JP2007218104A - Propeller fan and fluid feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propeller fan with the height of boss made further lower without degrading strength reliability and aerodynamic performance, having good stacking property and carrying property, and to provide a fluid feeding device having the same. <P>SOLUTION: The propeller fan 1 has a boss 10, and blades 20 formed to extend outward from the boss 10. The propeller fan 1 is rotated in one direction around a rotational shaft 40, and high pressure and low pressure are created across the propeller fan 1 as a boundary between them, to feed fluid from a low-pressure side to a high-pressure side of the propeller fan 1. The blade 20 has a front edge part 21, a rear edge part 23, a peripheral edge part 22, a front edge connection part 26, and a rear edge connection part 27. The front edge connection part 26 is formed to have a surface continuous to a low-pressure side end face 10n of the boss 10, and is formed not to be projected to a lower-pressure side than the low-pressure side end face 10n. The low-pressure side end face 10n of the boss 10 is positioned on the lower-pressure side than a stress concentration part S in a plane of a low-pressure side of the blade 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention generally relates to a propeller fan used in a fluid feeding device such as an outdoor unit of an air conditioner, an air purifier, a humidifier, a dehumidifier, a fan heater, a cooling device, and a ventilating device. It relates to the shape of the fan.

  Conventionally, a propeller fan is generally used for a blower or a cooler. For example, in an outdoor unit of an air conditioner, a propeller fan is attached to an air outlet. After the propeller fan rotates, the outside air is sucked into the outdoor unit from the air suction port, and then blown out from the air outlet.

  FIG. 14 is a perspective view showing a main part of a conventional fluid feeder.

  As shown in FIG. 14, the main part of the fluid feeder is composed of a propeller fan 2 and a bell mouth 60. The propeller fan 2 includes a cylindrical boss 10 and a plurality of blades 20. The blades 20 are provided along the circumferential direction of the outer peripheral surface of the boss 10, and a plurality of blades 20, in the example shown in FIG. 14, three blades 20 are arranged at equal intervals. When the propeller fan 2 is rotated in the direction indicated by the arrow Q, high pressure and low pressure are created with the propeller fan 2 as a boundary. That is, the fluid is sent out from the low pressure side to the high pressure side of the propeller fan 2 along the direction indicated by the arrow P. When propeller fan 2 rotates in the direction indicated by arrow Q, a flow is generated in the positive direction indicated by arrow P on rotating shaft 40.

  When the positive direction of the rotating shaft 40 of the boss 10 is determined in the direction indicated by the arrow P as described above, the blade 20 forms a curved surface twisted to the left with respect to the P direction. The curved surface of the wing 20 is formed by a front edge portion 21, a peripheral edge portion 22, and a rear edge portion 23 in addition to the side surface 11 of the boss 10. In general, the blade tip 24 has a sickle-pointed shape. The peripheral edge portion 22 is on a curved surface that is separated from the rotation shaft 40 by a distance of a diameter D.

  The bell mouth 60 is a plate-like body that is provided at a position separated from the outer diameter D of the propeller fan 2 by a predetermined gap ε and has an arc-shaped orifice as indicated by a broken line. The bell mouth 60 and the propeller fan 2 are fixed coaxially by an appropriate means. The propeller fan 2 is driven by driving means such as an electric motor, an internal combustion engine, and a pulley (not shown).

  The aerodynamic performance of a propeller fan is defined by the angle of attack. This angle of attack is calculated from the angle at which the airflow flows into the propeller fan with reference to the rotation axis of the propeller fan and the stagger angle of the propeller fan. The stagger angle is the angle between the rotation axis of the propeller fan and the chord. In order to obtain the desired performance from the propeller fan, it is necessary to design the angle of attack appropriately. Therefore, we will optimize the stagger angle that can be directly controlled when designing the propeller fan, and optimize the angle of attack.

Further, since the propeller fan requires a large transportation volume with respect to the volume of the molded product, various measures are taken in order to reduce transportation costs and save space. Generally, as a method for storing and transporting propeller fans, a method of stacking propeller fans in the axial direction is adopted. For this reason, in order to stack a large number of propeller fans, a method of reducing the height of the blades, for example, as described in JP-A-2004-308622 (Patent Document 1), a notch or the like is provided in the hub. A technique has been proposed in which the diameter of the suction-side hub portion is reduced so as to be easily stacked.
JP 2004-308622 A

  When the propeller fan is designed to obtain the desired performance, the angle of attack is almost uniquely determined, so the stagger angle is also fixed to some extent. For this reason, in order to ensure desired performance and to ensure strength reliability, it is necessary to ensure the necessary and sufficient height of the boss together with the stagger angle and the blade length.

  However, if a sufficient boss height is ensured, the number of propeller fans that can be stacked in the axial direction at a predetermined height decreases. For this reason, since the number of propeller fans that can be transported at one time decreases, the number of transports increases. As a result, there arises a problem that the cost for transport increases.

  If only the height of the boss is lowered in order to reduce the cost associated with conveyance, a new problem arises in that the area where the boss and the wing overlap is reduced and the strength reliability of the propeller fan is lowered. Further, when only the height of the boss is lowered, the strength for maintaining the wing shape is also lowered, so that the amount of deflection is increased. As a result, not only the aerodynamic performance of the propeller fan is deteriorated, but also the maximum stress value generated is further increased, and there is a problem that the strength reliability is further lowered.

  In other words, there has been a problem that the improvement of propeller fan stackability and strength reliability are in a trade-off relationship.

  Accordingly, an object of the present invention is to provide a propeller fan having a shape capable of satisfying stackability and strength reliability at the same time, that is, the height of the boss without deteriorating the strength reliability and further degrading the aerodynamic performance. The propeller fan having good stackability and transportability and a fluid feeding device including the propeller fan are further provided.

  A propeller fan according to the present invention includes a boss and wings formed so as to extend outward from the boss, and the propeller fan is rotated in one direction about a rotation axis so that the propeller fan is rotated. This is a propeller fan that creates high pressure and low pressure at the boundary and sends fluid from the low pressure side to the high pressure side of the propeller fan. The wing rotates by connecting the leading edge positioned on the side of the rotation direction, the trailing edge positioned on the side opposite to the rotation direction, the leading edge of the leading edge and the trailing edge of the trailing edge. A peripheral edge extending around the shaft, a front edge connecting part that connects the front edge part and the boss, and a rear edge connecting part that connects the rear edge part and the boss. The leading edge connecting portion is formed so as to have a continuous surface on the low pressure side end face of the boss, and is formed so as not to protrude to the low pressure side from the low pressure side end face of the boss. The low pressure side end surface of the boss is formed so as to be positioned on the low pressure side of the stress concentration portion on the low pressure side surface of the blade.

  By comprising in this way, since the height of a boss | hub can be made small, the cost concerning conveyance of the molded product of a propeller fan can be reduced. In addition, since the low-pressure side end face of the boss is formed so as to be positioned on the low-pressure side of the stress concentration part on the low-pressure side of the blade, the strength reliability and aerodynamic performance are not deteriorated. The height can be further reduced. For this reason, while ensuring reliability and desired performance, the cost concerning conveyance of the molded product of a propeller fan can be reduced.

  In the propeller fan according to the present invention, at least a part of the trailing edge is a surface connecting the high-pressure side surface and the low-pressure side surface of the blade, and a line segment positioned around the rotation axis is rotated about the rotation axis. It is preferable that it is formed by the surface formed by making it.

  By configuring in this way, the two flows on the low pressure surface side and the high pressure surface side of the blade smoothly merge at the trailing edge portion, so that the velocity deficit in the flow is reduced in the vicinity of the trailing edge portion. As a result, the amount of vortices generated from the trailing edge can be suppressed, aerodynamic noise can be reduced, and at the same time fan efficiency is improved.

  In the propeller fan of the present invention, it is preferable that at least a part of the trailing edge portion formed by the above-mentioned surface is formed in a region from the representative root mean square radius position of the blade to the trailing edge connecting portion.

  The area from the representative root mean square radius position of the wing to the trailing edge connecting portion is a surface connecting the high-pressure side and the low-pressure side of the wing because the ratio contributing to aerodynamic performance is relatively small, and around the rotation axis. Even if the surface formed by rotating the line segment positioned at the center of the rotation axis is formed at the trailing edge of the above region, the generation of vortexes is suppressed without significantly reducing the aerodynamic performance. And aerodynamic noise can be reduced. Thereby, a highly efficient and low noise propeller fan can be obtained.

  Furthermore, in the propeller fan of this invention, it is preferable that the trailing edge connecting portion is connected to the boss so as to have a continuous surface with the high-pressure side surface of the boss.

  By configuring in this way, the aerodynamic performance of the propeller fan can be maintained, and a space can be secured at the joint portion between the end surface of the boss and the end of the rear edge on the boss side, and a sufficiently large R portion can be formed. . For this reason, the stress concentration caused by the deflection of the blades during rotation of the propeller fan can be alleviated, and a propeller fan excellent in strength reliability can be provided.

  In the propeller fan according to the present invention, it is preferable that a step is formed by the trailing edge connecting portion projecting to the high-pressure side from the high-pressure end edge of the boss.

  With this configuration, when a plurality of propeller fans are stacked in the axial direction, the plurality of propellers are held so that the step at the high-pressure end of the boss is held by the low-pressure end of another boss. Since fans can be stacked, an efficient packaging can be realized.

  In the propeller fan of the present invention, it is preferable that the rear edge portion is formed so as to protrude to the high pressure side rather than the end edge on the high pressure side of the boss.

  By configuring in this way, the position of the trailing edge can be set regardless of the height of the boss, so that the wing area can be increased and the aerodynamic performance of the propeller fan can be increased efficiently. .

  A fluid feeder according to the present invention includes a propeller fan having at least one of the above-described features.

  According to this fluid feeder, reliability and desired performance can be ensured, and the cost for transporting the molded product of the propeller fan can be reduced.

  As described above, according to the present invention, the height of the boss can be further reduced without deteriorating the strength reliability and aerodynamic performance of the propeller fan. It is possible to reduce the cost for transporting the molded product.

(Embodiment 1)
A propeller fan according to Embodiment 1 of the present invention will be described. This propeller fan is integrally formed of a synthetic resin such as an AS (acrylonitrile-styrene) resin containing glass fiber.

  FIG. 1 is a perspective view seen from the high pressure side of the propeller fan according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view seen from the low pressure side of the propeller fan according to Embodiment 1 of the present invention.

  As shown in FIGS. 1 and 2, the propeller fan 1 includes a cylindrical boss 10 and a plurality of blades 20, and in the example shown in FIGS. 1 and 2, two blades 20. The plurality of blades 20 are provided at equal intervals along the circumferential direction of the outer peripheral surface of the boss 10.

  When the propeller fan 1 is rotated in the direction indicated by the arrow Q, high pressure and low pressure are created with the propeller fan 1 as a boundary. That is, the fluid is sent out from the low pressure side to the high pressure side of the propeller fan 1 along the direction indicated by the arrow P. When propeller fan 1 rotates in the direction indicated by arrow Q, a flow is generated in the positive direction indicated by arrow P of rotating shaft 40.

  The curved surface of the wing 20 is the front edge of the front edge 21 that smoothly connects the side surface 11 of the boss 10, the front edge 21, the peripheral edge 22, the rear edge 23, and the front edge 21 and the peripheral edge 22. The blade tip 24 including the blade, the peripheral edge 22 and the trailing edge 23 are smoothly connected, the blade trailing edge 25 including the trailing edge of the trailing edge 23, the boss low pressure side connecting portion between the leading edge 21 and the boss 10. A leading edge connecting portion 26 for smoothly connecting the rear edge portion 23 and a rear edge connecting portion 27 for smoothly connecting the rear edge portion 23 and the boss high-pressure side connecting portion 13 of the boss 10, and a rear edge portion 23 and a rear edge connecting portion 27. It is formed by the inner edge part 28 which connects smoothly. The boss 10 has a high-pressure side end face 10p and a low-pressure side end face 10n.

  At least a part of the trailing edge 23 is a surface that connects the high-pressure side surface and the low-pressure side surface of the blade 20, and is formed by rotating a line segment positioned around the rotation axis 40 around the rotation axis. It is formed by a curved surface 30 (the hatched portion in FIG. 1). The wing tip 24 is shaped like a sickle. The leading edge connecting portion 26 is formed in a shape that is smoothly curved from the leading edge portion 21, thereby dispersing stress generated in the blade 20 and improving strength reliability.

  Further, the rear edge portion 23 is formed on the high pressure side from the boss high pressure side connecting portion 13. That is, the rear edge 23 is formed so as to protrude to the high-pressure side from the end edge on the high-pressure side of the boss. For this reason, since the position of the trailing edge 23 can be set regardless of the boss height, the blade area can be increased, and the aerodynamic performance of the propeller fan 1 can be improved efficiently.

  The boss 10 connects the side surface 11 to which the wing 20 is attached, a fixing portion (not shown) fixed to the motor shaft, and the fixing portion and the side surface 11, and the propeller fan 1 and the bell mouth 60 (see FIG. And 14) a connecting portion formed at a position where the positional relationship is optimal. The cross section of the boss 10 is formed to have a concave shape, an H shape, or a diagonal flow shape according to the purpose.

  3 is a schematic sectional view showing the positional relationship between the trailing edge connecting portion 27 and the boss high-pressure side connecting portion 13 of the propeller fan according to Embodiment 1 of the present invention, and FIG. 4 is a comparative example showing the trailing edge connecting portion 27 and the boss high pressure side. It is a schematic sectional drawing in case the side connection part 13 is not connected smoothly.

  As shown in FIGS. 3 and 4, an angle formed between the surface of the boss 10 where the boss high-pressure side connecting portion 13 is located and the inner edge portion 28 is defined as α. As shown in FIG. 4, when the trailing edge connecting portion 27 and the boss high-pressure side connecting portion 13 are not smoothly connected, the angle α is 90 degrees or less. However, as shown in FIG. 3, when the trailing edge connecting portion 27 and the boss high-pressure side connecting portion 13 are smoothly connected, the angle α can be 90 ° or more. That is, the trailing edge connecting portion 27 is connected to the boss 10 so as to have a continuous surface with the high pressure side surface of the boss 10. For this reason, while maintaining the aerodynamic performance of the propeller fan 1, a space is secured between the trailing edge connecting portion 27 and the high pressure side end surface 10p where the boss high pressure side connecting portion 13 is located, and a sufficiently large R portion is formed. Can do. For this reason, the stress concentration caused by the deflection of the blade 20 during the rotation of the propeller fan 1 can be relaxed, and the propeller fan 1 excellent in strength reliability can be provided.

  In the embodiment shown in FIG. 3, the cross-sectional shape of the boss 10 is a concave shape, but the present invention is not limited to this. 5 is a schematic cross-sectional view showing the positional relationship between the trailing edge connecting portion 27 and the boss high-pressure side connecting portion 13 when the cross section of the boss 10 is H-shaped, and FIG. 6 is a case where the cross-sectional shape of the boss 10 is a diagonal flow shape. It is a schematic sectional drawing which shows the positional relationship of the trailing edge connection part 27 and the boss | hub high voltage | pressure side connection part 13. FIG. As shown in FIGS. 5 and 6, since the trailing edge connecting portion 27 and the boss high-pressure side connecting portion 13 are smoothly connected, it is possible to achieve the same effect as that of the embodiment shown in FIG. 3.

  FIG. 7 is a schematic diagram showing the positional relationship between the leading edge connecting portion 26 and the boss low-pressure side connecting portion 12 according to Embodiment 1 of the present invention. FIG. 8 is a front view and a side view of the propeller fan according to Embodiment 1 of the present invention as viewed from the high pressure side. FIG. 9 is a rear view and a side view of the propeller fan according to Embodiment 1 of the present invention as viewed from the low pressure side.

  As shown in FIG. 7, the front edge connecting portion 26 is formed such that a part (shaded portion) connected to the boss 10 of the front edge portion 21 is cut, and the boss low-pressure side connecting portion is formed. 12 is smoothly connected. That is, the leading edge connecting portion 26 is formed so as to have a continuous surface with the low pressure side end surface of the boss 10 and is formed so as not to protrude to the low pressure side from the low pressure side end surface 10 n of the boss 10.

  As shown in FIGS. 8 and 9, the typical tangent line A of the leading edge 21 and the typical tangent line B of the leading edge connecting portion 26 are caused by the deflection and centrifugal force of the blade 20 generated during the rotation of the propeller fan 1. Stress concentrates near the point where the crosses. This is the stress concentration part S. The maximum stress value at the stress concentration position (stress concentration portion) S is strongly influenced by the shapes and positions of the leading edge connecting portion 26 and the boss low-pressure side connecting portion 12. For example, in order to ensure the strength reliability and aerodynamic performance of the propeller fan 1, it is necessary to secure a sufficient area for the leading edge connecting portion 26 and the boss low-pressure side connecting portion 12. Conversely, if a part of the leading edge connecting portion 26 is cut carelessly, the areas of the leading edge connecting portion 26 and the boss low-pressure side connecting portion 12 cannot be secured, and the leading edge connecting portion 26 and the boss low-pressure side connecting portion cannot be secured. The stress applied to the portion 12 increases rapidly, and the strength reliability is impaired. In addition, the strength to retain the blade shape also decreases, and the amount of deflection increases, so the aerodynamic performance deteriorates and the maximum stress value generated further increases, further reducing the strength reliability.

  Therefore, in order to avoid the above problem, in the present embodiment, as shown in the lower diagram of FIG. 9, the end surface of the leading edge connecting portion 26 is slightly lower than the stress concentration portion S on the low pressure surface of the blade 20. In this position, a part of the leading edge connecting portion 26 is cut so that a surface perpendicular to the rotating shaft 40 of the propeller fan 1 is formed. In other words, the low pressure side end face 10n of the boss 10 is formed to be positioned on the low pressure side with respect to the stress concentration portion S on the low pressure side surface of the blade 20.

  With this configuration, the height of the boss 10 can be further reduced without deteriorating strength reliability and aerodynamic performance, so that reliability and desired performance can be ensured and the propeller fan molded product can be conveyed. Cost can be reduced.

  It should be noted that the limit position that can be cut to obtain the same effect as described above is the same position as the stress concentration portion S on the low pressure surface of the blade 20.

  Referring to FIG. 8, at least a part of the trailing edge portion 23 is a surface connecting the high pressure side surface and the low pressure side surface of the blade 20, and a line segment positioned around the rotation axis 40 is centered on the rotation axis. Will be described as being formed by a surface 30 formed by rotating as shown in FIG. The above-mentioned surface forming at least a part of the rear edge portion 23 is formed as a line segment positioned around the rotation axis 40, creating a cut line 30 symmetrically with the rotation axis 40 of the propeller fan 1. It is formed by cutting from the rear edge 23 a portion where the rotary body formed by rotating the cut line 30 as a center and the rear edge 23 intersect.

  Since the surface 30 always faces the tangential direction with respect to the rotation of the propeller fan 1, a shape having the least influence on the airflow with respect to the rotation can be obtained. Therefore, the two flows of the flow along the low pressure side surface and the flow along the high pressure side surface of the blade 20 smoothly merge at the trailing edge portion 23, and the velocity deficit in the flow is reduced in the vicinity of the trailing edge portion 23. As a result, the amount of discharge vortices generated at the trailing edge can be suppressed, and aerodynamic noise can be reduced. Further, it is possible to reduce the drag that acts to prevent the rotation of the propeller fan 1 and improve the fan efficiency.

  The reason for this will be described with reference to FIG. FIG. 10 is a schematic diagram for partially enlarging the trailing edge 23 and explaining the flow and vortex behavior in the vicinity of the trailing edge 23 in the present invention example and the conventional example. 10A is an ideal shape of a wing, FIG. 10B is a shape considering molding, FIG. 10C is a shape considering molding using a mold, and FIG. 10D is the present invention. An example shape is shown.

  In the wake of the blade 20, the flow along the high-pressure side 20p of the blade 20 and the flow along the low-pressure side 20n merge. As shown in FIG. 10A, the ideal trailing edge 23 intersects the high-pressure side 20p of the blade 20 because the high-pressure side 20p and the low-pressure side 20n intersect at the point where the thickness of the trailing edge 23 becomes zero. Since the two flows, the flow along the low pressure side surface 20n and the flow along the low pressure side surface 20n smoothly merge at the trailing edge 23, the flow velocity is not lost in the vicinity of the trailing edge 23.

  By the way, considering the securing of the strength of the molded product and the resin fluidity at the time of molding, the trailing edge portion 23 needs to have a certain thickness as shown in FIG. Furthermore, when molding with a mold, considering the molding cost and the durability of the mold, as shown in FIG. 10 (c), the rear edge 23 is a plane parallel to the sliding direction of the mold, that is, vertical. Since the surface is formed, the rear edge portion 23 is thick. Due to the thickness of the rear edge 23, the two flows of the flow along the high-pressure side surface 20p and the flow along the low-pressure side surface 20n cannot be smoothly joined to generate a discharge vortex 50, and aerodynamic noise is generated.

  However, as shown in FIG. 10D, when the trailing edge 23 includes the surface 30 described above, the two flows of the flow along the high-pressure side 20p and the flow along the low-pressure side 20n of the blade 20 cause the trailing edge. Since the flow smoothly merges at the portion 23, the flow velocity deficit is reduced in the vicinity of the rear edge portion 23. As a result, it is possible to suppress the generation amount of the discharge vortex at the trailing edge 23, reduce aerodynamic noise, and improve the fan efficiency at the same time.

  The shape of the rotator formed by rotating the cut line 30 around the rotation axis 40 is such as the shape of a concealed dish that has a substantially frustoconical protrusion in part as in this embodiment, or a cone A shape in which the base is changed to a cylinder, or a shape that is the same plane as the end surface on the rear side in the airflow direction in the boss 10 is possible, and is not particularly limited to the shape of the present embodiment. If the edge 23 has a shape that always faces the tangential direction with respect to the rotation of the propeller fan 1, the same effect as described above can be obtained.

(Embodiment 2)
A propeller fan according to a second embodiment of the present invention will be described. In addition, the propeller fan of this embodiment is the same as that of Embodiment 1 and the conventional propeller fan about the structure which is not described in particular below. Therefore, the propeller fan according to the second embodiment will be described with a focus on the different points, with the same reference numerals being assigned to the same configuration and parts having the same effects, and the detailed description thereof being omitted.

  FIG. 11 is a front view of the propeller fan according to Embodiment 2 of the present invention as viewed from the high pressure side.

With reference to FIG. 11, the surface 30 formed in the area | region from the position vicinity of the representative mean square radius Rr of the wing | blade 20 to the boss | hub 10 side is demonstrated. The representative root mean square radius Rr is defined by Rr = ((R ² + r ² ) / 2) ^1/2 . Here, R is a representative radius of the blade 20, and is represented by (R1 + R2) / 2, where R1 is the maximum outer radius and R2 is the minimum outer radius. r is a representative radius of the boss 10, and is represented by (r1 + r2) / 2 where r1 is the maximum outer radius and r2 is the minimum outer radius.

  In general, in the region from the position of the representative mean square radius Rr of the wing to the boss 10 side, that is, the region from the position of the representative mean square radius Rr of the wing to the trailing edge connecting portion 27, the ratio contributing to the aerodynamic performance is relative. Small. For this reason, a surface 30 that connects the high-pressure side surface and the low-pressure side surface of the blade and is formed by rotating a line segment positioned around the rotation axis about the rotation axis is used in the above region. Even if it is formed on the rear edge portion 23, the generation of discharge vortices can be suppressed and aerodynamic noise can be reduced without significantly reducing the aerodynamic performance. Thereby, a highly efficient and low noise propeller fan can be obtained.

(Embodiment 3)
A propeller fan according to Embodiment 3 of the present invention will be described. In addition, the propeller fan of this embodiment is the same as that of Embodiment 1 and the conventional propeller fan about the structure which is not described in particular below. Therefore, the propeller fan according to the third embodiment will be described with a focus on the different points, with the same reference numerals being assigned to the same configuration and parts having the same effects and the detailed description thereof being omitted.

  FIG. 12 is a schematic cross-sectional view showing a part of the propeller fan according to Embodiment 3 of the present invention.

  Referring to FIG. 12, a step is formed so that trailing edge connecting portion 27 is more convex than boss high-pressure side connecting portion 13. In other words, the rear edge connecting portion 27 protrudes to the high pressure side from the high pressure side edge of the boss 10, thereby forming a step.

  Since the step is formed so that the trailing edge connecting portion 27 is more convex than the boss high pressure side connecting portion 13, when a plurality of propeller fans 1 are stacked in the axial direction, the trailing edge connecting portion 27 and the boss high pressure side are stacked. The step with the connecting portion 13 is shaped to be held by another boss low-pressure side connecting portion 12, and an efficient load form can be realized.

(Embodiment 4)
A propeller fan according to Embodiment 4 of the present invention will be described. In addition, the propeller fan of this embodiment is the same as that of Embodiment 1 and the conventional propeller fan about the structure which is not described in particular below. Therefore, the propeller fan according to the fourth embodiment will be described with a focus on the different points, with the same reference numerals being assigned to the same configuration and the parts having the effects and the detailed description thereof being omitted.

  FIG. 13 is a schematic cross-sectional view showing a part of the propeller fan according to Embodiment 4 of the present invention.

  As shown in FIG. 13, the front edge connecting portion 26 and the boss low-pressure side connecting portion 12 may be provided with a step so that the front edge connecting portion 26 is more convex than the boss low-pressure side connecting portion 12. That is, the front edge connecting portion 26 protrudes to the low pressure side from the low pressure side edge of the boss 10, thereby forming a step. Thus, since the front edge connecting portion 26 is provided with a step so as to protrude from the boss low-pressure side connecting portion 12, the same effect as that of the third embodiment can be obtained.

  Further, when the propeller fan is driven by a motor, it is desirable that the motor is disposed on the lower pressure side than the propeller fan in order to minimize the influence of the motor from the airflow. In this case, since the step is located on the motor side, it is difficult for the user to see and the appearance is not impaired.

  In the above embodiment, the propeller fan is integrally molded of glass fiber AS resin. However, in addition to this, ABS (acrylonitrile-butadiene-styrene) resin or polypropylene (PP) is used. A propeller fan integrally molded with a synthetic resin such as the like may be used. Moreover, the propeller fan integrally molded with the synthetic resin which included mica etc. and increased the intensity | strength may be sufficient. Or the propeller fan may not be integrally molded.

  Further, by configuring the fluid feeder including the propeller fan 1 described above, the height of the boss can be further reduced without degrading the strength reliability and aerodynamic performance of the propeller fan. While ensuring desired performance, the cost concerning conveyance of the molded product of a propeller fan can be reduced.

  The embodiment disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the scope of claims, and includes all modifications and variations within the meaning and scope equivalent to the scope of claims.

  The propeller fan according to the present invention and the fluid feeding device including the propeller fan can be applied to an outdoor unit of an air conditioner, an air purifier, a humidifier, a dehumidifier, a fan heater, a cooling device, a ventilation device, and the like.

It is the perspective view seen from the high voltage | pressure side of the propeller fan which concerns on Embodiment 1 of this invention. It is the perspective view seen from the low voltage | pressure side of the propeller fan which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the positional relationship of the rear edge connection part of the propeller fan which concerns on Embodiment 1 of this invention, and a boss | hub high voltage | pressure side connection part. It is a schematic sectional drawing in case the trailing edge connection part of a propeller fan and the boss | hub high-pressure side connection part are not smoothly connected as a comparative example. It is a schematic sectional drawing of the propeller fan which shows the positional relationship of the trailing edge connection part and boss | hub high voltage | pressure side connection part at the time of making the cross section of a boss | hub into H shape. It is a schematic sectional drawing of the propeller fan which shows the positional relationship of the trailing edge connection part and boss | hub high voltage | pressure side connection part at the time of making the cross section of a boss into a diagonal flow shape. It is the schematic which shows the positional relationship of the front edge connection part and boss | hub low voltage | pressure side connection part of the propeller fan which concern on Embodiment 1 of this invention. It is the front view seen from the high voltage | pressure side of the propeller fan which concerns on Embodiment 1 of this invention, and its side view. It is the rear view seen from the low voltage | pressure side of the propeller fan which concerns on Embodiment 1 of this invention, and its side view. It is the schematic for demonstrating the flow and vortex behavior of the vicinity of the rear edge part in the example of the present invention and the conventional example by partially enlarging the rear edge part. It is the front view seen from the high voltage | pressure side of the propeller fan which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing which shows a part of propeller fan which concerns on Embodiment 3 of this invention. It is a schematic sectional drawing which shows a part of propeller fan which concerns on Embodiment 4 of this invention. It is a perspective view which shows the principal part of the conventional fluid feeder.

Explanation of symbols

  1: propeller fan, 10: boss, 10p: high pressure side end face, 10n: low pressure side end face, 11: side surface, 12: boss low pressure side connection part, 13: boss high pressure side connection part, 20: blade, 21: leading edge Part: 22: peripheral edge part, 23: trailing edge part, 24: blade tip part, 25: blade trailing edge part, 26: leading edge connecting part, 27: trailing edge connecting part, 28: inner edge part, 30: surface (cut) Line), 40: rotation axis.

Claims (7)

A boss and a wing formed to extend outward from the boss,
A propeller fan that creates high pressure and low pressure at the propeller fan as a boundary by rotating the propeller fan in one direction around the rotation axis, and sends fluid from the low pressure side to the high pressure side of the propeller fan,
The wing includes a front edge portion positioned on a rotation direction side, a rear edge portion positioned on a side opposite to the rotation direction, a leading edge of the front edge portion, and a rear edge of the rear edge portion. A peripheral edge portion that connects and extends around the rotation axis, a front edge connection portion that connects the front edge portion and the boss, and a rear edge connection portion that connects the rear edge portion and the boss;
The leading edge connecting portion is formed so as to have a surface continuous with the low pressure side end surface of the boss, and is formed so as not to protrude to the low pressure side from the low pressure side end surface of the boss,
The propeller fan formed so that the low-pressure side end surface of the boss is positioned on the low-pressure side of the stress concentration portion on the low-pressure side surface of the blade.   At least a part of the trailing edge is a surface connecting the high pressure side surface and the low pressure side surface of the blade, and is formed by rotating a line segment positioned around the rotation axis around the rotation axis. The propeller fan according to claim 1, wherein the propeller fan is formed by a surface.   3. The propeller fan according to claim 2, wherein at least a part of the trailing edge portion formed by the surface is formed in a region from a representative root mean square radius position of the blade to the trailing edge coupling portion.   The propeller fan according to any one of claims 1 to 3, wherein the trailing edge connecting portion is connected to the boss so as to have a surface continuous with a high-pressure side surface of the boss.   The propeller fan according to any one of claims 1 to 4, wherein a step is formed by projecting the trailing edge connecting portion to a higher pressure side than an end edge on the high pressure side of the boss.   The propeller fan according to any one of claims 1 to 5, wherein the rear edge portion is formed to protrude to a high-pressure side from an end edge on the high-pressure side of the boss. A fluid feeder comprising the propeller fan according to any one of claims 1 to 6.

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