WO2024009466A1

WO2024009466A1 - Axial fan, blower, outdoor unit, and air conditioner

Info

Publication number: WO2024009466A1
Application number: PCT/JP2022/027001
Authority: WO
Inventors: 勝幸山本; 拓矢寺本
Original assignee: 三菱電機株式会社
Priority date: 2022-07-07
Filing date: 2022-07-07
Publication date: 2024-01-11

Abstract

Provided are an axial fan, a blower, an outdoor unit, and an air conditioner that are advantageous in reducing noise.　The axial fan according to the present disclosure includes a plurality of rotating blades and a rotating ring connected to the outer periphery of the plurality of rotating blades. Each of the plurality of rotating blades includes a connecting part connected to the rotating ring and an extending blade part extending upstream past the position of the rotating ring in relation to the position along the direction of the rotation axis of the axial fan. At least part of the extending blade part has a blade radius that is smaller than the inner radius of the rotating ring. The blower according to the present disclosure includes the axial fan. The outdoor unit according to the present disclosure includes the blower. The air conditioner according to the present disclosure includes the outdoor unit.

Description

Axial fans, blowers, outdoor units, and air conditioners

The present disclosure relates to an axial fan, a blower, an outdoor unit, and an air conditioner.

Patent Document 1 below discloses a propeller fan with a shroud. This propeller fan with a shroud includes a casing, an air intake port provided in the casing, an air outlet provided in the casing, and a fan guide port provided on the air outlet side via a partition plate. , a heat exchanger located on the air inlet side in the casing; a heat exchanger located between the heat exchanger and the air outlet in the casing; A shrouded impeller rotatably fitted into the guide port is provided. The shroud is provided with its air suction side leading edge closer to the leading edge side of 1/4 to 3/4 of the chord width of the outer peripheral end of the blade of the impeller.

Japanese Patent Application Publication No. 2006-189039

The above-mentioned conventional technology has the problem that noise cannot necessarily be reduced sufficiently.

The present disclosure has been made to solve the above-mentioned problems, and aims to provide an axial fan, a blower, an outdoor unit, and an air conditioner that are advantageous in reducing noise.

An axial fan according to the present disclosure includes a plurality of rotary blades and a rotating ring connected to the outer periphery of the plurality of rotary blades, each of the plurality of rotary blades being connected to the rotating ring. and an extension wing extending upstream of the position of the rotating ring with respect to the position in the direction of the rotational axis of the axial fan, at least a portion of the extension wing extending upstream from the inner radius of the rotating ring. It has a small blade radius.
A blower according to the present disclosure includes the above-mentioned axial fan.
An outdoor unit according to the present disclosure includes the blower, a heat exchanger that exchanges heat between the air blown by the blower and a refrigerant.
An air conditioner according to the present disclosure includes the outdoor unit described above.

According to the present disclosure, it is possible to provide an axial fan, a blower, an outdoor unit, and an air conditioner that are advantageous in reducing noise.

1 is a front view showing an axial fan according to Embodiment 1. FIG. FIG. 2 is a plan view of a blower including the axial fan shown in FIG. 1. FIG. FIG. 3 is a front view showing an axial fan of a comparative example. FIG. 4 is a plan view of the blower including the axial fan shown in FIG. 3; FIG. 3 is a front view showing an axial fan according to a second embodiment. 6 is a plan view of the blower including the axial fan shown in FIG. 5. FIG. FIG. 7 is a plan view of a blower including an axial fan according to Embodiment 3; It is a figure which shows the air conditioner by Embodiment 4. It is a figure which shows the outdoor unit of a modification.

Hereinafter, embodiments will be described with reference to the drawings. Common or corresponding elements in each figure are denoted by the same reference numerals, and description thereof will be simplified or omitted. Note that when referring to angles in this disclosure, when there is a dominant angle and a recessive angle whose sum is 360 degrees, this generally refers to an inferior angle, and there are acute angles and obtuse angles whose sum is 180 degrees. In principle, it refers to an acute angle. Further, the configurations shown in the embodiments described below are examples of technical ideas according to the present disclosure, and can be combined with another known technology, or can be combined with multiple technologies described in the present disclosure. It is also possible to combine ideas. Further, it is also possible to omit or change a part of the configuration without departing from the gist of the present disclosure.

Embodiment 1.
FIG. 1 is a front view showing an axial fan 1 according to a first embodiment. FIG. 2 is a plan view of the blower 10 including the axial fan 1 shown in FIG. Note that the figures of the present disclosure are schematic diagrams. In the figures of the present disclosure, there are places where the thickness of the wall portion is omitted and is represented by a line.

As shown in FIGS. 1 and 2, the axial fan 1 according to the first embodiment includes a plurality of rotary blades 2 and a rotating ring 3 connected to the outer periphery of the plurality of rotary blades 2. The rotating ring 3 rotates together with the plurality of rotary blades 2. The axial fan 1 rotates counterclockwise in FIG. 1 . The airflow generated by the axial fan 1 mainly flows from the top to the bottom in FIG. That is, the upward direction in FIG. 2 corresponds to the upstream side, and the downward direction in FIG. 2 corresponds to the downstream side.

In the present disclosure, the upper direction in FIG. 2 corresponds to the "back" direction, and the lower direction in FIG. 2 corresponds to the "front" direction.

The plurality of rotary blades 2 are arranged at equal angular intervals with respect to a central angle around the rotation axis AX of the axial fan 1. The rotation axis AX is a straight line about which the axial fan 1 rotates. In the illustrated example, three rotary blades 2 are arranged at 120 degree intervals around the rotation axis AX. The number of rotary blades 2 included in the axial fan 1 is not limited to three. The number of rotary blades 2 included in the axial fan 1 may be two, four, or more.

Each of the plurality of rotary blades 2 includes a connecting portion 4 and an extension wing portion 5. The connecting part 4 is a part connected to the rotating ring 3. That is, the connecting portion 4 is a portion connected to the inner peripheral portion of the rotating ring 3.

In the present disclosure, a direction parallel to the rotation axis AX is referred to as a "rotation axis direction." As shown in FIG. 2, the dimension of the rotating ring 3 in the direction of the rotating shaft is L1. The rotating ring 3 includes a first edge 6 and a second edge 7. The first edge 6 corresponds to the upstream edge of the two annular edges of the rotating ring 3. The second edge 7 corresponds to the downstream edge of the two annular edges of the rotating ring 3 . The dimension L1 corresponds to the distance between the first edge 6 and the second edge 7.

Regarding the position in the direction of the rotation axis, the rotor blade 2 overlaps the rotary ring 3. Regarding the position in the direction of the rotation axis, the dimension of the portion where the rotor blade 2 overlaps the rotary ring 3 is defined as L2. In the illustrated example, dimension L2 is smaller than dimension L1.

When the axial fan 1 rotates, air is discharged downstream from the exhaust port 11. The exhaust port 11 is an opening formed in the wall 12. The wall 12 has a plate shape perpendicular to the rotation axis AX. The inner circumference of the exhaust port 11 is adjacent to the outer circumference of the rotating ring 3. In the illustrated example, a bell mouth 13 is provided on the inner circumference of the exhaust port 11 . The rotating ring 3 is surrounded by a bell mouth 13.

In the example of FIG. 2, the rotating ring 3 includes a curved surface portion 14 that curves along the curved surface of the bell mouth 13. The curved surface portion 14 is formed on the second edge 7 side. The radius of the curved surface portion 14 increases toward the downstream side. The outer peripheral surface of the curved surface portion 14 faces the inner peripheral surface of the bell mouth 13. In the example of FIG. 2, the rotating ring 3 further includes a curved surface portion 15 formed on the first edge 6 side. The radius of the curved surface portion 15 increases toward the upstream side.

The extension wing portion 5 is a portion of the rotor blade 2 that extends upstream from the position of the rotary ring 3 with respect to the position in the rotation axis direction. In other words, the extension wing portion 5 protrudes toward the upstream side, that is, the back side, from the first edge 6 of the rotating ring 3 with respect to the position in the rotation axis direction.

The rotor blade 2 includes a leading edge 16 and a trailing edge 17. A leading edge 16 is formed on the extension wing section 5 . A trailing edge 17 is formed on the connecting portion 4 .

The axial fan 1 of this embodiment further includes a boss 18 provided at the center of the axial fan 1. The root portion of each rotor blade 2 is connected to a boss 18. Each rotor blade 2 projects radially outward from the boss 18. Boss 18 is also called a "hub."

The axial fan 1 of the present disclosure does not need to have the boss 18. That is, the axial fan 1 of the present disclosure may be of a bossless type in which adjacent rotary blades 2 are directly connected to each other.

The blower 10 of this embodiment includes a motor 19 that rotates the axial fan 1. The axial fan 1 is attached to the output shaft of the motor 19. Motor 19 is supported by bracket 20.

The blower 10 of this embodiment includes a grill 21. The grill 21 is attached to the wall 12 so as to cover the exhaust port 11 from the outside of the wall 12. The airflow discharged from the exhaust port 11 passes through the grille 21. The grill 21 prevents people, animals, foreign objects, etc. from touching the axial fan 1.

The use of the blower 10 according to the present disclosure is not particularly limited. The blower 10 according to the present disclosure may be provided in an outdoor unit. The outdoor unit according to the present disclosure includes a heat exchanger that exchanges heat between the air blown by the blower 10 and the refrigerant. The outdoor unit may constitute part of an air conditioner. Alternatively, the outdoor unit may constitute part of a heat pump water heater. The outdoor unit may include a compressor that compresses refrigerant.

When the axial fan 1 rotates, the pressure acting on the surface of the rotor blade 2 facing upstream becomes negative pressure, and the pressure acting on the surface of the rotor blade 2 facing downstream becomes positive pressure. The surface of the rotor 2 facing upstream is called the suction surface. The surface of the rotor 2 facing downstream is called the pressure surface. When the axial fan 1 rotates, the pressure acting on the positive pressure side of the rotor blade 2 becomes greater than the pressure acting on the suction side of the rotor blade 2.

In this disclosure, the distance between the rotation axis AX and the outer edge of the rotary blade 2 is referred to as a "blade radius." At least a portion of the extended wing section 5 has a wing radius R1 smaller than the inner radius R2 of the rotating ring 3. The inner radius R2 of the rotating ring 3 is the distance between the rotating axis AX and the inner peripheral portion of the rotating ring 3.

As shown in FIG. 2, in this embodiment, the extension wing portion 5 is divided into a first portion 8 and a second portion 9. Regarding the position in the direction of the rotation axis, the second part 9 is between the connecting part 4 and the first part 8. The first part 8 has a blade radius R1 that is smaller than the inner radius R2 of the rotating ring 3. That is, the distance between the rotation axis AX and the outer edge of the first portion 8 is smaller than the inner radius R2 of the rotation ring 3. The blade radius of the portion of the second portion 9 connected to the connecting portion 4 is equal to the inner radius R2 of the rotating ring 3. The blade radius of the remaining portion of the second portion 9 changes from the blade radius R1 to the inner radius R2 of the rotating ring 3. Regarding the length in the rotation axis direction, the length L3 of the first portion 8 is longer than the length L4 of the second portion 9.

In the illustrated example, the blade radius R1 of the first portion 8 of the extension blade portion 5 is constant along the rotation axis direction and the circumferential direction. As a modification, the blade radius R1 of the first portion 8 of the extended blade portion 5 may change along the rotation axis direction and the circumferential direction.

The total height L5 of the rotor blade 2 corresponds to the dimension of the entire rotor blade 2 in the direction of the rotation axis. The length L6 corresponds to the length of the connecting portion 4 in the rotation axis direction. In this embodiment, the total height L5 of the rotor blade 2 is equal to the sum of the length L3 of the first portion 8, the length L4 of the second portion 9, and the length L6 of the connecting portion 4.

Unlike this embodiment, assuming that there is no rotating ring 3, a leakage flow flowing from the positive pressure surface to the negative pressure surface occurs in the space near the outer peripheral edge of the rotary blade 2. In contrast, in this embodiment, the outer circumferential edge of the rotor blade 2 is closed by the rotary ring 3, making it possible to prevent such leakage flow from occurring.

Unlike this embodiment, assuming that the rotary ring 3 covers the entire rotor blade 2 in terms of the position in the rotation axis direction, air cannot be sucked in from the side surface of the axial fan 1. In contrast, in the present embodiment, the axial fan 1 is provided with the extended blade section 5 extending upstream from the position of the rotating ring 3 in the direction of the rotation axis. Air can be sucked in not only from the back of the fan 1 but also from the side of the axial fan 1. Therefore, it becomes possible to increase the air volume. Furthermore, since the total height L5 of the rotor blade 2 can be increased, the amount of work of the rotor blade 2 increases. Therefore, it becomes possible to further increase the air volume.

In the example of FIG. 2, the total height L5 of the rotor blade 2 is larger than twice the dimension L2 of the overlapped portion of the rotor blade 2 and the rotary ring 3 in terms of the length in the rotation axis direction. This becomes more advantageous in further increasing the air volume.

FIG. 3 is a front view showing an axial fan 90 of a comparative example. FIG. 4 is a plan view of a blower 91 including the axial fan 90 shown in FIG. The blade radius of the extended blade section 5 of the rotary blade 2 included in the axial fan 90 of the comparative example is equal to the inner radius R2 of the rotating ring 3 over the entire extended blade section 5. That is, the extended blade portion 5 of the axial fan 90 does not have any portion where the blade radius is smaller than the inner radius R2 of the rotating ring 3.

As shown in FIGS. 3 and 4, a blade tip vortex TV is generated near the outer edge of the rotor blade 2 as air flows from the pressure surface to the suction surface. In the connecting portion 4 connected to the rotating ring 3, since the outer edge of the blade portion is closed by the rotating ring 3, no blade tip vortex TV is generated. On the other hand, a blade tip vortex TV is generated at the outer edge of the extended blade portion 5 that is not connected to the rotating ring 3 and is extended upstream. At the outer edge of the extended blade portion 5, a blade tip vortex TV is formed so as to gradually become stronger as it goes downstream. In the axial fan 90 of the comparative example, the blade tip vortex TV thus formed collides with the rotating ring 3, thereby generating large noise.

In contrast, with the axial fan 1 of this embodiment, such noise can be reliably reduced in the following manner. In this embodiment, at least a portion of the extension wing portion 5 has a wing radius R1 smaller than the inner radius R2 of the rotating ring 3. Therefore, as shown in FIGS. 1 and 2, the position of the blade tip vortex TV formed at the outer edge of the extended blade portion 5 is on the inner circumferential side from the rotating ring 3 compared to the axial flow fan 90 of the comparative example. change to a distant position. As a result, the collision of the blade tip vortex TV with the rotating ring 3 can be suppressed, so that noise can be reduced.

Furthermore, in this embodiment, the length L3 of the first portion 8 of the extension wing portion 5, which has a wing radius R1 smaller than the inner radius R2 of the rotating ring 3, is such that the inner radius R2 of the rotating ring 3 has a wing radius. It is greater than the length L4 of the second part 9 with equal parts. Further, the length L3 of the first portion 8 is larger than the dimension L1 of the rotating ring 3. By satisfying at least one of these conditions, collision of the blade tip vortex TV with the rotating ring 3 can be more reliably suppressed, and therefore noise can be reduced more reliably.

Embodiment 2.
Next, a second embodiment will be described with reference to FIGS. 5 and 6, but the explanation will focus on the differences from the first embodiment described above, and common explanations will be simplified or omitted. Further, elements common to or corresponding to those described above are given the same reference numerals.

FIG. 5 is a front view showing the axial fan 22 according to the second embodiment. FIG. 6 is a plan view of the blower 10 including the axial fan 22 shown in FIG. As shown in these figures, each of the plurality of rotor blades 2 of the axial flow fan 22 according to the second embodiment has an extended blade part 5 and a radius changing part 23. The radius changing portion 23 is located between the connecting portion 4 and the extension wing portion 5. The extension wing portion 5 has a first wing radius R1 smaller than the inner radius R2 of the rotating ring 3.

In the illustrated example, the first blade radius R1 of the extension blade portion 5 is constant along the rotation axis direction and the circumferential direction. As a modification, the first blade radius R1 of the extended blade portion 5 may change along the rotation axis direction and the circumferential direction.

The blade radius of the radius changing portion 23 changes from the first blade radius R1 to the inner radius R2 of the rotating ring 3. The blade radius of the radius changing part 23 at the first position 24 where the extended blade part 5 and the radius changing part 23 contact is equal to the first blade radius R1. The blade radius of the radius changing portion 23 at the second position 25 where the connecting portion 4 and the radius changing portion 23 are in contact is equal to the inner radius R2 of the rotating ring 3. In the example of FIG. 6, the blade radius of the radius changing portion 23 increases continuously from the first position 24 to the second position 25 toward the downstream side.

The second position 25 corresponds to the position in the radius changing portion 23 where the blade radius is maximum. A second position 25 where the blade radius is the largest among the radius changing portions 23 overlaps the rotating ring 3 with respect to the position in the rotational axis direction. That is, regarding the position in the direction of the rotation axis, the second position 25 is within the range indicated by the dimension L1 of the rotation ring 3.

The position of the blade tip vortex TV shifts toward the outer circumferential side in the radial direction as the blade radius of the radius changing portion 23 increases toward the downstream side. In this embodiment, when viewed from a direction perpendicular to the rotational axis direction as shown in FIG. It is smaller than the inner radius R2 of the ring 3. In other words, the blade radius is smaller than the inner radius R2 of the rotating ring 3 over the entire portion of the rotary blade 2 that protrudes upstream from the rotating ring 3 in terms of the position in the rotation axis direction. According to the present embodiment, with such a configuration, it is possible to more reliably suppress the position of the blade tip vortex TV from shifting toward the outer peripheral side in the radial direction. Therefore, collision of the blade tip vortex TV with the rotating ring 3 can be more reliably suppressed, and noise can be more reliably reduced.

In the example of FIG. 6, the length L7 corresponds to the length of the extended wing portion 5 in the direction of the rotation axis. The length L8 corresponds to the length of the radius changing portion 23 in the rotation axis direction. In this embodiment, the total height L5 of the rotary blade 2 is equal to the sum of the length 7 of the extension wing portion 5, the length L8 of the radius changing portion 23, and the length L6 of the connecting portion 4. In the example of FIG. 6, the length 7 of the extension wing portion 5 is longer than the length L8 of the radius changing portion 23.

In the example of FIG. 6, the first position 24 corresponds to the position of the radius changing portion 23 where the blade radius is the smallest. Regarding the position in the direction of the rotation axis, the first position 24 is located on the upstream side, that is, on the back side of the first edge 6 of the rotation ring 3.

Embodiment 3.
Next, Embodiment 3 will be described with reference to FIG. 7, focusing on differences from

Embodiments

1 and 2 described above, and common explanations will be simplified or omitted. Further, elements common to or corresponding to those described above are given the same reference numerals.

FIG. 7 is a plan view of the blower 10 including the axial fan 26 according to the third embodiment. As shown in these figures, each of the plurality of rotor blades 2 of the axial flow fan 26 according to the third embodiment includes an extended blade portion 5 and a radius changing portion located between the connecting portion 4 and the extended blade portion 5. 27. The extension wing portion 5 has a first wing radius R1 smaller than the inner radius R2 of the rotating ring 3.

The blade radius of the radius changing portion 27 changes from the first blade radius R1 to the inner radius R2 of the rotating ring 3. The blade radius of the radius changing part 27 at the first position 28 where the extended blade part 5 and the radius changing part 27 touch is equal to the first blade radius R1. The blade radius of the radius changing portion 27 at the second position 29 where the connecting portion 4 and the radius changing portion 27 are in contact is equal to the inner radius R2 of the rotating ring 3. In the example of FIG. 7, the blade radius of the radius changing portion 27 increases continuously from the first position 28 to the second position 29 toward the downstream side.

The second position 29 corresponds to the position in the radius changing portion 27 where the blade radius is maximum. A second position 29 where the blade radius is the largest among the radius changing portions 27 overlaps the rotating ring 3 with respect to the position in the rotational axis direction. That is, regarding the position in the direction of the rotation axis, the second position 29 is within the range indicated by the dimension L1 of the rotation ring 3.

The first position 28 corresponds to the position in the radius changing portion 23 where the blade radius is the smallest. A first position 28 where the blade radius is the smallest in the radius changing portion 23 overlaps the rotating ring 3 with respect to the position in the rotation axis direction. That is, regarding the position in the direction of the rotation axis, the first position 28 is within the range indicated by the dimension L1 of the rotation ring 3.

The position of the blade tip vortex TV shifts toward the outer circumferential side in the radial direction as the blade radius of the radius changing portion 27 increases toward the downstream side. In this embodiment, the extension wing portion 5 and the first edge 6 of the rotating ring 3 intersect when viewed from a direction perpendicular to the rotational axis direction as shown in FIG. In other words, the part of the rotor blade 2 that protrudes upstream from the rotary ring 3 in terms of its position in the rotation axis direction is entirely the extension wing part 5, and has a diameter smaller than the inner radius R2 of the rotary ring 3. It has a single blade radius R1. According to the present embodiment, with such a configuration, it is possible to more reliably suppress the position of the blade tip vortex TV from shifting toward the outer peripheral side in the radial direction. Therefore, collision of the blade tip vortex TV with the rotating ring 3 can be more reliably suppressed, and noise can be more reliably reduced.

Embodiment 4.
Next, Embodiment 4 will be described with reference to FIG. 8, but the explanation will focus on the differences from the above-described

Embodiments

1 and 2, and common explanations will be simplified or omitted. Further, elements common to or corresponding to those described above are given the same reference numerals.

FIG. 8 is a diagram showing an air conditioner 30 according to the fourth embodiment. As shown in FIG. 8, an air conditioner 30 according to the fourth embodiment includes an outdoor unit 31 and an indoor unit 32. The outdoor unit 31 and the indoor unit 32 are connected by a refrigerant pipe 33. In FIG. 8, the outdoor unit 31 is shown as a cross-sectional plan view, and the indoor unit 32 is shown as a perspective view. The indoor unit 32 can perform cooling operation or heating operation by blowing cooled or heated air indoors.

The outdoor unit 31 includes a blower 10, a heat exchanger 34, and a compressor 35. Compressor 35 compresses the refrigerant. The heat exchanger 34 exchanges heat between the air blown by the blower 10 and the refrigerant. In the example of FIG. 8, the blower 10 of the outdoor unit 31 includes the axial fan 26 of the third embodiment. As a modification, the blower 10 of the outdoor unit 31 may include the axial fan 1 of the first embodiment or the axial fan 22 of the second embodiment.

The heat exchanger 34 has a back portion 36 placed on the back side with respect to the axial fan 26 and a side portion 37 placed on the side of the axial fan 26. In plan view, the heat exchanger 34 has an L-shaped outer shape in which a back surface portion 36 and a side surface portion 37 are perpendicular to each other.

The outdoor unit 31 includes a housing 50 and a partition wall 51. The wall 12 forms the front wall of the housing 50. The partition wall 51 separates the internal space of the housing 50 into a machine room 52 and a blower room 53. A compressor 35 is arranged within the machine room 52. The blower 10 is arranged within the blower room 53.

When the axial fan 26 rotates, air outside the outdoor unit 31 passes through the heat exchanger 34 and flows into the blower room 53. The air that has flowed into the blower chamber 53 is discharged to the outside of the outdoor unit 31 through the exhaust port 11.

Regarding the position in the rotational axis direction, the first edge 6, which is the upstream edge of the two edges of the rotating ring 3, is located upstream of the downstream end 38 of the side portion 37 of the heat exchanger 34. In other words, the downstream end 38 of the side surface portion 37 of the heat exchanger 34 protrudes further downstream, that is, toward the front side, than the first edge 6 of the rotating ring 3 with respect to the position in the direction of the rotation axis.

FIG. 9 is a diagram showing a modified outdoor unit 40. As shown in FIG. 9, in the modified outdoor unit 40, the first edge 6 of the rotating ring 3 is located downstream of the downstream end 41 of the side portion 37 of the heat exchanger 34 in terms of the position in the rotational axis direction. . In other words, the downstream end 41 of the side portion 37 of the heat exchanger 34 is located on the upstream side, that is, on the back side, of the first edge 6 of the rotating ring 3 with respect to the position in the rotation axis direction.

In the case of the outdoor unit 40 of the modified example shown in FIG. Since the flow fan 26 is not covered by the heat exchanger 34, the air passing through the heat exchanger 34 cannot be sucked in. In this case, in conjunction with the generation of the blade tip vortex TV, there is a possibility that a backflow BF that blows out into a region without suction may occur.

In contrast, in the case of the outdoor unit 31 of FIG. 8, it is possible to ensure the inflow of air passing through the area near the rotating ring 3 in the side portion 37 of the heat exchanger 34, thereby preventing the occurrence of the above-mentioned backflow BF. This can be reliably prevented. Therefore, it is possible to further increase the amount of air passing through the heat exchanger 34 than in the outdoor unit 40 of the modified example.

Note that among the features of the plurality of embodiments described above, two or more features that can be combined may be combined and implemented.

1 -axis fan, 2 -turn wings, 3rd rotation, 4 connection portion, 5 extension wings, 6th edge, 7 second edge, 8th part, 9th part, 10 blower, 11 exhaust, 12 walls. , 13 bell mouth, 14 curved surface section, 15 curved surface section, 16 front edge, 17 rear edge, 18 boss, 19 motor, 20 bracket, 21 grill, 22 axial fan, 23 radius change section, 24th position, 25th position 2 positions, 26 Axial fan, 27 Radius change section, 28 First position, 29 Second position, 30 Air conditioner, 31 Outdoor unit, 32 Indoor unit, 33 Refrigerant piping, 34 Heat exchanger, 35 Compressor, 3 6 Back part, 37 Side part, 38 Downstream end, 40 Outdoor unit, 41 Downstream end, 50 Housing, 51 Partition wall, 52 Machine room, 53 Blower room, 90 Axial fan, 91 Blower

Claims

multiple rotary blades;
a rotating ring connected to the outer periphery of the plurality of rotary blades;
An axial fan comprising:
Each of the plurality of rotary blades includes a connection part connected to the rotary ring, and an extension blade part extending upstream from the position of the rotary ring with respect to the position in the direction of the rotation axis of the axial fan,
At least a portion of the extended blade portion has a blade radius smaller than an inner radius of the rotating ring.
Each of the plurality of rotary blades is located between the extension blade portion having a first blade radius smaller than the inner radius of the rotary ring, and the extension blade portion and the connecting portion, and the blade radius is a radius changing portion that changes from the first blade radius to the inner radius of the rotating ring;
The axial flow fan according to claim 1, wherein a position where the blade radius is maximum in the radius changing portion overlaps the rotating ring with respect to a position in the direction of the rotating shaft.
The axial flow fan according to claim 2, wherein a position where the blade radius is the smallest in the radius changing portion overlaps the rotating ring with respect to a position in the direction of the rotating shaft.
A blower comprising the axial fan according to any one of claims 1 to 3.
The blower according to claim 4;
a heat exchanger that exchanges heat between the air blown by the blower and a refrigerant;
Outdoor unit with.
The heat exchanger has a side portion disposed on a side of the axial fan,
The upstream edge of the two edges of the rotating ring is located upstream of the downstream end of the side portion of the heat exchanger with respect to the position in the direction of the rotational axis of the axial fan. Outdoor unit listed.
An air conditioner comprising the outdoor unit according to claim 5 or 6.