JPH07145798A - Impeller of axial blower - Google Patents

Abstract

PURPOSE:To restrain the reduction of ventilating ability and the increase of turbulent air current noise by providing in the vicinity of the negative pressure surface side front edge of a first blade the rear edge of a second blade arranged upstream of the negative pressure surface side air current of the first blade, forming one wing by means of both blades. CONSTITUTION:An impeller 5 is rotated in a predetermined direction by the drive force of a motor, and then, air flows into the impeller 5, and when it passes between wings consisting of plural first blades 7 and second blades 8, static pressure and dynamic pressure are added, and discharge is carried out from the impeller 5 to the outside, and ventilation operation is performed. Formation is made that by providing in the vicinity of the front edge 7b of the negative pressure surface side 7a of a first blade 7 the rear edge 8a of a second blade 8, upstream of the air current direction G of the negative pressure surface side 7a of the first blade 7, one wing may be realized by means of both blades 7, 8. Accordingly, even under a high static pressure condition, the air current G that has deflected on the pressurizing surface side 8b of the second blade 8, flows into the negative pressure surface side 7a from the front edge 7b of the first blade 7, and stabilizes a border layer current, and the peeling off of the air current G can be restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller of an axial blower used for a blower such as an air conditioner.

[0002]

2. Description of the Related Art In recent years, blowers such as air conditioners have been required to have higher performance and lower noise, and various methods for improving the performance of impellers such as improving the surface shape of the vane and the cross-sectional shape of the vane. Is proposed.

An impeller of an axial blower used for a conventional blower is disclosed in Japanese Utility Model Laid-Open No. 63-160400.

Hereinafter, the impeller of the conventional axial flow fan described above will be described with reference to the drawings.

FIG. 8 shows the structure of an impeller of a conventional axial flow fan, FIG. 9 is a sectional view of the main part of the impeller of the axial flow fan of FIG. 8 taken along the line AA ', and FIG. 10 is a conventional axial flow fan. It is a figure which shows the blade negative pressure surface side main part enlarged view of an impeller. In the figure, 1 is an impeller, and the impeller 1 is composed of a hub 2 and a plurality of blades 3 provided around the hub 2, and a suction surface side 3 a of the blade 3 has a direction of flow of an air flow F. An uneven separation preventing portion 4 for transitioning the boundary layer of the airflow to a turbulent boundary layer is provided on the upstream side portion,
It is formed in an uneven shape along a direction orthogonal to the flow direction of the air flow F.

The operation of the axial-flow type blower configured as described above will be described below. First, when the impeller 1 is rotated in a predetermined rotation direction by the driving force of a motor (not shown), air is introduced into the impeller 1 and static pressure and dynamic pressure are applied when passing between the plurality of blades 3. Is added and is discharged to the outside from the impeller 1 to perform an air blowing action.

At this time, on the suction surface side 3a of the blade 3, the air flow F flowing along the suction surface side 3a of the blade 3 by the uneven separation preventing portion 4 on the upstream side with respect to the flow direction of the air flow F.
The boundary layer is changed to a turbulent boundary layer, and the separation preventing portion 4 is formed in an uneven shape along the direction orthogonal to the flow direction of the air flow F, so that each air flow in the direction orthogonal to the flow direction of the air flow F. By providing a phase difference therebetween, the airflow F flowing along the suction surface side 3a of the blade 3 is effectively transitioned to the turbulent boundary layer,
Effectively preventing the separation flow from being formed in the boundary layer of the airflow F in the downstream side with respect to the flow direction of the airflow F on the negative pressure surface side 3a of the blade 3, lowering the blowing capacity and increasing turbulent noise. Can be suppressed.

[0008]

However, in the above structure, the effect of suppressing the separation of the air flow F flowing on the suction surface side 3a of the blade 3 by providing the separation prevention portion 4 on the suction surface side of the blade 3. Requires that the air flow F flowing along the suction surface side 3a of the blade 3 flows to the separation preventing portion 4 without separation, and when the static pressure addition is larger than the design condition, the suction surface side of the blade 3 is There was a problem that the airflow F flowing along 3a was separated up to the separation prevention part 4, and the desired effect could be obtained only within a very limited use range.

In view of the above problems, the present invention suppresses separation of the airflow flowing along the blade negative pressure surface side when used under a high static pressure condition, thereby lowering the blowing capacity and reducing turbulent noise. An impeller of an axial blower capable of suppressing the increase is provided.

[0010]

In order to solve this problem, an impeller of an axial blower according to the present invention comprises a motor, a hub attached to the motor, and a plurality of hubs provided around the hub. A first vane and is provided around the hub,
A plurality of second blades, which are located on the upstream side in the flow direction of the air flow of the first blades and are shorter than the chord length of the first blades, constitute an impeller, and a trailing edge of the second blades is formed. It is provided in the vicinity of the front edge of the first blade on the suction surface side, and the first blade and the second blade which are adjacent to each other form one blade.

Further, an impeller of an axial blower according to another invention is provided with a plurality of connecting plates which are located on substantially concentric circles and which connect the first blade and the second blade.

[0012]

In the impeller of the axial blower according to the present invention, the second blade is arranged on the suction side of the first blade on the upstream side in the flow direction of the air flow, and the trailing edge of the second blade is the first blade. Since the first blade and the second blade form one blade provided near the front edge of the negative pressure surface side, the airflow deflected by the second blade is
This helps the stable growth of the airflow boundary layer on the suction surface side of the blade, and the airflow flows from the leading edge to the trailing edge of the first blade without separation, resulting in a reduction in the blowing capacity and an increase in turbulent noise. Suppress.

Further, in the impeller of the axial blower according to another invention, since a plurality of connecting plates are provided which are located on substantially concentric circles and connect the first blade and the second blade, the impeller is provided in the impeller. Since the inflowing airflow is deflected toward the outer peripheral side of the impeller to the flow toward the discharge side of the impeller, it improves the blowing capacity and suppresses the increase of turbulent noise, and further, the impeller can be easily integrally molded, The strength of the impeller also increases.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an impeller of an axial blower according to the present invention will be described below with reference to the drawings. still,
In order to avoid duplication, the parts having the same configurations as those of the conventional example are denoted by the same reference numerals and the description thereof will be omitted.

1 and 2 show the structure of an impeller of an axial flow fan according to the first embodiment of the present invention.
[Fig. 2] is a cross-sectional view of the impeller of the axial blower of Fig. 1 taken along the line BB '.

In the figure, 5 is an impeller of an axial blower,
A motor 6, a hub 2 attached to the motor 6, a plurality of first blades 7 provided around the hub 2, and a plurality of first blades 7 provided around the hub 2 and upstream of the airflow of the first blade 7 And a plurality of second blades 8 located on the side of the first blades 7 and having a chord length shorter than the chord length of the first blades 7, and the trailing edge 8a of the second blades 8 is located on the suction surface side of the first blades 7. The first blade 7 and the second blade 8 which are provided in the vicinity of the front edge 7b of 7a and are adjacent to each other form one blade. G indicates an airflow flowing along the suction surface side 7a of the first blade 7.

The operation of the impeller of the axial blower configured as above will be described below.

First, the impeller 5 is driven by the driving force of the motor 6.
Is rotated in a predetermined rotation direction, air is introduced into the impeller 5 and static pressure and dynamic pressure are added when passing between the blades composed of the plurality of first blades 7 and the second blades 8. It is discharged to the outside from the impeller 5 and acts as an air blower.

Here, the second blade 8 is disposed on the suction side 7a of the first blade 7 on the upstream side in the flow direction of the air flow G, and the trailing edge 8a of the second blade 8 is located on the first blade 7. It is provided in the vicinity of the front edge 7b on the negative pressure surface side 7a, and the first blade 7 and the second blade 8 which are adjacent to each other are formed as one blade, so that it is used under a high static pressure condition. The airflow G deflected by the pressure surface side 8b of the second blade 8 flows into the suction surface side 7a from the front edge 7b of the first blade 7 even under conditions other than the design condition of the impeller, such as the first blade. The growth of the boundary layer on the suction surface side 7a of No. 7 is made stable, and the separation of the air flow G from the front edge 7b to the rear edge 7c of the first blade 7 is suppressed. It is possible to suppress the increase of flow noise.

As described above, according to this embodiment, the second blade 8 is arranged upstream of the suction surface side 7a of the first blade 7 in the flow direction of the air flow G, and the trailing edge of the second blade 8 is arranged. 8a is provided in the vicinity of the front edge 7b on the suction surface side 7a of the first blade 7 and
Since the second blade 8 and the second blade 8 form one blade,
The airflow G deflected by the blades 8 of the first blade 7 helps the stable growth of the airflow boundary layer on the suction surface side 7a of the first blade 7,
Since the air flows without being separated, it suppresses a decrease in the blowing capacity and an increase in turbulent noise.

Therefore, it is possible to prevent the airflow G flowing along the negative pressure surface side 7a of the first blade 7 from being separated, and to effectively suppress the reduction of the blowing capacity and the increase of the turbulent noise.

A second embodiment of the impeller of the axial blower according to the present invention will be described below with reference to the drawings.

4 and 5 show the structure of the impeller of the axial blower according to the second embodiment of the present invention.
FIG. 7 is an enlarged view of an essential part of a blade negative pressure surface side of an impeller of an axial flow fan according to a second embodiment of the present invention, and FIG. 7 is a sectional view taken along line DD ′ of the impeller of the axial flow fan of FIG. 4. It is shown.

In the figure, the difference from the first embodiment is that
The point is that a plurality of connecting plates 10 that connect the first blade 7 and the second blade 8 are provided on substantially concentric circles.

The operation of the impeller of the axial blower configured as above will be described below.

First, the impeller 9 is driven by the driving force of the motor 6.
Is rotated in a predetermined rotation direction, air is introduced into the impeller 9 and static pressure and dynamic pressure are added when passing between the blades composed of the plurality of first blades 7 and the second blades 8. The air is discharged from the impeller 9 and functions as an air blower.

Since a plurality of connecting plates 10 for connecting the first blade 7 and the second blade 8 are provided on the substantially concentric circles, the air flow H flowing into the impeller 9 is a blade. Since the flow toward the outer peripheral side of the vehicle is deflected by the connecting plate 10 to the flow toward the blade discharge side, the improvement of the blowing capacity and the increase of turbulent noise are suppressed, and further, the impeller 9 is easily molded integrally. The strength of the impeller 9 also increases.

As described above, according to this embodiment, the inside of the impeller 9 is provided by providing the plurality of connecting plates 10 which are located on substantially concentric circles and which connect the first blade 7 and the second blade 8. The airflow H flowing into the blade is deflected toward the outer peripheral side of the impeller 9 so as to be deflected to the blade discharge side, so that the blowing ability is improved and turbulent noise is prevented from increasing, and the impeller 9 is integrally molded. It becomes easier to remove, and the strength of the impeller 9 also increases.

Therefore, it is possible to improve the blowing ability and the increase of turbulent noise due to the deflection of the inflow airflow to the impeller 9, and to improve the moldability and strength of the impeller 9.

[0030]

As described above, the impeller of the axial blower according to the present invention includes a motor, a hub attached to the motor,
A plurality of first blades provided around the hub; and a plurality of first blades provided around the hub and located upstream of the negative pressure surface side of the first blades in the flow direction of the air flow. An impeller is constituted by a plurality of second blades having a shorter chord length, a trailing edge of the second blade is provided in the vicinity of a suction surface side front edge of the first blade, and the first blade is in close proximity. And the second blade is 1
By forming two blades, the airflow deflected on the pressure surface side of the second blade helps the stable growth of the airflow boundary layer on the suction surface side of the first blade, and thus the first blade is formed. The airflow flowing along the negative pressure surface side of the
It is possible to suppress a decrease in the blowing capacity and an increase in turbulent noise.

Further, by providing a plurality of connecting plates located on substantially concentric circles and connecting the first blade and the second blade, the airflow flowing into the impeller is directed toward the outer peripheral side of the impeller. Since the flow is deflected by the connecting plate to the flow toward the blade discharge side, the improvement of the blowing capacity and the increase of turbulent noise are suppressed, and further, the integral molding of the impeller is facilitated and the strength of the impeller is increased. Can be increased.

[Brief description of drawings]

FIG. 1 is a plan view of an impeller of an axial blower according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an impeller of an axial blower according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the main part of the impeller of the axial blower of FIG. 1 taken along the line BB ′.

FIG. 4 is a plan view of an impeller of an axial blower according to a second embodiment of the present invention.

FIG. 5 is a sectional view of an impeller of an axial blower according to a second embodiment of the present invention.

FIG. 6 is an enlarged view of a main portion of an impeller of an axial blower according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of the main part of the impeller of the axial blower of FIG. 4 taken along the line CC ′.

FIG. 8 is a perspective view of an impeller of a conventional axial blower.

9 is a cross-sectional view of the main part of the impeller of the axial blower of FIG. 8 taken along the line AA ′.

FIG. 10 is an enlarged view of a blade negative pressure surface side main part of a conventional axial blower impeller.

[Explanation of symbols]

 2 hub 5 impeller 6 motor 7 first blade 8 second blade 9 impeller 10 connecting plate

Claims (2)

[Claims] 1. A motor, a hub attached to the motor, a plurality of first blades provided around the hub, and a flow of air flow of the first blade provided around the hub. A plurality of second blades located upstream in the direction and having a chord length shorter than the chord length of the first blade, and forming an impeller.
The impeller of an axial blower in which the trailing edge of the blade is provided in the vicinity of the suction-side front edge of the first blade, and the adjacent first blade and second blade form one blade. 2. The first vane and the second vane are located on substantially concentric circles.
The impeller of an axial blower according to claim 1, further comprising a plurality of connecting plates for connecting the blades of the fan.