KR20140039976A - Propeller fan - Google Patents

Abstract

Provided is a propeller fan. The propeller fan is arranged on a falling edge of a wing to reduce the tendency of the flow around a pressed surface to lean on outer peripheral sides, and strongly attract the flow into the inner circumference sides to significantly enhance the wind power. A wing of the propeller fan is configured to rise from the center portion adjacent to the falling edge in a radial direction to a surface pressed by a negative pressure and is open toward the pressed surface, and includes a recess portion extending from the falling edge of the wing to a leading edge of the wing. The recess portion stands from the surface pressed by a negative pressure by a predetermined angle when seen in a radial direction and has a pair of side surface portions facing each other. The width in a span direction between the pair of side surface portions gradually widens as going from the upper stream to the downstream.

Description

Propeller fan and air conditioner using this propeller fan {Propeller Fan}

TECHNICAL FIELD This invention relates to the wing structure of the propeller fan used for the air conditioning apparatus, for example.

For example, when the propeller fan 100A including the general blade 110A, which is formed in a smooth curved shape as a whole and has no protrusions or recesses, is rotated, the pressure surface of the rotating blade ( The flow in the vicinity of 104A) becomes a distribution biased toward the outer circumferential side at the blade exit (wing trailing edge 103A side) by centrifugal force as shown in FIG. In addition, such a flow bias causes a problem that the flow tends to become unstable at a portion close to the cylindrical hub 111A at the center of the fan, thereby lowering the blowing efficiency.

In this document, in Patent Literature 1, as shown in FIG. 2, the leading edge 102B side of the propeller fan 100B near the wing trailing edge 103B toward the negative pressure surface 105B side. By making the convex arc-swelled bulge shape 106B, it is proposed to make it easy to flow out through this bulge part 106B, and to equalize the distribution of radial flow.

However, as shown in Patent Literature 1, when the blade trailing edge 103B portion is inflated, the angle becomes smooth in the rotational direction in the middle of the chord direction in the bending line of the blade of the same radial cross section. Therefore, in the blade trailing edge 103B, a portion where the air flow is not pushed by the blade is largely present, and the blowing force is lowered. In addition, since the blade trailing edge 103B portion has an arcuate shape 106B, the flow flowing into the portion flows smoothly in a direction orthogonal to the arc, thereby drawing the flow direction from the outside to the inside. Since the attraction force is small, the effect that can greatly improve the blowing efficiency cannot be obtained.

Accordingly, the present invention has been made in view of the above-described problems, and in the trailing edge of the wing, the flow in the vicinity of the pressure surface is biased toward the outer circumferential side, and the flow can be strongly attracted to the inner circumferential side, thereby greatly improving the blowing force. The purpose is to provide a propeller fan.

Another object of the present invention is to provide a propeller fan capable of improving the propulsion force of the wing, reducing the leakage airflow at the outer periphery of the wing, and suppressing the development of the wing tip vortex to improve the fan efficiency.

That is, the propeller fan of the present invention is a propeller fan having a plurality of wings mounted at predetermined intervals in the circumferential direction with respect to the outer peripheral surface of the cylindrical hub,

The blade has a concave inlet portion which rises to the negative pressure surface side in the radially central portion near the trailing edge and is open at least to the pressure surface side, and extends from the trailing edge of the blade to the leading edge side,

The concave portion has a pair of side portions facing each other, standing up at a predetermined angle with respect to the negative pressure surface when the radial cross section is viewed,

The span direction width between the said pair of side parts is comprised so that it may become gradually larger from the upstream to the downstream side.

In this configuration, since the recess portion stands at a predetermined angle with respect to the negative pressure surface and has a pair of side portions facing each other, the curvature changes greatly between the negative pressure surface and the recess portion, so that the pressure surface is near. Can increase the force attracted to the recess.

Further, since the span direction width between the pair of side portions is configured to gradually increase from the upstream side to the downstream side, along the direction in which the respective side portions extend and the pressure surface just before being attracted to the recessed portion. The angle formed by the flowing flow can be increased, and the flow can be changed vertically with respect to the side part, so that the direction of the flow on the outer circumferential side can be changed more.

Therefore, the flow near the pressure surface is easily attracted to the recess, and the direction of the flow can be greatly changed from the outer circumferential side to the inner circumferential side, so that the flow is almost uniformly distributed on the pressure surface at the trailing edge of the blade. In particular, the flow on the inner circumferential side becomes unstable, and noise and vibration can be prevented from occurring, and the blowing efficiency can be improved.

In order to form the concave portion at the position where the centrifugal flow tends to be biased outward on the pressure surface due to the centrifugal force generated as the propeller fan rotates, the fan rotation shaft can be effectively suppressed. The outer diameter of the blade is Rt, the inner diameter is Rh, and the radius to the end of the side portion on the inner diameter side at the trailing edge of the wing is Ri, and the radius Ro to the end of the side portion on the outer diameter side of the blade is referred to as the center. In the case where Ri = Rh + alpha (Rt-Rh) and Ro = Rh + beta (Rt-Rh), it is preferably set in the range of 0.2≤α≤0.6, 0.6≤β≤0.9.

In order to facilitate the flow of airflow along the pressure surface into the concave portion provided on the wing, and to make the vortex pairs formed along the respective side portions almost equal to increase the blowing efficiency, When the inclination angle of the side portion on the inner diameter side with respect to θi and the inclination angle of the side on the outer diameter side with respect to the fan rotation axis are θo, 5 ° ≤θi≤60 °, 5 ° ≤θo≤60 °, and θi≥θo are satisfied. It is desirable to.

The inflow into the concave portion provided in the blade is smoothed from the upstream side to the downstream end, and the outlet angle of the wing of the concave portion is substantially coincided with the outlet angle of the adjacent portions other than the concave portion, so that the air flows uniformly in the radial direction. In order to improve the efficiency, when the circumferential cross section in the radius at which the concave tip end edge is located is viewed, the length L1 from the trailing edge to the convex leading edge side end is L0 with respect to the blade length L0. Is preferably set to 10% to 60%.

In order to form an appropriate step in the adjacent portion of the concave portion and the pressure surface, to ensure the inflow of airflow to the concave portion, to suppress the centrifugal flow, and to improve the blowing efficiency, When the circumferential cross section in the radius is seen, the depth d toward the negative pressure surface side of the recess is gradually increased from the upstream side to the downstream side, and the depth d near the blade trailing edge is a predetermined depth dｘ. It is preferable that a depth constant area that is substantially constant is set.

In order to improve the blowing efficiency while preventing the decrease in the strength of the wings due to the formation of the recess, the bottom portion is formed on the negative pressure surface side of each side portion of the recess and the bottom portion is closed, and the bottom portion forms a curved surface substantially parallel to the negative pressure surface. desirable.

In order to suppress the peeling of the flow in the vicinity of the negative pressure surface by generating a longitudinal vortex to the negative pressure surface side of the wing due to the airflow flowing into the indentation portion, and to further improve the blowing efficiency, the recess portion is also on the negative pressure surface side. It is preferable that it is open and is comprised only by said pair of side parts. In such a configuration, since the blowing action is somewhat lowered due to the reduction of the wing area, it is necessary to increase the number of rotations in order to secure an equal blowing amount, but the air flow flowing into the indentation portion can be made larger, so that The blowing efficiency can be improved by the generated longitudinal vortex.

In order to reduce the disturbance and loss of the flow attracted to the concave portion provided in the blade and to further improve the blowing efficiency, it is preferable that the respective side portions and the pressure surface are connected to each other in a round manner.

Even when the recess is opened to both the pressure surface and the negative pressure surface, in order to prevent stress concentration caused by the centrifugal force at the upstream end of the recess, the strength can be increased, so that the breakage of the blade can be difficult. It is preferable that the vicinity of the upstream side edge part of the surface side is connected roundly.

Even when the recessed part provided in the blade is also open to the negative pressure side, the stress concentration caused by the centrifugal force at the upstream end can be further alleviated, so that the breakage is difficult between the upstream end of the pressure side of each side face. It is preferable that a filling portion is provided, and the filling portion is configured to form the same curved surface as the adjacent pressure surface.

According to the air conditioner using the propeller fan of this invention, it becomes possible to operate an air conditioner efficiently by the improvement of a blowing ability.

That is, the propeller fan of this invention is provided with the notch part by which the said blade cut | disconnects the trailing edge part, and is formed,

The outline of the cutout portion is composed of a first arc which is formed to bulge to the inner circumferential side of the blade and a second arc that is formed to bulge to the outer circumferential side of the blade, and is far from the trailing edge of the first arc and the second arc. Each end of the side is connected, characterized in that the tip is formed.

In such a configuration, the cutout portion has a front end formed at one end side of the first and second arcs, and therefore, the first vortex from the leading edge side to the trailing edge side along the first arc from the front end thereof. A second vortex is formed at the cutout from the leading edge side to the trailing edge side along the second arc while swirling in the opposite direction to the first vortex. And the thrust force of a wing | wing improves by mutual interference of the 1st and 2nd vortex which vortex mutually formed mutually, and the fall of the blowing performance by the fall of a wing area can be suppressed.

The arc referred to in the present invention is a concept including a circular arc, an elliptical arc, and a curve of a part of a parabola or a hyperbola.

By forming a cutout near the outer circumference of the blade, the contour of the cutout is formed so as to suppress the leakage airflow flowing from the pressure surface side of the outer circumference of the blade to the negative pressure surface side to suppress the development of the vortex of the blade tip. In the first and second arcs, the rotation center of the propeller fan is O, the radius from the rotation center O to the outer circumference of the blade is R1, and the radius of the hub is R2, and the trailing edge and the cutout of the blade are The two connection points with the contours of are called points P and points Q in order from the inner side close to the rotation center O, and the length of the line segment OP connecting the rotation center O and the point P is Rp and the rotation. When the length of the line segment OQ connecting the center O and the point Q is Rq,

0.35 (R1-R2) ≤ (Rp-R2) <(Rq-R2) ≤ (R1-R2)

It is preferable to form in the range which becomes.

In order to improve aerodynamic performance, it is preferable that only one said cutout part is formed with respect to one said blade | wing. This is because, when a plurality of cutouts are provided, in the case of the vortices formed between the cutout and the cutout, the flows reduce the speed in the outflow direction to each other, thereby reducing the effect of improving the propulsion force of the wing.

In order to efficiently form the first and second vortices swirling in opposite directions at the notches to further improve the propulsion force of the wing, the contour of the notches is defined between the first and second arcs. It is desirable to have a microcircle that is formed to reflect the dimensions of the minimum machining tool.

In order to maintain the distance between the first vortex and the second vortex so that the degree of mutual interference between the first vortex and the second vortex is appropriate, the first and second arcs are circular arcs, It is preferable that the line segment connecting the point A of dividing the first arc and the center point of the first arc and the line segment connecting the point B of dividing the second arc and the center point of the second arc intersect each other. .

In order to suppress the respective centerlines of the first and second vortices swirling in opposite directions from each other, the first and second arcs are circular arcs, and the first arcs are connected to the trailing edges. The first tangent to the first circular arc and the second tangent to the second circular arc at the second connection point at which the second circular arc is connected to the trailing edge are defined by the first connection point and the first centering center of rotation of the propeller fan. It is preferable that the angle formed with respect to the virtual tangent at the said 1st connection point and the 2nd connection point with respect to the virtual circle passing through 2 connection points, respectively becomes plus minus 15 degrees.

In order to keep the distance between the first vortex and the second vortex appropriately as the centerline of the first and second vortices swirling in the opposite directions toward the rear side of the wing, the point of the first arc is further suppressed. When F is a point where line segments connecting (A) and the center point of the first arc and the line segment connecting the point (B) of the second arc and the center point of the second arc intersect with each other, the point F is the It is preferably located inside the contour of the cutout.

In order to clarify the starting point of the contours of the cutout, the first and second vortices swirling in opposite directions to each other, the connection points of the first and second arcs at the tip of the contour of the cutout are included. It is preferable to provide an additional part or a rib in the pressure surface side of the said circumference | surroundings.

Similarly, it is preferable to provide a raised part or a rib on the negative pressure surface side of the wing around the blade including the connection point of the first and second arcs at the tip of the cutout.

In order to make the vortex tend to occur smoothly and to promote the interference of the first and second vortices swirling in opposite directions to each other so that the propulsion force of the wing is improved, the pressure surface of the tip of the cutout portion and the surroundings thereof It is preferable to provide raised portions or ribs on the side and the negative pressure surface side.

Similarly, it is preferable that the radial cross-sectional shape of the contour part of the notch is rounded from the negative pressure side of the blade toward the pressure side.

Furthermore, the radial cross-sectional shape of the contour part of the said notch part has that the edge part of the negative pressure surface side and the pressure surface side of the said blade is rounded.

In order to enhance the interference of the first and second vortex swirling in the opposite direction and to improve the propulsion force of the blade, it is preferable to provide a raised portion or a rib on the negative pressure surface side of the blade along the contour of the cutout. .

The height of the raised part or rib is increased at the leading edge side of the wing so that the interference of the first and second vortices swirling in opposite directions can be evenly strengthened over the entire length of the contour of the cutout and the wing propulsion is improved. It is preferable that it is a constant height toward the trailing edge side.

In order to be able to gradually reinforce the interference of the first and second vortex swirling in the opposite direction and to improve the propulsion force of the blade, the height of the raised portion or the rib is preferably increased gradually from the leading edge side of the blade toward the trailing edge side.

In order to enhance the interference of each other immediately after the first and second vortex swirling in the opposite direction, and the trajectory of the subsequent vortex flows easily to interfere with each other, so that the driving force of the wing is improved, The height of the rib is preferably smaller gradually from the leading edge side to the trailing edge side of the blade.

In the air conditioner employing the propeller fan of the present invention, it is possible to efficiently operate the air conditioner by improving the blowing ability.

Thus, according to the propeller fan of this invention, when the recessed part provided in the wing | blade saw a radial cross section, it has a pair of side parts standing up at a predetermined angle with respect to the said negative pressure surface, and opposing each other, The said pair Since the span direction width between the side portions of the side surface is configured to increase gradually from the upstream side to the downstream side, the flow flowing near the pressure surface can be strongly attracted to the concave inlet portion at the trailing edge of the blade, and is biased toward the outer diameter side in the usual case. The tendency of the flow can be distributed almost evenly in the radial direction at the trailing edge, which can greatly improve the blowing efficiency.

In addition, the blade has a cutout formed by cutting the trailing edge thereof, the contour of the cutout is composed of a first arc formed by bulging toward the inner circumferential side of the wing and a second arc formed by bulging toward the outer circumferential side of the wing, Since one end of each side far from the trailing edge of No. 1 and No. 2 is connected so that a tip is formed, the airflow which flows into the negative pressure surface side from the pressure side of the contour of the cutout part is provided in No. 1 and No. 2. Each form a swirling structure swirling in the reverse direction to improve the propulsion force of the wing by mutual interference between the first and second vortex and also reduce the leakage air flow at the outer periphery of the wing to suppress the development of the wing tip fan efficiency Can improve the blowing efficiency.

1 is a schematic perspective view showing the shape of the conventional propeller fan and the bias of the flow at the blade trailing edge,
FIG. 2 is a schematic diagram showing an example in which a bulging portion is provided at a trailing edge of a blade in a conventional propeller fan.
3 is a schematic perspective view of the propeller fan according to the first embodiment of the present invention,
4 is a cross-sectional view taken along the line AA of the first embodiment, illustrating a cross section in the chord longitudinal direction of the recessed part;
FIG. 5: is a schematic diagram when the negative pressure surface is seen along the fan rotation shaft of 1st Embodiment,
6 is a cross-sectional view taken along the line CC of the first embodiment, showing a radial cross section of a recess;
7 is a schematic perspective view showing a flow near the pressure surface of the first embodiment;
8 is a schematic diagram illustrating a parameter for indicating a position of the recessed part of the first embodiment;
9 is a schematic view illustrating the inclination angles of the side parts of the first embodiment,
10 is a schematic view showing the position and depth of the recessed part of the first embodiment in the wing,
FIG. 11 is a graph showing a relationship between a ratio occupied by the chord length of the recessed part of the first embodiment and a maximum efficiency ratio;
12 is a graph showing a change tendency of the depth of the recesses in the first embodiment;
It is a typical perspective view of the propeller fan which concerns on 2nd Embodiment of this invention,
14 is a schematic cross-sectional view taken along a line BB of the second embodiment, showing a cross section in the chord longitudinal direction of the recessed part;
15 is a schematic view of a negative pressure surface viewed along a fan rotation shaft of the second embodiment;
16 is a sectional view taken along the line DD of the second embodiment, showing a radial cross section of a recess;
17 is a schematic view showing a radial section of the recessed portion as a modification of the second embodiment,
FIG. 18: is a schematic diagram which shows the cross section of the chord longitudinal direction of a recessed part as a modification of 2nd Embodiment,
FIG. 19: is a schematic diagram when the negative pressure surface is seen along the fan rotation axis as a modification of 2nd Embodiment,
It is a graph which compared the fan efficiency of the propeller fan of 1st Embodiment, 2nd Embodiment, and a prior art example.
Fig. 21 is a schematic perspective view of the blade of the propeller fan according to the third embodiment of the present invention as seen from the side of the negative pressure surface thereof.
It is a schematic diagram seen from the pressure surface side along the fan rotation shaft of 3rd Embodiment,
FIG. 23 is a sectional view taken along the line NN in FIG. 21 of the third embodiment, illustrating a cross section in the chord longitudinal direction of a notch; FIG.
24 is an enlarged view of the main portion of the example having the minimum arc of the third embodiment as viewed from the pressure side along the fan rotation axis;
The schematic perspective view seen from the negative pressure surface side of the blade which shows the generation | occurrence | production state of the vortex in the notch part of 3rd Embodiment.
Fig. 26 is a schematic perspective view of the generation state of the vortex at the cutout of the third embodiment as seen from the negative pressure surface side of the blade shown with a comparative example;
It is a schematic diagram seen from the pressure surface side along the rotating shaft of the blade for showing the relationship of the dimension of each part of 3rd Embodiment,
FIG. 28: is a schematic diagram seen from the pressure surface side along the fan rotation axis which shows the conditions of the circular arc which specifies the shape of the notch part of 3rd Embodiment,
FIG. 29: is a schematic diagram seen from the pressure surface side along the fan rotation axis which shows the conditions of the circular arc which specifies the shape of the notch part of 3rd Embodiment,
30 is a schematic view seen from the pressure plane side along the fan rotation axis, showing the condition of an arc that specifies the shape of the cutout portion in the third embodiment;
Fig. 31 is a sectional view taken along the line S-S in Fig. 31A, showing a schematic perspective view of the vane surface of the blade of the propeller fan according to the fourth embodiment of the present invention, and the main portion of the fourth embodiment;
FIG. 32 is a sectional view taken along the line UU of FIG. 15A showing a schematic perspective view of the vane surface of the blade of the propeller fan according to the fifth embodiment of the present invention, and the principal parts of the fifth embodiment and its modifications. ,
FIG. 33 is a sectional view taken along the line VV in FIG. 16A, showing a schematic perspective view of the vane surface of the blade of the propeller fan according to the sixth embodiment of the present invention, and the principal parts of the sixth embodiment and modifications thereof. ,
34 is a graph comparing the fan efficiency between the propeller fan of the present invention and the propeller fan of the conventional example.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description of the preferred embodiments below is merely exemplary in nature and is not intended to limit the present invention, its application or its use.

 EMBODIMENT OF THE INVENTION The 1st Embodiment of this invention is described with reference to drawings.

The propeller fan 1 of 1st Embodiment is used for the outdoor unit of air-conditioning apparatus, for example, and is a some blade | wing 10 mounted at predetermined intervals in the circumferential direction with respect to the outer peripheral surface of the cylindrical hub 9 ) Is provided radially. In each figure, one of each blade 10 of the propeller fan 1 is described typically.

The blade length of the propeller fan 1 according to the first embodiment, taken along line AA in FIGS. 3 and 3, which is a schematic perspective view of the blade 10 viewed from the negative pressure surface 5 side. It demonstrates with reference to FIG. 4 which is sectional drawing of a direction.

As shown in FIG. 3, the mounting portion between the wing 10 and the cylindrical hub 9 is mounted such that a predetermined spiral is drawn on the side of the hub 9 from one end surface side to the other end side of the hub 9. And the leading edge 2 of the blade 10 protrudes forward in the rotational direction. In addition, as shown in FIG. 4, which is a cross-sectional view of the AA line shown in FIG. ) And the convex side of the blade 10 is the negative pressure surface 5.

3 and 4, the blade 10 is raised to the negative pressure surface 5 side at the center portion of the trailing edge 3 side, so that the recessed portion 6 in which the pressure surface 4 side is recessed is formed. Formed.

Hereinafter, features relating to the shape, dimensions, and the like of the recess 6 will be described in detail with reference to FIGS. 3 to 10.

The recess 6 is shown in FIG. 6, which is a cross-sectional view along line CC of FIG. 5, viewed from the negative pressure surface 5 of the blade 10 along the rotational axis C, in the radial center portion near the trailing edge 3. It rises to the negative pressure surface 5 side, and is open | released to the pressure surface 4 side, and is formed. As can be seen from FIG. 5, when the negative pressure surface 5 or the pressure surface 4 is seen along the direction in which the rotation axis C extends, the concave portion 6 has a substantially eight-shaped blade leading edge ( It is formed by spreading from the 2) side to the trailing edge 3 side.

Further, as is apparent from the radial cross section of the blade 10 including the recess 6 in FIG. 6, when the radial cross section of the recess 6 is seen, the bottom portion 62 is located on the negative pressure surface 5 side. It is roughly c-shaped with). More specifically, the concave inlet portion 6 has a pair of side portions 61 which stand up at a predetermined angle with respect to the negative pressure surface 5 and face each other when the radial section is viewed. The bottom part 62 which is a triangular curved surface with a substantially rounded angle is provided so that the negative pressure surface 5 side of each side part 61 may be closed. In other words, as can be seen from the cross-sectional view of FIG. 6, when the radial section is seen with respect to the portion having the recess 6, the pressure surface 4 or the negative pressure surface 5 and the side surface 61 and Is connected so that the curvature changes significantly.

Furthermore, as can be seen from FIGS. 3 and 5, the span direction width between the pair of side portions 61 is downstream from the upstream side (the leading edge 2 side) (the trailing edge 3 side). It is formed so that it may become large, and it becomes a substantially eight shape.

Since the recessed part 6 of such a shape is formed in the center of the blade trailing edge part, the flow of the vicinity of the pressure surface 4 shown by the streamline of FIG. 7 is attracted to this recessed part 6 in the blade trailing edge part. Will be. Therefore, as can be seen by comparing FIG. 1 with FIG. 5, the airflow biased toward the outer diameter side can be made almost uniform at the trailing edge of the blade, and is almost peeled off or flowed on the inner diameter side which is the connection side with the hub 9. It is possible to prevent the disorder from occurring.

Next, the position, dimension range, etc. of the recessed part 6 suitable for achieving the uniformity of such airflow are demonstrated.

First, the arrangement | positioning at the blade trailing edge part of the said recessed part 6 is demonstrated. As shown in FIG. 8, the concave indentation 6 is formed around the fan rotation axis C by Rt as the outer diameter of the blade 10, Rh as the inner diameter, and inner diameter at the trailing edge 3 of the blade 10. The radius to the end of the side part 61 at the side is Ri, the radius to the end of the side part 61 at the outer diameter side at the trailing edge 3 of the blade 10 is Ro, and Ri = Rh + α ( Rt-Rh) and Ro = Rh + β (Rt-Rh), the range is set to 0.2 ≦ α ≦ 0.6 and 0.6 ≦ β ≦ 0.9.

Next, the rising method of the said indentation part 6, ie, the method of standing up with respect to each side part 61 and the negative pressure surface 5, is demonstrated with reference to FIG. As shown in Fig. 9, in the recess 6, the inclination angle of the side portion 61 on the inner diameter side with respect to the fan rotation axis C is θi, and the inclination angle of the side surface on the outer diameter side with respect to the fan rotation axis C. When θo is set, 5 ° ≤θi≤60 °, 5 ° ≤θo≤60 °, and θi≥θo are satisfied. In other words, in the case of viewing from the pressure surface 4, the inclination of the outer diameter side is changed more drastically, and the force inducing the flow of the outer diameter side into the concave indentation 6 becomes stronger. By doing in this way, the magnitude | size of a pair of longitudinal vortex formed in the side part 61 of an inner diameter side, and the side part 61 of an outer diameter side can also be equalized, and it is easy to improve blow efficiency more.

Furthermore, the size and depth of the recessed part 6 which the recessed part 6 occupies in the blade length direction in the blade 10 are demonstrated. As shown in FIG. 10, which is a cross-sectional view along the line AA in FIG. 3, when the circumferential cross section in the radius at which the leading edge 2 side end of the concave inlet part 6 is located is viewed, the trailing edge (3) ), The length L1 from the tip of the recess 6 to the leading edge 2 side is set to 10% to 60% of L0. More specifically, if the ratio of the length L1 of the concave portion 6 to the chord length L0 is changed, the maximum efficiency when L1 is set between 10% and 60% of L0 as shown in the graph of FIG. It can be seen that the ratio takes the maximum value. In other words, L1 can be more preferably set to 20% to 45% of L0. More preferably, by setting L1 to approximately 30% of L0, the value of the maximum efficiency ratio can be maximized.

In addition, about the depth d of the recessed part 6, when the circumferential end surface in the radius where the edge part 2 side edge of the recessed part 6 is located is seen, the said negative pressure of the said recessed part 6 While the depth d toward the surface 5 is gradually increased from the upstream side to the downstream side, a depth constant region where the depth d near the blade trailing edge 3 is substantially constant to a predetermined depth dｘ is provided. Setting. The predetermined depth d 'is set to 2% to 10% of the blade length L0. More specifically, as shown in the graph of FIG. 12, the depth d of the concave inlet 6 rapidly changes in depth near the upstream starting point, and decreases the rate of change in the trailing edge of the wing.

By setting the size occupied by the wing 10 of the recess 6 as described above, it is possible to balance the function of the wing 10 original function and the function related to the correction of the centrifugal flow to improve the blowing efficiency. Preferably it can improve. If the depth d of the concave portion 6 is set to the value described above, the flow can be reliably introduced by the step between the pressure surface 4 and the concave portion 6 in the vicinity. Therefore, the centrifugal flow can be suppressed and the blowing efficiency can be improved.

Next, the propeller fan 1 which concerns on 2nd Embodiment of this invention is demonstrated with reference to FIGS.

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

The shape of the wing 10 of 2nd Embodiment is demonstrated in detail below.

As shown in Figs. 13 and 15, the bottom portion 62 of the recess 6 'is cut out in a triangular shape with a rounded angle, and is a cross-sectional view taken along line DD of Figs. As shown in Fig. 16, the recess 6 'is composed of only two side portions 61' standing up against the negative pressure surface 5.

That is, as can be seen when comparing FIG. 4 of the first embodiment with FIG. 14 of the second embodiment, the depth of the upstream end of the recess 6 'is the same, but at the recess 6' Removed the thin plate part downstream. In addition, as shown in FIG. 16, when the flow flowing near the pressure surface 4 is attracted to the concave portion 6 ′, it flows along the side portion 61 ′ and then flows out to the negative pressure surface 5 side, so that the negative pressure surface ( In 5) a longitudinal vortex is formed. Since the peeling of the flow in the vicinity of the negative pressure surface 5 is suppressed by the longitudinal vortex formed in this negative pressure surface 5, it is possible to further improve the blowing efficiency.

Moreover, the said upstream edge part vicinity 64 'of the negative pressure surface 5 side is rounded and connected in each said side part 61', and the curvature radius is set to 1 to 5 times the thickness of the blade 10. . By doing in this way, stress concentration by a centrifugal force can be prevented in the upstream end of the opening part provided in the blade 10, and it can be prevented from being damaged easily. In other words, it is possible to improve the blowing efficiency while preventing the strength decrease of the blade 10 caused by cutting off the bottom portion 62 of the recess 6 '.

Next, the modification of 2nd Embodiment is demonstrated with reference to FIGS. 17-19.

As shown in FIG. 17, the side surfaces 61 ′ and the pressure surfaces 4 may be rounded. In other words, each side portion 61 ′ and the pressure surface 4 are not connected to each other so as to form angles as shown in FIG. 16, but are formed in a round shape as shown in FIG. 61 '), the loss or the disturbance of the flow to the negative pressure surface 5 can be reduced to improve the blowing efficiency.

18 and 19, the filling portion 63 'in which the concave portions 6' are filled between the upstream end portions on the pressure surface 4 side of each of the side portions 61 '. The filling portion 63 'may be configured to form the same curved surface as the adjacent pressure surface 4. As can be seen by comparing FIG. 14 with FIG. 18, in FIG. 18, the portion of the tip portion of the tip portion 6 'of the recessed portion 6' that is filled up by the filling portion 63 'increases as compared with FIG. 14. have. By doing in this way, the stress concentration by centrifugal force can be further alleviated at the upstream end of the opening provided in the blade 10 ', and breakage can be prevented easily.

Finally, the comparison result of the blowing efficiency of the propeller fan 1 of 1st Embodiment, the propeller fan 1 of 2nd Embodiment, and the propeller fan 1 of a prior art example is shown.

As shown in the graph of FIG. 20, the propeller fan 1 of 1st Embodiment and 2nd Embodiment can make a substantially uniform flow of the blade | wing 10 exit flow by the attraction effect of the flow by the recessed part 6. Thus, it can be seen that the blowing efficiency can be improved as compared with the conventional propeller fan (1). In addition, as in the second embodiment, when the bottom surface of the concave portion 6 ′ is removed to form a cutout portion in the wing 10, the blowing efficiency can be most improved, and the blowing efficiency is about 10% compared with the conventional example. It can be seen that it can be improved.

Other embodiments will be described.

In each said embodiment, although the propeller fan used for the air conditioner was shown, the propeller fan of this invention can also be used for other uses. In addition, whether to leave or remove the bottom face of the concave indentation can be appropriately determined in consideration of, for example, a balance between the required blowing efficiency and the required strength of the blade.

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

The propeller fan 1 of 3rd Embodiment is used for the outdoor unit of an air-conditioning apparatus, for example, and is a some blade | wing 10 mounted at predetermined intervals in the circumferential direction with respect to the outer peripheral surface of the cylindrical hub 9 ) Is provided radially. In each figure, one of each blade | wing 10 of the propeller fan 1 is described typically.

Regarding the shape of the blade 10 of the propeller fan 1 of the third embodiment, FIG. 4 is a schematic perspective view of the blade 10 viewed from the negative pressure surface 5 side, and the pressure surface along the fan rotation axis X ( It demonstrates with reference to FIG. 5 which is a schematic diagram at the time of seeing 4).

As shown in FIG. 21, the mounting portion between the wing 10 and the cylindrical hub 9 is mounted so that a predetermined spiral is drawn on the side of the hub 9 from one end surface side to the other end side of the hub 9. The leading edge 2 of the blade 10 protrudes forward in the rotational direction. Moreover, the said blade | wing 10 has predetermined curvature in the chord length direction, The surface of the concave side of the blade | wing 10 is made into the pressure surface 4, and the surface of the convex side of the blade | wing 10 is a negative pressure surface. (5).

As shown in Figs. 21 and 22, the blade 10 is formed with a cutout 7 cut out toward the blade front side near the blade outer circumferential edge 6A on the trailing edge 3 side. One cutout portion 7 is provided for each wing 10. The cutout 7 has sidewalls 7a having the same thickness as that of the blade 10, as shown in FIG. On the other hand, depending on the size of the blade 10 may be considered to provide a plurality of cutouts (7), when a plurality of cutouts (7) provided, the vortices formed between the cutouts (7) flow out of each other It is not necessary to provide a plurality of cutouts 7 because the effect of improving the propulsive force of the blade 10 is reduced by the flow of decelerating the speed in the direction.

Hereinafter, features relating to the shape, dimensions, and the like of the cutouts 7 will be described in detail with reference to FIGS. 21 to 30.

The notch 7 is 6A wing outer circumferential edge 6A at the radial center of the trailing edge 8, as shown in FIG. 22, which has seen the pressure surface 4 of the wing 10 along the fan axis of rotation X. FIG. Contour formed by the first circular arc 11, which is the first arc bulging toward the inner circumferential side of the blade 10, and the second circular arc 12, which is bulged toward the outer circumferential side of the blade 10, at a position biased toward the side ( 13) The contour 13 is connected to one end of the side far from the trailing edge 8 of the first circular arc 11 to one end of the side far from the trailing edge 8 of the second circular arc 12. Each end of the first circular arc 11 and the second circular arc 12 is connected in a different direction by 180 degrees so that the first circular arc 11 and the second circular arc 12 are not continuous with each other, but the first circular arc ( One end of the second circular arc 11 and one end of the second circular arc 12 reach one point (connection point) from each other in a direction of less than 180 degrees, and the first circular arc 11 and the second circular arc 12 are connected to each other. Therefore, the first circular arc 11 and the second circular arc 12, which are two circular arcs, are not connected to each other to form a single circular arc, but rather form an angle at the connection point to form the first circular arc 11 and the second circular arc 12. Is discontinuously connected to each other, the notch 7 has a contour 13 formed by two circular arcs, the tip 14 of which is pointed in shape.

In addition, when it is expressed about the notch 7 from another viewpoint, the front end 14 of the notch 7 is the tangent of one end vicinity of the 1st circular arc 11, and the one end vicinity of the 2nd arc 12. As shown in FIG. It is preferable that the first circular arc 11 and the second circular arc 12 are connected to each other so that the tangent lines cross each other at an acute angle, that is, an angle of 90 degrees or less. The tip 14 preferably has the first and second circular arcs 11 and 12 substantially sharply sharpened in this manner, but when viewed microscopically, the tip 14 may not necessarily be an angular shape formed by crossing straight lines. It may be formed in a circular arc shape of a small diameter depending on the dimensions of the minimum machining tool in the cutting of the mold. That is, the tip 14 of the cutout 7 is limited in manufacturing constraints, for example, in the case of a synthetic resin propeller fan 1, that is, in a round shape required for removing the propeller fan of a molded product from a mold. It may be a round shape without an angle. In particular, the first circular arc 11 and the second constituting the contour 13 of the cutout 7 as shown in FIG. 7 showing the cutout part 7 along the fan rotation axis X in an enlarged manner. For example, the tip 14 of the notch 7 is formed between the one end with the circular arc 12 through the microcircle 14a of a radius of 5 mm.

In this way, the blade 10 is interposed between the end portions of the trailing edge portion 8 and the above-described minute arc 14a connects the first arc 11 and the second arc 12. If the front end 14 of the joint 7 is a pointed contour 13, as shown in Fig. 8, the negative pressure surface on the pressure surface 4 side starting from the front end 14 of the cutout 7 is shown. (5) The first vortex 15a and the second vortex 15c which swirl in opposite directions to each other are uniformly formed on the first arc 11 and the second arc 12, and the first and second The vortex 15a, 15c interferes with each other, and the propulsion force of the blade | wing 10 can be improved, and the fall of the blowing performance accompanying the fall of a blade | wing area can be suppressed.

On the other hand, the notch 7 'to which two circular arcs 11' and 12 'as smoothly connected as shown in FIG. 26A as a comparative example for comparing fan efficiency is the above-mentioned minute arc 14a. Is different from the one where the tip 14 of the cutout 7 'is formed, and the propeller fan 1' of the cutout 7 'is clearly defined in the outline 13' of the cutout 7 '. Since there is no pointed tip, the air flow (indicated by arrow in the figure) is not separated from the tip part, and the air flow generated in each arc 11 ', 12' is mixed with each other, so it is not a uniform vortex, so the driving force of the wing 10 ' You can't improve it.

On the other hand, in the propeller fan 1 of this 1st Embodiment shown to FIG. 26 (i), the 1st circular arc 11 and the 2nd circular arc 12 in the front-end | tip 14 of the notch 7 are shown. The boundary between the vortices is clear, and the air flow is separated from the tip 14, and thus uniformly formed in both the first arc 11 and the second arc 12, so that the propulsion force of the wing 10 can be improved. Indicates.

As can be seen from the above, the tip 14 is not formed by smoothly connecting one end of each of the first circular arc 11 and the second circular arc 12 from the opposite direction to each other, but the first circular arc 11. And one end of each of the second circular arcs 12 is connected from a direction other than the opposite direction to protrude to the outside of the notch 7. In other words, the distal end 14 is one end of each of the first circular arc 11 and the second circular arc 12 connected to each other, and is formed in a non-smooth curved linear contour shape. Therefore, even in the example having the above-described minute arcs 14a, the tangents of the first arcs 11 and the tangents of the second arcs 12 in the vicinity of the minute arcs 14a do not coincide with each other and are not less than a predetermined value. The tip 14 can be constituted if the inclination is different so that the contour 13 of the cutout portion 7 is formed as a whole so as to protrude from the cutout portion 7 as a whole.

Next, the position, dimension range, etc. of the notch 7 suitable for improving the propulsive force of such a wing 10 are demonstrated.

First, the arrangement | positioning in the trailing edge part 8 of the notch part 7 is demonstrated. As shown in FIG. 27, which is a schematic view when the pressure surface 4 is viewed along the fan rotation axis X of the blade 10, the first circular arc 11 forming the contour 13 of the cutout 7. And the second circular arc 12, the point passing through the rotation center of the propeller fan 1, that is, the fan rotation axis X, is O, the radius of the blade 10 is R1, and the radius of the hub 9 is R2. , The two connection points between the trailing edge 3 of the blade 10 and the contour 13 of the cutout 7 are called points P and points Q sequentially from the inner side of the fan radius (the hub 9 side), and the rotation center ( When the length of the line segment OP connecting O) and the point P is Rp, and the length of the line segment OQ connecting the rotational center O and the point Q is Rq, it is set with a relationship represented by the following equation.

0.35 (R1-R2) ≤ (Rp-R2) <(Rq-R2) ≤ (R1-R2)

In the above dimensional relationship, as shown in FIG. 28 which is the schematic diagram when seeing the pressure surface 4 along the fan rotation axis X of the blade | wing 10, the point A which divides the 1st circular arc 11 equally. And a line segment 11a connecting the center point H of the first arc 11 and the point B that divides the second arc 12 equally and the center point K of the second arc 12. ) Is the intersection of each other. That is, by setting the sizes of the first and second arcs 11 and 12 so that the line segment 11a and the line segment 12a intersect in this way, when the line segment 11a and the line segment 12a do not cross each other, The cutouts 7 can be prevented from excessively opening behind the blade 10. In this case, the intersection point F between the line segment 11a and the line segment 12a may exist inside the outline 13 of the cutout 7 shown in FIG. 11 or located outside the cutout 7. You may. The preferable position of the intersection F of this line segment 11a and the line segment 12a is demonstrated below.

As shown in FIG. 29 which is a schematic diagram when the pressure surface 4 is seen along the fan rotation axis X of the blade | wing 10, the point which divides the 1st circular arc 11 equally to A and the 2nd circular arc 12 The point where E is equally divided is called B, and the two connection points between the trailing edge 3 of the blade 10 and the contour 13 of the notch 7 are called points C and D in order from the inside of the fan radius. When the connection point of circular arcs in the front end 14 of the contour 13 of (7) is E, the line segment AH which connects the point A and the center point H of the circular arc ACE which is the 1st circular arc 11, the point B, and the 2nd The first circular arc 11 and the second circular arc 12 are set such that the line segments BK connecting the center points K of the circular arcs BDE which are the circular arcs 12 intersect each other. In this case, the intersection point F between the line segment AH and the line segment BK is located on the side of the rotational direction of the blade 10, that is, inside the cutout 7 contour 13, rather than the line segment CD. 2 Set the arc 12.

In addition, as shown in FIG. 30 which is a schematic diagram when the pressure surface 4 is seen along the fan rotation axis X of the blade 10, the point C of the 1st circular arc 11 and the 2nd circular arc 12 is shown. ) And points (C) and points of circles (L and M) of tangents (T1 and T2) at point (D) passing through point (C) and point (D) about the rotation center (O) The first circular arc 11 and the second circular arc 12 are set so that the angle formed with respect to the tangents T3 and T4 in (D) is in the range of plus or minus 15 degrees. In other words, when the tangent T1 (T2) and the tangent T3 (T4) overlap each other, the angle is 0 degrees, and the tangent T1 (T2) is a fan for the tangent T3 (T4), for example. It is a positive angle when it is located in the rotation direction side, and is a negative angle when the tangent T1 (T2) is located on the opposite side to the fan rotation direction with respect to the tangent T3 (T4). By defining the angle in this manner, it is possible to define the degree of flaring behind the contour 13 of the cutout 7.

Thus, by setting the 1st circular arc 11 and the 2nd circular arc 12, and providing the notch 7 near the outer peripheral edge 6A of the blade | wing 10, the pressure surface of the outer peripheral part of the blade | wing 10 is provided. The development of the vortex of a blade tip | tip can be suppressed by suppressing the leakage airflow which flows in from the (4) side to the negative pressure surface 5 side. Further, the centerline 15b of the first vortex 15a and the centerline 15d of the second vortex 15c, which swirl in opposite directions, are separated from the tip 14 of the notch 7 as shown in FIG. The propagation force of the wing 10 can be improved by spreading, that is, suppressing overlapping with each other, and reinforcing the interference between the vortices 15a and 15c.

Next, the propeller fan 1 which concerns on 4th Embodiment of this invention is demonstrated with reference to FIG.

In the fourth embodiment, as shown in FIG. 31, the thickness of the tip 14 of the notch 7B is made larger than the thickness of the other part of the blade 10 by the raised part 16 or the rib 17. One point differs from 3rd Embodiment. That is, in the first embodiment, all parts of the contour 13 of the notch 7B are formed to have the same thickness as the entire wing 10, but in the fourth embodiment, the tip 14 of the notch 7B is formed. However, the thickness is increased compared with other parts.

Hereinafter, the shape of the blade 10 of the fourth embodiment will be described in detail.

31 is a schematic perspective view of the negative pressure surface 5 along the fan rotation axis X of the blade 10, taken along line S-S of FIG. 31 and FIG. 31A. 31 (b) to (g) which are sectional drawing in the winging direction of the blade | wing 10, FIG. 31 (c)-(g) are the front-end | tips of the notch 7B of 2nd Embodiment ( The modification of 14) is shown.

The notch 7B is provided with the raised part 16 in the pressure surface 4 of the front-end | tip 14 in order to make thickness of the blade | wing 10 thick. The raised part 16 is hemispherical or semi-elliptical in shape in cross section, and is long in the rotational direction (front and rear direction) of the blade 10 along the notched center line 18 passing through the tip 14 of the notched portion 7B. Is formed. When the propeller fan 1 is made of metal or synthetic resin material, the raised portion 16 is formed of the same material as the wing 10. On the other hand, in FIG. 31, hatching was different from other parts of the wing 10 in order to clearly show the raised part 16 and the rib 17. In FIG.

Thus, by making the thickness of the tip 14 of the notch 7B larger than the other part of the blade | wing 10 by the raised part 16, the 1st vortex 15a and the 2nd vortex 15c which swirl in opposite directions mutually ), The starting point is formed more clearly, the flow can be controlled as intended, so that the driving force of the wing 10 can be easily improved.

This raised portion 16 may be provided on the negative pressure surface 5 of the blade 10, as shown in (c) and (d) of FIG. 31, the pressure surface 4 and the negative pressure surface (5) It may be provided on both sides.

Furthermore, the rib 17 may be provided instead of the raised part 16. The rib 17 is formed to extend in the rotational direction (front and rear direction) of the blade 10 along the notch centerline 18 passing through the tip 14 of the notch 7B. Even when the ribs 17 are provided, the ribs 17 are provided on the pressure surface 4 (FIG. 31E), and the negative pressure surfaces 5 are provided (FIG. 31B). ), And provided on both sides of the pressure surface 4 and the negative pressure surface 5 (FIG. 31G). Also in the case of such a rib 17, the same effect as when the said raised part 16 is provided in the position of the front end 14 of the notch 7 is exhibited.

Furthermore, the propeller fan 1 which concerns on 5th Embodiment of this invention is demonstrated with reference to FIG. FIG. 32 is a blade along the UU line of FIG. 32A and FIG. 15A which is a schematic perspective view when the negative pressure surface 5 is seen along the fan rotation axis X of the blade 10. 32 (b) to (d) which are sectional views in the radial direction of 10), and FIG. 32 (c) and (d) show the modification of 5th Embodiment.

In this 5th Embodiment, the cross-sectional shape of the contour 13 part of 7 C of cutouts is the structure rounded toward the negative pressure surface 5 side from the pressure surface 4 side of the blade | wing 10. As shown in FIG. That is, the contour 13 of the notch 7C has the pressure surface 4 of the blade | wing 10 and the side wall 7a of the notch 7C mutually cut off, and the negative pressure surface 5 of the blade | wing 10 and the notch. The side wall 7a of the coupling portion 7C is formed by an edge portion formed by contacting each other. As shown in Fig. 32 (iii), the cross-sectional shape is obtained by removing the edge portion on the pressure surface 4 side. The chamfer part 19 which made round was formed. As the cross-sectional shape of the contour 13 portion is rounded in this way, the generation of the vortex 15 can be made faster, so that the first vortex 15a and the second vortex vortexed in opposite directions at the cutout 7 are circulated. The interference of 15c can be promoted to improve the propulsion force of the wing 10.

As a modification of this fifth embodiment, as shown in FIGS. 32C and 32D, the chamfer portion 20 is provided at the corner of the negative pressure surface 5 side of the cutout portion 7C to form a contour ( 13) The cross-sectional shape of the part is rounded from the negative pressure surface 5 side of the blade 10 toward the pressure surface 4 side (FIG. 32C), and the pressure surface 4 side and the negative pressure surface. The chamfers 19 and 20 are provided at corners of the side of 5 so that the cross-sectional shape of the portion of the contour 13 is rounded toward both sides of the pressure surface 4 side and the negative pressure surface 5 side of the blade 10. (D) of FIG. 32 can be mentioned. The same effect is obtained in such a configuration.

In addition, the propeller fan 1 which concerns on 6th Embodiment of this invention is demonstrated with reference to FIG. FIG. 33 is a cutaway view taken along the contour 13 of FIG. 33A and a cutout 7D, which are schematic perspective views when the negative pressure surface 5 is viewed along the fan rotation axis X of the blade 10. 33 includes (b) to (d), which are cross-sectional views of the VV line shown in (a) of FIG. 33, and FIGS. 33 (c) and (d) show a modification of the sixth embodiment. .

In the sixth embodiment, as shown in FIG. 33A, the raised portions 21 along the contour 13 of the notch 7D are provided on the negative pressure surface 5 side of the blade 10. It is a structure to prepare. In other words, the elongated raised portion 21 is formed along the first arc 11 and the second arc 12 of the cutout 7D, that is, along the contour 13. In the case of the sixth embodiment, an elongated raised portion 21 of constant thickness is formed over the entire length of the contour 13 of the cutout 7D. The thickness of the long raised portion 21 can be less than the thickness of the wing 10 itself. When the propeller fan 1 is made of a metal or synthetic resin material, the elongated raised part 21 is formed integrally with the wing 10, and its cross-sectional shape may be a semi-circular shape.

Thus, by providing the long raised part 21 along the contour 13 at the negative pressure surface 5 side, and making the height of the long raised part 21 constant over the full length, the 1st swirling in the opposite direction mutually The interference of the vortex 15a and the second vortex 15c can be strengthened constantly, so that the driving force of the wing 10 can be improved.

Instead of the long raised portion 21, a rib having a cross-sectional shape of quadrilateral (square, rectangular) may be provided along the contour 13 of the cutout portion 7C on the negative pressure surface 5 side of the blade 10.

In addition, the raised portion (rib) 21 may have a configuration in which its height gradually increases from the leading edge 2 side to the trailing edge 3 side of the blade 10 as shown in FIG. According to such a structure, the interference of the 1st vortex 15a and the 2nd vortex 15c which vortex mutually reversely can be strengthened gradually, and the propulsion force of the blade | wing 10 can be improved.

In addition, the raised portion (rib) 21 may be configured such that its height gradually decreases toward the trailing edge 3 side from the leading edge 2 side of the wing 10 as shown in FIG. According to this configuration, mutual interference immediately after the occurrence of the first vortex 15a and the second vortex 15c which are swirled in opposite directions to each other can be strengthened, and then the trajectories of the first and second vortices 15a and 15c are It is possible to improve the propulsive force of the wing 10 by flowing through the place where it is easy to interfere with each other.

As shown in FIG. 34, the propeller fan 1 of the present application described above has a total blowing efficiency of 10% or more compared to a conventional propeller fan at all flow rates when the vertical axis shows the total blowing efficiency and the horizontal axis shows the flow rate. Improvement was confirmed.

The propeller fan 1 of this invention may be used for an axial flow fan, a four-flow fan, and also a ventilation apparatus.

In the above embodiment, it has been described that the arc forming the contour 13 of the cutout 7 is an arc, but one arc is an arc and the other arc is an elliptical arc, one arc is an elliptical arc, and the other arc is a parabola. It may be a combination of various kinds of arcs, such as being part of and furthermore, both arcs being elliptical arcs or part of a parabola or hyperbola.

In addition, combinations or modifications of various embodiments may be made without departing from the spirit of the invention.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but variations and modifications may be made without departing from the scope of the present invention. And can be replaced, modified and replaced.

1: propeller fan
10: wings
9: hub
2: leading edge
3: trailing edge
4: pressure side
5: negative pressure surface
6:
7:
61: side
61: each side
62: bottom
63: filling
64: near the upstream end
65: opening
C ： rotary shaft

Claims (28)

A propeller fan having a plurality of vanes mounted at predetermined intervals in a circumferential direction with respect to an outer circumferential surface of a cylindrical hub,
The blade has a concave inlet portion which rises to the negative pressure surface side in the radially central portion near the trailing edge and is open to at least the pressure surface side and extends from the trailing edge of the blade to the leading edge side,
The concave portion has a pair of side portions facing each other, standing up at a predetermined angle with respect to the negative pressure surface when the radial cross section is viewed,
The propeller fan which is comprised so that the span direction width | variety between the said pair of side parts may become gradually larger from an upstream to a downstream side. The method of claim 1,
Around the fan axis of rotation, the outer diameter of the blade is Rt, the inner diameter is Rh, the radius to the end of the side portion on the inner diameter side at the trailing edge of the blade is Ri, the radius to the end of the side portion on the outer diameter side of the blade trailing edge. When Ro is set to Ri = Rh + alpha (Rt-Rh) and Ro = Rh + beta (Rt-Rh), the propeller fan is set in a range such that 0.2≤α≤0.6 and 0.6≤β≤0.9. . The method of claim 1,
In the recess, when the inclination angle of the side portion on the inner diameter side with respect to the fan rotation axis is θi and the inclination angle of the side surface on the outer diameter side with respect to the fan rotation axis is θo, 5 ° ≤θi≤60 °, 5 ° ≤θo≤ Propeller fan which satisfies 60 degrees and (theta) i≥ (theta) o. The method of claim 1,
When the circumferential cross section in the radius at which the tip end side of the concave part is located is viewed, the length L1 from the trailing edge to the tip end side of the concave part is 10% to 60% of L0 with respect to the blade length L0. Propeller fan set to. 5. The method of claim 4,
When the circumferential cross section in the radius at which the tip end side of the concave part is located is seen, the depth d toward the negative pressure surface side of the concave part gradually increases from the upstream side to the downstream side, and also the depth near the blade trailing edge. The propeller fan whose depth fixed area | region where (d) becomes substantially constant at predetermined depth d 'is set. 6. The method of claim 5,
The propeller fan whose said predetermined depth d 'is set to 2%-10% of the blade length L0. The method of claim 1,
The propeller fan whose bottom part is formed and closed in the negative pressure surface side of each said side part of the said recessed part, and the said bottom part forms the curved surface substantially parallel to a negative pressure surface. The method of claim 1,
The propeller fan which the said recessed part is opened also in the negative pressure surface side, and consists only of the said pair side part. The method of claim 1,
The propeller fan which said each side part and the said pressure surface were mutually connected roundly. 9. The method of claim 8,
A propeller fan in which a vicinity of an upstream end of the opening of the concave portion is connected roundly. 11. The method of claim 10,
The said indentation part is provided with the filling part which filled up between the upstream end part of the pressure surface side of each said side part, The said filling part is comprised so that the same curved surface may be formed with the adjacent pressure surface. An air conditioning apparatus using the propeller fan according to any one of claims 1 to 12. The method of claim 1,
The wing is provided with a cutout formed by cutting the trailing edge thereof,
The outline of the cutout portion is composed of a first arc which is formed to bulge to the inner circumferential side of the blade and a second arc that is formed to bulge to the outer circumferential side of the blade, and is far from the trailing edge of the first arc and the second arc. A propeller fan, wherein one end of each side is connected to form a tip. 14. The method of claim 13,
In the first and second arcs forming the contour of the cutout portion, the rotation center of the propeller fan is O, the radius from the rotation center O to the outer circumference of the blade is R1, and the radius of the hub is R2. , And two connection points between the trailing edge of the blade and the contour of the cutout are called points P and points Q in order from the inner side close to the rotation center O, and a line segment connecting the rotation center O and the point P ( When the length of OP) is Rp and the length of the line segment OQ connecting the rotation center O and the point Q is Rq,
0.35 (R1-R2) ≤ (Rp-R2) <(Rq-R2) ≤ (R1-R2)
Propeller fan formed in the range to become. 14. The method of claim 13,
Propeller fan, wherein only one cutout is formed for one wing. 14. The method of claim 13,
The propeller fan provided with the microcircular arc in which the outline of the said cutout part is formed reflecting the dimension of the minimum machining tool between the said 1st and 2nd arcs. 14. The method of claim 13,
The first and second arcs are circular arcs, and the line segment connecting the point A that divides the first arc and the center point of the first arc, the point B that divides the second arc and the center point of the second arc. The propeller fan where the line segments intersect each other. The method of claim 13,
The first tangent to this first arc at a first connection point where the first and second arcs are circular arcs and the first arc is connected to the trailing edge, and the second connection point to which the second arc is connected to the trailing edge. A second tangent to a second circular arc is made with respect to a virtual tangent at the first and second connection points for the virtual circle passing through the first and second connection points about the center of rotation of the propeller fan, respectively. A propeller fan whose angle is plus or minus 15 degrees. 18. The method of claim 17,
F is a point at which the line segment connecting the point A of the first arc and the center point of the first arc and the line segment connecting the point B of the second arc and the center point of the second arc intersect each other. The point F is a propeller fan located in the inside of the outline of the cutout. 19. The method of claim 18,
A propeller fan providing a raised portion or a rib on the pressure surface side of the blade around it, including a connection point of the first and second arcs at the tip of the cutout contour. 21. The method of claim 20,
A propeller fan providing a raised portion or a rib on the negative pressure side of the blade around the blade including the connection point of the first and second arcs at the tip of the cutout. 22. The method of claim 21,
A radial cross-sectional shape of the contour portion of the cutout portion is rounded from the pressure surface side of the blade toward the negative pressure surface side. 22. The method of claim 21,
A radial cross-sectional shape of the contour portion of the cutout portion is rounded from the negative pressure side of the blade toward the pressure side. 22. The method of claim 21,
A propeller fan provided with a raised portion or a rib on the negative pressure side of the blade along the contour of the cutout. 25. The method of claim 24,
The height of the raised part or the rib is a propeller fan having a constant height from the leading edge side to the trailing edge side of the blade. 25. The method of claim 24,
The height of the said raised part or rib is a propeller fan gradually increasing toward the trailing edge side from the leading edge side of the said wing | blade. 25. The method of claim 24,
The height of the said raised part or rib becomes a propeller fan gradually decreasing toward the trailing edge side from the leading edge side of the said blade. An air conditioning apparatus using the propeller fan according to any one of claims 13 to 27.

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