WO2024009490A1

WO2024009490A1 - Axial flow fan, air blower, and air conditioner

Info

Publication number: WO2024009490A1
Application number: PCT/JP2022/027062
Authority: WO
Inventors: 勝幸山本; 拓矢寺本
Original assignee: 三菱電機株式会社
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2024-01-11

Abstract

This axial flow fan is provided with a hub that is rotationally driven and forms a rotational axis, and a blade that is formed around the hub and comprises a leading edge part, a trailing edge part, an inner edge part which is a portion connected to the hub, and an outer edge part forming an outer edge between the leading edge part and the trailing edge part. The blade comprises: a reduced part that forms, in a leading edge part-side portion of the portion forming the outer edge part, a portion in which the outer diameter of the blade is reduced compared to a trailing edge part-side portion forming the maximum diameter of the blade; and an outer peripheral part that forms, in the reduced part, a pressure side that curves from the downstream side to the upstream side in a direction in which a fluid that flows during rotation of the blade flows, as the pressure side extends from the inner edge part-side portion toward the outer edge part. The outer peripheral part is formed so that the width thereof in a radial direction about the rotational axis is greater in the trailing edge part-side portion than in the leading edge part–side portion.

Description

Axial fans, blowers, and air conditioners

The present disclosure relates to an axial fan including a plurality of blades, a blower including the axial fan, and an air conditioner including the blower.

Conventionally, an axial fan has been proposed that has a hub serving as a rotation center and a plurality of blades provided on the outer peripheral surface of the hub (for example, see Patent Document 1). The axial fan of Patent Document 1 has a bent portion on the outer circumference of each blade that is bent upward toward the suction side, and the width of the bent portion in the radial direction gradually increases from the leading edge to the trailing edge. It is formed to be. The axial fan disclosed in Patent Document 1 has such a configuration that a blade tip vortex is guided smoothly from the leading edge side to the trailing edge side, and the generated blade tip vortex is difficult to leave the suction surface.

Patent No. 3979388

In an axial flow fan, when there is no structure upstream of the fan or when the fan is away from the structure, a less turbulent airflow flows toward the blade, so the blade tip vortices that occur on the leading edge side of the blade is small. However, if there is a structure such as a motor support upstream of the axial fan, the airflow downstream of the structure is turbulent. In an axial fan, when turbulent airflow flows into the leading edge of the blade's outer periphery, it is affected by the circumferential speed of the fan's outermost periphery, causing a large leakage of airflow on the leading edge side of the blade, resulting in a blade tip vortex. Increase formation. If there is a structure such as a motor support upstream of the axial fan, the axial fan of Patent Document 1 cannot stabilize the blade tip vortices due to the small warpage at the bending part on the leading edge side of the blade. efficiency may decrease.

The present disclosure is intended to solve the above-mentioned problems, and provides an axial fan, a blower, and a fan in which blade tip vortices are stabilized even when a turbulent airflow flows toward the blade, and the efficiency is increased. The purpose is to provide air conditioners.

The axial fan according to the present disclosure includes a hub that is rotationally driven and forms a rotating shaft, a front edge, a rear edge, an inner edge that is a part connected to the hub, and a front edge that is formed around the hub. a wing having an outer edge forming an outer edge between the outer edge and the trailing edge; A reduced part that forms a part where the outer diameter of the blade is smaller than that of the outer diameter part, and in the reduced part, from the inner edge side toward the outer edge, the downstream side in the flow direction of the fluid that flows when the blade rotates. an outer circumferential portion forming a positive pressure surface that curves toward the upstream side from It is formed in such a way that one part is larger than the other.

A blower according to the present disclosure includes an axial fan configured as described above and a drive source that applies driving force to the axial fan.

An air conditioner according to the present disclosure includes a blower configured as described above, a motor support that supports a drive source, a condenser that condenses a refrigerant, and an evaporator that evaporates the refrigerant. Air is blown to at least one side of the container.

According to the present disclosure, the axial fan has a reduced diameter on the leading edge side of the blade by having a reduced portion in the blade, and the portion on the leading edge side is smaller than the portion forming the outermost diameter of the blade. Since the blade is also close to the rotation axis, the circumferential speed of the blade portion on the leading edge side becomes smaller. Therefore, even if a fluid flow turbulent due to a structure such as a motor support flows into the axial fan, the circumferential speed of the leading edge side of the blade is small, so the part of the leading edge side of the blade The blade tip vortices formed in the air become smaller. Furthermore, the axial fan has an outer circumferential portion in the reduced portion that forms a positive pressure surface that curves from the downstream side toward the upstream side as it goes from the inner circumferential side toward the outer edge. The outer peripheral portion is formed such that the width in the radial direction about the rotation axis is larger at the rear edge side than at the front edge side. By having the outer circumferential portion with this configuration, the axial fan can cause a blade tip vortex that expands from the leading edge side portion to the trailing edge side portion to follow the outer circumferential portion. Therefore, in the axial fan, the blade tip vortices on the negative pressure surface are not disturbed and stabilized, and the fan efficiency can be improved and high efficiency can be achieved.

1 is a front view showing a schematic configuration of an axial fan according to Embodiment 1. FIG. FIG. 3 is a front view of a blade in the axial fan according to the first embodiment. FIG. 3 is a cross-sectional view of a blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a first modification of the blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a second modification of the blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a third modification of the blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a fourth modification of the blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a fifth modification of the blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a sixth modification of the blade in the axial fan according to the first embodiment. FIG. 7 is a front view of a seventh modification of the blade in the axial fan according to the first embodiment. FIG. 3 is a conceptual diagram of a radial cross section of an axial fan according to a comparative example. FIG. 7 is a perspective view of an axial fan according to a second comparative example. FIG. 7 is a side view of an axial fan according to a second comparative example. FIG. 7 is a conceptual diagram of an outdoor unit used in an air conditioner equipped with an axial fan according to a second comparative example. 15 is a conceptual diagram showing the relationship between the motor support and the axial fan in the outdoor unit used in the air conditioner shown in the comparative example of FIG. 14. FIG. FIG. 7 is a front view of a blade in an axial fan according to a second embodiment. FIG. 3 is a cross-sectional view of a blade in an axial fan according to a second embodiment. FIG. 7 is a front view of a first modification of the blade in the axial fan according to the second embodiment. FIG. 7 is a front view of a second modification of the blade in the axial fan according to the second embodiment. FIG. 7 is a front view of a third modification of the blade in the axial fan according to the second embodiment. FIG. 7 is a front view of a fourth modification of the blade in the axial fan according to the second embodiment. FIG. 7 is a front view of a fifth modification of the blade in the axial fan according to the second embodiment. FIG. 7 is a front view of a blade in an axial fan according to a third embodiment. FIG. 7 is a cross-sectional view of a blade in an axial fan according to Embodiment 3. FIG. 7 is a cross-sectional view of a blade in an axial fan according to a fourth embodiment. FIG. 7 is a cross-sectional view of a blade in an axial fan according to a fifth embodiment. FIG. 7 is a cross-sectional view of a first modification of the blade in the axial fan according to the fifth embodiment. FIG. 7 is a cross-sectional view of a blade in an axial fan according to a sixth embodiment. FIG. 7 is a schematic diagram of an air conditioner according to Embodiment 7. FIG. 12 is a perspective view of the outdoor unit of the air conditioner according to Embodiment 7, viewed from the outlet side. FIG. 3 is a diagram for explaining the configuration of the outdoor unit from the top side. FIG. 3 is a diagram showing a state in which the fan grill is removed from the outdoor unit. FIG. 2 is a diagram illustrating the internal configuration of the outdoor unit with the fan grill, front panel, etc. removed.

Hereinafter, an axial fan, a blower, and an air conditioner according to embodiments will be described with reference to the drawings. Note that in the following drawings including FIG. 1, the relative dimensional relationships, shapes, etc. of each component may differ from the actual ones. In addition, in the following drawings, parts with the same reference numerals are the same or equivalent, and this is common throughout the entire specification. In addition, to facilitate understanding, we use terms indicating directions (for example, "top," "bottom," "right," "left," "front," and "back," etc.) as appropriate; This is only described for convenience of explanation, and does not limit the arrangement or orientation of the device or parts.

Embodiment 1.
[Axial flow fan 100]
FIG. 1 is a front view showing a schematic configuration of an axial fan 100 according to the first embodiment. Note that the rotation direction DR indicated by the arrow in the figure indicates the direction in which the axial fan 100 rotates. Further, a counter-rotation direction OR indicated by an arrow in the figure indicates a direction opposite to the direction in which the axial fan 100 rotates. Further, a circumferential direction CD indicated by a double-headed arrow in the figure indicates the circumferential direction of the axial fan 100. The circumferential direction CD includes a rotation direction DR and a counter-rotation direction OR.

Further, the Y axis shown in FIG. 1 is a direction perpendicular to the rotation axis RA of the axial fan 100, and represents the radial direction of the axial fan 100. In the radial direction, the portion on the Y2 side is located on the outer peripheral side with respect to the portion on the Y1 side, and the portion on the Y1 side is located on the inner peripheral side with respect to the portion on the Y2 side. That is, the Y1 side of the axial fan 100 is the inner peripheral side of the axial fan 100, and the Y2 side of the axial fan 100 is the outer peripheral side of the axial fan 100.

An axial fan 100 according to Embodiment 1 will be described using FIG. 1. The axial fan 100 is an axial impeller, and is a device that forms a fluid flow. The axial fan 100 is used in a blower 55 (see FIG. 31), which will be described later, and is used, for example, as a fan for an air conditioner or a ventilation device. The axial fan 100 forms a fluid flow by rotating in the rotation direction DR about the rotation axis RA. The fluid is, for example, a gas such as air, and the axial fan 100 forms an airflow by rotating.

The front side with respect to the paper surface of FIG. 1 is the downstream side with respect to the axial fan 100 in the fluid flow direction, and the back side with respect to the paper surface of FIG. 1 is with respect to the axial fan 100 in the fluid flow direction. This will be the upstream side. Therefore, FIG. 1 is a view of the axial fan 100 viewed from the downstream side in the fluid flow direction. The upstream side of the axial fan 100 is the air suction side of the axial fan 100, and the downstream side of the axial fan 100 is the air outlet side of the axial fan 100.

As shown in FIG. 1, the axial fan 100 includes a hub 10 connected to a rotating shaft rotated by a drive source such as a motor (not shown), and a plurality of blades 20 extending from the hub 10 toward the outer circumference. , is provided. The axial fan 100 includes a so-called bossless type fan in which the leading edge side and the trailing edge side of adjacent blades 20 among a plurality of blades 20 are connected so as to form a continuous surface without using a boss. .

(Hub 10)
The hub 10 is connected to a rotating shaft of a drive source such as a motor (not shown). The hub 10 may have a cylindrical shape, for example, or a plate shape such as a disk shape. The shape of the hub 10 is not limited as long as it is connected to the rotating shaft of the drive source as described above.

The hub 10 is rotationally driven by a motor (not shown) or the like to form a rotation axis RA. The hub 10 rotates around a rotation axis RA. The rotation direction DR of the axial fan 100 is a clockwise direction as shown by the arrow in FIG. However, the rotation direction DR of the axial fan 100 is not limited to clockwise. The hub 10 may be rotated counterclockwise by changing the mounting angle of the blades 20 or the orientation of the blades 20.

(Wing 20)
The blades 20 are provided around the hub 10 and are formed to extend radially outward from the hub 10. The plurality of blades 20 are arranged radially outward from the hub 10 in the radial direction. The plurality of blades 20 are provided spaced apart from each other in the circumferential direction CD. Note that in the first embodiment, the axial fan 100 having three blades 20 is illustrated, but the number of blades 20 is not limited to three.

The plurality of wings 20 are each formed in the same shape around the hub 10. Further, the plurality of blades 20 are provided at equal intervals in the circumferential direction CD. Note that the wing 20 is not limited to this configuration. The plurality of blades 20 may be formed in different shapes, and may be formed at different intervals in the circumferential direction CD.

The blade 20 is formed in the shape of a forward-swept blade in which the outer circumference side portion protrudes more forward in the rotational direction DR than the inner circumference side portion. Note that the blades 20 are not limited to forward-swept blades, and may be formed in other shapes. The blade 20 is formed in a substantially triangular shape, when viewed in the axial direction of the rotation axis RA, the width of the outer circumferential portion in the circumferential direction CD is larger than the width of the inner circumferential portion in the circumferential direction CD. Note that the blades 20 are not limited to those formed in a substantially triangular shape when viewed in the axial direction of the rotation axis RA.

The wing 20 includes a leading edge 21 , a trailing edge 22 , an inner edge 24 that is connected to the hub 10 , and an outer edge 23 that forms an outer edge between the leading edge 21 and the trailing edge 22 . have The leading edge portion 21 is formed at a portion of the blade 20 on the forward side in the rotational direction DR. That is, the front edge portion 21 is located forward of the rear edge portion 22 in the rotation direction DR. The leading edge 21 is located on the upstream side of the trailing edge 22 in the flow direction of the fluid to be generated.

The trailing edge portion 22 is formed on the rearward side of the blade 20 in the rotational direction DR. That is, the rear edge portion 22 is located rearward with respect to the front edge portion 21 in the rotation direction DR. The trailing edge portion 22 is located downstream of the leading edge portion 21 in the flow direction of the generated fluid. The axial fan 100 has a leading edge 21 as a blade end facing in the rotational direction DR of the axial fan 100, and a trailing edge 22 as a blade end opposite to the leading edge 21 in the rotational direction DR. have.

The outer edge portion 23 is a portion extending back and forth in the rotation direction DR so as to constitute a portion between the outermost circumferential portion of the front edge portion 21 and the outermost circumferential portion of the rear edge portion 22. The outer edge portion 23 constitutes an end portion on the outer peripheral side in the radial direction (Y-axis direction) in the axial fan 100. The outer edge portion 23 forms the outer circumferential edge of the blade 20 and also forms the outer circumferential edge of the axial fan 100.

The outer edge portion 23 is formed in an arc shape when viewed in a direction parallel to the rotation axis RA. However, the outer edge portion 23 is not limited to an arcuate configuration when viewed in a direction parallel to the rotation axis RA. Note that the outer edge portion 23 includes a portion formed in an arc shape when viewed in a direction parallel to the rotation axis RA.

When the blade 20 is viewed in a direction parallel to the rotation axis RA, the length of the outer edge portion 23 in the circumferential direction CD is longer than the length of the inner edge portion 24 in the circumferential direction CD. However, in the blade 20, the relationship between the length of the outer edge portion 23 and the length of the inner edge portion 24 in the circumferential direction CD is not limited to this configuration. For example, in the blade 20, the length of the outer edge 23 and the inner edge 24 in the circumferential direction CD may be equal, or the length of the inner edge 24 may be longer than the length of the outer edge 23.

The inner edge portion 24 is a portion extending back and forth in the rotation direction DR so as to constitute a portion between the innermost circumferential portion of the front edge portion 21 and the innermost circumferential portion of the rear edge portion 22. The inner edge portion 24 constitutes an end portion on the inner peripheral side in the radial direction (Y-axis direction) in the axial fan 100. The inner edge portion 24 forms the inner peripheral edge of the blade 20 and constitutes the root portion of the blade 20.

The inner edge portion 24 is formed in an arc shape when viewed in a direction parallel to the rotation axis RA. However, the inner edge portion 24 is not limited to an arcuate configuration when viewed in a direction parallel to the rotation axis RA. The inner edges 24 of the wings 20 are connected to the hub 10, such as being formed integrally with the hub 10. As an example, the inner edge portion 24 of the blade 20 is formed integrally with the outer circumferential wall of the hub 10, which is formed in a cylindrical shape.

The blades 20 are formed to be inclined with respect to a plane perpendicular to the rotation axis RA. The blades 20 transport fluid by pushing the fluid existing between the blades 20 with the blade surfaces 28 as the axial fan 100 rotates. At this time, among the blade surfaces 28 of the blades 20, the surface on the side where the pressure increases by pushing the fluid when the axial fan 100 rotates is defined as the positive pressure surface 25, and the surface on the back side of the positive pressure surface 25 forms the surface on which the pressure decreases. The side surface is defined as a negative pressure surface 26.

In the direction of fluid flow, the blade surface 28 has a surface facing the upstream side of the blade 20 as the negative pressure surface 26 and a surface facing the downstream side as the positive pressure surface 25. Further, the positive pressure surface 25 is a surface facing the rotation direction DR, and the negative pressure surface 26 is a surface facing the opposite side to the rotation direction DR. In FIG. 1, the front surface of the blade 20 is a pressure surface 25, and the rear surface of the blade 20 is a negative pressure surface 26.

(Details of wing 20)
FIG. 2 is a front view of the blades 20 in the axial fan 100 according to the first embodiment. Note that, in FIG. 2, in order to explain the configuration of the blades 20, only one blade 20 among the plurality of blades 20 is illustrated, and illustration of the other blades 20 is omitted. The cylindrical surface CS shown by a dotted line in FIG. 2 is a virtual cylinder whose radius is the outermost diameter of the axial fan 100 centered on the rotation axis RA when the axial fan 100 is viewed in the axial direction of the rotation axis RA. Indicates the position of the surface.

The virtual cylindrical surface CS indicates the position of the blade 20 that forms the outermost diameter of the axial fan 100, and is determined by the portion that forms the outermost diameter of the axial fan 100 when the axial fan 100 rotates. It shows the rotation trajectory. The portion of the blade 20 that forms the virtual cylindrical surface CS is the outer edge portion 23 of the blade 20. The detailed structure of the wing 20 will be further explained using FIG. 2. The wing 20 has a reduced portion 23a and an outer peripheral portion 30.

(Reduction part 23a)
The blade 20 has a reduced portion 23 a at a portion on the outer peripheral side of the axial fan 100 that constitutes the outer edge of the axial fan 100 . The axial fan 100 has a reduced portion 23a, and the axial fan 100 has a region where the fan diameter is reduced on the front edge side of the outer edge of the fan.

The reduced portion 23a of the blade 20 is such that the outer diameter of the blade 20 is reduced in a portion on the leading edge 21 side of the portion forming the outer edge 23 than in a portion on the trailing edge 22 side that forms the maximum diameter of the blade 20. form the part. The reduced portion 23a is formed on the outer edge portion 23 of the blade 20.

The outer edge portion 23 has a tip portion 201, an inflection portion 202, and a rear end portion 203. The tip portion 201 is a portion of the outer edge portion 23 located closest to the front edge portion 21 side, and is a boundary portion with the front edge portion 21 . The bending portion 202 is a portion of the outer edge portion 23 that forms the outermost diameter of the blade 20 and is located closest to the tip portion 201 side. The rear end portion 203 is a portion of the outer edge portion 23 located closest to the rear edge portion 22, and is a boundary portion with the rear edge portion 22.

The reduced portion 23a is formed between the distal end portion 201 and the rear end portion 203, and is formed from the distal end portion 201 toward the rear end portion 203 side. In the wing 20, the tip portion 201 is located closest to the leading edge portion 21 of the reduced portion 23a. That is, the reduced portion 23a includes the tip portion 201.

The reduced portion 23a is a portion formed such that the outer diameter of the wing 20 portion is smaller in the portion located on the leading edge portion 21 side than the portion located on the trailing edge portion 22 side. In other words, the reduced portion 23a is a portion formed such that the outer diameter of the blade 20 portion is larger in the portion located on the trailing edge 22 side than in the portion located on the leading edge 21 side. . Note that the outer diameter of the blade 20 portion is the outer diameter of the axial fan 100 centered on the rotation axis RA, and refers to the rotation in the radial direction of the axial fan 100 when viewed in the axial direction of the rotation axis RA. It is the distance between the axis RA and the outer edge 23 of the wing 20.

The reduced portion 23a is formed, for example, in the circumferential direction CD such that the outer diameter of the blade 20 portion gradually decreases from the portion located on the trailing edge portion 22 side to the portion located on the leading edge portion 21 side. There is. That is, the reduced portion 23a is formed such that the outer diameter of the blade 20 portion gradually decreases as it goes in the rotation direction DR. The reduced portion 23a is a portion formed such that the length of the blade 20 portion in the radial direction gradually decreases as it goes in the rotation direction DR.

In other words, the reduced portion 23a is formed such that the outer diameter of the blade 20 portion gradually increases from the portion located on the leading edge portion 21 side toward the trailing edge portion 22 in the circumferential direction CD. That is, the reduced portion 23a is formed such that the outer diameter of the blade 20 portion gradually increases in the direction opposite to the rotational direction DR. The reduced portion 23a is formed such that the length of the blade 20 portion in the radial direction gradually increases in the direction opposite to the rotational direction DR.

Note that the outer diameter of the blade 20 portion is limited to one that is formed so that in the circumferential direction CD, the outer diameter of the blade 20 portion gradually decreases from the portion located on the trailing edge portion 22 side to the portion located on the leading edge portion 21 side. It's not something you can do. The reduced portion 23a may be formed such that the outer diameter of the blade 20 portion is smaller than that of the portion where the tip portion 201 is located on the trailing edge portion 22 side when viewing the blade 20 as a whole. The reduced portion 23a is not limited to one in which the outer diameter of the blade 20 portion gradually changes in the circumferential direction CD, and may include a radially recessed portion or a radially protruding portion. May contain. However, the outer diameter of the reduced portion 23a is smaller than the outermost diameter of the blade 20.

The blade 20 has a cutout shape at the reduced portion 23a compared to the virtual outer edge 23 located on the cylindrical surface CS, which would be the outer edge 23 of the blade 20 without the reduced portion 23a. is formed. As shown in FIG. 2, the reduced portion 23a is formed to be located on the inner circumferential side (Y1 side) of the cylindrical surface CS near the rotation axis RA.

In the reduced portion 23a of the blade 20, when viewed in the axial direction of the rotation axis RA, from the tip portion 201 toward the trailing edge portion 22, the cylindrical surface CS and the outer edge portion 23 in the radial direction centering on the rotation axis RA. is formed so that its width is small. In other words, in the reduced portion 23a of the blade 20, when viewed in the axial direction of the rotation axis RA, the radial direction around the rotation axis RA increases from the portion located on the trailing edge portion 22 side toward the tip portion 201. The width between the cylindrical surface CS and the outer edge portion 23 is increased.

The reduced portion 23a is formed in a portion of the outer edge 23 on the front edge 21 side in the circumferential direction CD. The reduced portion 23a is formed from the tip portion 201 to the bent portion 202 in the circumferential direction CD. The reduced portion 23a is formed in the entire region between the tip portion 201 and the bending portion 202 in the circumferential direction CD centered on the rotation axis RA.

The bending part 202 is provided between the leading end part 201 and the rear end part 203 at the outer edge part 23. Further, the bending portion 202 may be provided at the same position as the rear end portion 203. The reduced portion 23a may be formed in a portion of the outer edge 23 on the front edge 21 side in the circumferential direction CD, or may be formed from the front edge 21 to the rear edge 22.

The inflection portion 202 is a portion that forms a different curvature with respect to the cylindrical surface CS at the outer edge portion 23 of the blade 20. The inflection portion 202 is a portion that forms a larger curvature than the curvature of the cylindrical surface CS in the outer edge portion 23 of the blade 20. The inflection portion 202 is a portion where the curvature of the portion forming the maximum diameter of the blade 20 and the portion forming the leading edge portion 21 side is changed. The bending portion 202 is a portion forming the outermost diameter of the axial fan 100 and the blades 20, and is a portion located on the virtual cylindrical surface CS when viewed in the axial direction of the rotation axis RA. The inflection portion 202 is a boundary between the reduced portion 23a and a rear outer edge portion 23b, which will be described later. That is, the bending portion 202 is the rear end portion of the reduced portion 23a and the tip portion of the rear outer edge portion 23b.

If the positions of the bending part 202 and the rear end part 203 are different, the outer edge part 23 of the wing 20 includes a rear outer edge part 23b in a portion between the bending part 202 and the rear end part 203. The wing 20 has a rear outer edge portion 23b at a portion of the outer edge portion 23 closer to the rear edge portion 22 than the reduced portion 23a. The rear outer edge portion 23b is a portion of the blade 20 formed to have a constant outer diameter.

The rear outer edge portion 23b is a portion of the outer edge portion 23 that forms a constant outer diameter from a portion located on the front edge portion 21 side to a portion located on the rear edge portion 22 side. The rear outer edge portion 23b is a portion formed along the cylindrical surface CS when viewed in the axial direction of the rotation axis RA. The rear outer edge portion 23b is a portion that forms the outermost diameter of the axial fan 100 and the blades 20. The rear outer edge portion 23b may be formed in a portion between the bending portion 202 and the rear end portion 203, or may be formed in the entire portion between the bending portion 202 and the rear end portion 203. .

Note that the wing 20 may include a portion having a shape that does not follow the cylindrical surface CS in the outer edge portion 23 that constitutes the portion between the bending portion 202 and the rear end portion 203. For example, when viewed in the axial direction of the rotation axis RA, the blade 20 may include a linear portion in the outer edge portion 23 that constitutes a portion between the bending portion 202 and the rear end portion 203. . Further, when the blade 20 is viewed in the axial direction of the rotation axis RA, the outer diameter of the blade 20 is smaller than the outer diameter of the blade 20 at a part of the outer edge portion 23 that constitutes a portion between the bending portion 202 and the rear end portion 203. It may include a portion that is smaller than the outermost diameter of 20.

(Outer periphery 30)
FIG. 3 is a cross-sectional view of the blades 20 in the axial fan 100 according to the first embodiment. FIG. 3 is a cross-sectional view of the blade 20 in FIG. 2 taken along line AA when viewed in the direction of the arrows. The outer peripheral portion 30 of the blade 20 will be explained using FIGS. 2 and 3. In the reduced portion 23a, the outer peripheral portion 30 forms a positive pressure surface 25 that curves from the downstream side to the upstream side in the flow direction of the fluid flowing when the blade 20 rotates as it goes from the inner edge 24 side toward the outer edge 23. do.

The outer peripheral part 30 is a part that has the function of reducing air resistance by rectifying the flow of air near the blade tip on the outer peripheral side of the blade 20, thereby reducing the blade tip vortex, or moving the generation direction upward. The outer peripheral portion 30 is formed in the reduced portion 23a. Further, the outer peripheral portion 30 is formed along the outer edge portion 23 of the blade 20. The outer peripheral portion 30 is formed from the outer edge 23 to a specific portion on the inner edge 24 side in the radial direction centered on the rotation axis RA.

The outer peripheral portion 30 is a portion of the blade 20 that forms the outer peripheral positive pressure surface 25a. The pressure surface 25 of the blade 20 includes an outer peripheral pressure surface 25a. The outer peripheral positive pressure surface 25a forms an outwardly facing surface of the blade 20, as shown in FIG. The outer peripheral positive pressure surface 25a forms a surface that has a radial component around the rotation axis RA. The outer peripheral positive pressure surface 25a forms a side surface of the axial fan 100.

The outer peripheral positive pressure surface 25a is formed to curve from the downstream side to the upstream side in the direction in which the fluid formed by the axial fan 100 flows as it goes from the inner peripheral side toward the outer edge 23. Alternatively, the outer peripheral positive pressure surface 25a is formed to curve upward from the downstream side toward the upstream side in the direction in which the fluid formed by the axial fan 100 flows as it goes from the inner peripheral side toward the outer edge 23. . The outer circumferential positive pressure surface 25a is formed so as to bulge on the downstream side and on the outer circumferential side.

The outer circumferential portion 30 is formed in the reduced portion 23a, and for example, is formed from the tip portion 201 to the bent portion 202 in the circumferential direction CD. The outer peripheral portion 30 is formed in the entire area of the reduced portion 23a in the circumferential direction CD centered on the rotation axis RA. Further, the outer circumferential portion 30 is formed such that the width W in the radial direction around the rotation axis RA is larger on the rear edge 22 side than on the front edge 21 side.

As an example, the outer circumferential portion 30 is formed such that the width W in the radial direction around the rotation axis RA gradually increases from the tip portion 201 toward the bending portion 202. That is, the outer circumferential portion 30 is formed such that the width W in the radial direction around the rotation axis RA gradually increases from the portion on the front end portion 201 side to the portion on the rear edge portion 22 side. The outer peripheral portion 30 is formed such that the width W in the radial direction gradually increases from the portion on the front edge portion 21 side to the portion on the rear edge portion 22 side.

The width W of the outer peripheral portion 30 shown in FIG. 2 is the width W1 in the radial direction centered on the rotation axis RA when viewed in the axial direction of the rotation axis RA (see FIG. 3). Note that the width W of the outer peripheral portion 30 may be defined as the width W2 along the positive pressure surface 25 in the radial direction centered on the rotation axis RA, as shown in FIG.

The cylindrical surface CL shown by the dotted line in FIG. It shows the position of the cylindrical surface. In the blade 20 shown in FIG. 2, the outer circumferential portion 30 is formed in a range between the virtual cylindrical surface CL and the outer edge portion 23 in the radial direction centered on the rotation axis RA. Note that the formation position of the outer circumferential portion 30 is not limited to this range, and the inner circumferential portion of the outer circumferential portion 30 may be formed to a position closer to the inner edge portion 24 than the cylindrical surface CL. That is, in the blade 20, the formation position of the cylindrical surface CL may be included in the formation range of the outer peripheral portion 30.

The blade 20 has an outer peripheral positive pressure surface 25a that curves upstream toward the outer peripheral side in the radial direction in the outer peripheral portion 30. The outer peripheral part 30 is formed from an arbitrary position on the leading edge part 21 side to an inflection part 202 reaching the maximum diameter in the reduced part 23a, which is a region where the blade diameter is reduced. The outer circumferential portion 30 has a radial width W greater at a portion on the side of the bending portion 202 that forms the maximum diameter of the blade 20 than at any arbitrary position on the leading edge portion 21 side.

FIG. 4 is a front view of a first modification of the blades 20 in the axial fan 100 according to the first embodiment. The outer circumferential portion 30 only needs to be formed in the reduced portion 23a, and the outer circumferential portion 30 is limited to an aspect in which it is formed in the entire region from the tip portion 201 to the inflection portion 202 in the circumferential direction CD. isn't it. The outer peripheral portion 30 may be formed in a part of the reduced portion 23a in the circumferential direction CD centered on the rotation axis RA.

The outer peripheral portion 30 may be formed at the rear of the tip portion 201, that is, at a portion closer to the rear edge portion 22 than the tip portion 201. As shown in FIG. 4, the outer circumferential portion 30 may not include the tip portion 201 and may be formed from a position closer to the bending portion 202 than the tip portion 201 to a position of the bending portion 202 in the circumferential direction CD. That is, the outer peripheral portion 30 may be formed in the entire area between a specific position between the tip portion 201 and the bending portion 202 and the position of the bending portion 202 in the circumferential direction CD.

FIG. 5 is a front view of a second modification of the blades 20 in the axial fan 100 according to the first embodiment. As described above, the outer circumferential portion 30 may be formed in a partial region of the reduced portion 23a in the circumferential direction CD centered on the rotation axis RA.

As shown in FIG. 5, the outer peripheral portion 30 may not include the bending portion 202 and may be formed from the tip portion 201 to the front of the bending portion 202 in the counter-rotation direction OR. That is, the outer circumferential portion 30 may be formed in the entire area between the position of the tip portion 201 and a specific position between the tip portion 201 and the bending portion 202 in the circumferential direction CD.

FIG. 6 is a front view of a third modification of the blades 20 in the axial fan 100 according to the first embodiment. As described above, the outer circumferential portion 30 may be formed in a partial region of the reduced portion 23a in the circumferential direction CD centered on the rotation axis RA.

As shown in FIG. 6, the outer peripheral portion 30 may not include the tip portion 201 and the bending portion 202 and may be formed in a region between the tip portion 201 and the bending portion 202 in the circumferential direction CD. That is, the outer peripheral part 30 may be formed from a specific position on the front edge part 21 side to a specific position on the rear edge part 22 side between the tip part 201 and the inflection part 202 in the circumferential direction CD.

FIG. 7 is a front view of a fourth modification of the blades 20 in the axial fan 100 according to the first embodiment. The formation area of the outer circumferential portion 30 is arranged behind the tip portion 201, and the outer circumferential portion 30 is formed such that the width W gradually increases from the tip portion 201 side toward the bending portion 202 side. There is. As shown in FIG. 7, the outer circumferential portion 30 may be formed in a triangular shape with one of its vertices being the tip portion on the front edge portion 21 side when viewed in the axial direction of the rotation axis RA.

FIG. 8 is a front view of a fifth modification of the blades 20 in the axial fan 100 according to the first embodiment. The number of outer peripheral portions 30 in the reduced portion 23a of the blade 20 in FIGS. 1 to 7 is one. The number of outer peripheral parts 30 in the reduced part 23a of the blade 20 is not limited to one, and may be plural as shown in FIG. 8. That is, the reduced portion 23a of the blade 20 may have one outer circumferential portion 30 or may have a plurality of outer circumferential portions 30.

FIG. 9 is a front view of a sixth modification of the blades 20 in the axial fan 100 according to the first embodiment. FIG. 10 is a front view of a seventh modification of the blade 20 in the axial fan 100 according to the first embodiment. The blade 20 may have a non-linear change in diameter at the reduced portion 23a. That is, in the blade 20, in the reduced portion 23a, the change in diameter in the rotational direction DR does not need to be a simple decrease, and the change in the diameter in the counter-rotation direction OR does not need to be a simple increase. In the reduced part 23a, when comparing the part on the distal end part 201 side and the part on the rear edge part 22 side, the outer diameter of the part on the distal end part 201 side is the same as that of the part on the rear edge part 22 side of the reduced part 23a as a whole. It is sufficient if it is formed to be smaller than the outer diameter.

The reduced portion 23a is not limited to a shape in which the diameter gradually increases in the counter-rotation direction OR, but as shown in FIG. It may have a recessed portion 23c that is recessed compared to a shape in which the diameter is larger.

Further, as shown in FIG. 10, the reduced portion 23a is protruded between the tip portion 201 and the bending portion 202 compared to a shape in which the diameter gradually increases toward the counter-rotation direction OR. It may have a protruding portion 23d. However, the outer diameter of the protruding portion 23d is smaller than the maximum diameter of the blade 20.

The outer edge portion 23 of the reduced portion 23a is not limited to a curved shape, and may include a straight portion. Further, the outer edge portion 23 of the reduced portion 23a may be formed in a wavy line shape or may be formed in a sawtooth shape.

[Operation of axial fan 100]
When the axial fan 100 rotates in the rotation direction DR shown in FIG. 1, each blade 20 pushes out surrounding air by the positive pressure surface 25. As a result, the fluid flows in a direction perpendicular to the paper plane of FIG. More specifically, when the axial fan 100 rotates in the rotational direction DR shown in FIG. 1, a fluid flow is generated from the back side of the page of FIG. 1 toward the front side of the page. Furthermore, when the axial fan 100 rotates, the pressure on the negative pressure surface 26 side becomes smaller than the pressure on the positive pressure surface 25 side, and a pressure difference occurs between the positive pressure surface 25 side and the negative pressure surface 26 side around each blade 20. .

[Effects of axial fan 100]
FIG. 11 is a conceptual diagram of a radial cross section of an axial fan 100L according to a comparative example. The axial fan 100L is a commonly used fan. First, an image of the formation of the blade tip vortex WL formed in a normal axial fan 100L will be explained using FIG. 11.

Normally, the rotation of the fan causes the axial fan 100L to move between a suction surface 26, which is an upstream surface on the blade surface, and a positive pressure surface 25, which is a downstream surface, in the direction in which fluid flows by the axial fan 100L. A pressure difference occurs. At the outer edge of the axial fan 100L, a blade tip vortex WL is generated by a fluid flow leaking from the positive pressure surface 25 to the negative pressure surface 26 due to the pressure difference. The blade tip vortex WL is gradually stacked and increased from the leading edge 21 side to the trailing edge 22 side of the blade 20, and the vortex diameter is expanded.

FIG. 12 is a perspective view of an axial fan 100R according to a second comparative example. FIG. 13 is a side view of an axial fan 100R according to a second comparative example. The axial fan 100R is a fan that has a bent portion 140 like the fan of Patent Document 1.

The axial fan 100R has a bent portion 140 on the outer peripheral edge of each blade 20R, which is bent upward toward the suction side, and the radial width of the bent portion 140 varies from the leading edge 21 side to the trailing edge. It is formed so that it gradually becomes larger toward the portion 22 side. With this configuration, the axial fan 100R can smoothly guide the blade tip vortex WL from the leading edge 21 side to the trailing edge 22 side, and the generated blade tip vortex WL can be guided from the suction surface 26 of the blade 20. It becomes difficult to leave.

The blade tip vortex WL is generated from the leading edge 21 side at the outer edge 23 and flows rearward while gradually expanding. As described above, in the axial fan 100R, the size of the bent portion 140 is gradually increased from the leading edge 21 side to the trailing edge 22 side, so that the expanding blade tip vortex WL is transferred to the bent portion 140. The blade tip vortex WL is stabilized without being disturbed.

In the direction of fluid flow by the axial fan 100R, if there is no structure upstream of the axial fan 100R, or if the axial fan 100R is separated from a structure placed upstream of the axial fan 100R, the axial Airflow with little turbulence flows into the flow fan 100R. Therefore, when there is no structure upstream of the axial fan 100R, the blade tip vortex WL generated on the leading edge 21 side is smaller than the blade tip vortex WL generated on the trailing edge 22 side, and The flow fan 100R does not need to take into account the influence of the blade tip vortex WL generated in the portion on the leading edge 21 side.

FIG. 14 is a conceptual diagram of an outdoor unit 150R used in an air conditioner equipped with an axial fan 100R according to a second comparative example. FIG. 15 is a conceptual diagram showing the relationship between the motor support 155 and the axial fan 100R in the outdoor unit 150R used in the air conditioner shown in the comparative example of FIG. 14. Next, using the outdoor unit 150R used in an air conditioner, the influence of the wake WT of the structure on the blade tip vortex WL will be described.

The outdoor unit 150R used in the air conditioner is a device that performs air conditioning by adjusting the temperature and humidity of the air in the indoor space to be air-conditioned. The outdoor unit 150R is a refrigeration cycle device that forms a refrigerant circuit in which a compressor 153, a condenser, an expansion valve, an evaporator, etc. are connected via piping. The fan 100R is housed inside a housing 151 and installed outdoors.

The air conditioner 150 includes an axial fan 100R, a heat exchanger 152, and a housing 151 that houses the axial fan 100R and the heat exchanger 152 inside. The axial fan 100R is connected to a motor 154. Motor 154 is fixed to motor support 155. The motor support 155 is a structure disposed upstream of the axial fan 100R in the direction in which fluid flows by the axial fan 100R.

As shown in FIGS. 14 and 15, when there is a structure such as the motor support 155, the flow of the wake WT flowing downstream of the structure is disturbed by the structure. Therefore, structures such as the motor support 155 disposed upstream of the axial fan 100R cause turbulence in the flow of fluid flowing into the axial fan 100R.

When a turbulent fluid flow such as the wake WT flows into the leading edge 21 on the outer peripheral side of the axial fan 100R, the blade 20 is influenced by the circumferential speed of the outer edge 23 located at the outermost periphery of the blade 20. Large fluid leakage also occurs on the leading edge 21 side of the blade, increasing the formation of blade tip vortices WL. The outer edge portion 23 located at the outermost periphery of the blade 20 is a portion where the circumferential speed is the highest in the radial position of the axial fan 100R. When the wake WT disturbed by the motor support 155 and the like flows into the leading edge 21 of the outer edge, a large blade tip vortex WL is also formed on the leading edge 21 side in combination with the influence of the circumferential speed. Note that the circumferential speed of the blade 20 decreases as it approaches the rotation axis RA, and increases as it moves away from the rotation axis RA.

If the portion on the front edge 21 side is only slightly curved like the bent portion 140 of the axial fan 100R, the turbulent fluid flow such as the wake WT will not flow into the axial fan 100R. In this case, the blade tip vortex WL may become unstable and the fan efficiency may decrease.

The outer diameter of the blade 20 of the axial fan 100 is smaller in the portion on the leading edge 21 side of the portion forming the outer edge 23 than in the portion on the trailing edge 22 side forming the maximum diameter of the blade 20. It has a reduced portion 23a that forms a reduced portion. In addition, the blades 20 of the axial fan 100 are curved from the downstream side to the upstream side in the direction in which fluid flows when the blades 20 rotate, from the inner edge 24 side toward the outer edge 23 in the reduced portion 23a. It has an outer peripheral portion 30 forming a positive pressure surface 25. The outer circumferential portion 30 is formed such that the width W in the radial direction around the rotation axis RA is larger on the rear edge 22 side than on the front edge 21 side.

The axial fan 100 has a reduced diameter on the leading edge 21 side of the blade 20 by having the reduced portion 23a in the blade 20, and the portion on the leading edge 21 side forms the outermost diameter of the blade 20. Since the blade 20 is closer to the rotation axis RA than the blade 20, the circumferential speed of the portion of the blade 20 on the leading edge 21 side becomes smaller. Therefore, even if a fluid flow disturbed by a structure such as a motor support flows into the axial fan 100, the front edge of the blade 20 is The blade tip vortex WL formed on the edge 21 side becomes smaller. Furthermore, the axial fan 100 has an outer circumferential part 30 in the reduced part 23a, and the outer circumferential part 30 has a width W in the radial direction around the rotation axis RA that is smaller at the rear edge than at the front edge 21 side. The portion on the 22 side is formed to be larger. With this configuration, the axial fan 100 can cause the blade tip vortex WL, which expands from the leading edge 21 side to the trailing edge 22 side, to follow the outer circumference 30 . Therefore, in the axial fan 100, the blade tip vortex WL on the negative pressure surface 26 is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Furthermore, the outer peripheral portion 30 may be formed in a partial region of the reduced portion 23a in the circumferential direction CD centered on the rotation axis RA. The axial fan 100 has an outer peripheral part 30 in a part of the reduced part 23a, and the outer peripheral part 30 has a width W in the radial direction around the rotation axis RA that is closer to the rear edge than a part on the front edge 21 side. The portion on the part 22 side is formed to be larger. With this configuration, the axial fan 100 can cause the blade tip vortex WL, which expands from the leading edge 21 side to the trailing edge 22 side, to follow the outer circumference 30 . Therefore, in the axial fan 100, the blade tip vortex WL on the negative pressure surface 26 is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Furthermore, the outer peripheral portion 30 may be formed in the entire area of the reduced portion 23a in the circumferential direction CD centered on the rotation axis RA. The axial fan 100 has an outer circumferential portion 30 in all areas of the reduced portion 23a, and the outer circumferential portion 30 has a width W in the radial direction centered on the rotation axis RA that is rearward than the portion on the front edge 21 side. The portion on the edge 22 side is formed to be larger. With this configuration, the axial fan 100 can cause the blade tip vortex WL, which expands from the leading edge 21 side to the trailing edge 22 side, to follow the outer circumference 30 . Therefore, in the axial fan 100, the blade tip vortex WL on the negative pressure surface 26 is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency. Here, the circumferential speed of the blade 20 increases as the diameter increases. The entire region of the reduced portion 23a is the region from the tip portion 201 to the inflection portion 202. The bending portion 202 is a portion that constitutes the maximum diameter of the blade 20 and is a portion of the blade 20 where the circumferential speed is faster than the tip portion 201. The axial fan 100 can further improve the stability of the blade tip vortex WL by forming the outer circumferential portion 30 from the tip portion 201 to the inflection portion 202.

Further, the outer peripheral portion 30 is formed such that the width W in the radial direction around the rotation axis RA gradually increases from the portion on the front end portion 201 side to the portion on the rear edge portion 22 side. By having the configuration, the axial fan 100 can cause the blade tip vortex WL, which expands from the portion on the leading edge 21 side to the portion on the trailing edge 22 side, to further follow the outer peripheral portion 30. Therefore, in the axial fan 100, the blade tip vortex WL on the negative pressure surface 26 is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Embodiment 2.
FIG. 16 is a front view of the blades 20 in the axial fan 100 according to the second embodiment. FIG. 17 is a cross-sectional view of the blades 20 in the axial fan 100 according to the second embodiment. In FIG. 16, in order to explain the configuration of the blade 20, only one blade 20 among the plurality of blades 20 is illustrated, and illustration of the other blades 20 is omitted. FIG. 17 is a cross-sectional view of the blade 20 in FIG. 16 taken along line BB when viewed in the direction of the arrows. Note that parts having the same configuration as the axial fan 100 of FIGS. 1 to 10 are designated by the same reference numerals, and the description thereof will be omitted. In the axial fan 100 according to the second embodiment, the configuration of the rear outer edge portion 23b is further specified.

The rear outer edge portion 23b may have a rear outer peripheral portion 40. That is, the wing 20 may further include a rear outer circumferential portion 40 in addition to the outer circumferential portion 30 . The rear outer peripheral part 40 extends from the inner edge 24 side toward the outer edge 23 on the trailing edge 22 side than the reduced part 23a, from the downstream side to the upstream side in the direction of fluid flowing when the blade 20 rotates. to form a curved positive pressure surface 25.

The rear outer peripheral portion 40 is formed in the region of the rear outer edge portion 23b. The rear outer circumferential portion 40 is formed at the rear of the outer circumferential portion 30 in the rotation direction DR, and is formed at a portion closer to the rear edge portion 22 than the outer circumferential portion 30 is.

Similar to the outer circumferential part 30, the rear outer circumferential part 40 reduces the wing tip vortex WL by rectifying the air flow near the wing tip on the outer circumferential side of the blade 20, or moves the generation direction upward, thereby reducing air resistance. This is the part that has the function of reducing The rear outer peripheral portion 40 is formed in the region of the rear outer edge portion 23b. Further, the rear outer peripheral portion 40 is formed along the outer edge portion 23 of the wing 20. The rear outer peripheral portion 40 is formed from the outer edge 23 to a specific portion on the inner edge 24 side in the radial direction centered on the rotation axis RA.

The rear outer peripheral portion 40 is a portion of the blade 20 that forms the rear outer peripheral positive pressure surface 25b. The pressure surface 25 of the blade 20 includes a rear outer peripheral pressure surface 25b. The rear outer peripheral positive pressure surface 25b forms an outwardly facing surface of the blade 20, as shown in FIG. The rear outer peripheral positive pressure surface 25b forms a surface having a radial component around the rotation axis RA. The rear outer peripheral positive pressure surface 25b forms a side surface of the axial fan 100.

The rear outer peripheral positive pressure surface 25b is formed to curve from the downstream side to the upstream side in the direction in which the fluid formed by the axial fan 100 flows from the inner peripheral side toward the outer edge 23. Alternatively, the rear outer peripheral positive pressure surface 25b is formed to curve upward from the downstream side toward the upstream side in the direction in which the fluid formed by the axial fan 100 flows as it goes from the inner peripheral side toward the outer edge 23. There is. The rear outer circumferential positive pressure surface 25b is formed so that its downstream side and outer circumferential side are bulged.

The rear outer peripheral part 40 may be formed in the rear outer edge part 23b, and as an example, as shown in FIG. ing. The rear outer peripheral portion 40 is formed behind the reduced portion 23a in the rotation direction DR, and is formed to extend from the bending portion 202 to the rear edge portion 22.

The rear outer circumferential portion 40 is formed in a range between the virtual cylindrical surface CL and the outer edge portion 23 in the radial direction centered on the rotation axis RA. Note that the formation position of the rear outer peripheral part 40 is not limited to this range, and the inner peripheral side part of the rear outer peripheral part 40 may be formed to a position closer to the inner edge part 24 than the cylindrical surface CL. . That is, in the blade 20, the formation position of the cylindrical surface CL may be included in the formation range of the rear outer peripheral portion 40.

FIG. 18 is a front view of a first modification of the blades 20 in the axial fan 100 according to the second embodiment. The rear outer circumferential portion 40 may be formed in the rear outer edge portion 23b.The rear outer circumferential portion 40 may be formed in the entire region from the bending portion 202 to the rear end portion 203 in the circumferential direction CD. It is not limited.

The rear outer peripheral portion 40 may be formed at the rear of the reduced portion 23a, that is, at a portion closer to the rear edge portion 22 than the reduced portion 23a. As shown in FIG. 18, the rear outer peripheral part 40 does not include the bending part 202, and is formed from a position closer to the rear end part 203 than the bending part 202 to a position of the rear end part 203 in the circumferential direction CD. Good too. That is, the rear outer peripheral portion 40 may be formed in the entire area between a specific position between the bending portion 202 and the rear end portion 203 and the position of the rear end portion 203 in the circumferential direction CD. . The rear outer peripheral portion 40 is formed behind the reduced portion 23a in the rotation direction DR, and is formed to extend from a position closer to the rear end portion 203 than the bending portion 202 to the rear edge portion 22.

FIG. 19 is a front view of a second modification of the blades 20 in the axial fan 100 according to the second embodiment. As shown in FIG. 19, the rear outer circumferential portion 40 may not include the rear end portion 203 and may be formed from the bending portion 202 to the front of the rear end portion 203 in the counter-rotation direction OR. That is, the rear outer circumferential portion 40 may be formed in all areas between the position of the bending portion 202 and a specific position between the bending portion 202 and the rear end portion 203 in the circumferential direction CD. good. The rear outer circumferential portion 40 is formed behind the reduced portion 23a in the rotation direction DR, and is formed from a portion on the front edge 21 side to a portion on the rear edge 22 side, and does not extend to the rear edge 22. do not have.

FIG. 20 is a front view of a third modification of the blades 20 in the axial fan 100 according to the second embodiment. As shown in FIG. 20, the rear outer peripheral part 40 does not include the bending part 202 and the rear end part 203, and is formed in a region between the bending part 202 and the rear end part 203 in the circumferential direction CD. Good too. That is, the rear outer peripheral portion 40 may be formed from a specific position on the front edge 21 side to a specific position on the rear edge 22 side between the bending portion 202 and the rear end portion 203 in the circumferential direction CD. good. The rear outer circumferential portion 40 is formed behind the reduced portion 23a in the rotation direction DR, and is formed from a portion on the front edge 21 side to a portion on the rear edge 22 side, and does not extend to the rear edge 22. do not have.

FIG. 21 is a front view of a fourth modification of the blades 20 in the axial fan 100 according to the second embodiment. The rear outer circumferential portion 40 is formed such that the width BW in the radial direction centering on the rotation axis RA gradually increases from the portion on the bending portion 202 side to the portion on the rear end portion 203 side. That is, the rear outer circumferential portion 40 is formed such that the width W in the radial direction gradually increases from the portion on the front edge 21 side to the portion on the rear edge 22 side. The rear outer circumferential portion 40 may be formed in a triangular shape with one of its vertices being the tip portion on the front edge portion 21 side when viewed in the axial direction of the rotation axis RA.

FIG. 22 is a front view of a fifth modification of the blades 20 in the axial fan 100 according to the second embodiment. The rear outer circumferential portion 40 is formed such that the width BW in the radial direction centering on the rotation axis RA gradually decreases from the portion on the bending portion 202 side to the portion on the rear end portion 203 side. That is, the rear outer circumferential portion 40 is formed such that the width W in the radial direction gradually decreases from the portion on the front edge 21 side to the portion on the rear edge 22 side. The rear outer circumferential portion 40 may be formed in a triangular shape with one of its vertices being the tip portion on the rear edge portion 22 side when viewed in the axial direction of the rotation axis RA.

[Effects of axial fan 100]
In the blade 20 of the second embodiment, on the trailing edge 22 side of the contracted part 23a, from the inner edge 24 side toward the outer edge 23, from the downstream side to the upstream side in the flow direction of the fluid flowing when the blade 20 rotates. It further includes a rear outer circumferential portion 40 forming a pressure surface 25 that curves toward the side. In the axial fan 100, the blade tip vortex WL stabilized by the reduced portion 23a and the outer peripheral portion 30 flows rearward as it is. By having the rear outer peripheral portion 40, the axial fan 100 can continuously form a stabilized blade tip vortex WL, and can maintain the stability of the blade tip vortex WL until it is blown out from the blade 20. . Therefore, in the axial fan 100, the blade tip vortex WL on the negative pressure surface 26 is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Embodiment 3.
FIG. 23 is a front view of the blades 20 in the axial fan 100 according to the third embodiment. FIG. 24 is a cross-sectional view of the blades 20 in the axial fan 100 according to the third embodiment. In FIG. 23, in order to explain the configuration of the blade 20, only one blade 20 among the plurality of blades 20 is illustrated, and illustration of the other blades 20 is omitted. FIG. 24 is a cross-sectional view of the blade 20 in FIG. 23 taken along line AA when viewed in the direction of the arrows. Note that parts having the same configuration as the axial fan 100 of FIGS. 1 to 22 are designated by the same reference numerals, and a description thereof will be omitted. In the axial fan 100 according to the third embodiment, the configuration of the outer peripheral portion 30 is further specified.

The outer circumferential portion 30 has a first region 25a1 including the outer edge portion 23 of the fan and a second region 25a2 formed continuously on the inner circumferential side of the first region 25a1 in a radial cross section centered on the rotation axis RA. The outer peripheral positive pressure surface 25a of the outer peripheral portion 30 includes a first region 25a1 and a second region 25a2.

In the radial direction of the axial fan 100, the first region 25a1 forms a region located on the outer peripheral side with respect to the second region 25a2, and includes the outer edge portion 23 of the blade 20. In the radial direction of the axial fan 100, the second region 25a2 forms a region located on the inner peripheral side with respect to the first region 25a1. The first region 25a1 and the second region 25a2 are formed continuously in the radial direction of the axial fan 100. The first region 25a1 and the second region 25a2 may be flat surfaces or may be curved surfaces.

Here, in the cross section along the radial direction of the axial fan 100, a straight line connecting the inner end point and the outer end point in the radial direction of the first region 25a1 is defined as a locus L1, and the diameter of the second region 25a2 is A straight line connecting the end points on the inner circumferential side and the end points on the outer circumferential side in the direction is defined as a locus L2.

Further, in a cross section along the radial direction of the axial fan 100, a line representing a plane perpendicular to the rotation axis RA is defined as a straight line FL. As shown in FIG. 24, in the cross section along the radial direction of the axial fan 100, the angle between the locus L1 of the first region 25a1 and the straight line FL is defined as a first angle θ1. Further, in the cross section along the radial direction of the axial fan 100, the angle between the locus L2 of the second region 25a2 and the straight line FL is defined as a second angle θ2.

The axial fan 100 according to the third embodiment is formed such that the first angle θ1 of the first region 25a1 is larger than the second angle θ2 of the second region 25a2. In other words, the axial fan 100 according to the third embodiment is formed such that the second angle θ2 of the second region 25a2 is smaller than the first angle θ1 of the first region 25a1.

As described above, in the radial cross section centered on the rotation axis RA, the outer circumferential portion 30 has a locus L1 connecting the inner circumferential end point and the outer circumferential end point in the radial direction of the first region 25a1, and the rotation axis. A first angle θ1 is formed with the straight line FL representing a plane perpendicular to RA. Further, the outer circumferential portion 30 is an angle formed between a locus L2 connecting an end point on the inner circumferential side and an end point on the outer circumferential side in the radial direction of the second region 25a2 and a straight line FL representing a plane perpendicular to the rotation axis RA. A second angle θ2 is configured.

The outer peripheral portion 30 is formed such that when comparing the first angle θ1 and the second angle θ2, the first angle θ1 of the first region 25a1 is larger than the second angle θ2 of the second region 25a2. . That is, the line formed by the locus connecting the inner end point and the outer end point of each region in the radial direction of the first region 25a1 and the second region 25a2 and a straight line representing a plane perpendicular to the fan axis direction. The angle is larger in the first region 25a1 than in the second region 25a2.

[Effects of axial fan 100]
The outer circumferential portion 30 of the axial fan 100 according to the third embodiment is formed continuously with the first region 25a1 including the outer edge portion 23 on the inner circumferential side thereof in a radial cross section centered on the rotation axis RA. and a second region 25a2. The outer peripheral portion 30 is formed such that the first angle θ1 of the first region 25a1 is larger than the second angle θ2 of the second region 25a2. That is, the line formed by the locus connecting the inner end point and the outer end point of each region in the radial direction of the first region 25a1 and the second region 25a2 and a straight line representing a plane perpendicular to the fan axis direction. The angle is larger in the first region 25a1 than in the second region 25a2. The axial fan 100 according to the third embodiment has the outermost peripheral portion of the blade 20 curved more steeply in the radial direction around the rotation axis RA, thereby reducing the amount of fluid that separates from the positive pressure surface 25 at the outer edge of the fan. The flow becomes gentler, and the blade tip vortex WL becomes more stable. Therefore, in the axial fan 100, the blade tip vortex WL is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Embodiment 4.
FIG. 25 is a cross-sectional view of the blades 20 in the axial fan 100 according to the fourth embodiment. FIG. 25 is a cross-sectional view of the blade 20 in FIG. 23 taken along line AA when viewed in the direction of the arrows. Note that parts having the same configuration as the axial fan 100 of FIGS. 1 to 24 are designated by the same reference numerals, and a description thereof will be omitted. In the axial fan 100 according to the fourth embodiment, the configuration of the negative pressure surface 26 of the outer peripheral portion 30 is further specified.

The outer circumference 30 of the axial fan 100 according to the fourth embodiment has a negative pressure surface 26 from the upstream side to the downstream side in the direction in which fluid flows when the blades 20 rotate, in a radial cross section centered on the rotation axis RA. is depressed. More specifically, the outer peripheral portion 30 of the axial fan 100 according to the fourth embodiment has an outer peripheral negative pressure surface 26a. The suction surface 26 of the blade 20 includes an outer peripheral suction surface 26a.

As shown in FIG. 25, in the radial cross section of the axial fan 100, the outer negative pressure surface 26a has a cross-sectional shape concave from the upstream side to the downstream side in the direction of fluid flow by the axial fan 100. . That is, in the radial cross section of the axial fan 100, the cross-sectional shape of the outer peripheral negative pressure surface 26a is curved in a convex shape from the upstream side to the downstream side in the direction of fluid flow by the axial fan 100. The outer peripheral negative pressure surface 26a is, for example, curved in an arc shape.

The outer peripheral negative pressure surface 26a forms a surface facing inward of the blade 20, as shown in FIG. The outer peripheral negative pressure surface 26a forms a surface that has a radial component around the rotation axis RA. The outer peripheral negative pressure surface 26a forms a surface on the inner side of the axial fan 100.

The outer peripheral negative pressure surface 26a is formed to curve from the downstream side to the upstream side in the direction in which the fluid formed by the axial fan 100 flows as it goes from the inner peripheral side toward the outer edge 23. Alternatively, the outer peripheral negative pressure surface 26a is formed to curve upward from the downstream side toward the upstream side in the flow direction of the fluid formed by the axial fan 100 as it goes from the inner peripheral side toward the outer edge 23. .

Due to the outer peripheral positive pressure surface 25a and the outer peripheral negative pressure surface 26a, the outer peripheral portion 30 of the blade 20 moves from the downstream side to the upstream side in the direction in which the fluid formed by the axial fan 100 flows from the inner peripheral side toward the outer edge 23. The blades are curved toward the Due to the outer peripheral positive pressure surface 25a and the outer peripheral negative pressure surface 26a, the outer peripheral portion 30 of the blade 20 moves from the downstream side to the upstream side in the direction in which the fluid formed by the axial fan 100 flows from the inner peripheral side toward the outer edge 23. The blades are shaped so that they curve upward.

[Effects of axial fan 100]
The outer circumference 30 of the axial fan 100 according to the fourth embodiment has a negative pressure surface 26 from the upstream side to the downstream side in the direction in which fluid flows when the blades 20 rotate, in a radial cross section centered on the rotation axis RA. is depressed. That is, the shape of the negative pressure surface 26 in the radial cross section is convex toward the downstream side. Since the blade tip vortex WL is spiral, the outer edge of the blade tip vortex WL is adjusted by forming the negative pressure surface 26 through which the blade tip vortex WL passes. Therefore, the axial fan 100 according to the fourth embodiment can stably form the blade tip vortex WL. In the axial fan 100, the blade tip vortex WL is stabilized without being disturbed, and the fan efficiency can be improved to achieve high efficiency.

Embodiment 5.
FIG. 26 is a cross-sectional view of the blades 20 in the axial fan 100 according to the fifth embodiment. FIG. 26 is a cross-sectional view of the blade 20 in FIG. 23 taken along line AA when viewed in the direction of the arrows. Note that parts having the same configuration as the axial fan 100 of FIGS. 1 to 25 are designated by the same reference numerals, and the description thereof will be omitted. In the axial fan 100 according to the fifth embodiment, the configuration of the outer edge portion 23 of the outer peripheral portion 30 is further specified.

The outer circumferential portion 30 of the axial fan 100 according to the fifth embodiment has a rounded outer edge portion 23 in a radial cross section centered on the rotation axis RA. That is, in the axial fan 100 according to the fifth embodiment, the outer edge in the radial cross section is rounded. A round is a rounded portion, and is a portion formed in an R shape.

In the axial fan 100 according to the fifth embodiment, in the radial cross section of the axial fan 100, the corner portion between the outer surface 23e and the negative pressure surface 26 and the corner portion between the outer surface 23e and the outer peripheral positive pressure surface 25a are rounded. It is formed to have. The outer surface 23e is formed linearly in the radial cross section of the axial fan 100.

FIG. 27 is a sectional view of a first modification of the blade 20 in the axial fan 100 according to the fifth embodiment. The blade 20 of the first modification is curved so that the outer surface 23e has a round shape in the radial cross section of the axial fan 100. The blade 20 of the first modification forms a continuous curved surface such that the outer edge portion 23 forms one round. In the blade 20 of the first modification, in the radial cross section of the axial fan 100, the outer peripheral positive pressure surface 25a and the negative pressure surface 26 are connected in one round at the outer edge portion 23.

[Effects of axial fan 100]
The outer peripheral portion 30 of the axial fan 100 according to the fifth embodiment has a rounded outer edge portion 23 in a radial cross section centered on the rotation axis RA. In the axial fan 100 according to the fifth embodiment, when the flow on the positive pressure surface 25 of the outer peripheral portion 30 is directed toward the negative pressure surface 26, the outer edge portion 23 located therebetween is connected by a rounded portion, Since the fluid flow proceeds smoothly, the formation of the blade tip vortex WL can be stabilized. Therefore, in the axial fan 100, the blade tip vortex WL is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Embodiment 6.
FIG. 28 is a cross-sectional view of the blades 20 in the axial fan 100 according to the sixth embodiment. FIG. 28 is a cross-sectional view of the blade 20 in FIG. 23 taken along line AA when viewed in the direction of the arrows. Note that parts having the same configuration as the axial fan 100 of FIGS. 1 to 27 are designated by the same reference numerals, and the description thereof will be omitted. In the axial fan 100 according to the sixth embodiment, the configuration of the outer edge portion 23 of the outer peripheral portion 30 is further specified.

In the outer peripheral portion 30 of the axial fan 100 according to the sixth embodiment, the outer edge portion 23 is formed at an acute angle by the pressure surface 25 and the negative pressure surface 26 of the blade 20 in a radial cross section centered on the rotation axis RA. ing. That is, in the axial fan 100 according to the sixth embodiment, the outer edge in the radial cross section is formed at an acute angle.

More specifically, the blades 20 are formed such that the negative pressure surface 26 and the outer pressure surface 25a form an acute angle in the radial cross section of the axial fan 100. In the blade 20 of the axial fan 100 according to the sixth embodiment, the negative pressure surface 26 and the outer peripheral positive pressure surface 25a are formed in a triangular shape so that the outer edge 23 forms the apex in the radial cross section of the axial fan 100. ing.

The outer circumferential portion 30 of the axial fan 100 according to the sixth embodiment is formed such that the blade thickness becomes thinner from the inner circumferential side toward the outer circumferential side in the radial cross section of the axial fan 100. The outer circumferential portion 30 of the axial fan 100 according to the sixth embodiment has a negative pressure surface 26 and an outer circumferential positive pressure surface 25a in the axial direction of the rotation axis RA from the inner circumferential side to the outer circumferential side in the radial cross section of the axial fan 100. It is formed so that the distance between the two is small.

[Effects of axial fan 100]
In the outer peripheral portion 30 of the axial fan 100 according to the sixth embodiment, the outer edge portion 23 is formed at an acute angle by the pressure surface 25 and the negative pressure surface 26 of the blade 20 in a radial cross section centered on the rotation axis RA. ing. If the outer edge portion 23 is thick, the fluid flow generated at the outer edge comes into contact with the blade wall surface, making the fluid flow unstable. In the axial fan 100, the outer edge portion 23 is formed at an acute angle by the positive pressure surface 25 and the negative pressure surface 26 of the blades 20, so that when the fluid flow separates from the positive pressure surface 25 at the outer edge portion 23, Since the blade tip vortex WL is immediately drawn into the negative pressure surface 26 without contacting the blade wall surface, the blade tip vortex WL is stabilized. Therefore, in the axial fan 100, the blade tip vortex WL is not disturbed and stabilized, and the fan efficiency can be improved to achieve high efficiency.

Embodiment 7.
[Air conditioner 70]
Embodiment 7 will describe a case where the axial fan 100 and the like of Embodiments 1 to 6 described above are applied to the outdoor unit 50 of an air conditioner 70 as the blower 55.

FIG. 29 is a schematic diagram of an air conditioner 70 according to Embodiment 7. In the following description, the air conditioner 70 will be described as a device using the axial fan 100, but the axial fan 100 is not limited to that used in the air conditioner 70. The axial fan 100 is used for refrigeration or air conditioning applications, such as refrigerators or freezers, vending machines, air conditioners, refrigeration equipment, water heaters, and the like.

As shown in FIG. 29, the air conditioner 70 includes a compressor 64 that compresses and discharges refrigerant, a condenser 72 that condenses the refrigerant, an expansion valve 74, and an evaporator 73 that evaporates the refrigerant. ing. The air conditioner 70 also includes a blower 55 (see FIG. 31). The air conditioner 70 forms a refrigerant circuit 71 in which a compressor 64, a condenser 72, an expansion valve 74, and an evaporator 73 are connected in order through refrigerant piping.

A condenser fan 72a that blows air for heat exchange to the condenser 72 is arranged in the condenser 72. Further, an evaporator fan 73 a that blows air for heat exchange to the evaporator 73 is arranged in the evaporator 73 . At least one of the condenser fan 72a and the evaporator fan 73a is configured by the axial fan 100 of any one of the first to sixth embodiments described above. Note that the air conditioner 70 may have a configuration in which the refrigerant circuit 71 is provided with a flow path switching device such as a four-way valve that switches the flow of the refrigerant to switch between heating operation and cooling operation.

FIG. 30 is a perspective view of the outdoor unit 50 of the air conditioner 70 according to Embodiment 7, viewed from the outlet side. FIG. 31 is a diagram for explaining the configuration of the outdoor unit 50 from the top side. FIG. 32 is a diagram showing a state in which the fan grill 54 is removed from the outdoor unit 50. FIG. 33 is a diagram showing the internal configuration of the outdoor unit 50 with the fan grill 54, front panel 51b, etc. removed.

As shown in FIGS. 30 to 33, the outdoor unit main body 51, which is a casing, is configured as a housing having a pair of left and right side surfaces 51a and 51c, a front surface 51b, a back surface 51d, a top surface 51e, and a bottom surface 51f. Openings (not shown) for sucking air from the outside are formed in the side surface 51a and the back surface 51d.

On the front surface 51b, a blowout port 53 is formed in the front panel 52 as an opening for blowing air out to the outside. Furthermore, the air outlet 53 is covered with a fan grill 54, thereby preventing contact between the axial fan 100 and objects outside the outdoor unit main body 51, thereby ensuring safety. Note that the arrow AR in FIG. 31 indicates the flow of air.

A blower 55 is housed within the outdoor unit main body 51. The blower 55 includes an axial fan 100 and a drive source 61, as shown in FIG. The drive source 61 is a fan motor and provides driving force to the axial fan 100.

The axial fan 100 is connected to a rotating shaft 62 of a drive source 61 on the back side 51d, and is rotationally driven by this drive source 61. The drive source 61 is attached to a motor support 69. The motor support 69 is arranged between the drive source 61 and the heat exchanger 68 and supports the drive source 61.

The inside of the outdoor unit main body 51 is divided by a partition plate 51g, which is a wall, into a ventilation chamber 56 in which an axial fan 100 is installed and a machine room 57 in which a compressor 64 and the like are installed. A heat exchanger 68 is provided on the side surface 51a side and the rear surface 51d side in the ventilation chamber 56 so as to extend in a substantially L-shape when viewed from above. Note that the shape of the heat exchanger 68 is not limited to this shape, and may be formed, for example, on a straight line in a plan view. The heat exchanger 68 functions as an evaporator 73 during heating operation, and functions as a condenser 72 during cooling operation.

A bell mouth 63 is arranged on the radially outer side of the axial fan 100 arranged in the ventilation chamber 56. The bell mouth 63 surrounds the outer peripheral side of the axial fan 100 and adjusts the flow of gas generated by the axial fan 100 and the like. The bell mouth 63 is located outside the outer peripheral end of the blade 20 and is annularly provided along the rotational direction of the axial fan 100. Furthermore, a partition plate 51g is located on one side of the bell mouth 63, and a part of the heat exchanger 68 is located on the other side.

The front end of the bell mouth 63 is connected to the front panel 52 of the outdoor unit 50 so as to surround the outer periphery of the air outlet 53. Note that the bell mouth 63 may be configured integrally with the front panel 52, or may be prepared as a separate body connected to the front panel 52. With this bell mouth 63, a flow path between the suction side and the blowout side of the bellmouth 63 is configured as an air path near the blowout port 53. That is, the air path near the blower outlet 53 is separated from other spaces within the blower chamber 56 by the bell mouth 63.

The heat exchanger 68 provided on the suction side of the axial fan 100 includes a plurality of fins arranged in parallel so that their plate-like surfaces are parallel to each other, and heat transfer tubes passing through each fin in the direction in which the fins are arranged in parallel. It is equipped with A refrigerant circulating in the refrigerant circuit flows within the heat transfer tube. The heat exchanger 68 of this embodiment is configured such that the heat transfer tubes extend in an L-shape between the side surface 51a and the back surface 51d of the outdoor unit main body 51, and the heat transfer tubes in multiple stages meander while penetrating the fins. .

The heat exchanger 68 is connected to the compressor 64 via piping 65, etc., and is further connected to an indoor heat exchanger, an expansion valve 74, etc. (not shown), and constitutes a refrigerant circuit 71 of the air conditioner 70. do. Further, a board box 66 is arranged in the machine room 57, and a control board 67 provided in the board box 66 controls the equipment mounted in the outdoor unit.

The air conditioner 70 shown in FIG. 29 includes a blower 55, a motor support 69 that supports the drive source 61, a condenser 72 that condenses refrigerant, and an evaporator 73 that evaporates the refrigerant. The blower 55 shown in FIG. 31 blows air to at least one of the condenser 72 and the evaporator 73.

[Operations and effects of the blower 55 and air conditioner 70]
The blower 55 includes the axial fan 100 according to the first to sixth embodiments. Furthermore, the air conditioner 70 includes a blower 55 having the axial fan 100 according to the first to sixth embodiments. Therefore, in the blower 55 and the air conditioner 70 according to the seventh embodiment, the same effects as the axial fan 100 according to the first to sixth embodiments described above can be obtained. The axial fan 100 of the blower 55 and the air conditioner 70 has a small circumferential velocity on the leading edge 21 side of the blade 20 even if a fluid flow disturbed by a structure such as a motor support flows into the axial fan 100. Therefore, the blade tip vortex WL formed on the leading edge 21 side of the blade 20 becomes smaller. Further, the axial fan 100 of the blower 55 and the air conditioner 70 can cause the blade tip vortex WL, which expands from the leading edge 21 side part to the trailing edge part 22 side part, to follow the outer peripheral part 30. . Therefore, in the blower 55 and air conditioner 70 equipped with the axial fan 100, the blade tip vortex WL on the negative pressure surface 26 of the axial fan 100 is stabilized without being disturbed, improving fan efficiency and achieving high efficiency. be able to.

The configuration shown in the above embodiments is an example, and it is possible to combine it with another known technology, and a part of the configuration can be omitted or changed without departing from the gist. It is possible. For example, the inventions according to Embodiments 3 to 6 specify the configuration of the outer circumferential portion 30, but the inventions according to Embodiments 3 to 6 may be applied to the configuration of the rear outer circumferential portion 40.

10 hub, 20 wing, 20R wing, 21 leading edge, 22 trailing edge, 23 outer edge, 23a reduced part, 23b rear outer edge, 23c concave part, 23d protruding part, 23e outer surface, 24 inner edge, 25 positive Pressure surface, 25a outer circumference positive pressure surface, 25a1 first region, 25a2 second region, 25b rear outer circumference positive pressure surface, 26 negative pressure surface, 26a outer circumference negative pressure surface, 28 wing surface, 30 outer circumference, 40 rear outer circumference, 50 outdoor unit, 51 Outdoor unit body, 51a side, 51b front, 51c side, 51d back, 51e top, 51f bottom, 51g partition plate, 52 front panel, 53 air outlet, 54 fan grill, 55 blower, 56 blower room, 57 machine room, 61 Drive source, 62 Rotating shaft, 63 Bell mouth, 64 Compressor, 65 Piping, 66 Board box, 67 Control board, 68 Heat exchanger, 69 Motor support, 70 Air conditioner, 71 Refrigerant circuit, 72 Condenser, 72a Condensation dexterous fan, 73 evaporator, 73a evaporator fan, 74 expansion valve, 100 axial fan, 100L axial fan, 100R axial fan, 140 bending section, 150 air conditioner, 150R outdoor unit, 151 housing, 152 heat exchanger, 153 compressor, 154 motor, 155 motor support, 201 tip, 202 bending part, 203 rear end.

Claims

a hub that is rotationally driven and forms a rotating shaft;
It is formed around the hub, and includes a front edge, a rear edge, an inner edge that connects with the hub, and an outer edge that forms an outer edge between the front edge and the rear edge. having wings;
Equipped with
The wing is
a reduced portion forming a portion where the outer diameter of the blade is reduced in a portion on the leading edge side of the portion forming the outer edge portion than a portion on the trailing edge side forming the maximum diameter of the blade; ,
In the contracted portion, an outer peripheral portion forming a positive pressure surface that curves from the downstream side to the upstream side in the direction of flow of fluid flowing when the blade rotates from the inner edge side toward the outer edge;
has
The outer peripheral portion is
The axial flow fan is formed such that a width in a radial direction around the rotating shaft is larger in a portion on the rear edge side than in a portion on the front edge side.
The outer peripheral portion is
The axial fan according to claim 1, wherein the axial fan is formed in a part of the reduced portion in a circumferential direction around the rotating shaft.
The outer peripheral portion is
The axial flow fan according to claim 1, wherein the axial flow fan is formed in all areas of the reduced portion in a circumferential direction around the rotation axis.
The wing is
a tip portion that is the portion of the outer edge located closest to the front edge;
an inflection portion that is a portion of the outer edge portion that forms the outermost diameter of the blade and is located closest to the tip end;
has
The reduction part is
is formed in all areas between the tip portion and the bending portion in the circumferential direction around the rotation axis,
The outer peripheral portion is
Any one of claims 1 to 3, wherein the width in the radial direction about the rotation axis gradually increases from the tip end side toward the rear edge side. Axial fan described in.
The wing is
On the trailing edge side of the contracting part, a pressure surface is curved from the downstream side to the upstream side in the flow direction of the fluid flowing when the blade rotates from the inner edge side toward the outer edge. The axial fan according to any one of claims 1 to 4, further comprising a rear outer peripheral portion forming a rear outer peripheral portion.
The outer peripheral portion is
In a radial cross section centered on the rotation axis, the first region includes a first region including the outer edge portion, and a second region is formed continuously on the inner peripheral side of the first region,
In a radial cross section centered on the rotational axis, a line formed by a locus connecting an inner circumferential end point and an outer circumferential end point in the radial direction of the first region and a straight line representing a plane perpendicular to the rotational axis. A first angle that is an angle, a locus that connects an end point on the inner peripheral side and an end point on the outer peripheral side in the radial direction of the second region, and a straight line that represents a plane perpendicular to the rotation axis. 6. The first angle of the first region is formed so as to be larger than the second angle of the second region when two angles are compared. axial fan.
The outer peripheral portion is
7. A suction surface according to claim 1, wherein in a radial cross section centered on the rotation axis, the suction surface is concave from the upstream side to the downstream side in the direction in which fluid flows when the blade rotates. Axial fan.
The outer peripheral portion is
The axial fan according to any one of claims 1 to 7, wherein the outer edge portion is formed in a rounded shape in a radial cross section centered on the rotating shaft.
The outer peripheral portion is
The axial fan according to any one of claims 1 to 7, wherein in a radial cross section centered on the rotation axis, the outer edge portion is formed at an acute angle by a pressure surface and a suction surface of the blade. .
The axial fan according to any one of claims 1 to 9,
a drive source that provides driving force to the axial fan;
Blower with.
The blower according to claim 10;
a motor support that supports the drive source;
a condenser that condenses the refrigerant;
an evaporator that evaporates the refrigerant;
Equipped with
The blower is
An air conditioner that blows air to at least one of the condenser and the evaporator.