WO2013018359A1

WO2013018359A1 - Once through fan

Info

Publication number: WO2013018359A1
Application number: PCT/JP2012/004867
Authority: WO
Inventors: 木田　琢己; 杉尾　孝
Original assignee: パナソニック株式会社
Priority date: 2011-08-01
Filing date: 2012-07-31
Publication date: 2013-02-07
Also published as: CN103717904A; JPWO2013018359A1; CN103717904B

Abstract

Provided is a once through fan in which a plurality of impellers, comprising a plurality of blades disposed in a cylindrical shape, are provided connected in the axial direction. The impellers comprise a circular or disk shaped reinforcement plate having an outer diameter smaller than the diameter of the inner end part of the plurality of blades disposed in a cylindrical shape, and a plurality of projections formed so as to project inward in the radial direction of the cylindrical shape from a portion of the inner end part of each of the blades. The blades, the projections and the reinforcement plate are formed integrally so that the reinforcement plate connects, via the respective projections, to the inner end parts of each of the blades.

Description

Cross-flow fan

The present invention relates to a once-through fan used in an air conditioner that performs indoor cooling or heating.

A once-through fan used in an indoor unit of an air conditioner as a home air conditioner is required to improve its air blowing performance (air volume, noise) in order to reduce the size and power consumption of the air conditioner. Further, there is a demand for operating the once-through fan at a higher rotational speed and further expanding the variable range of the rotational speed. For this reason, while reducing the thickness of the blades constituting the impeller of the once-through fan, the strength of the impeller itself is secured by increasing the amount of glass fiber and carbon fiber mixed into the resin material that is the blade forming material. ing.

Also, in recent years, in order to increase the air volume of the indoor unit in order to save power, there is a demand for increasing the diameter of the once-through fan, but the increase in diameter is reaching the limit in terms of blade strength.

Therefore, a once-through fan that can achieve a larger size without impairing the strength and processing accuracy of the blades and impellers has been proposed (for example, see Patent Document 1).

7 to 9 show the structure of the once-through fan described in Patent Document 1. FIG. As shown in FIG. 7, the once-through fan 1 includes a plurality of impellers 2, an end plate 3, and an end plate 4. Each impeller 2, end plate 3, and end plate 4 are formed by resin injection molding. Then, the crossflow type fan 1 is completed by abutting each other's connection part and joining by ultrasonic welding.

As shown in FIG. 8, the impeller 2 includes an annular substrate 5, a plurality of blades 6 extending from the side surface of the annular substrate 5 and arranged in a cylindrical shape, and inner end portions (inner peripheral portions) of the blades 6. A ring plate 8 that connects the blades 6 to each other via a connecting portion 7 is provided, and each component is integrally injection-molded. Further, on the outer peripheral surface of the ring plate 8, a guide convex portion 8 b having a guide surface 8 a serving as a guide when the impellers 2 are welded and joined is extended from the blade 6 and integrally formed.

In order to ensure dimensional accuracy and strength at the component level of the impeller 2, the ring plate 8 is further displaced in the circumferential direction and expanded in the radial direction due to pressure applied during joining by ultrasonic welding. It is provided to prevent. The width dimension L1 of the ring plate 8 is set to about 2 mm in order to minimize the influence on the blowing performance (air volume, noise), and the dimension L2 of the connecting portion 7 between the ring plate 8 and each blade 6 (that is, The length dimension in which the outer peripheral surface of the ring plate 8 and the inner end of the blade 6 overlap is set to about 1 mm. Each blade 6 has an airfoil shape in cross section. A welding convex portion 6 a is formed on one connecting portion 7 of the impeller 2 joined to each other, and a welding concave portion 6 b is disposed on the annular substrate 5 on the other side.

In addition, the disc-shaped end plate 3 has a boss 3a into which a motor shaft (not shown) is inserted and fixed at an axial center portion thereof, a welding concave portion 3b into which a welding convex portion 6a of each blade 6 is inserted, and an assembly. A guide recess 3c serving as a time guide is formed.

In addition, the disc-shaped end plate 4 disposed at the other end opposite to the end plate 3 has a bearing (not shown) in which the shaft 4 a is inserted and a ring substrate 5. A welding convex portion 4b inserted into the welding concave portion 5b and a guide convex portion 4c serving as a guide during assembly are formed.

As shown in FIG. 9, such a conventional once-through fan 1 is used in an indoor unit 100 of an air conditioner. The indoor unit 100 includes a heat exchanger 101, a once-through fan 1 serving as a blowing means, a fan casing 103, an outer box 104, a grill 105, and the like.

Next, a method for assembling the conventional once-through fan 1 having such a configuration will be described. First, the end plate 3 and the impeller 2 are joined. At this time, the outer peripheral surface 8 a of the ring plate 8 of the impeller 2 is guided and inserted into the inner peripheral surface 3 d of the guide concave portion 3 c of the end plate 3, and then the welding convex portion 6 a of each blade 6 is welded to the end plate 3. The connection preparation is completed by fitting into the recess 3b. Then, each blade | wing 6 and the end plate 3 are integrally connected by ultrasonic welding. Here, the ultrasonic welding technique for applying ultrasonic energy is a well-known technique and will not be described.

Next, the impeller 2 to which the end plate 3 is connected and the other impeller 2 having the same shape as the impeller 2 are connected. The connection method is the same as the connection method between the end plate 3 and the impeller 2 described above.

Thereafter, the same procedure is repeated, and a plurality of impellers 2 are connected. Finally, the end plate 4 is connected to complete the once-through fan 1. The connection method of the end plate 4 is the same as the connection method of the end plate 3 and the impeller 2 described above.

In the configuration of such a conventional once-through fan 1, the ring plate 8 is arranged on the inner peripheral side (inner side from the inner end) of each blade 6, and therefore the radial thickness dimension L3 can be freely set. Can be set to Therefore, sufficient strength of the ring plate 8 can be ensured, and the possibility that weld or whitening occurs between the blades 6 of the ring plate 8 can be reduced.

The operation of the indoor unit 100 equipped with the once-through fan 1 configured as described above will be described below.

The once-through fan 1 is disposed in the fan casing 103 on the leeward side of the heat exchanger 101 in a state where the fan casing 103 and a predetermined back surface clearance dimension (Y2) are secured and pivotally supported. It is rotated by a motor (not shown).

Also, an outdoor unit (not shown) is connected to the indoor unit 100 by piping to constitute a refrigeration cycle, and a refrigerant is supplied to the heat exchanger 101 from the outdoor unit. When the once-through fan 1 is rotated, the air introduced from the room is cooled by the heat exchanger 101 and blown out as cold air from the air outlet 106.

In the once-through fan 1 of Patent Document 1, the ring plate 8 and the blade 6 are integrally formed by injection molding so that the ring plate 8 that connects the blades 6 to each other is connected to the inner end of the blade 6. ing. In a molded product formed by such injection molding, a parting line that is a step is generated on the outer surface of the molded product for the purpose of punching out the mold. In the configuration of the impeller 2 of Patent Document 1, a parting line (step) is formed in the vicinity of the inner end of the blade 6. Specifically, a step is formed on the outer surface of the blade 6 in a cross-sectional shape perpendicular to the rotation axis of the once-through fan 1.

Therefore, as shown in FIGS. 10 to 12, the blade structure in which the inclined portion 16 is positively provided in the step 15 portion in order to reduce the step 15 generated in the vicinity of the inner end portion of the blade 6 in contact with the ring plate 8. Has been proposed (see, for example, Patent Document 2). In such a blade structure, the step 15 portion is reduced, the turbulence component generated from the step 15 portion can be reduced, deterioration of the air blowing performance can be suppressed, and an increase in noise can be suppressed.

Japanese Patent Laid-Open No. 2002-31080 JP 2004-124819 A

However, in the conventional configurations described in

Patent Documents

1 and 2 described above, it is possible to increase the diameter by ensuring the strength of the blades of the once-through fan, but it is not possible to eliminate the step formed on the outer surface of the blades. . In other words, the conventional once-through fan is provided with a ring plate that connects the blades to each other, and the ring plate and the blades are integrally formed so that the inner end of the blade is connected to the outer peripheral surface of the ring plate. The structure to be adopted is adopted. In such a structure, a step (parting line) is generated on the outer surface of the blade in order to remove the mold.

If the slopes are provided before and after this step, the step on the outer surface of the blade itself cannot be eliminated, air flow separation due to the step occurs, the flow in the impeller is disturbed, the air blowing performance deteriorates, and the turbulent fluid flows into the room. There is a problem that noise increases due to the emission.

The object of the present invention is to solve the above-described conventional problems, and can ensure the strength of the blade and increase the diameter, and further eliminate the step on the outer surface of the blade to suppress separation due to the step, thereby improving the blowing performance. An object of the present invention is to provide a once-through fan capable of suppressing deterioration and noise.

In order to solve the above-described conventional problems, a cross-flow fan according to the present invention is a cross-flow fan including a plurality of impellers in which a plurality of blades are arranged in a cylindrical shape and connected in the axial direction. An annular or disk-shaped reinforcing plate having an outer diameter smaller than the diameter of the inner end portions of the plurality of blades arranged in a shape, and a cylindrical radial inward from a part of the inner end portion of each of the blades A plurality of protrusions formed so as to protrude from the blades, and the reinforcing plate is connected to the inner ends of the blades via the protrusions. The protrusion and the reinforcing plate are formed integrally.

According to the present invention, there is provided a once-through fan that can ensure the strength of the blade and increase the diameter, and further eliminate the step on the outer surface of the blade to suppress separation due to the step, thereby suppressing deterioration in blowing performance and noise. Can be provided.

1 is an exploded cross-sectional view of a once-through fan according to Embodiment 1 of the present invention. Sectional drawing which shows one impeller of the once-through type fan of Embodiment 1 AA line sectional view of the impeller of FIG. Sectional view (portion (a) of FIG. 3) showing the connection location of blades, protrusions, and reinforcing plates in the impeller of the first embodiment. Sectional view taken along line BB at the connection point of the blade, protrusion, and reinforcing plate in FIG. Sectional drawing which shows one impeller of the once-through type fan in Embodiment 2 of this invention Exploded sectional view of a conventional once-through fan A perspective view showing an impeller of a conventional once-through fan Internal structure diagram of indoor unit of home air conditioner using conventional once-through fan Front view of another conventional once-through fan X1-X2 sectional view of the cross-flow fan of FIG. (B) part enlarged view of the once-through fan of FIG.

A cross-flow fan according to a first aspect of the present invention is the cross-flow fan including a plurality of impellers in which a plurality of blades are arranged in a cylindrical shape and connected in the axial direction. The impeller includes the plurality of impellers arranged in a cylindrical shape. An annular or disk-shaped reinforcing plate having an outer diameter smaller than the diameter of the inner end portion of the blade, and formed so as to protrude inward in the cylindrical radial direction from a part of the inner end portion of each blade. A plurality of protrusions, and the blades, the protrusions, and the reinforcement plates are connected to the inner end portions of the blades via the protrusions. It is designed to be integrally molded.

By adopting such a configuration, the outer diameter of the reinforcing plate is made smaller than the inner peripheral diameter of the blade, and a protrusion that connects the reinforcing plate and the blade is provided to ensure the strength of the blade and increase the diameter. be able to. In addition, when the blade, the protrusion, and the reinforcing plate are integrally formed, a step (parting line) that can be used for removing the mold is disposed at a portion other than the blade, for example, radially inward of the blade. It can be positioned on a protrusion or the like. Thereby, there is no level | step difference in the cross-sectional shape of a blade | wing, the airflow separation by a level | step difference can be prevented, the disorder | damage | failure by airflow separation can be suppressed, and the fall of an air volume and the increase in noise can be suppressed. Therefore, it is possible to realize a cross-flow fan that can increase the diameter by ensuring the strength of the blades, suppress turbulence in the blades, and suppress a decrease in air volume and an increase in noise.

According to a second aspect of the present invention, in the cross-flow fan according to the first aspect of the invention, the protrusion is formed at the blade end in the rotational axis direction of the impeller, and the protrusion is connected to a side surface of the reinforcing plate. It is what I did.

By adopting such a configuration, it is possible to reduce the influence on the air blowing performance by forming the protrusion and the reinforcing plate at the blade end. In addition, even when the impeller has a longer blade in the axial direction, the strength of the blade can be secured and the once-through fan can be configured.

According to a third aspect of the present invention, in the cross-flow fan according to the first or second aspect, the parting line generated when the blade, the protrusion, and the reinforcing plate are integrally injection-molded using a mold. The blades are not formed between the inner end portion and the outer end portion of the blade.

By adopting such a configuration, since there is no parting line that generates airflow separation on the surface of the blade that exhibits the air blowing action, it is possible to suppress turbulence due to airflow separation and to suppress a decrease in air volume and an increase in noise. .

According to a fourth aspect of the present invention, in the cross-flow fan according to the third aspect of the invention, the parting line is generated at the protrusion.

With this configuration, the parting line generated when the blade, the protrusion, and the reinforcing plate are integrally injection-molded using a mold can be positioned at the protrusion. It is possible to prevent a step from being formed on the surface. Therefore, turbulence due to airflow separation can be suppressed, and a decrease in air volume and an increase in noise can be suppressed.

According to a fifth aspect of the present invention, in the cross-flow fan according to the fourth aspect of the invention, the thickness of the blades and the protrusions becomes smaller toward the outer side of the cylindrical radial direction than the parting line. The blades and the protrusions are formed so that the thickness of the protrusions increases as they go radially inward.

By adopting such a configuration, the thickness of the projection portion for obtaining the required strength at the connection portion between the reinforcing plate and the projection portion is secured, and the thickness is reduced at the connection portion with the inner end portion of the blade. The protrusions can be connected along the outer surface of the blades. Accordingly, it is possible to increase the diameter by securing the strength of the blades, and it is possible to suppress air flow separation without forming a step or the like in the blades.

According to a sixth aspect of the present invention, in the cross-flow fan according to any one of the third to fifth aspects, the blade has a smooth blade shape having no step between an inner end portion and an outer end portion. The connecting portion between the inner end of the projection and the projection has a smooth surface.

By adopting such a configuration, it is possible to suppress airflow separation without forming a step or the like in the blade and without forming a step or the like in the connection portion between the projection and the blade.

A seventh aspect of the present invention is the cross-flow fan according to any one of the first to sixth aspects of the present invention, wherein the protruding length of the protrusion from the inner end of the blade to the cylindrical radial inward direction is the reinforcing plate. The height in the rotation axis direction of the impeller at the protrusion is in the range of 1% to 15% with respect to the height in the rotation axis direction of the impeller. is there.

By adopting such a configuration, it is possible to suppress the occurrence of airflow separation in the entire protrusion while ensuring sufficient strength to connect the reinforcing plate and the blade at the protrusion, and the air volume in the cross-flow fan Decrease in noise and increase in noise can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is an exploded cross-sectional view of a cross-flow fan according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing one impeller of the once-through fan in the first embodiment. 3 is a cross-sectional view taken along the line AA of the once-through fan of FIG. FIG. 4 is a cross-sectional view of a main part showing a connecting portion of the blade, the protrusion, and the reinforcing plate in the impeller of the first embodiment. FIG. 5 is a cross-sectional view taken along the line BB in the connecting portion of FIG. The same constituent elements as those of the once-through fan in the prior art documents (FIGS. 7 to 12) are denoted by the same reference numerals and description thereof is omitted.

1 to 5, the once-through fan 21 has a plurality of impellers 22 in which a plurality of blades 9 are arranged in a cylindrical shape connected in the axial direction (rotating shaft 21 x), and

end plates

3 and 4 are provided at both ends. It has a configuration. A disk-shaped reinforcing plate 10 is provided inside the impeller 2. The outer diameter of the reinforcing plate 10 is smaller than the inner peripheral diameter of the plurality of blades 9 arranged in a cylindrical shape (that is, the diameter of the inner end portion 9a of the blade 9). The side surface of the reinforcing plate 10 and the inner end portions 9 a of the plurality of blades 9 are connected via the protruding portions 11. In addition, the several blade | wing 9, the reinforcement board 10, and the projection part 11 are integrally shape | molded by injection molding, such as resin. In addition, since the joining structure of each impeller 22 and the joining structure of the impeller 22 and the

end plates

3 and 4 employ | adopt the same structure as the once-through fan of a prior art document, the description is abbreviate | omitted. .

Here, the configuration of the blade 9, the reinforcing plate 10, and the protrusion 11 included in the impeller 22 will be described in detail mainly with reference to FIGS. 4 and 5. One end 9x of the blade 9 in the axial direction of the impeller 22 (the end opposite to the annular substrate 5) is radially inward from the inner end 9a of each blade 9 (direction toward the rotating shaft 21x). ) Is formed so as to protrude.

As shown in FIG. 4, the protrusion 11 has a substantially triangular shape in plan view, and the protrusion length from the inner end portion 9 a of the blade 9 increases as it approaches the side surface of the reinforcing plate 10. It is formed so that the protruding length becomes smaller as it approaches the side surface of the reinforcing plate 10. The reinforcing plate 10 is formed in a disc shape, and is connected to the protruding portion 11 on the side surface in the vicinity of the outer periphery thereof. The outer peripheral end of the reinforcing plate 10 is located on the radially inner side of the inner end portion 9 a of the blade 9.

As shown in FIG. 5, the blade 9 has a smooth wing shape having no step between the inner end portion 9a and the outer end portion 9c. The protruding portion 11 formed so as to protrude inward in the radial direction from a part of the inner end portion 9a of the blade 9 has a form in which the wing shape is extended as it is. In the impeller 22 of the first embodiment, the end surface of the end 9x of the blade 9 and the side surface of the reinforcing plate 10 (the inner side surface of the impeller 22) are located at the same position in the axial direction.

The cross-sectional shape of the protrusion 11 that connects the reinforcing plate 10 and the inner ends 9a of the plurality of blades 9 on the plane perpendicular to the rotational axis 1x of the once-through fan 21 has a step 12 on the axial center side of the rotational axis 1x. is doing. The step 12 is formed on the outer surface of the projection 11 as a parting line by an injection mold. As shown in FIGS. 4 and 5, the step 12 is formed around the outer surface of the protrusion 11 so as to extend along the outer end surface of the reinforcing plate 10.

The thickness (wall thickness) of the protrusion 11 and the blade 9 decreases as it goes radially outward from the step 12 of the protrusion 11, and the protrusion increases as it goes radially inward from the step 12 of the protrusion 11. The blades 9 and the protrusions 11 are formed so that the thickness (wall thickness) of 11 is increased.

The operation, action, and effect of the once-through fan 21 of the first embodiment configured as described above will be described below.

First, when the impeller 22 is configured, the outer diameter of the reinforcing plate 10 is made smaller than the diameter (inner peripheral diameter) of the inner end portion 9 a of the blade 9, and the protrusion 11 that connects the reinforcing plate 10 and the blade 9 is provided. By providing, the diameter of the impeller 22 can be increased and integrally molded while ensuring the strength of the blade 9.

In addition, since the outer diameter of the reinforcing plate 10 is smaller than the inner peripheral diameter of the blade 9, a parting line (that is, an outer surface of the reinforcing plate 10 that occurs on the outer surface of the reinforcing plate 10 in order to remove the mold during injection molding) A step 12) can be formed in the protrusion 11. That is, in the cross-sectional shape of the protrusion 11 on the surface perpendicular to the rotation axis 1x of the cross-flow fan 21, the party is formed on the outer surface of the protrusion 10, not on the portion between the inner end 9 a and the outer end 9 c of the blade 9. The step 12 can be generated in the protrusion 11 by arranging the molds so that the ing line is located. Therefore, there is no step in the cross-sectional shape of the blade 9 (between the inner end portion 9a and the outer end portion 9c), and both the pressure surface side 9p and the negative pressure surface side 9s are partyed from the inner end portion 9a to the outer end portion 9c of the blade 9. No air line separation can be prevented due to unevenness. Therefore, in the once-through fan 21 using the integrally formed impeller 22, turbulence due to airflow separation can be suppressed, and a decrease in the air volume of the once-through fan 1 and an increase in noise can be suppressed.

Furthermore, since the blade 9 has a smooth blade shape with no step from the inner end portion 9a to the outer end portion 9c, noise generated from the blade 9 can be reduced.

Further, a step 12 is formed on the outer surface of the blade 9 by forming the step 12 on the outer surface of the projection 11 positioned radially inward from the inner end 9 a at the end 9 x of the blade 9. Compared with the case, airflow separation can be suppressed and noise can be reduced.

Further, the thickness of the outer peripheral portion 11b of the protrusion 11 is gradually reduced as it goes outward in the radial direction from the step 12 of the protrusion 11, and the inside of the protrusion 11 is increased as it goes inward in the radial direction from the step 12. The thickness of the peripheral portion 11a is gradually increased. Thereby, while obtaining a required strength at the connecting portion (that is, the inner peripheral portion 11a) between the reinforcing plate 10 and the protruding portion 11, the connecting portion (that is, the outer peripheral portion 11b) with the inner end portion 9a of the blade 9 is obtained. ), The protrusion 11 can be connected with a smooth surface along the outer surface of the thin blade-shaped blade 9. Therefore, airflow separation can be suppressed from occurring in the blade 9 without forming a step or the like.

Further, in the axial direction of the plurality of blades 9 arranged in a cylindrical shape, the reinforcing plate 10 is connected to the blades 9 via the protrusions 11 at the end portions 9x opposite to the annular substrate 5 (that is, at one end side). Is connected to the inner end 9a. Thereby, even when the axial height of the impeller 22 is longer, the strength of the blades 9 can be secured and the cross-flow fan 21 can be configured.

Therefore, the once-through fan 21 according to the first embodiment can increase the diameter of the blade 9 while ensuring the strength of the blade 9, and can prevent the step 12 and the parting line from occurring in the portion of the blade 9. . Therefore, in the indoor unit of the air conditioner in which such a once-through fan 21 is incorporated, it is possible to increase the air volume to save power and to suppress an increase in noise due to airflow separation as much as possible.

(Embodiment 2)
FIG. 6 is a diagram illustrating a main part of the impeller 32 provided in the once-through fan 31 according to the second embodiment of the present invention. In addition, about the same component as the once-through type fan 21 of above-mentioned Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 6, the protrusion length (length in the left-right direction in FIG. 6) inward in the radial direction from the inner end 9a of the blade 9 in the protrusion 13 connected to the reinforcing plate 10 is the axial direction. It forms so that it may become small gradually as it leaves | separates from the reinforcement board 10. As shown in FIG. The axial height h (vertical length in FIG. 6) of the impeller 32 at the protrusion 13 is 1% to 15% with respect to the axial height H of the blade 9 (impeller 32). The range is set (that is, h / H = 1% to 15%).

Thus, by setting the shape of the protrusion 13 with respect to the entire impeller 32, the protrusion 13 is formed on the entire protrusion 13 or the protrusion 13 while ensuring sufficient strength for connecting the reinforcing plate 10 and the blade 9. The occurrence of airflow separation at the step 12 is suppressed, and the turbulence at the protrusion 13 can be suppressed by airflow separation. As a result, it is possible to suppress a decrease in air volume and an increase in noise in the once-through fan 31 as much as possible.

In the above-described embodiment, the case where the reinforcing plate is disk-shaped has been described as an example, but the reinforcing plate may be formed in an annular shape.

Further, the case where the inner side surface of the reinforcing plate 10 and the end surface of the blade 9 are positioned at the same position in the axial direction has been described as an example, but various other positional relationships can be adopted. For example, when the impellers are connected to each other, it is only necessary to realize a positional relationship such that the annular substrate 5 and the reinforcing plate 10 are arranged at positions overlapping in the axial direction. The influence of the presence of the reinforcing plate 10 on the blowing performance can be reduced.

Further, the parting line (step 12) may be formed on the outer surface of the protrusion, and is not limited to the position where it is formed.

In addition, as the joining configuration of each impeller and the end plate, the configuration disclosed in the prior art document can be adopted, but other known joining configurations may be applied.

It should be noted that, by appropriately combining arbitrary embodiments of the above-described various embodiments, the respective effects can be achieved.

Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

Japanese patent application No. filed on August 1, 2011 The disclosure of the specification, drawings, and claims of 2011-168102 is hereby incorporated by reference in its entirety.

As described above, the once-through fan having the configuration according to the present invention can increase the diameter of the blade by ensuring the strength of the blade, and further, the flow in the impeller is disturbed, the air flow performance is deteriorated, and the turbulent fluid is in the room. The noise rise is sufficiently suppressed when released. In addition, by applying such a once-through fan to an indoor unit of an air conditioner, the air volume of the indoor unit can be increased and power saving of the air conditioner can be achieved.

Therefore, it can be applied not only to separate indoor units for household air conditioners and indoor units for commercial air conditioners, but also to commercial refrigeration equipment and commercial and industrial air curtain equipment.

21, 31

Cross-flow fan

22, 32 Impeller 9 Blade

9a Inner end

9c Outer end 9x End 10 Reinforcing

plate

11, 13 Protruding part 11a Inner peripheral part of protruding part 11b Outer peripheral part of protruding part 12 Step

Claims

In the once-through fan provided with a plurality of impellers in which a plurality of blades are arranged in a cylindrical shape connected in the axial direction,
The impeller is
An annular or disk-shaped reinforcing plate having an outer diameter smaller than the diameter of the inner ends of the plurality of blades arranged in a cylindrical shape;
A plurality of protrusions formed so as to protrude radially inward from a part of the inner end of each of the blades,
The reinforcing plate is integrally formed with the blade, the projecting portion, and the reinforcing plate so as to be connected to the inner end portion of each of the blades through the projecting portion. Expression fan.
The cross-flow fan according to claim 1, wherein the protrusion is formed at the blade end in the rotational axis direction of the impeller, and the protrusion is connected to a side surface of the reinforcing plate.
The parting line generated when the blade, the protrusion, and the reinforcing plate are integrally injection-molded using a mold does not occur between the inner end portion and the outer end portion of the blade. Item 3. The cross-flow fan according to item 1 or 2.
The once-through fan according to claim 3, wherein the parting line is generated in the protrusion.
The thickness of the blade and the protrusion decreases as it goes radially outward in the cylindrical direction from the parting line, and the thickness of the protrusion increases as it goes radially inward from the parting line. The cross-flow fan according to claim 4, wherein the blades and the protrusions are formed so as to be large.
The blade has a smooth wing shape without a step between an inner end portion and an outer end portion, and a connecting portion between the inner end portion of the blade and the protrusion has a smooth surface. The once-through fan according to any one of 1 to 5.
The projecting length of the projecting portion from the inner end of the blade toward the radially inward direction of the cylindrical shape decreases as the distance from the reinforcing plate increases, and the height of the projecting portion in the rotational axis direction of the impeller is The once-through fan according to any one of claims 1 to 6, which is in a range of 1% to 15% with respect to a height of the impeller in a rotation axis direction.