft is attached. As shown in a front view (b), the auxiliary wing 6 is more than the main wing 5 when viewed from the front. The fan diameter of the auxiliary wing 6 is small and covers the trailing edge 52 of the main wing 5 in the fan diameter range of the auxiliary wing 6. That is, in the range 50, the trailing edge 62 of the auxiliary wing 6 covers the trailing edge 52 of the main wing 5. Further, when viewed from the front view (b), the auxiliary wings 6 are disposed inside the main wings 5 and do not block the space of other main wings adjacent to the main wings 5. Looking at the side view (c), the auxiliary wing 6 is installed on the downstream side of the main wing 5, and the space 8 between the main wing 5 and the auxiliary wing 6 has a substantially constant width.

  That is, as shown in FIG. 1, the axial fan 101 is attached to a rotating shaft (not shown), and gas is blown out in the blowing direction 3 that is the direction of the fan rotating shaft 14 by the rotation of the rotating shaft. The axial fan 101 is installed in the hub 1 in a one-to-one correspondence with each wing of the boss 1 (hub) attached to the rotating shaft, the plurality of main wings 5 installed in the hub, and the plurality of main wings 5. The same number of auxiliary wings 6 as the main wings are provided. In FIG. 1, the auxiliary wing 6 corresponds to the main wing 5. As shown in the perspective view (a), the side view (c), etc., the auxiliary blade 6 is installed at a position shifted from the main blade 5 toward the downstream side in the direction of the fan rotation shaft 14. In addition, as shown in the front view (a), when the auxiliary wing 6 is projected on a plane with the main wing 5 and the fan rotation shaft 14 as a normal line, the trailing edge 62 of the auxiliary wing 6 is located behind the main wing 5. The shape overlaps with the edge 52 or is positioned in the reverse rotation direction (the direction opposite to the rotation direction 31: the counterclockwise direction in the front view) with respect to the rear edge 52 of the main wing 5. Further, as shown in the front view (b) of FIG. 1, the auxiliary wing 6 is smaller than the smallest fan diameter of the main wing 5 even at the largest fan diameter of the auxiliary wing 6. That is, in the front view (b) of FIG. 1, the auxiliary wing 6 has an outer periphery (a peripheral portion of the auxiliary wing 6 excluding the front edge 61 and the rear edge 62 of the auxiliary wing 6). Of the main wing 5 excluding the leading edge 51 and the trailing edge 52).

  Next, the operation will be described with reference to FIGS.

(Conventional flow 1)
FIG. 2 is a perspective view (a) and a side view (b) schematically showing the results of observing the air flow around the blades 2 of a conventional propeller fan by numerical analysis. The airflow 9 on the fan outer peripheral side flows along the blade surface from the leading edge 201 to the trailing edge 202, and energy is supplied from the blade 2 to the airflow 9 during that time. However, as shown in the side view (b), the air flow 10 on the fan inner peripheral side leaves downstream before reaching the trailing edge 202. As used herein, the inner peripheral side and the outer peripheral side refer to, for example, the front fan (radius R2) having the larger fan radius in FIG. 1B as the outer peripheral side, and the smaller fan radius (radius R1). Called the side. Due to this separation, the air passing through the inner peripheral side is not sufficiently supplied with energy from the blades 2, and the efficiency of the fan is poor. In addition, the outer peripheral airflow 9 and the inner peripheral airflow 10 illustrate the relative flows observed from the blade 2.

(Conventional flow 2)
Next, the blow-out flow direction of the fan will be considered with reference to FIG. The blowout flow velocity vector 11 (absolute velocity vector) is represented by a vector synthesized from the relative velocity vector 12 and the peripheral velocity vector 13 of the blade. The fan rotation direction is a hatched arrow 32 (meaning a vector indicating the speed direction indicated on the fan rotation shaft 14). In this case, as shown in FIG. 3A, in the case of the flow along the blade 2 (relative velocity vector 12 a), the blowing flow direction 11 a faces the direction of the fan rotation shaft 14. On the other hand, as shown in FIG. 3B, in the case of a flow separating from the blades 2 (relative velocity vector 12b), the blowing flow direction 11b is directed to the turning direction of the fan. That is, as shown in FIG. 3B, in the case of the flow separating from the blade 2 (relative velocity vector 12b), the “angle θ” is smaller than in the case of FIG. Since the flow on the inner peripheral side of the conventional fan is as shown in FIG. 3B, the blowout flow velocity vector 11 tends to face the rotation direction vector 32. When the swirl component becomes strong, there is a problem that the air current colliding with the fan grille and ribs 4 installed in the downstream of the fan by a blower or the like is disturbed to generate vortex and increase noise.

(Flow in axial fan 101)
FIG. 4 is a schematic diagram (a perspective view (a) and a side view (b)) of the flow around the blades of the axial fan 101 according to the first embodiment. Since the flow 10 on the fan inner peripheral side enters between the main wing 5 and the auxiliary wing 6, as shown in the side view (b), the air flow does not detach from the main wing surface to the downstream side. Therefore, energy is actively supplied from the blade surface to the airflow. Further, since the blowout relative velocity vector 12 on the inner peripheral side is along the main wing 5, the direction of the blowout flow velocity vector 11 approaches the direction of the fan rotation shaft 14. For this reason, the airflow is less likely to be disturbed when passing through a fan grille bar placed on the downstream side of the axial fan 101, and noise is reduced. Although the airflow 15 flowing on the pressure surface of the auxiliary blade 6 is easily separated from the blade surface, the loss is small because the blade length is short. Even if the same measures as the main blade 5 are applied to the auxiliary blade 6, the entire fan The effect obtained is small.

  As described above, in the first embodiment, in the axial fan in which a plurality of blades are provided on the peripheral surface of the hub 1 attached to the rotating shaft and the air is blown in the axial direction by the rotation, the main blade 5 and the auxiliary blade 6 are axially arranged. The auxiliary wing 6 is located downstream of the main wing 5 in the axial direction and covers the trailing edge 52 of the main wing 5, and the fan diameter of the auxiliary wing 6 is smaller than the fan diameter of the main wing 5. The axial flow fan 101 is described. By using this axial flow fan 101, it is possible to improve the fan efficiency by increasing the energy given to the airflow by the blades and to direct the blown flow toward the fan rotation axis, thereby reducing the noise generated in the fan grille. it can. Further, since the auxiliary wing 6 does not block the wing between the main wing 5 and another main wing adjacent to the main wing 5, it is difficult for the air volume to decrease.

Embodiment 2. FIG.
Next, the axial fan 102 according to the second embodiment will be described with reference to FIG. FIG. 5 shows a perspective view (a) and a blade cross-sectional view (b) of the axial fan 102 according to the second embodiment.

  This will be described with reference to the blade cross-sectional view (b). In the blade cross-sectional view (b), the inter-blade width is defined by the diameter 16 of a circle that fits between two-dimensional blade cross sections having the same radius. That is, FIG. 5B shows a cross section of the main wing 5 and the auxiliary wing 6 in the cross section when the main wing 5 and the auxiliary wing 6 are cut at the side surface of the virtual cylinder 33 with the fan rotation shaft 14 as the central axis. The space becomes narrower toward the trailing edge of the main wing 5. Thus, the axial fan 102 has a smaller diameter (this circle is a circle drawn on the side surface of the virtual cylinder) as it goes toward the rear edge of the main wing 5 (diameter 16a> diameter 16b). That is, the distance between the wings becomes narrower toward the rear edge of the main wing 5.

  As described with reference to FIG. 2B, the airflow on the pressure surface on the inner peripheral side is more easily separated from the rear edge, so that the space between the main wing 5 and the auxiliary wing 6 becomes narrower toward the rear edge 52 of the main wing 5. By doing so, the effect of pressing the airflow against the pressure surface is increased, and more energy from the blades can be transmitted to the air. Further, the blowing relative velocity vector 12 is increased by gradually narrowing the distance between the blades. Then, since the velocity vector relationship (relative velocity vector 12 becomes longer) as shown in FIG. 6, the blowout flow velocity vector 11 becomes easier to face in the axial direction (the angle θ becomes larger). As a result, the effect that the disturbance of the fan grille does not occur becomes stronger, and the noise can be further reduced.

Embodiment 3 FIG.
Next, the axial flow fan 103 according to the third embodiment will be described with reference to FIGS. The axial fan 103 is an embodiment relating to the forward tilt angle of the main wing 5 and the auxiliary wing 6.

First, a description will be given with reference to FIG. FIG. 7A is a front view.
Determine the forward tilt angle of the wing as follows.
(1) First, one point 34 constituting the line 17 in FIG. 7A is the next point. When a three-dimensional shaped blade (assuming no thickness) is cut at the side surface of the virtual cylinder 35 having a radius R with the fan rotation axis 14 as the central axis, an intersection line connecting the leading edge and the trailing edge on the cylinder side surface Can do. The point 34 is a central point on the intersection line (a point on the intersection line where distances from both ends are equal when going from the both ends of the intersection line to the point). Each point constituting the line 17 is a center (center position) obtained for each virtual cylinder having a different radius R. The line 17 is a line formed by connecting these points (the center line of the chord line). The forward tilt angle of the wing is expressed by an angle 21 formed by the line 19 in FIG. 7B, which is obtained by rotating and projecting the line 17 onto the cylindrical section 18, and the horizontal plane 20. The following (2) will be described in detail.
(2) The forward tilt angle of the wing is expressed by an angle 21 formed by a horizontal plane 20 and a line 19 in FIG. Here, the cylindrical cross section 18 shown in FIG. 7 (a) is a plane extending in the direction of the fan rotation shaft 14 when viewed in the front view (a), and means the cylindrical cross section 18 shown in FIG. 7 (c). ing. “The line 17 is rotationally projected onto the cylindrical section 18” means that the line 17 in the front view (a) of FIG. 7 has a three-dimensional shape (that is, the depth is in the normal direction of the front view (a)). Yes, it means that the line 17 projected onto the cylindrical cross section 18 is the line 19 when the fan on which the line 17 is formed is rotated while fixing the cylindrical cross section 18 which is a plane.

FIG. 8 shows the forward tilt angle of the blades of the axial fan 103 according to the third embodiment (however, in order to make it easy to understand, the blade outline is abbreviated and described only with the projected lines). The axial fan 103 is characterized in that the angle 21 (forward tilt angle) formed by the projection line and the horizontal line is different between the main wing 5 and the auxiliary wing 6. Earlier inclination theta ₆ aileron 6, is characterized in that is smaller than the forward inclination theta ₅ wing 5. This means that the larger the fan radius, the wider the space between the main wing 5 and the auxiliary wing 6 at the radial position. In other words, the smaller the fan radius (the inner peripheral side), the narrower the distance between the main wing 5 and the auxiliary wing 6 at that radial position. Thus, since the flow is more easily separated from the main wing 5 toward the inner peripheral side of the fan, the efficiency is improved and the blowing direction is controlled by narrowing the space between the wings and suppressing the flow.

  On the other hand, since the leakage vortex 22 generated from the outer peripheral edge of the auxiliary wing 6 interferes with the flow on the main wing 5 as shown in FIG. Aims to spread. As a result, it is possible to improve fan efficiency and reduce noise by blowing air direction control while preventing adverse effects due to the installation of the auxiliary blade fan.

Embodiment 4 FIG.
Next, the axial fan 104 according to the fourth embodiment will be described with reference to FIG. FIG. 10 shows a perspective view (a) and a front view (b) of the axial flow fan 104. As shown in the front view (b), in the axial fan 104, the front edge 61 of the auxiliary wing 6 has a front edge 51 and a rear edge 52 of the same diameter of the main wing 5 as the fan radius increases, as viewed from the front view. It is characterized in that it is relatively closer to the rear edge side with respect to the circumferential section 24 connecting the two. In other words, when viewed from the front view (b), the leading edge 61 of the auxiliary wing 6 is located closer to the trailing edge 52 of the main wing 5 than the leading edge 51 of the main wing 5, and the leading edge 61 of the auxiliary wing 6 The leading edge 51 of the main wing 5 is separated from each other along the outer periphery of the fan. In other words, when the auxiliary wing 6 is projected onto a plane having the fan rotation axis 14 as a normal line together with the main wing 5, the larger the fan radius, the more the fan wing 6 is located on the circumference of the circle of the fan radius. The distance between the front edge 61 of the auxiliary wing 6 and the front edge 51 of the main wing 5 is large.

  The above feature is an example in which the auxiliary wing 6 covers only the place where the main wing pressure surface is easily separated from the wing. Since the flow on the inner peripheral side tends to separate from the pressure surface earlier, the auxiliary wing 6 is installed from the leading edge of the main wing to improve the fan efficiency and the air flow direction. On the other hand, the auxiliary wing 6 is installed from the vicinity of the rear edge because it is difficult to separate to the vicinity of the rear edge at the outer peripheral portion.

  According to this shape, since the weight of the auxiliary wing 6 is reduced as compared with the third embodiment, an increase in torque applied to the wing can be suppressed. As a result, the fan efficiency can be further improved.

Embodiment 5 FIG.
Next, the axial fan 105 of the embodiment will be described with reference to FIG. FIG. 11 shows a perspective view (a) and a front view (b) of the axial flow fan 105. In the axial fan 105, the auxiliary blade 6 is on the downstream side of the main blade 5 as shown in the perspective view (a). When viewed from the front view (b), the fan diameter 25 of the auxiliary wing 6 becomes longer toward the rear edge side of the main wing 5. This is in consideration of the fact that the airflow flowing on the blade pressure surface tends to separate toward the trailing edge and the inner peripheral side. In other words, when the auxiliary wing 6 is projected on a plane with the main wing 5 and the fan rotation axis 14 as a normal line, the fan diameter of the auxiliary wing 6 increases from the front edge side to the rear edge side of the main wing 5. .

  Since the flow follows the blade surface at the front edge portion of the main wing 5 at the fan diameter intermediate position, the auxiliary wing 6 does not cover the main wing 5. The main wing 5 is covered with the auxiliary wing 6 from the vicinity of the trailing edge where the flow is easily separated. On the other hand, on the inner peripheral side, the airflow is peeled off immediately after passing through the leading edge, and therefore, the auxiliary wing 6 covers the entire main wing so as to be attached to the wing.

  According to the shape of the axial fan 105, the weight of the auxiliary blade 6 can be reduced, so that the torque applied to the blade can be reduced and the fan efficiency can be further increased.

Embodiment 6 FIG.
Next, the axial fan 106 according to the sixth embodiment will be described with reference to FIG.
FIG. 12A shows a perspective view.
FIG. 12B shows a front view.
FIG. 12C shows a blade cross section cut along a cylindrical side surface of a cylinder having a fan rotation axis as a central axis.

  In the axial fans of the first to fifth embodiments, as shown in the front view (b) of FIG. 1, the shapes of the trailing edges of the main wing 5 and the auxiliary wing 6 are substantially the same as seen from the axial direction. (Overlapping). On the other hand, in the axial fan 106, when viewed from the front view, the rear edge 62 of the auxiliary blade 6 protrudes beyond the rear edge 52 of the main wing 5 to the reverse rotation side and covers the rear edge 52 of the main wing 5. (A range 36 indicated by a broken line). In other words, the configuration of the axial flow fan 106 is such that when the auxiliary blade 6 is projected on a plane having the fan rotation axis as a normal line together with the main blade 5, the auxiliary blade 6 has the trailing edge 62 of the main blade 5. The rear edge region including the rear edge 62 of the auxiliary wing 6 is located in the reverse rotation direction with respect to the rear edge 52 and covers the rear edge region including the rear edge 52 of the main wing 5.

  The configuration of the axial fan 106 is effective when it is desired to earn a work amount up to the trailing edge of the main wing 5.

  The trailing edge end has the highest blade pressure, so if the airflow can follow the wing to this position, the airflow can receive more energy, but the problem is that the flow is easily separated. . Therefore, the aim is to increase the amount of energy absorbed by extending the auxiliary wing 6 downstream from the rear edge end of the main wing 5 so that the airflow is stuck to the main wing end. The length of extending the auxiliary wing 6 is set to be within 1/3 of the circumferential section 27 between the adjacent main wings so as not to completely block between the main wings so as not to cause a decrease in the air volume. As a result, a more efficient fan can be realized. Further, since the flow follows the blade, the blowout flow tends to be in the axial direction, and noise at the fan grill can be reduced.

  1 boss, 2 wings, 3 blowing direction, 4 ribs, 5 main wings, 6 auxiliary wings, 8 between the wings of the main wing and auxiliary wings, 9 air current on the fan outer peripheral side, 10 air current on the inner peripheral side of the fan, 11 blowout flow velocity vector, 12 Relative velocity vector, 13 Wing peripheral speed vector, 14 Fan rotation axis, 15 Airflow flowing through the pressure surface of the auxiliary wing, 16 diameter, 17 chord line centerline, 18 cylindrical cross section, 19 cylindrical projection Line, 20 horizontal plane, 21 forward tilt angle, 22 leakage vortex, 24 circumferential section connecting the leading edge to the trailing edge of the main wing, 25 fan diameter of the auxiliary wing, 26 area protruding from the trailing edge to the reverse rotation side, 27 circle between the main wings Circumference section, 31 rotation direction, 32 rotation direction vector, 33 virtual cylinder, 34 points, 35 virtual cylinder, 50 range, 51 leading edge, 52 trailing edge, 61 leading edge, 62 trailing edge, 101, 102, 103, 10 4,105,106 Axial fan.

Claims (7)

In an axial fan that is attached to a rotating shaft and blows gas in the axial direction of the rotating shaft by rotation of the rotating shaft,
A hub attached to the rotating shaft;
A plurality of main wings installed in the hub;
The main wings of the plurality of main wings are provided with the same number of auxiliary wings as the main wings installed on the hub in a one-to-one correspondence,
The auxiliary wing is
Installed at a position shifted to the downstream side in the axial direction from the corresponding main wing,
When projected onto a plane having the rotation axis as a normal along with the corresponding main wing, the trailing edge of the auxiliary wing overlaps with the trailing edge of the main wing, or in the reverse rotation direction from the trailing edge of the main wing. Position to,
An axial fan, wherein the fan diameter of the auxiliary wing is smaller than the fan diameter of the main wing. The main wing and the auxiliary wing corresponding to the main wing are:
2. The axial fan according to claim 1, wherein a distance between the blades becomes narrower toward a trailing edge of the main wing. Each said aileron is
3. An axial fan according to claim 1, wherein a forward tilt angle is smaller than a forward tilt angle of the corresponding main wing. Each said aileron is
When projected onto a plane with the rotation axis as a normal along with the corresponding main wing,
The axial fan according to any one of claims 1 to 3, wherein the larger the fan radius, the larger the distance between the front edge of the auxiliary wing and the corresponding front edge of the main wing. Each said aileron is
5. When projected onto a plane having the rotation axis as a normal along with the corresponding main wing, the fan diameter increases from the front edge side to the rear edge side of the corresponding main wing. The described axial flow fan. In an axial fan that is attached to a rotating shaft and blows gas in the axial direction of the rotating shaft by rotation of the rotating shaft,
A hub attached to the rotating shaft;
A plurality of main wings installed on the outer peripheral surface of the hub;
The pressure surfaces of the main wings corresponding to the airflow flowing on the inner peripheral side of the main wings corresponding to the main wings of the plurality of main wings, which are installed on the hub in a one-to-one correspondence. An axial fan comprising the same number of auxiliary blades as the plurality of main wings pressed against the axial wing.   The outdoor unit for air conditioners provided with the axial fan in any one of Claims 1-6.

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