JP2014066135A - Propeller fan and air conditioner with propeller fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propeller fan capable of reducing a tendency that a flow near a pressure surface at a blade rear edge part is displaced toward an outer peripheral side, inducing the flow strongly toward an inner peripheral side and substantially improving blow power.SOLUTION: A blade 10 is provided with a concavity 6 that is thick-walled at a radial central part near a rear edge 3 of the blade toward a suction surface 5 side, opened at least at a pressure surface 4 side and extending from the rear edge 3 to a front edge 2 of the blade 10, the concavity 6 has a pair of side face parts 61 raised up to form a prescribed angle in respect to the suction surface 5 as viewed from a radial section and a span width between the pair of side face parts 61 is set to be gradually increased from its upstream side to its downstream side.

Description

  The present invention relates to a blade structure of a propeller fan used in, for example, an air conditioner.

  For example, when a propeller fan 100A having a general blade 10A that is formed in a smooth curved shape as shown in FIG. 1 and has no protrusions or recesses is rotated, the pressure of the rotating blade is rotated. The flow in the vicinity of the surface 4A has a distribution biased toward the outer peripheral side at the blade outlet (blade trailing edge 3A side) due to centrifugal force as shown in FIG. And since such a flow non-uniformity occurs, the flow tends to become unstable near the cylindrical hub 11A in the center of the fan, and there is a problem of reducing the blowing efficiency.

  With respect to such a problem, in Patent Document 1, as shown in FIG. 2, a shape 6B in which the vicinity of the blade trailing edge 3B of the propeller fan 100B bulges in an arc shape with the blade leading edge 2B side projecting toward the suction surface 5B side. Thus, it has been proposed to make the flow easier to flow out from the bulging portion 6B and to make the distribution of the flow in the radial direction uniform.

  However, as shown in Patent Document 1, when the blade trailing edge 3B portion is bulged, the angle of the blade warping line having the same radial cross section becomes loose in the rotation direction in the middle of the chord direction. Accordingly, there is a large portion of the blade trailing edge 3B where the flow is not pushed by the blade, and the blowing force is reduced. Further, since the blade trailing edge 3B portion has a shape 6B bulged in an arc shape, the flow flowing into this portion smoothly flows in a direction orthogonal to the substantially arc shape, so the flow direction is drawn from the outside to the inside. The attractive force is small, and an effect that greatly improves the blowing efficiency cannot be obtained.

JP 2006-37800 A

  Therefore, the present invention has been made in view of the above-described problems, and reduces the tendency that the flow near the pressure surface is biased toward the outer peripheral side at the blade trailing edge, and strongly attracts the flow toward the inner peripheral side. An object of the present invention is to provide a propeller fan that can significantly improve the blowing power.

That is, the propeller fan of the present invention is a propeller fan including a plurality of blades attached to the outer peripheral surface of a cylindrical hub at predetermined intervals in the circumferential direction,
The blade is raised to the suction surface side in the radial center near the trailing edge, and is open at least to the pressure surface side, and includes a recess extending from the trailing edge of the blade to the leading edge side,
The concave portion has a pair of side portions that stand up at a predetermined angle with respect to the suction surface when viewed in a radial direction and are opposed to each other.
The spanwise width between the pair of side surfaces is configured to gradually increase from the upstream side to the downstream side.

  If it is such, since the said recessed part stands at a predetermined angle with respect to a suction surface and has a pair of side part which mutually opposes, a curvature changes a lot between a suction surface and a recessed part. Therefore, the force that the flow near the pressure surface is attracted to the concave portion can be increased.

  Further, since the span direction width between the pair of side surface portions is configured to gradually increase from the upstream side to the downstream side, the extending direction of each side surface portion and the state immediately before being attracted to the recess portion are configured. The angle formed by the flow along the pressure surface can be increased, and since the flow is intended to enter perpendicularly to the side surface portion, the flow direction on the outer peripheral side can be changed more greatly.

  Accordingly, the flow in the vicinity of the pressure surface is easily attracted to the concave portion, and the direction of the flow can be greatly changed from the outer peripheral side to the inner peripheral side. In particular, it is possible to prevent the flow on the inner peripheral side from becoming unstable and generate noise, vibration, and the like, and to improve the blowing efficiency.

To form the concave portion at a position where a centrifugal flow that tends to be biased toward the outer peripheral side on the pressure surface due to the centrifugal force generated by the rotation of the propeller fan is generated, so that the uneven flow can be effectively suppressed. Centering on the fan rotation axis, the outer diameter of the blade is R _t , the inner diameter is R _h , the radius to the end of the side surface on the inner diameter side at the trailing edge of the blade is R _i , and the outer diameter side at the trailing edge of the blade When it is assumed that the radius R _o to the end of a certain side surface portion is R _i = R _h + α (R _t −R _h ) and R _o = R _h + β (R _t −R _h ), 0.2 ≦ α It suffices if they are set in the ranges satisfying ≦ 0.6 and 0.6 ≦ β ≦ 0.9.

The airflow flowing along the pressure surface into the recess provided in the wings easily flows into the recess, and the vortex pairs formed along the side surfaces are substantially uniform so that the blowing efficiency can be improved. In the recess, when the inclination angle of the side surface portion on the inner diameter side with respect to the fan rotation axis is θ _i and the inclination angle of the side surface portion on the outer diameter side with respect to the fan rotation axis is θ _o , 5 ° ≦ θ _i ≦ 60 °, 5 ° ≦ θ _o ≦ 60 °, and θ _i ≧ θ _o may be satisfied.

The inflow into the recess provided on the wing is smooth from the upstream side to the downstream end, and the exit angle of the wing of the recess is substantially the same as the exit angle of the adjacent portion other than the recess so that the flow is uniform in the radial direction. to improve the air blowing efficiency, when the leading edge side end portion of the recess as viewed in the circumferential direction section at radius position, relative to the chord length L _0, the leading edge side end portion of the recess from the trailing edge until the length _{L 1} may be set at 10% to 60% of _{L 0.}

  In order to improve the ventilation efficiency by forming an appropriate level difference between the concave portion and the adjacent portion of the pressure surface, thereby making it possible to suppress the centrifugal flow by ensuring the inflow of airflow into the concave portion, the front edge side end portion of the concave portion is When viewing a circumferential cross section at a positioned radius, the depth d of the recess toward the suction surface side gradually increases from the upstream side to the downstream side, and the depth d in the vicinity of the blade trailing edge is a predetermined depth. It is only necessary to set a constant depth region that is substantially constant at dx.

  In order to improve the air blowing efficiency while preventing the strength reduction of the blade due to the formation of the recess, a bottom is formed and closed on the suction surface side of each side surface of the recess, and the bottom is a suction surface. What is necessary is just to form the substantially parallel curved surface.

  In order to further suppress the flow in the vicinity of the suction surface by generating a vertical vortex on the suction surface side of the blade due to the air flow taken into the recess, the recess can be further improved in blowing efficiency. It is sufficient that it is also open on the side, and is configured only by the pair of side surface portions. In such a case, since the air blowing effect due to the reduction in the blade area is slightly reduced, it is necessary to increase the number of rotations in order to ensure the same amount of air blowing, but the airflow flowing into the concave portion should be increased. The vertical vortex generated on the suction surface described above can improve the blowing efficiency.

  In order to reduce the disturbance and loss of the flow induced to the concave portion provided on the blade and further improve the air blowing efficiency, the side surfaces and the pressure surface are rounded and connected. Good.

  Even when the recess is open to both the pressure surface and the suction surface, the strength can be increased by preventing stress concentration due to the centrifugal force at the upstream end of the recess, and the blade is less likely to be damaged. It is sufficient that the vicinity of the upstream end on the suction surface side is rounded and connected in each side surface portion.

  Even when the concave portion provided in the blade is open on the suction side, the stress concentration due to the centrifugal force at the upstream end can be further alleviated, and in order to make it difficult to break, the concave portion is the pressure surface of each side portion. It suffices to have a solid filling portion between the upstream end portions on the side, and the filling portion may be configured to form the same curved surface as the adjacent pressure surface.

  If it is an air conditioning apparatus using the propeller fan of this invention, it will become possible to drive | operate an air conditioning apparatus efficiently by the improvement of ventilation capability.

  As described above, according to the propeller fan of the present invention, the recesses provided in the blades stand at a predetermined angle with respect to the suction surface when viewed in a radial cross section, and a pair of side surface portions facing each other. And the spanwise width between the pair of side surfaces gradually increases from the upstream side to the downstream side, so that the flow flowing in the vicinity of the pressure surface strongly resists the recess at the blade trailing edge. The flow that tends to be biased to the outer diameter side can be distributed almost evenly in the radial direction at the rear edge portion, and the blowing efficiency can be greatly improved.

The typical perspective view shown about the shape of the conventional propeller fan and the deviation of the flow in a blade trailing edge. The schematic diagram which shows the example which provided the bulging part in the blade trailing edge part in the conventional propeller fan. 1 is a schematic perspective view of a propeller fan according to a first embodiment of the present invention. It is an AA line sectional view of a 1st embodiment, and is a mimetic diagram showing a section of a chord length direction of a crevice. The schematic diagram at the time of seeing a negative pressure surface along the fan rotating shaft of 1st Embodiment. It is CC sectional view taken on the line of 1st Embodiment, Comprising: The schematic diagram which shows the radial direction cross section of a recessed part. The typical perspective view which shows the flow of the pressure surface vicinity of 1st Embodiment. The schematic diagram shown about the parameter for showing the position of the recessed part of 1st Embodiment. The schematic diagram shown about the inclination-angle of each side part of 1st Embodiment. The schematic diagram shown about the position which the recessed part of 1st Embodiment occupies in a wing | blade, and its depth. The graph which shows the relationship between the ratio which occupies for the chord length of the recessed part of 1st Embodiment, and the maximum efficiency ratio. The graph shown about the change tendency of the depth of the recessed part in 1st Embodiment. The typical perspective view of the propeller fan which concerns on 2nd Embodiment of this invention. It is a BB line sectional view of a 2nd embodiment, and is a mimetic diagram showing a section of a chord length direction of a crevice. The schematic diagram at the time of seeing a negative pressure surface along the fan rotating shaft of 2nd Embodiment. It is the DD sectional view taken on the line of 2nd Embodiment, Comprising: The schematic diagram which shows the radial direction cross section of a recessed part. It is a modification of 2nd Embodiment, Comprising: The schematic diagram which shows the radial direction cross section of a recessed part. It is a modification of 2nd Embodiment, Comprising: The schematic diagram which shows the cross section of the chord length direction of a recessed part. It is a modification of 2nd Embodiment, Comprising: The schematic diagram at the time of seeing a suction surface along a fan rotating shaft. The graph which compared the fan efficiency of the propeller fan of 1st Embodiment, 2nd Embodiment, and a prior art example.

  A first embodiment of the present invention will be described with reference to the drawings.

  The propeller fan 100 according to the first embodiment is used, for example, in an outdoor unit of an air conditioner, and includes a plurality of blades attached to the outer peripheral surface of a cylindrical hub 11 at predetermined intervals in the circumferential direction. 10 is provided radially. In each drawing, one of the blades 10 of the propeller fan 100 is shown as a representative.

  FIG. 3 is a schematic perspective view of the blade 10 of the propeller fan 100 according to the first embodiment as viewed from the suction surface 5 side, and FIG. 3 is a cross-sectional view in the chord length direction along the line AA in FIG. This will be described with reference to FIG.

  As shown in FIG. 3, the attachment portion of the blade 10 and the cylindrical hub 11 is attached from one end surface side of the hub 11 to the other end surface side so that a predetermined spiral is drawn on the side surface of the hub 11. The leading edge 2 of the wing 10 extends forward in the rotational direction. The blade 10 has a predetermined warp in the chord length direction as shown in FIG. 4 which is a cross-sectional view taken along line AA shown in FIG. A pressure surface 4 is used, and a convex surface of the blade 10 is a suction surface 5.

  As shown in FIGS. 3 and 4, the blade 10 swells toward the negative pressure surface 5 at the central portion on the trailing edge 3 side, and is formed with a concave portion 6 that is recessed on the pressure surface 4 side.

  In the following, the features relating to the shape and dimensions of the recess 6 will be described in detail with reference to FIGS.

  The recess 6 is a suction surface at the radial center near the trailing edge 3 as shown in FIG. 6 which is a cross-sectional view taken along the line CC of FIG. 5 when the suction surface 5 of the blade 10 is viewed along the rotation axis C. It swells on the 5 side and is formed to open on the pressure surface 4 side. As can be seen from FIG. 5, the concave portion 6 is formed in a generally square shape when viewed from the suction surface 5 or the pressure surface 4 along the direction in which the rotation axis C extends, from the blade leading edge 2 side to the trailing edge 3 side. It is spread and formed.

  Further, as apparent from the radial cross section of the blade 10 including the concave portion 6 in FIG. 6, when the radial cross section of the concave portion 6 is viewed, a substantially U-shape having a bottom 62 on the suction surface 5 side is formed. Yes. More specifically, the concave portion 6 has a pair of side surface portions 61 that stand up at a predetermined angle with respect to the negative pressure surface 5 and face each other when viewed in a radial section. A bottom portion 62 that is a curved surface having a generally rounded triangular shape is provided so as to close the suction surface 5 side of the side surface portion 61. In other words, as can be seen from the cross-sectional view of FIG. 6, when the radial cross section of the portion having the recess 6 is viewed, the curvature of the connecting portion between the pressure surface 4 or the suction surface 5 and the side surface portion 61 changes greatly. So that they are connected.

  Further, as can be seen from FIGS. 3 and 5, the spanwise width between the pair of side surfaces 61 gradually increases from the upstream side (front edge 2 side) to the downstream side (rear edge 3 side). It is formed so as to have a letter shape.

  Since the recess 6 having such a shape is formed at the center of the blade trailing edge, the flow in the vicinity of the pressure surface 4 indicated by the streamline in FIG. 7 is attracted to the recess 6 at the blade trailing edge. Become. Therefore, as can be seen from a comparison between FIG. 1 and FIG. 5, the airflow that is normally biased toward the outer diameter side can be made substantially uniform at the blade trailing edge, and the inner diameter side that is the connection side with the hub 11. In this case, almost no separation or turbulence in flow can be caused.

  Next, a description will be given of the position, size range, and the like of the recess 6 suitable for achieving such uniform airflow.

First, the arrangement of the recess 6 at the blade trailing edge will be described. As shown in FIG. 8, the concave portion 6 is formed by setting the outer diameter of the blade 10 to R _t , the inner diameter to R _h , and the end of the side surface portion 61 on the inner diameter side of the trailing edge 3 of the blade 10. R _{i is} a radius to the portion, and R _i is a radius R _o to the end of the side surface portion 61 on the outer diameter side of the trailing edge 3 of the blade 10, and R _i = R _h + α (R _t −R _h ), R _o = When R _h + β (R _t −R _h ), the ranges are set to 0.2 ≦ α ≦ 0.6 and 0.6 ≦ β ≦ 0.9.

Next, how the concave portion 6 swells, that is, how to stand up the side surfaces 61 and the suction surface 5 will be described with reference to FIG. As shown in FIG. 9, in the concave portion 6, the inclination angle of the side surface portion 61 on the inner diameter side with respect to the fan rotation axis C is θ _i , and the inclination angle of the side surface on the outer diameter side with respect to the fan rotation axis C is θ _o In addition, 5 ° ≦ θ _i ≦ 60 °, 5 ° ≦ θ _o ≦ 60 °, and θ _i ≧ θ _o are satisfied. In other words, when viewed from the pressure surface 4, the inclination on the outer diameter side changes abruptly, and the force that attracts the flow on the outer diameter side into the recess 6 is increased. is there. By doing in this way, the magnitude | size of a pair of vertical vortex respectively formed in the side part 61 by the side of an inner diameter and the side part 61 by the side of an outer diameter can also be equalized, and it becomes easier to improve ventilation efficiency.

Further, the size of the recess 6 in the blade chord length direction in the blade 10 and the depth of the recess 6 will be described. As shown in FIG. 10 which is a cross-sectional view taken along line AA in FIG. 3, when the circumferential cross section at the radius where the front edge 2 side end portion of the recess 6 is located is viewed, the chord length L _{0 is} The length L ₁ from the rear edge 3 to the front edge 2 side end portion of the recess 6 is set to 10% to 60% of L ₀ . More specifically, when gradually changing the ratio of the length _{L 1} of the recess 6 for the chord length _{L 0,} while _{L 1} is 10% to 60% of the _{L 0} as shown in the graph of FIG. 11 It can be seen that the maximum efficiency ratio takes the maximum value when set to. That is, L ₁ is more preferably set to 20% to 45% of L ₀ . More preferably, the value of the maximum efficiency ratio can be maximized by setting L ₁ to approximately 30% of L ₀ .

Further, regarding the depth d of the concave portion 6, the depth d of the concave portion 6 toward the negative pressure surface 5 side when the circumferential cross section at the radius where the front edge 2 side end portion of the concave portion 6 is located is viewed. A constant depth region is set in which the depth d in the vicinity of the blade trailing edge 3 becomes substantially constant at the predetermined depth dx while gradually increasing from the upstream side to the downstream side. The predetermined depth dx has been set to 2% to 10% of the chord length _{L 0.} More specifically, as shown in the graph of FIG. 12, the depth d of the concave portion 6 is rapidly changed in the vicinity of the upstream start point, and the rate of change is reduced at the blade trailing edge. It is like that.

  As described above, by setting the size of the recess 6 in the blade 10, it is possible to balance the original function of the blade 10 and the function related to correction of the centrifugal flow, and the air blowing efficiency can be preferably improved. Further, if the depth d of the recess 6 is set to the above-described value, the flow can be surely introduced by the step between the pressure surface 4 and the recess 6 in the vicinity. Therefore, the centrifugal flow can be suppressed and the air blowing efficiency can be improved.

  Next, a propeller fan 100 according to a second embodiment of the present invention will be described with reference to FIGS.

  In the second embodiment, as shown in FIG. 13, the concave portion 6 is opened not only on the pressure surface 4 side but also on the negative pressure surface 5 side, and the concave portion 6 is formed only by each side surface portion 61. This is different from the embodiment. In other words, in the first embodiment, the recess 6 has the bottom 62, but in the second embodiment, the opening 65 is formed in the shape of the bottom 62 cut out.

  Details of the shape of the wing 10 of the second embodiment will be described below.

  As shown in FIGS. 13 and 15, the bottom 62 of the recess 6 is cut into a substantially rounded triangular shape, and is a cross-sectional view taken along the line BB in FIG. 13 and a cross-sectional view taken along the line DD in FIG. As shown in FIG. 16, the recess 6 is composed of only two side portions 61 that stand up with respect to the suction surface 5.

  That is, as can be seen by comparing FIG. 4 of the first embodiment and FIG. 14 of the second embodiment, the depth of the upstream end of the recess 6 is the same, but the downstream thin plate portion in the recess 6 is It has been lost. As shown in FIG. 16, when the flow flowing in the vicinity of the pressure surface 4 is attracted to the recess 6, it flows along the side surface portion 61 and then flows out toward the suction surface 5, forming a vertical vortex on the suction surface 5. Will do. Since the vertical vortex formed on the suction surface 5 suppresses the separation of the flow in the vicinity of the suction surface 5, the blowing efficiency can be further improved.

  Further, in each of the side surfaces 61, the vicinity of the upstream end 64 on the suction surface 5 side is rounded and the radius of curvature is set to 1 to 5 times the blade 10 thickness. By doing in this way, the stress concentration by a centrifugal force can be prevented at the upstream end of the opening part provided in the wing | blade 10, and it can make it hard to break. In other words, the blowing efficiency can be improved while preventing the strength of the blade 10 from being reduced by cutting off the bottom 62 of the recess 6.

  Next, a modification of the second embodiment will be described with reference to FIGS.

  As shown in FIG. 17, the side portions 61 and the pressure surface 4 may be rounded and connected. That is, the side surfaces 61 and the pressure surface 4 are not connected so as to form a ridge as shown in FIG. 16, but are rounded as shown in FIG. It is possible to reduce the loss and turbulence of the flow that flows along the negative pressure surface 5 and improve the blowing efficiency.

  Further, as shown in FIGS. 18 and 19, the concave portion 6 includes a buried portion 63 in which the space between the upstream end portions on the pressure surface 4 side of each side surface portion 61 is solid, and the buried portion 63 may be configured to form the same curved surface as the adjacent pressure surface 4. As can be seen from a comparison between FIG. 14 and FIG. 18, in FIG. 18, the solid portion of the front end portion of the recess 6 is made larger than that of FIG. By doing in this way, the stress concentration by centrifugal force can further be relieve | moderated in the upstream end of the opening part provided in the wing | blade 10, and it becomes easy to prevent a failure | damage.

  Finally, a comparison result of the blowing efficiency of the propeller fan 100 of the first embodiment, the propeller fan 100 of the second embodiment, and the propeller fan 100A of the conventional example is shown.

  As shown in the graph of FIG. 20, the propeller fan 100 according to the first embodiment and the second embodiment can make the blade 10 outlet flow substantially uniform due to the flow drawing effect by the recess 6. It can be seen that the ventilation efficiency is improved in comparison. In addition, when the bottom surface of the recess 6 is eliminated and a notched portion is formed in the blade 10 as in the second embodiment, the blowing efficiency can be improved most, and the blowing efficiency is 10% compared to the conventional example. It can be seen that the degree has been improved.

  Other embodiments will be described.

  In each of the above embodiments, the propeller fan used in the air conditioner is shown, but the propeller fan of the present invention may be used for other purposes. Whether to leave or remove the bottom surface of the recess may be determined as appropriate in consideration of, for example, the required air blowing efficiency and the required blade strength.

  Further, various combinations and modifications of the embodiments may be performed without departing from the spirit of the present invention.

100: Propeller fan 10: Wing 11: Hub 2: Front edge 3: Rear edge 4: Pressure surface 5: Negative pressure surface 6: Concave portion 61: Side surface portion 61: Each side surface portion 62: Bottom portion 63: Buried portion 64: Upstream end Near part 65: opening C: rotation axis

Claims (12)

A propeller fan comprising a plurality of blades attached at predetermined intervals in the circumferential direction to the outer peripheral surface of a cylindrical hub,
The blade is raised to the suction surface side in the radial center near the trailing edge, and is open at least to the pressure surface side, and includes a recess extending from the trailing edge of the blade to the leading edge side,
The concave portion has a pair of side portions that stand up at a predetermined angle with respect to the suction surface when viewed in a radial direction and are opposed to each other.
A propeller fan, characterized in that a spanwise width between the pair of side surfaces gradually increases from an upstream side to a downstream side. Centering on the fan rotation axis, the outer diameter of the blade is R _t , the inner diameter is R _h , the radius to the end of the side surface on the inner diameter side at the trailing edge of the blade is R _i , and the outer diameter side at the trailing edge of the blade When it is assumed that the radius R _o to the end of a certain side surface portion is R _i = R _h + α (R _t −R _h ) and R _o = R _h + β (R _t −R _h ), 0.2 ≦ α The propeller fan according to claim 1, wherein the propeller fan is set in a range satisfying ≦ 0.6 and 0.6 ≦ β ≦ 0.9. In the concave portion, when the inclination angle of the side surface portion on the inner diameter side with respect to the fan rotation axis is θ _i , and the inclination angle of the side surface on the outer diameter side with respect to the fan rotation shaft is θ _o , 5 ° ≦ θ _i ≦ 60 ° The propeller fan according to claim 1, wherein 5 ° ≦ θ _o ≦ 60 ° and θ _i ≧ θ _o are satisfied. When viewed in the circumferential direction cross-section at a radius leading edge side end portion of the recess is positioned, relative to the chord length L _0, from the rear edge to the front edge end portion of the recess length L ₁ L The propeller fan according to any one of claims 1 to 3, wherein the propeller fan is set to 10% to 60% of ₀ .   When the circumferential cross section at the radius where the front edge side end of the recess is located is viewed, the depth d of the recess toward the suction surface gradually increases from the upstream side to the downstream side, and in the vicinity of the blade trailing edge 5. The propeller fan according to claim 1, wherein a constant depth region is set in which the depth d is substantially constant at a predetermined depth dx. The propeller fan having a predetermined depth dx 2% have been set according to claim 5, wherein the 10% of the chord length L _0.   The propeller fan according to any one of claims 1 to 6, wherein a bottom portion is formed and closed on a suction surface side of each side surface portion of the recess, and the bottom portion forms a curved surface substantially parallel to the suction surface.   The propeller fan according to any one of claims 1 to 6, wherein the concave portion is also opened on the suction surface side and is configured only by the pair of side surface portions.   The propeller fan according to any one of claims 1 to 8, wherein each side surface portion and the pressure surface are connected in a rounded manner.   The propeller fan according to claim 8 or 9, wherein the vicinity of the upstream end of the opening of the recess is rounded and connected.   The concave portion includes a filling portion in which a space between the upstream end portions on the pressure surface side of each side surface portion is solid, and the filling portion is configured to form the same curved surface as an adjacent pressure surface. The propeller fan according to claim 10.   An air conditioner using the propeller fan according to any one of claims 1 to 11.