WO2023188420A1

WO2023188420A1 - Axial-flow impeller and axial-flow blower

Info

Publication number: WO2023188420A1
Application number: PCT/JP2022/016977
Authority: WO
Inventors: 隆太郎浅野; 俊勝新井
Original assignee: 三菱電機株式会社
Priority date: 2022-04-01
Filing date: 2022-04-01
Publication date: 2023-10-05
Also published as: JPWO2023188420A1; JP7195490B1

Abstract

This axial-flow impeller is provided with a hub that is driven to rotate and that forms a rotation axis, and vanes that are formed on the periphery of the hub and extend radially outward from the hub. Each of the vanes comprises: a main blade that has a front edge section, a rear edge section, an inner peripheral edge section that is formed integrally with the hub, and an outer peripheral edge section that forms an outer edge between the front edge section and the rear edge section; and a plate-like auxiliary blade that, on half of the outer peripheral side of the main blade, protrudes from a blade surface of the main blade and extends radially outward. The main blade comprises a diminishing section that is formed in the outer peripheral edge section so that the outer diameter of the main blade portion decreases gradually from a portion located on the front edge section side toward the rear edge section. The auxiliary blade comprises an expanding section that is a portion that forms an outer peripheral edge of the auxiliary blade and is formed so that the outer diameter of the auxiliary blade portion increases gradually from a portion located on the front edge section side toward the rear edge section. Each of the vanes is formed so that, when viewed in the axial direction of the rotating axis, the diminishing section of the main blade and the expanding section of the auxiliary blade mutually intersect.

Description

Axial flow impeller and axial flow blower

The present disclosure relates to an axial flow impeller and an axial flow blower, and particularly relates to the shape of a blade.

Conventionally, axial flow blowers have been proposed that include an axial flow impeller and a bell mouth surrounding the outer circumferential side of the axial flow impeller. In the axial flow impeller of an axial flow blower, a large pressure difference occurs between the negative pressure surface and the positive pressure surface of the blade, particularly in the outer peripheral side portion of the blade where the rotation speed is high. When the axial impeller rotates, the resulting pressure difference causes air to flow from the positive pressure side to the negative pressure side, forming a large vortex at the outer peripheral end of the blade. This vortex is called a blade tip vortex, and the blade tip vortex acts as resistance to the rotation of the blade and reduces the air blowing efficiency. In addition, the blade tip vortex causes aerodynamic noise by colliding with the blade that generated the vortex itself, another blade adjacent to the blade that generated the vortex, or a structure on the downstream side of the axial flow impeller. It may occur. Therefore, in conventional axial flow impellers, in order to suppress noise caused by blade tip vortices, a curved part is provided at the outer peripheral end of the blade, the width of which gradually increases from the leading edge to the trailing edge. An axial flow impeller that reduces noise by suppressing blade tip vortices has been proposed (see Patent Document 1).

Patent No. 3629702

The axial flow impeller of Patent Document 1 has a warped part on the blade in order to suppress the development of blade tip vortices, but the work of the warped part of the blade is to enable the blade to effectively function as a pressure surface. As a result, there is a risk that the air blowing capacity will decrease and the fan efficiency will decrease.

The present disclosure is intended to solve the above-mentioned problems, and aims to provide an axial flow impeller and an axial flow blower that suppress noise and improve fan efficiency without reducing air blowing capacity. shall be.

An axial flow impeller according to the present disclosure includes a hub that is rotationally driven and forms a rotating shaft, and blades that are formed around the hub and extend radially outward from the hub, and the blades include a front edge, a rear A main wing having an edge, an inner peripheral edge formed integrally with the hub, and an outer peripheral edge forming an outer edge between the leading edge and the trailing edge, and a main wing in the outer peripheral half of the main wing. a plate-shaped secondary wing that protrudes from the wing surface and extends radially outward; The secondary wing has a reduced part formed so that the diameter gradually decreases, and the secondary wing is a part forming the outer peripheral edge of the secondary wing, and the secondary wing becomes smaller from the part located on the leading edge side toward the trailing edge. The blade has an enlarged portion formed such that the outer diameter of the wing portion gradually increases, and the reduced portion of the main wing and the enlarged portion of the secondary wing intersect with each other when viewed in the axial direction of the rotation axis. It is formed like this.

An axial flow blower according to the present disclosure includes an axial flow impeller having the above configuration and a bell mouth disposed on the radially outer side of the axial flow impeller so as to surround the axial flow impeller.

An axial flow blower according to the present disclosure includes an axial flow impeller having the above configuration, and a bell mouth arranged to surround the axial flow impeller on the radially outer side of the axial flow impeller, and the secondary blades include: On the outer circumferential edge of the secondary wing, there is a sub-outer circumferential edge part on the trailing edge side of the enlarged part, and the sub-outer circumferential edge part is from the part located on the leading edge side of the main wing on the outer circumferential edge of the secondary wing. The bell mouth is a part that forms a constant outer diameter toward the trailing edge of the main wing.The bell mouth is formed in a cylindrical shape, and extends from the upstream side to the downstream side in the direction of air flow formed by the blades. There is a condensed flow section where the flow path gradually becomes smaller towards the end, a direct flow section where the width of the flow path is constant from the upstream side to the downstream side, and a direct flow section where the width of the flow path is constant from the upstream side to the downstream side. an enlarged pipe portion formed such that the channel gradually increases in size, the enlarged portion of the secondary wing is located inside the constriction portion of the bell mouth, and the secondary outer peripheral edge of the secondary wing is located inside the contracted flow portion of the bell mouth. It is located inside the contraction part and the direct current part.

According to the present disclosure, the blades of the axial impeller are formed such that the contracted portion of the main blade and the expanded portion of the secondary blade intersect with each other when viewed in the axial direction of the rotating shaft. In addition, when viewed in the axial direction of the rotating shaft, the axial flow impeller is formed so that the contracted portion and the expanded portion intersect with each other, so that the secondary blade of the blade overlaps the contracted portion of the main blade. is formed. By having the main wing with the reduced portion, it is possible to prevent the wing tip vortices generated at the outer peripheral edge of the main wing from developing near the trailing edge. Since the main wing has the reduced portion, it is possible to prevent the development of the wing tip vortex, thereby preventing the generated wing tip vortex from becoming a noise source. In addition, the main wing can prevent the development of blade tip vortices by having a reduced part, which can prevent the generated blade tip vortices from creating a large resistance to the rotation of the blades, and can suppress a reduction in fan efficiency. . In addition, the axial flow impeller has a main wing with a condensed part that prevents the tip vortices generated on the main wing from acting as resistance to the rotation of the blade, and the secondary wing compensates for the reduced workload of the main wing, resulting in a decrease in air blowing capacity. can be prevented. Therefore, the axial flow impeller can suppress noise and improve fan efficiency without reducing air blowing capacity.

1 is a perspective view showing a typical configuration of an axial impeller according to Embodiment 1. FIG. 1 is a perspective view showing a typical configuration of blades of an axial impeller according to Embodiment 1. FIG. FIG. 2 is a plan view of a part of the axial impeller according to Embodiment 1, viewed in the direction of the rotation axis A. FIG. 3 is a plan view of a portion of a modification of the axial impeller according to Embodiment 1, as viewed in the direction of the rotation axis A. FIG. 3 is a perspective view showing a typical configuration of blades of an axial impeller according to Embodiment 2; FIG. 7 is a plan view of a part of the axial impeller according to Embodiment 2, viewed in the direction of the rotation axis A. FIG. 7 is a perspective view showing a typical configuration of blades of an axial impeller according to Embodiment 3; FIG. 11 is a conceptual diagram showing a typical cross section of the axial impeller according to Embodiment 3 taken along an arbitrary plane along the rotation axis A of the axial impeller. FIG. 7 is a perspective view showing a typical configuration of blades of an axial impeller according to Embodiment 4; FIG. 7 is a conceptual diagram showing a typical cross section of the axial impeller according to Embodiment 4, taken along an arbitrary plane along the rotation axis A of the axial impeller. FIG. 7 is a plan view of a part of an axial impeller according to Embodiment 5, viewed in the direction of the rotation axis A. FIG. 7 is a plan view of a part of an axial impeller according to Embodiment 6, viewed in the direction of the rotation axis A. FIG. 7 is a meridional view of an axial blower according to a seventh embodiment. 14 is an enlarged view of the axial blower and bell mouth of FIG. 13. FIG.

Hereinafter, an axial impeller and an axial blower according to embodiments will be described with reference to the drawings. Note that each drawing may differ from the actual relative dimensions or positional relationships of each component. Further, in the following drawings, 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 impeller 100]
FIG. 1 is a perspective view showing a typical configuration of an axial flow impeller 100 according to the first embodiment. Note that the rotation direction R indicated by the arrow in the figure indicates the direction in which the axial flow impeller 100 rotates. Further, a circumferential direction CD indicated by a double-headed arrow in the figure indicates the circumferential direction of the axial flow impeller 100. Further, a direction F indicated by a white arrow in FIG. 1 indicates a direction in which fluid flows due to rotation of the axial impeller 100.

In the fluid flow direction F, the Y1 side with respect to the axial impeller 100 is the upstream side of the airflow with respect to the axial impeller 100, and the Y2 side with respect to the axial impeller 100 is the axial impeller 100. It is on the downstream side of the airflow. That is, the Y1 side is a fluid suction side with respect to the axial flow impeller 100, and the Y2 side is a fluid blowout side with respect to the axial flow impeller 100.

Further, the X axis shown in FIG. 1 is a direction perpendicular to the rotation axis A of the axial impeller 100, and represents the radial direction of the axial impeller 100. In the radial direction, the portion on the X2 side is located on the outer peripheral side with respect to the portion on the X1 side, and the portion on the X1 side is located on the inner peripheral side with respect to the portion on the X2 side. That is, the X1 side of the axial impeller 100 is the inner peripheral side of the axial impeller 100, and the X2 side of the axial impeller 100 is the outer peripheral side of the axial impeller 100.

An axial flow impeller 100 according to Embodiment 1 will be described using FIG. 1. The axial flow impeller 100 is an axial flow type impeller, and is a device that forms a fluid flow. The axial impeller 100 is used in an axial blower 200, which will be described later, and is used, for example, as a fan for an air conditioner, a ventilation device, or the like. The axial flow impeller 100 forms a fluid flow by rotating in a rotation direction R around a rotation axis A. The fluid is, for example, a gas such as air.

The axial impeller 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 50 extending from the hub 10 toward the outer circumference. More specifically, the axial impeller 100 includes a hub 10 connected to a rotating shaft rotated by a drive source such as a motor (not shown), a plurality of main wings 20 extending from the hub 10, and a plurality of main wings 20. A secondary wing 30 is provided that extends from a portion of each wing surface 28 toward the outer circumferential side.

(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 be formed in a cylindrical shape, or may be formed in 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. In the axial flow impeller 100 shown in FIG. 1, the main wings 20 of adjacent blades 50 are connected via the hub 10.

The hub 10 may be formed continuously with the main wing 20 of the blade 50, or may be formed integrally with the parts constituting the main wing 20 without clear distinction. The axial flow impeller 100 includes a so-called bossless type fan in which the leading edge side and the trailing edge side of adjacent main wings 20 among a plurality of main wings 20 are connected so as to form a continuous surface without a boss.

The hub 10 is rotationally driven by a motor (not shown) or the like to form a rotation axis A. The hub 10 rotates around a rotation axis A. When the axial impeller 100 is viewed from the Y1 side, which is the upstream side of the airflow, the rotation direction R of the axial impeller 100 is counterclockwise as shown by the arrow in FIG. This is the direction of rotation. However, the rotation direction R of the axial flow impeller 100 is not limited to counterclockwise. The hub 10 has a configuration in which the mounting angle of the blades 50 or the direction of the blades 50 is changed so that the axial flow impeller 100 can be viewed from the Y1 side, which is the upstream side of the airflow with respect to the axial flow impeller 100. It may be rotated clockwise if the

(feather 50)
The axial flow impeller 100 has a plurality of blades 50. The vanes 50 are formed around the hub 10 and extend radially outward from the hub 10. The blade 50 has a main wing 20 and a secondary wing 30. Note that in the first embodiment, the axial flow impeller 100 having three blades 50 is illustrated, but the number of blades 50 is not limited to three.

The plurality of blades 50 having the main wing 20 and the sub-wing 30 are each formed in the same shape around the hub 10. Further, the plurality of blades 50 are provided at equal intervals in the circumferential direction CD. Note that the blade 50 is not limited to this configuration. The plurality of blades 50 may be formed in different shapes, and may be formed at different intervals in the circumferential direction CD.

The blades 50 transport fluid by pushing the fluid existing between the blades 50 as the axial impeller 100 rotates. At this time, among the blade surfaces 28 of the blades 50, the surface on the side where the pressure increases by pushing the fluid when the blade 50 rotates is defined as the positive pressure surface 25, and the surface on the back side of the positive pressure surface 25 constitutes the surface on the side where the pressure decreases. The surface is defined as a negative pressure surface 26. In the fluid flow direction F, the surface of the wing surface 28 facing the upstream side (Y1 side) of the main wing 20 becomes the suction surface 26, and the surface facing the downstream side (Y2 side) becomes the positive pressure surface 25. Further, the positive pressure surface 25 is a surface facing the rotation direction R, and the negative pressure surface 26 is a surface facing the opposite side to the rotation direction R.

(Main wing 20)
The main wings 20 transport fluid by pushing the fluid existing between the main wings 20 with the wing surfaces 28 as the axial impeller 100 rotates. The main wing 20 constitutes the main part of the blade 50. The wing area of the main wing 20 is larger than the wing area of the secondary wing 30. The main wing 20 is formed to extend radially outward from the hub 10. The plurality of main wings 20 are arranged radially outward from the hub 10 in the radial direction.

The main wing 20 is formed around the hub 10. The plurality of main wings 20 are provided spaced apart from each other in the circumferential direction CD. In addition, in Embodiment 1, although the axial flow impeller 100 having three main wings 20 is illustrated, the number of main wings 20 is not limited to three.

The main wing 20 is formed in a substantially triangular shape, when viewed in the axial direction of the rotation axis A, the width of the outer circumference side portion in the circumferential direction CD is larger than the width of the inner circumference side portion. Note that the main wing 20 is not limited to a substantially triangular shape when viewed in the axial direction of the rotation axis A.

The main wing 20 is formed in the shape of a forward-swept wing in which the outer circumference side portion protrudes more forward in the rotational direction R than the inner circumference side portion. The main wings 20 of the axial impeller 100 are often formed as forward-swept wings, especially when used in a ventilation fan. Note that the main wing 20 is not limited to a forward-swept wing, and may be formed in other shapes.

Here, the cross section when the blade 50 is cut at a cylindrical cross section with a radius centered on the rotation axis A is defined as the blade cross section. The blade cross section of the main wing 20 may have a cross-sectional shape in which the thickness of the blade is constant from the leading edge side part to the trailing edge side part, or the blade cross section from the leading edge side part to the trailing edge side part like a streamline shape. It may also have a cross-sectional shape with varying thickness.

The main wing 20 includes a leading edge 21 , a trailing edge 22 , an inner peripheral edge 24 integrally formed with the hub 10 , and an outer peripheral edge forming an outer edge between the leading edge 21 and the trailing edge 22 23. The leading edge portion 21 is formed at a portion of the main wing 20 on the forward movement side in the rotational direction R. That is, the front edge portion 21 is located forward of the rear edge portion 22 in the rotation direction R. The leading edge 21 is located on the upstream side of the trailing edge 22 in the direction F in which fluid generated by the axial impeller 100 flows.

The trailing edge portion 22 is formed on the rearward side of the main wing 20 in the rotational direction R. That is, the rear edge portion 22 is located rearward with respect to the front edge portion 21 in the rotation direction R. The trailing edge portion 22 is located downstream of the leading edge portion 21 in the direction F in which fluid generated by the axial impeller 100 flows. The axial impeller 100 has a leading edge 21 as a blade end facing in the rotation direction R of the axial impeller 100, and a trailing edge as a blade end opposite to the leading edge 21 in the rotation direction R. It has a section 22.

The outer peripheral edge portion 23 is an edge portion extending forward and backward of the main wing 20 in the rotational direction R so as to connect the outermost peripheral portion of the leading edge portion 21 and the outermost peripheral portion of the trailing edge portion 22. The outer peripheral edge portion 23 is located at the outer peripheral end of the axial impeller 100 in the radial direction (X-axis direction), and forms the outer peripheral edge of the main wing 20 .

The outer peripheral edge portion 23 is formed in an arc shape when viewed in the axial direction of the rotation axis A. However, the outer peripheral edge portion 23 is not limited to an arcuate configuration when viewed in the axial direction of the rotation axis A. The outer peripheral edge 23 has a leading edge 201 and a trailing edge 203 (see FIG. 2). The front edge end portion 201 is a portion of the outer peripheral edge portion 23 located closest to the front edge portion 21 side, and is a boundary portion with the front edge portion 21 . The trailing edge end portion 203 is a portion of the outer peripheral edge portion 23 located closest to the trailing edge portion 22, and is a boundary portion with the trailing edge portion 22.

When the main wing 20 is viewed in the axial direction of the rotation axis A, the length of the outer peripheral edge 23 in the circumferential direction CD is longer than the length of the inner peripheral edge 24 in the circumferential direction CD. However, in the main wing 20, the relationship between the length of the outer peripheral edge 23 and the length of the inner peripheral edge 24 is not limited to this configuration. For example, in the main wing 20, the length of the outer peripheral edge 23 and the inner peripheral edge 24 in the circumferential direction CD may be equal, or the length of the inner peripheral edge 24 may be longer than the length of the outer peripheral edge 23. .

The inner peripheral edge portion 24 is an edge portion extending back and forth of the main wing 20 in the rotational direction R so as to connect the innermost peripheral portion of the leading edge portion 21 and the innermost peripheral portion of the trailing edge portion 22. The inner peripheral edge portion 24 constitutes an end portion on the inner peripheral side in the radial direction (X-axis direction) in the axial impeller 100.

The inner peripheral edge portion 24 becomes the root portion of the main wing 20. The inner peripheral edge portion 24 is formed in an arc shape when viewed in the axial direction of the rotation axis A. However, the inner circumferential edge portion 24 is not limited to an arcuate configuration when viewed in the axial direction of the rotation axis A. An inner peripheral edge 24 of the main wing 20 is connected to the hub 10. As an example, the inner circumferential edge portion 24 of the main wing 20 is formed integrally with the outer circumferential wall of the hub 10, which is formed in a cylindrical shape.

The main wing 20 is formed to be inclined with respect to a plane perpendicular to the rotation axis A. More specifically, the main wing 20 is formed so that the pressure surface 25 faces in the rotation direction R and faces toward the Y2 side, which is the downstream side with respect to the main wing 20. Further, the main wing 20 is formed such that the suction surface 26 faces in a direction opposite to the rotational direction R and faces toward the Y1 side, which is the upstream side with respect to the main wing 20.

FIG. 2 is a perspective view showing a typical configuration of the blades 50 of the axial impeller 100 according to the first embodiment. FIG. 3 is a plan view of a part of the axial impeller 100 according to the first embodiment, viewed in the direction of the rotation axis A. FIG. 4 is a plan view of a portion of a modified example of the axial flow impeller 100 according to the first embodiment, as viewed in the direction of the rotation axis A. Further, in FIGS. 3 and 4, only one blade 50 is shown for the sake of explanation of the blade 50, and illustration of the other blades 50 is omitted. The detailed structure of the blade 50 will be further explained using FIGS. 2 to 4.

The cylindrical surface B indicated by the dotted line in FIGS. 3 and 4 has a radius that is the outermost diameter of the axial impeller 100 centered on the rotation axis A when the axial impeller 100 is viewed in the axial direction of the rotation axis A. The position of the virtual cylindrical surface B is shown. The virtual cylindrical surface B indicates the position of the blade 50 that forms the outermost diameter of the axial impeller 100, and forms the outermost diameter of the axial impeller 100 when the axial impeller 100 rotates. The figure shows the rotation locus of the parts. The portion of the blade 50 forming the virtual cylindrical surface B may be the outer circumferential edge 23 of the main wing 20, which will be described later, or may be the sub outer circumferential edge 33 of the sub-wing 30. Alternatively, the portion of the blade 50 forming the virtual cylindrical surface B may be both the outer circumferential edge 23 of the main wing 20 and the sub-outer circumferential edge 33 of the sub-wing 30, which will be described later.

The main wing 20 has a reduced portion formed in the outer peripheral edge 23 so that the outer diameter of the main wing 20 portion gradually decreases from the portion located on the leading edge 21 side toward the trailing edge 22 in the circumferential direction CD. 23b. The reduced portion 23b is formed such that the outer diameter of the main wing 20 portion gradually decreases in the direction opposite to the rotational direction R. The reduced portion 23b is formed such that the length of the main wing 20 portion in the radial direction gradually decreases as it goes in the direction opposite to the rotational direction R. Note that the outer diameter of the main wing 20 portion is the outer diameter of the axial flow impeller 100 centered on the rotation axis A, and is the outer diameter of the rotation axis A and the outer edge of the main wing 20 when viewed in the axial direction of the rotation axis A. is the distance between

In the reduced portion 23b of the main wing 20, when viewed in the axial direction of the rotation axis A, the cylindrical surface in the radial direction around the rotation axis A gradually increases from the portion located on the leading edge 21 side toward the rear edge 22. The width between B and the outer peripheral edge portion 23 is formed to be large. For example, the main portion constituting the reduced portion 23b is formed such that the outer diameter of the main wing 20 decreases monotonically from the portion located on the leading edge 21 side toward the trailing edge 22.

The main wing 20 has a notched portion at the reduced portion 23b compared to a virtual outer edge 23c located on the cylindrical surface B, which is the outer peripheral edge 23 of the main wing 20 without the reduced portion 23b. formed into a shape. As shown in FIGS. 3 and 4, the reduced portion 23b is formed to be located on the inner peripheral side (X1 side) of the cylindrical surface B near the rotation axis A.

The reduced portion 23b is formed on the rear edge 22 side of the outer peripheral edge 23 in the circumferential direction CD. The reduced portion 23b is formed from the starting point 202 to the rear edge end 203 in the circumferential direction CD. The starting point 202 is provided between the leading end 201 and the trailing end 203 in the outer peripheral edge 23 . Furthermore, as shown in FIG. 4, the starting point 202 may be provided at the same position as the leading edge 201, but at a different position from the trailing edge 203. In this case, the reduced portion 23b may be formed in a portion of the outer peripheral edge 23 on the rear edge 22 side in the circumferential direction CD, or may be formed from the front edge 21 to the rear edge 22.

As described above, the starting point 202 is provided at the position of the leading edge 201 or between the leading edge 201 and the trailing edge 203 in the outer peripheral edge 23. When the reduced portion 23b is not formed in the main wing 20, it is effective and desirable to form the starting point 202 at a portion of the outer peripheral edge 23 of the main wing 20 where the tip vortex develops. The optimal position for forming the starting point 202 in the outer peripheral edge 23 of the main wing 20 is determined by the shape of the main wing 20 or the operating point of the axial blower. That is, in the axial impeller 100, the optimal position for forming the starting point 202 may change depending on the operating point at which the blower is operating. The operating point represents the operating state in which the blower is used. Specifically, the operating point is the air volume obtained by each fan when the rotation speed is constant, depending on the pressure drop in the air path where the fan is installed (≒ pressure increase required of the fan), but the pressure and air volume vary. This point is determined by the pairing with.

The starting point portion 202 is a portion of the outer peripheral edge portion 23 of the main wing 20 that forms a different curvature with respect to the cylindrical surface B. The starting point portion 202 is a portion of the outer peripheral edge portion 23 of the main wing 20 that forms a larger curvature than the curvature of the cylindrical surface B. That is, the reduced portion 23b is a portion that moves away from the cylindrical surface B and toward the inner peripheral side (X1 side) when going in the opposite direction to the rotational direction R.

It is desirable that the main wing 20 is provided such that the leading edge end 201 and the starting point 202 are located at different positions. In this case, the main wing 20 has a front outer edge portion 23 a between the leading edge end portion 201 and the starting point portion 202 .

The front outer edge portion 23a is a portion of the main wing 20 formed to have a constant outer diameter, and is a portion formed along the cylindrical surface B when viewed in the axial direction of the rotation axis A. The front outer edge portion 23a is a portion forming the outermost diameter of the axial flow impeller 100. The front outer edge portion 23a may be formed in a portion between the front edge end portion 201 and the starting point portion 202, or may be formed in the entire portion between the front edge end portion 201 and the starting point portion 202. .

The main wing 20 has a front outer edge portion 23a in the outer peripheral edge portion 23 at a portion closer to the leading edge portion 21 than the reduced portion 23b. The front outer edge portion 23a is a portion of the outer circumferential 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, and is This is the part that forms the outermost diameter.

It is desirable that the blade 50 has a leading end 201 and a starting point 202 located at different positions, and that the entire portion between the leading end 201 and the starting point 202 is formed by the front outer edge 23a. That is, the blade 50 has a leading edge end 201 and a starting point 202 located at different positions, and the outer diameter of the main blade 20 is constant in the portion between the leading edge end 201 and the starting point 202, and the axial flow impeller 100 has a constant outer diameter. It is desirable to form the outermost diameter. The blade 50 has a front outer edge 23a formed between the leading edge 201 and the starting point 202 of the main wing 20, and a reduced portion 23b between the starting point 202 and the trailing edge 203. is desirable.

The blade 50 is not limited to having the front outer edge 23a between the leading edge end 201 of the main wing 20 and the starting point 202. For example, as shown in FIG. 4, in the blade 50, the leading edge 201 and the starting point 202 are aligned, and the reduced portion 23b is formed from the leading edge 201 to the trailing edge 203. It's okay.

As shown in FIG. 4, in the blade 50, the entire outer peripheral edge 23 of the main wing 20 has a reduced portion 23b, and the outer diameter of the main wing 20 gradually decreases from the leading edge 201 to the trailing edge 203. It may be formed to be small. That is, as shown in FIG. 4, when the main wing 20 is viewed in the axial direction of the rotation axis A, as it goes from the leading edge end 201 to the trailing edge end 203, the main wing 20 increases in the radial direction around the rotation axis A. The width between the cylindrical surface B and the outer peripheral edge 23 is increased.

Further, in the blade 50, the outer peripheral edge 23 that constitutes the portion between the leading edge end 201 and the starting point 202 of the main wing 20 does not have to be formed in a shape along the cylindrical surface B. For example, the blade 50 may be formed such that the curvature of the outer peripheral edge 23 that constitutes the portion between the leading edge end 201 and the starting point 202 of the main wing 20 is different from the curvature of the reduced portion 23b.

Alternatively, the blade 50 is a linear portion formed on the outer peripheral edge 23 that constitutes a portion between the leading edge end 201 and the starting point 202 of the main wing 20 when viewed in the axial direction of the rotation axis A. May include. The blade 50 has an outer diameter of the main wing 20 in a part of the outer peripheral edge 23 that constitutes the part between the leading edge end 201 and the starting point 202 of the main wing 20 when viewed in the axial direction of the rotation axis A. It may have a portion that becomes smaller.

Further, the blades 50 extend outward from the main wing 20 from the starting point 202 toward the trailing edge end 203 in a part of the reduced portion 23b that constitutes the part between the starting point 202 and the trailing edge end 203 of the main wing 20. It may also include a portion where the diameter does not monotonically decrease. The reduced portion 23b may include a portion where the outer diameter of the main wing 20 does not decrease as it goes from the starting point portion 202 to the trailing edge end portion 203, or may include a portion where the outer diameter of the main wing 20 decreases at a smaller rate. It may also include a portion where the rate increases. Note that the reduced portion 23b is formed so that the outer diameter of the main wing 20 decreases as a whole from the portion located on the leading edge portion 21 side toward the trailing edge portion 22.

By having the reduced portion 23b, the main wing 20 can prevent the blade tip vortices generated at the outer peripheral edge 23 of the main wing 20 from further developing, particularly near the trailing edge end 203. By having the reduced portion 23b, the main wing 20 can prevent the development of a blade tip vortex, thereby preventing the generated blade tip vortex from becoming a noise source. In addition, the main wing 20 can prevent the development of a blade tip vortex by having the reduced portion 23b, and can prevent the generated blade tip vortex from becoming a large resistance to the rotation of the blade 50, reducing fan efficiency. can be suppressed.

In an axial flow type impeller, a larger amount of work can be obtained nearer to the outer peripheral edge of the blade. Therefore, in the case of an axial flow type impeller, if the main blade 20 is configured to simply have the reduced portion 23b at the outer peripheral edge 23 of the main blade 20, the amount of work performed by the main blade 20 will be greatly reduced, and the air blowing capacity will be reduced. However, the air blowing efficiency also decreases. Therefore, the blades 50 of the axial flow impeller 100 according to the first embodiment are provided with a secondary blade 30 in addition to the main blade 20.

(Secondary wing 30)
The secondary wing 30 protrudes from the wing surface 28 of the main wing 20 in the outer peripheral half of the main wing 20 and extends radially outward. The secondary wing 30 is provided, for example, in a part of the main wing 20 on the suction surface 26 side. The secondary wing 30 is, for example, a swept wing. However, the secondary wing 30 is not limited to a swept wing as long as it has an enlarged portion 31, which will be described later.

The secondary wing 30 is provided so as to protrude from a portion of the main wing 20 on the suction surface 26 side. The secondary wing 30 is formed to branch from a part of the outer peripheral half of the suction surface 26 of the main wing 20 and extend toward the outer peripheral side of the blade 50 . The secondary wing 30 is formed smaller than the main wing 20 when viewed in the axial direction of the rotation axis A. The secondary wing 30 is formed at a position closer to the outer circumferential edge 23 of the main wing 20 than the inner circumferential edge 24 in the radial direction about the rotation axis A.

The secondary wing 30 is formed at a position closer to the trailing edge 22 of the main wing 20 than the leading edge 21 in the circumferential direction CD when viewed in the axial direction of the rotation axis A. Note that the formation position of the secondary wing 30 in the circumferential direction CD is not limited to a mode in which it is formed at a position closer to the trailing edge 22 than the leading edge 21 of the main wing 20. The secondary wing 30 may be formed at a position closer to the leading edge 21 of the main wing 20 than the trailing edge 22 in the circumferential direction CD when viewed in the axial direction of the rotation axis A, or , it may be formed near the midpoint between the leading edge 21 and the trailing edge 22 of the main wing 20.

As shown in FIGS. 3 and 4, the secondary blade 30 is formed to overlap at least a portion of the reduced portion 23b when viewed in the axial direction of the rotation axis A. The secondary wing 30 is formed to be located on the upstream side (Y1 side) of the airflow with respect to the reduced portion 23b. In the axial direction of the rotation axis A, at least a portion of the secondary wing 30 is formed to face the suction surface 26 of the main wing 20 in the portion where the reduced portion 23b is formed.

The secondary wing 30 is formed into a plate shape. The secondary wing 30 has an enlarged portion 31 , a secondary trailing edge 32 , a secondary outer peripheral edge 33 , and a secondary inner peripheral edge 34 . The enlarged portion 31, the secondary trailing edge 32, and the secondary outer peripheral edge 33 form an outer peripheral edge 30a of the secondary wing 30. The enlarged portion 31 forms a leading edge portion of the secondary wing 30, and is formed in a portion of the secondary wing 30 on the forward side in the rotational direction R. That is, the enlarged portion 31 is located forward of the sub-rear edge portion 32 in the rotation direction R. The enlarged portion 31 is located on the upstream side of the sub-rear edge portion 32 in the direction F in which fluid generated by the axial impeller 100 flows.

The enlarged portion 31 is a portion forming the outer peripheral edge 30a of the secondary wing 30, and the outer diameter of the secondary wing 30 portion increases from the portion located on the leading edge 21 side of the main wing 20 toward the trailing edge 22 of the main wing 20. is formed to gradually increase in size. That is, the enlarged portion 31 is formed such that the outer diameter of the secondary wing 30 portion gradually increases in the direction opposite to the rotational direction R. The enlarged portion 31 is formed such that the length of the sub-wing 30 portion in the radial direction gradually increases as it goes in the direction opposite to the rotational direction R.

As shown in FIGS. 3 and 4, the blade 50 is formed such that the reduced portion 23b of the main wing 20 and the enlarged portion 31 of the secondary wing 30 intersect with each other when viewed in the axial direction of the rotation axis A. There is. That is, the blades 50 are configured such that, when viewed in the axial direction of the rotation axis A, a portion of the outer edge of the main wing 20 and a portion of the outer edge of the secondary wing 30 intersect with each other.

The secondary trailing edge portion 32 is formed on the backward moving side of the secondary wing 30 in the rotational direction R. That is, the sub-rear edge portion 32 is located rearward with respect to the enlarged portion 31 in the rotation direction R. The sub trailing edge portion 32 is located downstream of the enlarged portion 31 in the direction F in which fluid generated by the axial impeller 100 flows. The axial impeller 100 has an enlarged part 31 as a blade tip facing in the rotation direction R of the axial impeller 100, and has a sub trailing edge part as a blade tip on the opposite side to the enlarged part 31 in the rotation direction R. It has 32.

The secondary outer peripheral edge portion 33 is an edge portion that extends forward and backward of the secondary wing 30 in the rotational direction R so as to connect the outermost peripheral portion of the enlarged portion 31 and the outermost peripheral portion of the secondary trailing edge portion 32. The secondary outer peripheral edge portion 33 is located at the outer peripheral end of the secondary blade 30 in the radial direction (X-axis direction), and forms an outer peripheral edge 30a of the secondary blade 30. The secondary wing 30 has a secondary outer peripheral edge 33 on the outer peripheral edge 30a of the secondary wing 30 at a portion closer to the enlarged portion 31 where the trailing edge 22 of the main wing 20 is located.

The sub outer peripheral edge portion 33 is formed in an arc shape when viewed in the axial direction of the rotation axis A. As shown in FIGS. 3 and 4, the sub-outer peripheral portion 33 is formed in a shape along a cylindrical surface B when viewed in the axial direction of the rotation axis A. The secondary outer peripheral edge 33 is a portion of the outer peripheral edge 30a of the secondary wing 30 that forms a constant outer diameter from a portion located on the leading edge 21 side of the main wing 20 to a portion located on the trailing edge 22 side of the main wing 20. It is.

Note that the sub-outer peripheral portion 33 is not limited to having an arc shape when viewed in the axial direction of the rotation axis A, and is also limited to having a shape along the cylindrical surface B. isn't it. For example, the sub-outer peripheral portion 33 may include a linear portion when viewed in the axial direction of the rotation axis A, or may include a portion located on the inner peripheral side of the cylindrical surface B.

The sub-inner peripheral edge portion 34 is an edge portion extending back and forth of the sub-wing 30 in the rotational direction R so as to connect the innermost circumferential portion of the enlarged portion 31 and the innermost circumferential portion of the sub-rear edge portion 32. The sub-inner circumferential edge portion 34 constitutes an end portion of the sub-wing 30 on the inner circumferential side in the radial direction (X-axis direction). The sub-inner peripheral edge portion 34 is a root portion of the sub-wing 30 and is a portion rising from the negative pressure surface 26 of the main wing 20. The sub-inner peripheral edge portion 34 is a portion formed integrally with the main wing 20.

When the secondary wing 30 is viewed in the axial direction of the rotation axis A, the length of the secondary inner peripheral edge 34 in the circumferential direction CD is longer than the length of the secondary outer peripheral edge 33 in the circumferential direction CD. However, in the secondary wing 30, the relationship between the length of the secondary inner peripheral edge part 34 and the length of the secondary outer peripheral edge part 33 is not limited to this configuration. For example, in the secondary wing 30, the length of the secondary inner peripheral edge 34 and the length of the secondary outer peripheral edge 33 in the circumferential direction CD may be equal, and the length of the secondary outer peripheral edge 33 is longer than the length of the secondary inner peripheral edge 34. It can also be long.

The sub-inner peripheral edge portion 34 has an inner edge front end portion 301 and an inner edge rear end portion 304. The sub-outer peripheral edge portion 33 has an outer edge front end portion 302 and an outer edge rear end portion 303. The inner edge front end portion 301 is a portion of the sub-inner peripheral edge portion 34 located closest to the enlarged portion 31, and is a boundary portion with the enlarged portion 31. In other words, the inner edge front end portion 301 is a portion of the enlarged portion 31 located closest to the sub-inner circumferential edge portion 34, and is a boundary portion with the sub-inner circumferential edge portion 34.

The inner edge rear end portion 304 is a portion of the sub-inner circumferential edge portion 34 located closest to the sub-rear edge portion 32 side, and is a boundary portion with the sub-rear edge portion 32. In other words, the inner edge rear end portion 304 is a portion of the sub-rear edge portion 32 located closest to the sub-inner circumferential edge portion 34 side, and is a boundary portion with the sub-inner circumferential edge portion 34 .

The outer edge front end portion 302 is a portion of the sub outer peripheral edge portion 33 located closest to the enlarged portion 31 and is a boundary portion with the enlarged portion 31. In other words, the outer edge front end portion 302 is a portion of the enlarged portion 31 located closest to the sub outer circumferential edge portion 33, and is a boundary portion with the sub outer circumferential edge portion 33.

The outer edge rear end portion 303 is a portion of the sub outer peripheral edge portion 33 located closest to the sub rear edge portion 32 side, and is a boundary portion with the sub rear edge portion 32. In other words, the outer edge rear end portion 303 is a portion of the sub rear edge portion 32 located closest to the sub outer circumferential edge portion 33 side, and is a boundary portion with the sub outer circumferential edge portion 33.

The secondary blade 30 is formed such that the outer diameter of the secondary blade 30 gradually increases from the inner edge front end 301 to the outer edge front end 302 in the circumferential direction CD. That is, the portion forming the enlarged portion 31 of the secondary wing 30 is formed such that the outer diameter of the secondary wing 30 gradually increases from the front to the rear in the rotation direction R. Note that the outer diameter of the secondary blade 30 is the outer diameter of the axial impeller 100 centered on the rotation axis A, and is the diameter of the rotation axis A and the secondary blade 30 when viewed in the axial direction of the rotation axis A. This is the distance from the outer edge. The outer edge of the secondary wing 30 has an enlarged portion 31 whose outer diameter gradually increases from the inner edge front end 301 of the secondary wing 30 to the outer edge front end 302 located on the rear side thereof.

It is desirable that the outer diameter of the secondary wing 30 of the blade 50 is constant from the outer edge front end 302 to the outer edge rear end 303 in the circumferential direction CD. That is, it is desirable that the secondary outer peripheral edge portion 33 is formed to have a constant outer diameter from the outer edge front end portion 302 to the outer edge rear end portion 303 in the circumferential direction CD.

The secondary wing 30 is not limited to the configuration having the enlarged portion 31 , the secondary trailing edge 32 , the secondary outer peripheral edge 33 , and the secondary inner peripheral edge 34 . For example, in the secondary wing 30, the inner edge front end portion 301 and the outer edge front end portion 302 may be integrally formed, or the enlarged portion 31 and the secondary outer peripheral edge portion 33 may be integrally formed.

In the case where the enlarged portion 31 and the sub-outer peripheral edge portion 33 are integrally formed and this portion is defined as the enlarged portion 31, the configuration of the blade 50 may be considered as follows. The blade 50 is formed such that the reduced portion 23b of the main wing 20 and the enlarged portion 31 of the secondary wing 30 intersect with each other when viewed in the axial direction of the rotation axis A. That is, the blades 50 are configured such that, when viewed in the axial direction of the rotation axis A, a portion of the outer edge of the main wing 20 and a portion of the outer edge of the secondary wing 30 intersect with each other.

[Actions and effects of the axial flow impeller 100]
The blades 50 of the axial flow impeller 100 are formed such that the reduced portion 23b of the main blade 20 and the enlarged portion 31 of the secondary blade 30 intersect with each other when viewed in the axial direction of the rotation axis A. . Further, in the axial flow impeller 100, when viewed in the axial direction of the rotation axis A, the reduced portion 23b and the enlarged portion 31 are formed to intersect with each other, so that the secondary blade 30 of the blade 50 is It is formed at a position overlapping with the reduced portion 23b of 20.

By having the reduced portion 23b, the main wing 20 can prevent the wing tip vortices generated at the outer peripheral edge 23 of the main wing 20 from developing near the trailing edge end 203. By having the reduced portion 23b, the main wing 20 can prevent the development of a blade tip vortex, thereby preventing the generated blade tip vortex from becoming a noise source. In addition, the main wing 20 can prevent the development of a blade tip vortex by having the reduced portion 23b, and can prevent the generated blade tip vortex from becoming a large resistance to the rotation of the blade 50, reducing fan efficiency. can be suppressed. In addition, the axial flow impeller 100 prevents the blade tip vortices generated in the main blade 20 from acting as resistance to the rotation of the blades 50 by the main blade 20 having the reduced portion 23b, and also transfers the work decreased by the main blade 20 to the secondary blade. 30 compensates for this, it is possible to prevent a decrease in air blowing capacity. Therefore, the axial flow impeller 100 can suppress noise and improve fan efficiency without reducing air blowing capacity.

Further, the blade surface 28 on which the secondary blade 30 is formed is a negative pressure surface 26 that constitutes the surface on the back side of the positive pressure surface 25 where pressure increases by pushing fluid when the blade 50 rotates. The axial flow impeller 100 prevents the blade tip vortices generated in the main blade 20 from acting as resistance to the rotation of the blades 50 by the main blade 20 having the reduced portion 23b, and also transfers the work reduced by the main blade 20 to the suction surface 26. Since the formed auxiliary blades 30 compensate, it is possible to prevent a decrease in air blowing ability. Therefore, the axial flow impeller 100 can suppress noise and improve fan efficiency without reducing air blowing capacity.

Further, the front outer edge portion 23a is a portion of the outer circumferential 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, and is This is the part forming the outermost diameter of 100 mm. Further, the secondary outer peripheral edge 33 forms a constant outer diameter in the outer peripheral edge 30a of the secondary wing 30 from a portion located on the leading edge 21 side of the main wing 20 to a portion located on the trailing edge 22 side of the main wing 20. This is the part to do. By having the configuration, the axial flow impeller 100 has the main wing 20 and the sub-wing 20, for example, compared to a vane 50 where the main wing 20 portion does not form the outermost diameter and a wing 50 where the sub-wing 30 has the reduced portion 23b. The workload of both blades 30 can be increased.

Embodiment 2.
FIG. 5 is a perspective view showing a typical configuration of the blades 50 of the axial impeller 100 according to the second embodiment. FIG. 6 is a plan view of a part of the axial flow impeller 100 according to the second embodiment, viewed in the direction of the rotation axis A. In addition, in FIG. 6, only one blade 50 is shown for the purpose of explaining the blade 50, and illustration of the other blades 50 is omitted. The axial flow impeller 100 according to the second embodiment is different from the axial flow impeller 100 according to the first embodiment in the positional relationship between the main blade 20 and the secondary blade 30, and the other configurations are different from the axial flow impeller 100 according to the first embodiment. This is the same as the axial flow impeller 100 according to the first embodiment. Components having the same configuration as the axial flow impeller 100 of FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted.

(Axial flow impeller 100)
The axial flow impeller 100 includes a hub 10 connected to a rotating shaft rotated by a drive source such as a motor (not shown), a plurality of main wings 20 extending from the hub 10, and a pressure surface 25 of each of the plurality of main wings 20. The secondary wing 30 extends from a portion of the blade toward the outer circumferential side.

(Secondary wing 30)
The secondary wing 30 of the first embodiment is provided on a part of the main wing 20 on the suction surface 26 side, whereas the secondary wing 30 of the second embodiment is provided on a part of the main wing 20 on the pressure surface 25 side. It is provided. The secondary wing 30 of the second embodiment is provided so as to protrude from a portion of the main wing 20 on the pressure surface 25 side. The secondary wing 30 of the second embodiment is formed so as to branch from a part of the outer peripheral half of the pressure surface 25 of the main wing 20 and extend toward the outer peripheral side of the blade 50 .

As shown in FIG. 6, the secondary wing 30 of the second embodiment is formed to overlap at least a portion of the reduced portion 23b when viewed in the axial direction of the rotation axis A. The secondary wing 30 is formed so as to be located on the downstream side (Y2 side) of the airflow with respect to the reduced portion 23b. In the axial direction of the rotation axis A, at least a portion of the secondary blade 30 is formed to face the pressure surface 25 of the main blade 20 in the portion where the reduced portion 23b is formed.

The secondary wing 30 has an enlarged portion 31 , a secondary trailing edge 32 , a secondary outer peripheral edge 33 , and a secondary inner peripheral edge 34 . As shown in FIG. 6, the blade 50 is formed such that the reduced portion 23b of the main wing 20 and the enlarged portion 31 of the secondary wing 30 intersect with each other when viewed in the axial direction of the rotation axis A. That is, the blades 50 are configured such that, when viewed in the axial direction of the rotation axis A, a portion of the outer edge of the main wing 20 and a portion of the outer edge of the secondary wing 30 intersect with each other. The secondary blade 30 of the second embodiment is formed such that the secondary outer peripheral edge 33 is located on the downstream side (Y2 side) of the airflow with respect to the secondary inner peripheral edge 34.

[Actions and effects of the axial flow impeller 100]
The axial flow impeller 100 according to the second embodiment includes a main wing 20 having a reduced portion 23b, similar to the axial flow impeller 100 of the first embodiment, and a main wing 20 that is formed to extend from the main wing 20 and overlap the reduced portion 23b. It has a secondary wing 30 formed in. Therefore, the axial flow impeller 100 of the second embodiment can exhibit the same effects as the axial flow impeller 100 of the first embodiment.

The axial flow impeller 100 prevents the blade tip vortices generated in the main blade 20 from acting as resistance to the rotation of the blades 50 by the main blade 20 having the reduced portion 23b, and also transfers the reduced work of the main blade 20 to the pressure surface 25. Since the formed auxiliary blades 30 compensate, it is possible to prevent a decrease in air blowing ability. The axial flow impeller 100 according to the second embodiment has the main blade 20 and the secondary blade 30 configured as described above, thereby suppressing the resistance and aerodynamic noise caused by the blade tip vortices, and achieving low noise and low noise while maintaining the air blowing ability. High efficiency can be achieved.

Further, the blade surface 28 on which the secondary blade 30 is formed is a positive pressure surface 25 that pushes fluid and increases pressure when the blade 50 rotates. In the axial flow impeller 100 according to the second embodiment, the pressure surface 25 of the main blade 20 and the wake of the main blade 20 are located on the suction surface 26 side of the secondary blade 30, and the boundary on the suction surface 26 of the secondary blade 30 Appropriate energy can be supplied to the layer. Therefore, the axial flow impeller 100 according to the second embodiment can suppress the adverse pressure gradient on the negative pressure surface 26 of the secondary blade 30, prevent separation of fluid flow, and prevent a decrease in blowing efficiency caused by this. This can prevent noise from worsening. Therefore, the axial flow impeller 100 according to the second embodiment can suppress resistance due to the development of blade tip vortices and resistance due to fluid separation from the suction surface 26, and suppress aerodynamic noise.

Embodiment 3.
FIG. 7 is a perspective view showing a typical configuration of the blades 50 of the axial impeller 100 according to the third embodiment. FIG. 8 is a conceptual diagram showing a typical cross section of the cross section of the axial flow impeller 100 taken along an arbitrary plane along the rotation axis A of the axial flow impeller 100 according to the third embodiment. In addition, in FIG. 7, only one blade 50 is shown for the purpose of explaining the blade 50, and illustration of the other blades 50 is omitted. In FIG. 8, plane H is a plane perpendicular to rotation axis A.

The axial flow impeller 100 according to the third embodiment has the shapes of the main blade 20 and the secondary blade 30 specified compared to the axial flow impeller 100 according to the first embodiment, and other configurations are not implemented. This is the same as the axial flow impeller 100 according to the first embodiment. Components having the same configuration as the axial flow impeller 100 of FIGS. 1 to 6 are given the same reference numerals, and the description thereof will be omitted.

Here, on a plane along the rotation axis A of the axial flow impeller 100 according to the third embodiment, the blades are obtained by cutting the axial flow impeller 100 along the rotation axis A at a specific position in the circumferential direction CD. The cross section of 50 is called a span cross section. As shown in FIGS. 7 and 8, the cross section of the blade 50 along the a-a1 line is defined as a span cross section S1, the cross section of the blade 50 along the b-b1 line is defined as a span cross section S2, and the cross section of the blade 50 along the c-c1 line is defined as a span cross section S2. The cross section of the blade 50 is defined as a span cross section S3.

Here, point a, point b, and point c are points located on the inner peripheral edge portion 24 of the main wing 20 when viewed in the axial direction of the rotation axis A. Moreover, point a1, point b1, and point c1 are points located on the virtual cylindrical surface B when viewed in the axial direction of the rotation axis A. Point a and point a1 are points located closer to the front edge 21 than the rear edge 22 in the circumferential direction CD. Point c and point c1 are points located closer to the rear edge 22 than the front edge 21 in the circumferential direction CD. Point b is a point located between point a and point c in the circumferential direction CD, and point b1 is a point located between point a1 and point c1 in the circumferential direction CD.

The span cross section S1 is a span cross section that includes the rotation axis A, a point a, and a point a1, and is a cross section of the blade 50 that includes the inner peripheral edge 24 of the main wing 20 and the front outer edge 23a of the main wing 20. The span cross section S2 is a span cross section that includes the rotation axis A, point b, and point b1, and includes the inner peripheral edge 24 of the main wing 20, the reduced portion 23b of the main wing 20, and the sub inner peripheral edge 34 of the secondary wing 30. It is a cross section of the blade 50 including the enlarged portion 31 and the expanded portion 31 . The span cross section S3 is a span cross section that includes the rotation axis A, a point c, and a point c1, and includes the inner peripheral edge 24 of the main wing 20, the reduced part 23b of the main wing 20, and the sub inner peripheral edge 34 of the secondary wing 30. It is a cross section of the blade 50 including the sub-outer peripheral edge portion 33.

The span cross section S2 and the span cross section S3 are cross sections including a portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A in the axial flow impeller 100 according to the third embodiment. be. In the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the main wing 20 is bent toward the pressure surface 25 side with respect to the plane H. It is sloping.

In other words, in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the main wing 20 is flat in the fluid flow direction F. It is inclined toward the downstream side (Y2 side) with respect to H.

The inclination of the main wing 20 is such that when the upstream side (Y1 side) is at the top and the downstream side (Y2 side) is at the bottom in the fluid flow direction F, the inclination is such that it goes downward as it goes radially outward from the rotation axis A. is inclined to. The main wing 20 is configured such that the outer circumferential side is lower than the inner circumferential side in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. slopes monotonically.

In the aspect of Embodiment 3 shown in FIG. 8, the monotonous inclination of the main wing 20 is the inclination of the main wing 20 in a shape that constitutes a "monotonic decrease" in the mathematical term. That is, in the span section S2 and the span section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the main wing 20 is divided from the inner circumferential side to the outer circumferential side. It is sloped so that the outer circumferential side is downward no matter which point you look at. In other words, the main wing 20 has a shape in which the position in the Y direction monotonically decreases from the inner circumferential side to the outer circumferential side, and the main wing 20 has a shape in which the position in the Y direction decreases as it goes from the inner circumferential side to the outer circumferential side. The shape extends from the Y1 side to the Y2 side.

Assume that the blade shape of the main wing 20 shown in FIG. 8 is expressed by a function of y=f(x). At this time, the Y-axis direction in FIG. 8 is the y-axis direction of the function y=f(x), and the X-axis direction in FIG. 8 is the x-axis direction of the function y=f(x). The main wing 20 has a shape that expresses a monotonically decreasing function such that y decreases as x increases, and the main wing 20 has a downward-sloping shape toward the Y2 side as it goes toward the outer circumference. In FIG. 8, when the shape of the main wing 20 is assumed to be a function of y=f(x), if x1 is the inner peripheral part of the main wing 20 and x2 is the outer peripheral part of the main wing 20, then the main wing 20 is The shape forms a graph of a function that satisfies f(x1)>f(x2) if x1<x2.

Furthermore, in the span cross section S2 and the span cross section S3, the secondary blade 30 is bent and inclined toward the suction surface 26 with respect to the plane H. In other words, in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap in a top view seen from the axial direction of the rotation axis A, the secondary wing 30 is, in the fluid flow direction F, It is inclined toward the upstream side (Y1 side) with respect to the plane H.

When the upstream side (Y1 side) is the upper side and the downstream side (Y2 side) is the lower side in the fluid flow direction F, the slope of the secondary blade 30 increases as it goes outward in the radial direction from the rotation axis A. It's slanted like that. The outer circumferential side of the secondary wing 30 is higher than the inner circumferential side in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. It slopes monotonically.

In the aspect of Embodiment 3 shown in FIG. 8, the monotonous inclination of the secondary wing 30 is an inclination of a shape such that the secondary wing 30 constitutes a "monotonic increase" in the mathematical term. That is, in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the secondary wing 30 extends from the inner circumferential side to the outer circumferential side. It is sloped so that the outer circumferential side is upward no matter which point you look at. In other words, the secondary wing 30 has a shape in which the position in the Y direction increases monotonically from the inner circumferential side to the outer circumferential side, and the secondary wing 30 has a shape in which the position in the Y direction increases from the inner circumferential side to the outer circumferential side. It has a shape whose position is from the Y2 side to the Y1 side.

It is assumed that the wing shape of the secondary wing 30 shown in FIG. 8 is expressed by a function of y=f(x). At this time, the Y-axis direction in FIG. 8 is the y-axis direction of the function y=f(x), and the X-axis direction in FIG. 8 is the x-axis direction of the function y=f(x). The secondary wing 30 has a shape that represents a monotonically increasing function such that y increases as x increases, and the secondary wing 30 has a shape that rises to the right such that it is located closer to the Y1 side as it goes toward the outer circumference. In FIG. 8, when the shape of the secondary wing 30 is assumed to be a function of y=f(x), if x1 is the inner peripheral part of the secondary wing 30 and x2 is the outer peripheral part of the secondary wing 30, then The blade 30 has a shape that forms a graph of a function that satisfies f(x1)<f(x2) if x1<x2.

In the axial flow impeller 100, the span cross section of the main wing 20 curves toward the pressure surface 25 and is monotonically inclined at the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. The span cross section of the secondary wing 30 is curved toward the suction surface 26 and is monotonically inclined.

Here, in a span cross section of the blade 50 taken along a plane along the rotation axis A, the shape in which the blade 50 is bent toward the positive pressure surface 25 and monotonically inclined is referred to as backward tilting, and the shape in which the blade 50 is bent toward the suction surface 26 is referred to as a backward tilt. A monotonically inclined shape is called anteversion.

The axial flow impeller 100 according to the third embodiment is configured such that the span section of the main wing 20 is tilted backward in the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. The secondary wing 30 is formed such that the span cross section of the secondary wing 30 is inclined forward.

When the blade 50 is viewed in the axial direction of the rotation axis A, the main wing 20 and the sub-wing 30 are located at a position where the reduced portion 23b of the main wing 20 and the enlarged portion 31 of the sub-wing 30 intersect with each other with respect to the plane H. It's sloped. In the blade 50, at the intersection of the reduced portion 23b and the enlarged portion 31 when viewed in the axial direction of the rotation axis A, the main wing 20 in a cross section of the main wing 20 cut along a plane along the rotation axis A is tilted backward. Therefore, the secondary wing 30 in a cross section taken along a plane along the rotation axis A is inclined forward.

[Actions and effects of the axial flow impeller 100]
Axial flow impellers used in ventilation fans and the like are often made by molding resin or metal using a mold. The axial flow impeller 100 according to the third embodiment has a cross section of the blade 50 at a portion where the reduced portion 23b of the main blade 20 and the enlarged portion 31 of the secondary blade 30 intersect with each other when viewed in the axial direction of the rotation axis A. In terms of shape, the main wing 20 is tilted backward, and the secondary wing 30 is tilted forward.

That is, in the axial flow impeller 100, the span section of the main wing 20 curves toward the pressure surface 25 and is monotonically inclined at the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. The span cross section of the secondary wing 30 is curved toward the suction surface 26 and is monotonically inclined. Therefore, when the axial flow impeller 100 according to the third embodiment is formed by molding using a mold, it is possible to release the mold in two directions in the axial direction of the rotating shaft A and in multiple directions outward in the radial direction. The molded product can be taken out.

On the other hand, in the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, one or both of the main wing 20 and the secondary wing 30 is formed in a complicated shape. Consider the case where In such a case, the axial flow impeller is undercut with respect to the mold release direction, which requires an additional mold structure and increases manufacturing costs. Note that an undercut is a shape in which a molded product cannot be released from the mold as it is when taken out from the mold.

By having the above configuration, the axial flow impeller 100 according to the third embodiment can exhibit the same effects as the axial flow impeller 100 according to the first embodiment without significantly increasing the manufacturing cost. , low noise and high efficiency can be achieved.

Embodiment 4.
FIG. 9 is a perspective view showing a typical configuration of the blades 50 of the axial impeller 100 according to the fourth embodiment. FIG. 10 is a conceptual diagram showing a typical cross section of the cross section of the axial flow impeller 100 taken along an arbitrary plane along the rotation axis A of the axial flow impeller 100 according to the fourth embodiment. In addition, in FIG. 9, only one blade 50 is shown for explanation of the blade 50, and illustration of the other blades 50 is omitted.

The axial flow impeller 100 according to the fourth embodiment specifies the shapes of the main blade 20 and the secondary blade 30 compared to the axial flow impeller 100 according to the second embodiment, and other configurations are not implemented. This is the same as the axial flow impeller 100 according to the second embodiment. Components having the same configuration as the axial flow impeller 100 of FIGS. 1 to 8 are designated by the same reference numerals, and the description thereof will be omitted.

The span cross section S2 and the span cross section S3 are cross sections including a portion where the main wing 20 and the sub wing 30 overlap when viewed from above in the axial direction of the rotation axis A in the axial flow impeller 100 according to the fourth embodiment. be. In the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the main wing 20 is bent toward the suction surface 26 with respect to the plane H. It is sloping.

In other words, in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the main wing 20 is flat in the fluid flow direction F. It is inclined toward the upstream side (Y1 side) with respect to H.

The inclination of the main wing 20 is such that when the upstream side (Y1 side) is the upper side and the downstream side (Y2 side) is the lower side in the fluid flow direction F, the inclination is such that it increases toward the outside in the radial direction from the rotation axis A. is inclined to. The main wing 20 is configured such that the outer circumferential side is higher than the inner circumferential side in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. slopes monotonically.

In the aspect of the fourth embodiment shown in FIG. 10, the monotonous inclination of the main wing 20 is the inclination of the main wing 20 in a shape that constitutes a "monotonic increase" in the mathematical term. That is, in the span section S2 and the span section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the main wing 20 is divided from the inner circumferential side to the outer circumferential side. It is sloped so that the outer circumferential side is upward no matter which point you look at. In other words, the main wing 20 has a shape in which the position in the Y direction increases monotonically from the inner circumferential side to the outer circumferential side, and the main wing 20 has a shape in which the position in the Y direction increases from the inner circumferential side to the outer circumferential side. It has a shape that goes from the Y2 side to the Y1 side.

Assume that the blade shape of the main wing 20 shown in FIG. 10 is expressed by a function of y=f(x). At this time, the Y-axis direction in FIG. 10 is the y-axis direction of the function y=f(x), and the X-axis direction in FIG. 10 is the x-axis direction of the function y=f(x). The main wing 20 has a shape that represents a monotonically increasing function such that y increases as x increases, and the main wing 20 has a shape that rises to the right as it goes toward the outer circumference, being located on the Y1 side. In FIG. 10, when the shape of the main wing 20 is assumed to be a function of y=f(x), if x1 is the inner circumferential part of the main wing 20 and x2 is the outer circumferential part of the main wing 20, then the main wing 20 is The shape forms a graph of a function that satisfies f(x1)<f(x2) if x1<x2.

Furthermore, in the span cross section S2 and the span cross section S3, the secondary blade 30 is bent and inclined toward the pressure surface 25 with respect to the plane H. In other words, in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap in a top view seen from the axial direction of the rotation axis A, the secondary wing 30 is, in the fluid flow direction F, It is inclined toward the downstream side (Y2 side) with respect to the plane H.

When the upstream side (Y1 side) is the upper side and the downstream side (Y2 side) is the lower side in the fluid flow direction F, the slope of the secondary blade 30 decreases as it goes radially outward from the rotation axis A. It's slanted like that. The outer circumferential side of the secondary wing 30 is lower than the inner circumferential side in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. It slopes monotonically.

In the aspect of Embodiment 4 shown in FIG. 10, the monotonous inclination of the subwing 30 is an inclination of a shape such that the subwing 30 constitutes a "monotonic decrease" in the mathematical term. That is, in the span cross section S2 and the span cross section S3 of the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, the secondary wing 30 extends from the inner circumferential side to the outer circumferential side. It is sloped so that the outer circumferential side is downward no matter which point you look at. In other words, the secondary wing 30 has a shape in which the position in the Y direction monotonically decreases from the inner circumferential side to the outer circumferential side, and the secondary wing 30 has a shape in which the position in the Y direction decreases from the inner circumferential side to the outer circumferential side. It has a shape whose position is from the Y1 side to the Y2 side.

Assume that the wing shape of the secondary wing 30 shown in FIG. 10 is expressed by a function of y=f(x). At this time, the Y-axis direction in FIG. 10 is the y-axis direction of the function y=f(x), and the X-axis direction in FIG. 10 is the x-axis direction of the function y=f(x). The secondary wing 30 has a shape that expresses a monotonically decreasing function such that y decreases as x increases, and the secondary wing 30 has a shape that slopes downward to the right so that it is located closer to the Y2 side as it goes toward the outer circumference. In FIG. 10, when the shape of the secondary wing 30 is assumed to be a function of y=f(x), if x1 is the inner peripheral part of the secondary wing 30 and x2 is the outer peripheral part of the secondary wing 30, then The blade 30 has a shape that forms a graph of a function that satisfies f(x1)>f(x2) if x1<x2.

In the axial flow impeller 100, the span section of the main wing 20 curves toward the suction surface 26 and is monotonically inclined at the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. , the span cross section of the secondary wing 30 is curved toward the pressure surface 25 and is monotonically inclined. The axial flow impeller 100 according to the fourth embodiment is formed such that the span cross section of the main wing 20 is inclined forward at the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. The span cross section of the secondary wing 30 is formed to be inclined rearward.

When the blade 50 is viewed in the axial direction of the rotation axis A, the main wing 20 and the sub-wing 30 are located at a position where the reduced portion 23b of the main wing 20 and the enlarged portion 31 of the sub-wing 30 intersect with each other with respect to the plane H. It's sloped. In the blade 50, at the intersection of the reduced portion 23b and the enlarged portion 31 when viewed in the axial direction of the rotation axis A, the main wing 20 is tilted forward in a cross section of the main wing 20 taken along a plane along the rotation axis A. Therefore, the secondary wing 30 in a cross section taken along a plane along the rotation axis A is inclined backward.

[Actions and effects of the axial flow impeller 100]
The axial flow impeller 100 according to the fourth embodiment has a cross section of the blade 50 at a portion where the reduced portion 23b of the main blade 20 and the enlarged portion 31 of the secondary blade 30 intersect with each other when viewed in the axial direction of the rotation axis A. In terms of shape, the main wing 20 is tilted forward, and the secondary wing 30 is tilted backward.

That is, in the axial flow impeller 100, the span cross section of the main wing 20 curves toward the suction surface 26 and is monotonically inclined at the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A. The span cross section of the secondary wing 30 is curved toward the pressure surface 25 and is monotonically inclined. Therefore, when the impeller according to Embodiment 4 is manufactured by molding using a mold, the molded product is molded by releasing the mold in two directions in the axial direction of the rotating shaft A and in multiple directions outward in the radial direction. can be taken out.

On the other hand, in the portion where the main wing 20 and the secondary wing 30 overlap when viewed from above in the axial direction of the rotation axis A, one or both of the main wing 20 and the secondary wing 30 is formed in a complicated shape. In this case, the manufacturing cost increases as described in the third embodiment. By having the above configuration, the axial flow impeller 100 according to the fourth embodiment can exhibit the same effects as the axial flow impeller 100 according to the second embodiment without significantly increasing the manufacturing cost. Low noise and high efficiency can be achieved.

Embodiment 5.
FIG. 11 is a plan view of a part of the axial flow impeller 100 according to the fifth embodiment, viewed in the direction of the rotation axis A. Note that in FIG. 11, only one blade 50 is shown for the sake of explanation of the blade 50, and illustration of the other blades 50 is omitted. The axial flow impeller 100 according to the fifth embodiment specifies the position with respect to the secondary blade 30 in the circumferential direction CD, and the other configurations are the same as those of the axial flow impellers according to the first to fourth embodiments. Same as 100. Parts having the same configuration as the axial flow impeller 100 of FIGS. 1 to 10 are given the same reference numerals, and the description thereof will be omitted.

(Secondary wing 30)
The secondary wing 30 is formed at a position closer to the trailing edge 22 of the main wing 20 than the leading edge 21 in the circumferential direction CD, and is formed closer to the inner peripheral edge 24 of the main wing 20 in the radial direction centered on the rotation axis It is formed at a position closer to the outer peripheral edge part 23 than the outer peripheral edge part 23. The secondary wing 30 is arranged so as to fit in a portion closer to the trailing edge 22 than the center portion L of the main wing 20 in the rotational direction R of the main wing 20 .

A central portion L shown by a curve in FIG. 11 indicates the central portion of the width of the main wing 20 in the circumferential direction CD when the blade 50 is viewed in the axial direction of the rotation axis A. In the main wing 20, a portion close to the leading edge 21 with respect to the center portion L is referred to as a front portion W1, and a portion close to the rear edge portion 22 with respect to the center portion L is referred to as a rear portion W2. The secondary wing 30 is formed at the rear portion W2 of the main wing 20. In the blade 50 of the fifth embodiment, when viewed in the axial direction of the rotation axis A, the secondary wing 30 overlaps only the rear portion W2 of the main wing 20. The blade 50 is configured such that the outer edge of the rear portion W2 of the main wing 20 and the outer edge of the secondary wing 30 intersect with each other when viewed in the axial direction of the rotation axis A.

[Actions and effects of the axial flow impeller 100]
The secondary blade 30 of the axial impeller 100 according to the fifth embodiment is arranged so as to fit in a portion closer to the trailing edge 22 than the center portion L of the main blade 20 in the rotation direction R of the main blade 20. The blade tip vortex in an axial impeller develops more strongly near the trailing edge. In the blade 50 of the fifth embodiment, when viewed in the axial direction of the rotation axis A, the secondary wing 30 overlaps only the rear portion W2 of the main wing 20. The axial flow impeller 100 has the secondary blade 30 located near the trailing edge 22 where the blade tip vortex is largely developed, so it is more effective than when the secondary blade 30 is located near the leading edge 21. It is possible to achieve lower noise and higher efficiency.

Here, irrespective of the configuration of the axial impeller 100 according to the fifth embodiment, the secondary blades 30 are provided on most of the outer circumference of the blades 50 from a portion close to the leading edge 21 to a portion close to the trailing edge 22. Consider an axial flow impeller with In the axial flow impeller in which the secondary blade 30 is provided on most of the outer circumference of the blade 50, the friction loss on the surface of the secondary blade 30 is reduced by the blade tip vortex caused by the axial flow impeller 100 of the first or second embodiment. This may cancel out the reduction effect and reduce the ventilation efficiency.

In the axial flow impeller 100 according to the fifth embodiment, the secondary blades 30 are arranged near the trailing edge 22 where the blade tip vortices largely develop, so the blade tip vortices can be effectively used without impairing the air blowing ability. This makes it possible to achieve high efficiency and low noise of the axial blower 200.

Further, the axial flow impeller 100 according to the fifth embodiment has a main wing 20 and a sub-wing 30, and when it has the same configuration as the first to fourth embodiments, the axial flow impeller 100 according to the fifth embodiment Effects similar to those of the axial flow impeller 100 according to Embodiments 1 to 4 can be exhibited.

Embodiment 6.
FIG. 12 is a plan view of a part of the axial flow impeller 100 according to the sixth embodiment, viewed in the direction of the rotation axis A. In addition, in FIG. 12, only one blade 50 is shown for explanation of the blade 50, and illustration of the other blades 50 is omitted. The axial flow impeller 100 according to the sixth embodiment specifies the shape of the blades 50, and the other configurations are the same as the axial flow impeller 100 according to the first to fifth embodiments. Parts having the same configuration as the axial flow impeller 100 of FIGS. 1 to 11 are given the same reference numerals, and the description thereof will be omitted.

The axial flow impeller 100 according to the sixth embodiment has a virtual cylindrical surface B that forms the outermost diameter of the axial flow impeller 100 centered on the rotation axis A when viewed in the axial direction of the rotation axis A. Suppose. In the axial flow impeller 100, when viewed in the axial direction of the rotation axis A, a portion of the main blade 20 that forms the outermost diameter of the blade 50 and a portion of the secondary blade 30 that forms the outermost diameter of the blade 50 are arranged. , is located on the virtual cylindrical surface B.

In the axial flow impeller 100 according to the sixth embodiment, when viewed in the axial direction of the rotation axis A, the portions forming the outermost diameters of the main blades 20 and the secondary blades 30 are located on the same cylindrical surface B. are doing. In other words, when viewed in the axial direction of the rotation axis A, the portions forming the outermost diameter of the axial flow impeller 100 according to the sixth embodiment are the main wing 20 and the sub-wing 30. Note that the outermost diameter is the radius when the virtual cylindrical surface B is viewed from the axial direction of the rotation axis A, and the virtual cylindrical surface B is formed by the part of the blade 50 that is farthest from the rotation axis A. Ru.

A part of the outer peripheral edge 23 of the main wing 20 and at least a part of the secondary outer peripheral edge 33 of the secondary wing 30 are located on a virtual cylindrical surface B when viewed in the axial direction of the rotation axis A. . However, the shape of the blade 50 may be distorted during the manufacturing process, and the shape of the main wing 20 and the secondary wing 30 is not necessarily limited to the completely same cylindrical surface. The outer peripheral edge 23 or the secondary outer peripheral edge 33 of the secondary wing 30 may be slightly shifted in the radial direction.

[Actions and effects of the axial flow impeller 100]
If the outer diameter of one part of the main wing 20 and the secondary wing 30 is smaller than the outer diameter of the other part, the wing with the smaller outer diameter will not be able to perform the maximum amount of work, and the axial flow blade will The air blowing capacity of the vehicle as a whole may be reduced. In such a case, the rotational speed of the axial impeller to obtain the rated air volume increases, which may result in increased noise. In addition, the outermost diameter of the axial flow impeller is the same when comparing the case where the outer diameter of the main wing part and the outer diameter of the sub-wing part are different and the case where the outer diameter of the main wing part and the outer diameter of the sub-wing part are the same. Suppose that it is the size.

The axial flow impeller 100 according to the sixth embodiment has a portion forming the outermost diameter of the blade 50 in the main wing 20 and a portion forming the outermost diameter of the blade 50 in the sub-wing 30 when viewed in the axial direction of the rotation axis A. are located on the virtual cylindrical surface B. That is, in the axial flow impeller 100 according to the sixth embodiment, when viewed in the axial direction of the rotation axis A, the portions forming the outermost diameters of the main blades 20 and the secondary blades 30 are both virtual cylindrical surfaces. It is located on B. In the axial flow impeller 100 according to the sixth embodiment, the outer diameter of the main wing portion and the outer diameter of the auxiliary wing portion are the same size.

By having the configuration, the axial flow impeller 100 according to the sixth embodiment has an outer diameter smaller than the outer diameter of one of the main wing 20 and the secondary wing 30 than the other. , the main wing 20 and the secondary wing 30 can each perform their work to the maximum extent. Therefore, the axial flow impeller 100 according to the sixth embodiment can further improve the air blowing ability and suppress noise compared to the axial flow impeller 100 according to the first to fifth embodiments.

Further, the axial flow impeller 100 according to the sixth embodiment has a main wing 20 and a sub-wing 30, and when it has the same configuration as the first to fifth embodiments, the axial flow impeller 100 according to the sixth embodiment Effects similar to those of the axial flow impeller 100 according to Embodiments 1 to 5 can be exhibited.

Embodiment 7.
FIG. 13 is a meridional view of an axial blower 200 according to the seventh embodiment. FIG. 14 is an enlarged view of the axial blower 200 and bell mouth 40 of FIG. 13. Note that the meridional view is a cross-sectional view of a figure created when the blade 50 is rotated around the rotation axis A, taken along a plane that includes the rotation axis A. The axial impeller 100 of the axial blower 200 according to the seventh embodiment is the axial impeller 100 according to the first to sixth embodiments. Parts having the same configuration as the axial flow impeller 100 of FIGS. 1 to 12 are given the same reference numerals, and the description thereof will be omitted. Note that in the following explanation, the above-mentioned fluid will be explained as air.

The axial blower 200 is a device that creates a fluid flow and is used to blow air. For example, the axial blower 200 is equipped with a ventilation device or a heat exchanger and is used as an air conditioner. The axial blower 200 according to the seventh embodiment surrounds the axial impeller 100 of any one of the first to sixth embodiments and the axial impeller 100 on the outside in the radial direction of the axial impeller 100. It has a bell mouth 40 arranged as follows. The axial blower 200 also includes a motor 60 that rotates the axial impeller 100, and a housing 210 that houses the axial impeller 100, the motor 60, and the bell mouth 40.

The bell mouth 40 forms a flow path through which the air flow formed by the axial impeller 100 passes. The bell mouth 40 is provided at an air outlet 212 a formed in the housing 210 and is arranged to surround the outer periphery of the axial flow impeller 100 . The bell mouth 40 surrounds the outer peripheral side of the axial flow impeller 100 and adjusts the flow of air formed by the axial flow impeller 100. The bell mouth 40 is located outside the outer peripheral end of the blade 50 and is formed in an annular shape along the rotation direction R of the axial flow impeller 100.

In the axial direction of the rotation axis A, one end of the bell mouth 40 is connected to the front wall 212 of the housing 210 so as to surround the outer periphery of the air outlet 212a. Although the bell mouth 40 is formed integrally with the front wall 212, it is not limited to this configuration, and may be formed separately from the front wall 212 and connected to the front wall 212. May be provided.

The axial blower 200 shown in FIGS. 13 and 14 includes a so-called half-ducted bell mouth 40. That is, the axial blower 200 is arranged such that the bell mouth 40 surrounds the downstream portion of the axial impeller 100 in the direction F in which the air generated by the axial impeller 100 flows. In the axial blower 200, a part of the blades 50 of the axial impeller 100 is arranged in the flow path formed by the bell mouth 40, and the blades 50 are arranged in the flow direction F of the air generated by the axial impeller 100. The upstream portion protrudes from the flow path formed by the bell mouth 40.

The axial blower 200 is not limited to the so-called half-ducted bell mouth 40. For example, the axial blower 200 may be configured with a so-called full ducted bell mouth 40 in which the entire blade 50 of the axial impeller 100 is disposed within the flow path of the bell mouth 40.

The bell mouth 40 is formed into a cylindrical shape so as to extend in the axial direction of the rotation axis A. Further, the bell mouth 40 has both end portions formed in a trumpet shape, with the end portions being enlarged and the center portion being reduced.

Here, the direction in which the air formed by the blades 50 of the axial flow impeller 100 flows, and is the direction from the inside of the housing 210 to the outside through the opening 45 of the bell mouth 40, is defined as the first direction E1. In the bell mouth 40, as it goes in the first direction E1, the opening diameter of the flow path formed by the opening 45 decreases, becoming a flow path with a constant opening diameter, and becoming a flow path with an enlarged opening diameter. . The bell mouth 40 includes a contracting flow section 41, a direct current section 42, and an expanding tube section 43 from the upstream side to the downstream side of the air flowing through the opening 45 in the first direction E1.

In the flow contraction section 41, the flow path width gradually decreases toward the first direction E1. The flow contraction section 41 is formed such that the opening diameter on the upstream side of the air flow is larger than the opening diameter on the downstream side in the first direction E1. The flow contraction section 41 is formed so that the opening diameter gradually decreases as it goes in the first direction E1, and the flow path gradually decreases from the upstream side to the downstream side.

The direct current section 42 is formed so that the width of the flow path is constant from the upstream side to the downstream side in the direction in which the air formed by the blades 50 flows. The DC portion 42 is formed in the shape of a straight tube with a constant opening diameter in the first direction E1.

The passage width of the enlarged tube portion 43 gradually increases as it goes in the first direction E1. In the first direction E1, the enlarged tube portion 43 is formed so that the opening diameter on the downstream side of the air flow is larger than the opening diameter on the upstream side. The enlarged tube portion 43 is formed so that its opening diameter gradually increases in the first direction E1, and the flow path gradually increases from the upstream side to the downstream side.

A part of the outer edge of the secondary blade 30 of the axial impeller 100 is entirely located inside the contracting flow section 41 , and a part of the outer edge is located inside the DC section 42 . For example, in the secondary blade 30 of the axial flow impeller 100, the enlarged part 31 is entirely located inside the contracting flow part 41, and a part of the secondary outer peripheral edge part 33 is located inside the DC part 42. That is, in the axial blower 200, the enlarged portion 31 of the secondary blade 30 is entirely disposed within the flow path formed by the contracted flow portion 41, and a portion of the secondary outer peripheral edge portion 33 is formed by the DC portion 42. placed within the flow path.

In the secondary blade 30 of the axial flow impeller 100, the enlarged part 31 and the secondary outer peripheral edge part 33 are arranged at the above positions, and a part of the secondary outer peripheral edge part 33 is located inside the contracted flow part 41. It's okay. In this case, in the first direction E1, the axial blower 200 has an upstream portion of the sub-outer periphery 33 disposed in the flow path formed by the contracted flow portion 41, and a downstream portion of the auxiliary outer periphery 33. The portion is disposed within the flow path formed by the direct current section 42 . Therefore, in the axial blower 200, as shown in FIG. It is formed to be located inside the contraction section 41 and the direct current section 42 of the mouse 40.

As shown in FIGS. 13 and 14, the axial blower 200 has a gap G between the axial impeller 100 and the bell mouth 40. The axial blower 200 prevents the axial impeller 100 and the bell mouth 40 from coming into contact with each other by providing a gap G between the axial impeller 100 and the bell mouth 40.

It is desirable that this gap G is as small as possible, especially in the DC section 42 of the bell mouth 40. This is because, in this gap G, a blade tip vortex generated by the rotation of the blades 50 generates an air flow in the opposite direction to the direction of air blowing by the axial impeller 100. In the axial blower 200, if the gap G is large, the loss of air flow due to backflow of air will be large, so it is desirable to make the gap G as small as possible.

The axial flow impeller 100 according to Embodiments 1 to 6 has a virtual cylinder in which a part of the outer edge of the main wing 20 and a part of the outer edge of the secondary wing 30 have the outermost diameter of the axial flow impeller 100. It is designed to be smaller than surface B. Specifically, the axial impeller 100 is designed such that the reduced portion 23b of the main wing 20 and the enlarged portion 31 of the secondary wing 30 are smaller than the imaginary cylindrical surface B.

When parts such as the reduced part 23b of the main wing 20 and the enlarged part 31 of the secondary wing 30 are located inside the DC part 42 of the bell mouth 40, the axial blower 200 The width of the gap G in the DC section 42 is wider than that of an axial flow impeller that does not have this. Therefore, when parts such as the reduced part 23b and the enlarged part 31 are located inside the DC part 42 of the bell mouth 40, the axial blower 200 has an axial flow blade that does not have the reduced part 23b and the enlarged part 31. Compared to a car, the loss in air volume due to the aforementioned backflow of air may be greater.

In the axial blower 200, a part of the outer edge of the secondary blade 30 is located inside the vena contracta part 41 of the bell mouth 40, and another part of the outer edge of the auxiliary blade 30 is located inside the vena contracta part 41 of the bell mouth 40. It is formed so as to be located from the inside of the DC section 42. Specifically, in the axial blower 200, the enlarged part 31 of the secondary blade 30 is located inside the contracting part 41 of the bell mouth 40, and the secondary outer peripheral edge part 33 of the secondary blade 30 is located inside the contracting part 41 of the bell mouth 40. It is formed so as to be located from the inside of 41 to the inside of DC section 42 . In the axial flow blower 200, the secondary blades 30 and the bell mouth 40 are arranged in the above-mentioned positional relationship, compared to the case where the reduced part 23b and the enlarged part 31 are arranged inside the DC part 42. Thus, the gap G between the blade 50 and the bell mouth 40 can be reduced.

The axial blower 200 has a housing 210 that constitutes an outer shell of the axial blower 200. The housing 210 is formed in the shape of a rectangular parallelepiped box. Note that the shape of the housing 210 is not limited to a rectangular parallelepiped, and may be formed in other shapes such as a columnar shape or a polygonal columnar shape.

A suction port 211a is formed in the rear wall 211 of the casing 210 as an opening for sucking air from the outside, and a suction port 211a is formed in the front wall 212 of the casing 210 to suck air from the inside of the casing 210 to the outside. A blower outlet 212a is formed as an opening for blowing out.

The motor 60 provides driving force to the axial flow impeller 100. The axial flow impeller 100 is connected to a motor 60 that is a drive source, and is rotated by the drive of the motor 60.

[Actions and effects of the axial blower 200]
The axial blower 200 according to the seventh embodiment includes the axial impeller 100 of any one of the first to sixth embodiments, and the axial impeller 100 on the radially outer side of the axial impeller 100. It has a bell mouth 40 arranged so as to surround it. Therefore, the axial blower 200 can exhibit the same effects as the axial impeller 100. By having the axial flow impeller 100, the axial flow blower 200 can suppress resistance and aerodynamic noise due to blade tip vortices, and achieve lower noise and higher efficiency while maintaining air blowing ability. When the axial blower 200 includes the axial impeller 100 according to the second embodiment, the resistance due to the development of blade tip vortices and the resistance due to separation of fluid from the negative pressure surface 26 is suppressed, and the blowing ability is maintained. It is possible to achieve low noise and high efficiency.

In the axial blower 200 according to the seventh embodiment, the enlarged part 31 of the secondary blade 30 is located inside the contracted flow part 41 of the bell mouth 40, and the secondary outer peripheral edge part 33 of the secondary blade 30 is located inside the contracted flow part 41 of the bell mouth 40. It is located inside the contraction section 41 and the direct current section 42 . In the axial flow blower 200, the secondary blades 30 and the bell mouth 40 are arranged in the above-described positional relationship, so that the gap G between the secondary blades 30 and the bell mouth 40 does not widen, and the gap G between the secondary blades 30 and the bell mouth 40 does not widen. It is possible to minimize the backflow of air and prevent a decrease in air blowing capacity.

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.

10 hub, 20 main wing, 21 leading edge, 22 trailing edge, 23 outer periphery, 23a front outer edge, 23b reduced part, 23c outer edge, 24 inner periphery, 25 pressure surface, 26 suction surface, 28 wing surface , 30 Secondary wing, 30a Outer peripheral edge, 31 Enlarged part, 32 Secondary trailing edge, 33 Secondary outer peripheral edge, 34 Secondary inner peripheral edge, 40 Bell mouth, 41 Contraction part, 42 Direct flow part, 43 Expansion tube part, 45 Opening, 50 Blade, 60 Motor, 100 Axial impeller, 200 Axial blower, 201 Front edge end, 202 Starting point, 203 Trailing edge end, 210 Housing, 211 Rear wall, 211a Suction port, 212 Front wall portion, 212a blowout port, 301 inner edge front end, 302 outer edge front end, 303 outer edge rear end, 304 inner edge rear end.

Claims

a hub that is rotationally driven and forms a rotating shaft;
a vane formed around the hub and extending radially outward from the hub;
Equipped with
The blade is
a main wing having a leading edge, a trailing edge, an inner peripheral edge integrally formed with the hub, and an outer peripheral edge forming an outer edge between the leading edge and the trailing edge;
a plate-shaped secondary wing protruding from the wing surface of the main wing and extending outward in the radial direction in a half portion on the outer peripheral side of the main wing;
has
The main wing is
The outer peripheral edge has a reduced portion formed such that the outer diameter of the main wing portion gradually decreases from the portion located on the leading edge side toward the rear edge;
The secondary wing is
An enlarged part that forms the outer peripheral edge of the secondary wing and is formed such that the outer diameter of the secondary wing gradually increases from the part located on the leading edge side toward the trailing edge. has
The blade is
The axial flow impeller is formed such that the reduced portion of the main wing and the enlarged portion of the secondary wing intersect with each other when viewed in the axial direction of the rotating shaft.
The wing surface is
The axial flow impeller according to claim 1, wherein the axial flow impeller is a negative pressure surface that constitutes a surface on the back side of a positive pressure surface that pushes fluid and increases pressure when the blade rotates.
The wing surface is
The axial flow impeller according to claim 1, wherein the axial flow impeller is a positive pressure surface that pushes fluid and increases pressure when the blade rotates.
The blade is
In a cross section of the blade cut along a plane along the rotation axis, a shape in which the blade bends toward the pressure side and is monotonically inclined is referred to as a backward tilt, and a shape in which the blade bends toward the suction side and slopes monotonically. When referred to as forward leaning,
When viewed in the axial direction of the rotation axis, the main wing is tilted backward and the secondary wing is tilted forward at a portion where the contracted portion of the main wing and the enlarged portion of the secondary wing intersect with each other. The axial flow impeller according to claim 2.
The blade is
In a cross section of the blade cut along a plane along the rotation axis, a shape in which the blade bends toward the pressure side and is monotonically inclined is referred to as a backward tilt, and a shape in which the blade bends toward the suction side and slopes monotonically. When referred to as forward leaning,
When viewed in the axial direction of the rotation axis, the main wing is tilted forward and the secondary wing is tilted backward at a portion where the contracted portion of the main wing and the enlarged portion of the secondary wing intersect with each other. The axial flow impeller according to claim 3.
The secondary wing is
The axial flow impeller according to any one of claims 1 to 5, wherein the axial flow impeller is arranged so as to fit in a portion closer to the trailing edge than a center portion of the main wing in the rotational direction of the main wing.
When viewed in the axial direction of the rotating shaft, assuming a virtual cylindrical surface forming the outermost diameter of the axial flow impeller centered on the rotating shaft,
When viewed in the axial direction of the rotating shaft, a portion of the main wing forming the outermost diameter of the blade and a portion of the secondary wing forming the outermost diameter of the blade are on the virtual cylindrical surface. The axial flow impeller according to any one of claims 1 to 6, which is located at.
The main wing is
The outer peripheral edge has a front outer edge at a portion closer to the front edge than the reduced portion,
The front outer edge portion is
A portion of the outer peripheral edge that forms a constant outer diameter from a portion located on the front edge side to a portion located on the rear edge side, and that portion forms the outermost diameter of the axial flow impeller. and
The secondary wing is
In the outer peripheral edge of the secondary wing, a secondary outer peripheral edge is provided at a portion closer to the trailing edge than the enlarged part,
The secondary outer peripheral edge portion is
The outer peripheral edge of the secondary wing is a portion that forms a constant outer diameter from a portion located on the leading edge side of the main wing to a portion located on the trailing edge side of the main wing. The axial flow impeller according to any one of the items.
The axial flow impeller according to any one of claims 1 to 8,
a bell mouth arranged to surround the axial impeller on the radially outer side of the axial impeller;
Axial blower with.
The axial flow impeller according to any one of claims 1 to 7,
a bell mouth arranged to surround the axial impeller on the radially outer side of the axial impeller;
Equipped with
The secondary wing is
In the outer peripheral edge of the secondary wing, a secondary outer peripheral edge is provided at a portion closer to the trailing edge than the enlarged part,
The secondary outer peripheral edge portion is
A portion of the outer peripheral edge of the secondary wing that forms a constant outer diameter from a portion located on the leading edge side of the main wing to a portion located on the trailing edge side of the main wing,
The bell mouth is
It is formed into a cylindrical shape,
In the direction in which the air formed by the blades flows,
a contracted flow section formed such that the flow path gradually becomes smaller from the upstream side to the downstream side;
a direct current section in which the width of the flow path is constant from the upstream side to the downstream side;
an enlarged pipe portion formed such that the flow path gradually becomes larger from the upstream side to the downstream side;
has
The enlarged part of the secondary wing is located inside the contraction part of the bellmouth, and the secondary outer peripheral edge part of the secondary wing is located inside the contraction part and the direct flow part of the bellmouth. axial flow blower.