JPH07243397A - Air blower - Google Patents

Abstract

PURPOSE:To restrain flow turbulence from occurring and turbulent noise from increasing by mounting a hub on a motor, constituting a blower with an impeller with multiple vanes around the hub and an orifice which surrounds the outer periphery of the impeller, and forming multiple small holes on the outer periphery of the vanes for blowing out an air flow. CONSTITUTION:When an impeller is rotated in its rotational direction by a motor, an air flow W3 is blown out through multiple small holes 9 from the pressure surface side 8b1 to the negative pressure surface side 8b2 of the vane 8b. As a result, a flow W4, which flows into the negative pressure surface side 8b2 between the peripheral edge 8d of the vane and the orifice 6, is reduced, and a flow W5, which is discharged onto the outer periphery of the vane, is deflected in its peripheral direction by the air flow W3, thereby maintaining a vortex U2 small and restraining flow turbulence at the peripheral part 8b of the vane. It is thus possible to prevent the turbulent noise of the blower from increasing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower used in an air conditioner or the like.

[0002]

2. Description of the Related Art In recent years, blowers such as axial blowers have been widely used as blowers for separate type air conditioners from commercial use to household use, and are being used for downsizing of equipment and diversification of equipment installation conditions. Accordingly, there is a tendency for higher performance and lower noise.

Hereinafter, with reference to the drawings, Japanese Patent Laid-Open No. 3-6
A conventional blower proposed in Japanese Patent No. 4697 will be described.

7 to 8 show the structure of a conventional blower. In the figure, 1 is an axial flow type blower, 2 is a motor, 3 is a hub 4 attached to the motor 2.
And a plurality of blades 5 provided around the hub 4, and 6 is an orifice that surrounds the outer circumference of the discharge side 5c of the blade 5. The blade 5 has a front edge 7 which is a straight line as shown in FIG. 8 and is advanced in the rotational direction.

The operation of the blower configured as described above will be described below. First, the impeller 3 is driven by the motor 2.
When is rotated in a predetermined rotation direction, air flows into the impeller 3, and static pressure and dynamic pressure are added by the action of the vanes 5 and the air is discharged to the outside of the impeller 3 to blow out the air to the outside of the blower 1. Do

Since the front edge 7 of the blade 5 is advanced in the rotation direction, as shown in FIG.
On the P ′ line (line indicating the radial direction), the pressure rises on the outer peripheral side 5b first than on the hub side 5f, and the centripetal force from the outer peripheral side 5b of the blade 5 to the hub side 5f acts, causing a boundary on the surface of the blade 5. The layer is prevented from being biased toward the outer peripheral side 5b, and the development of the boundary layer on the surface of the blade 5 on the outer peripheral side 5b is suppressed.

[0007]

However, in the above-mentioned structure, as shown in FIG. 9, the centrifugal force acting on the air flow increases at the outer peripheral portion 5b of the impeller 3 and the radial velocity component increases. Therefore, the flow is inclined toward the outer peripheral side, and a part thereof is blown out to the outer periphery of the blade 5 from the vicinity of the pressure surface side 5b1 and the vicinity of the negative pressure surface side 5b2 of the outer peripheral portion 5b of the blade 5, respectively.

In particular, since the pressure distribution of the blade 5 is high on the pressure surface side and low on the suction surface side, it blows out from the vicinity of the pressure surface side 5b1 of the outer peripheral portion 5b of the blade 5 to the outer circumference, and from between the orifice 6 and the suction surface side. The airflow W1 that suddenly circulates around 5b2 and the airflow W2 that blows out from the vicinity of the negative pressure surface side 5b2 of the outer peripheral portion 5b of the blade 5 to the outer periphery are the negative pressure surface side 5d2 of the outer peripheral end portion 5d of the blade 5.
Since they flow in opposite directions with a certain distance at,
A vortex U1 is generated on the suction surface side of the outer peripheral end 5d. This vortex U
By 1, the flow on the suction surface side 5b2 of the blade outer peripheral portion 5b is disturbed, and the flow on the blade outer peripheral portion 5b is greatly disturbed. Therefore,
There is a problem that the turbulent noise generated in the impeller 3 increases.

In view of the above-mentioned problems, the present invention generates vortices generated on the suction surface side of the blade outer peripheral end portion by the air current flowing from the pressure surface side of the blade outer peripheral portion to the suction surface side and the air flow blowing from the vicinity of the suction surface to the outer periphery. It is intended to provide a blower which suppresses a large flow turbulence at the outer peripheral portion of the blade and suppresses an increase in blowing noise.

[0010]

In order to solve this problem, the blower of the present invention comprises a motor, a hub attached to the motor, and a plurality of blades provided around the hub. And a plurality of small holes are provided in the outer peripheral portion of the blade.

Further, another blower of the present invention is a motor,
A hub attached to the motor, an impeller composed of a plurality of blades provided around the hub, and an orifice surrounding an outer periphery of the discharge side of the blade, and an outer peripheral portion of the blade. A plurality of small holes are provided, and the opening ratio of the small holes provided in the outer peripheral portion of the blade surrounded by the orifice is made larger than the opening ratio of the small holes provided in the outer peripheral portion of the blade not surrounded by the orifice.

[0012]

In the blower of the present invention, the air flow is blown from the pressure surface side of the outer peripheral portion of the blade to the negative pressure surface side through a plurality of small holes to reduce the flow circling from the pressure surface side to the negative pressure surface side at the outer peripheral edge of the blade. Moreover, since the air flow blows out toward the suction surface side, the flow discharged to the outer circumference of the blade is deflected from the outer peripheral direction to the circumferential direction, so that the vortex generated on the suction surface side of the outer peripheral portion of the blade is suppressed to be small, and Reduces turbulence in the flow.

Further, in another blower of the present invention, since the inflow of airflow from the outer circumference of the blade is promoted and the aerodynamic performance is improved,
If the orifice surrounds only the outer circumference of the blade discharge side, the suction side of the outer circumference of the blade is not surrounded by the orifice.
On the suction side, from near the pressure surface side and near the suction surface side,
The air flow blown to the outer circumference not surrounded by the orifice is increased as compared with the case surrounded by the orifice, and the vortex generated on the blade suction surface side becomes larger. When this vortex flows into the orifice, the flow that wraps around from the pressure surface side at the outer peripheral edge of the blade is suddenly reduced from that on the suction side that is not surrounded by the orifice, and is suppressed by the flow that wraps around from the pressure surface side. Also, the flow discharged from the vicinity of the negative pressure surface side to the outer circumference becomes large and pushes the vortex to the outer circumference side.

Here, by setting the opening ratio of the small holes provided in the outer peripheral portion of the blade surrounded by the orifice to be larger than the opening ratio of the small holes provided in the outer peripheral portion of the blade not surrounded by the orifice, it is surrounded by the orifice. The flow of air blown out from the small holes in the outer periphery of the blade toward the suction surface increases, and the flow discharged to the outer periphery of the blade is deflected from the outer peripheral direction to the peripheral direction. The vortex is prevented from coming into contact with the suction side and collapsing, and the turbulence of the flow at the outer peripheral portion of the blade inside the orifice is suppressed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In addition, in order to avoid duplication, the same components as those of the conventional example will be denoted by the same reference numerals and description thereof will be omitted.

1 and 2 show the structure of a blower according to the first embodiment of the present invention. In the figure, 8 is a plurality of blades provided around the hub 4, and a plurality of small holes 9 are provided in the outer peripheral portion 8b of the blade 8.

The operation of the blower configured as described above will be described below. First, the impeller 3 is driven by the motor 2.
When the blade rotates in a predetermined rotation direction, air flows into the impeller 3, and static pressure and dynamic pressure are added by the action of the blade 8 to cause the impeller 3 to move.
It is discharged to the outside and blows out to the outside of the blower 1.

Here, as shown in FIG. 3, the blade outer peripheral portion 8
b from the pressure surface side 8b1 to the suction surface side 8b2.
The air flow W3 is blown out through the air flow W3 to reduce the flow W4 flowing from the pressure surface side 8b1 to the suction surface side 8b2 from between the blade outer peripheral end 8d and the orifice 6, and the air flow W3 is blown to the suction surface side 8b2. By deflecting the flow W5 discharged to the outer periphery of the blade from the outer peripheral direction to the peripheral direction,
The vortex U2 generated on the suction surface side 8b2 of the blade outer peripheral portion 8b is suppressed to be small, and the turbulence of the flow in the blade outer peripheral portion 8b is suppressed.

As described above, according to the first embodiment of the present invention, by providing a plurality of small holes 9 in the outer peripheral portion 8b of the blade 8, the pressure outer surface 8b1 to the negative pressure surface 8 of the blade outer peripheral portion 8b.
The air flow W3 is blown out into the b2 through the plurality of small holes 9 to reduce the flow W4 flowing between the outer peripheral end portion 8d of the blade and the orifice 6 to the suction surface side 8b2 from the pressure surface side 8b1 and the air flow W3 to the suction surface side 8b2. By blowing out
By deflecting the flow W5 discharged to the outer periphery of the blade from the outer peripheral direction to the peripheral direction, the vortex U2 generated on the suction surface side 8b2 of the outer peripheral portion 8b of the blade is suppressed small, and the turbulence of the flow of the outer peripheral portion 8b of the blade can be suppressed. . Therefore, an increase in turbulent noise of the blower 1 can be suppressed.

In the first embodiment of the present invention, a plurality of small holes are provided in the outer peripheral portion of the blade, but in addition, the outer peripheral portion of the blade is provided with a breathable porous resin material or a metal sintered material. The same effect can be obtained even with the above configuration.

The second embodiment of the present invention will be described below with reference to the drawings. The same components as those in the first embodiment are designated by the same reference numerals to avoid duplication, and the description thereof will be omitted.

4 to 5 show the structure of the blower according to the second embodiment of the present invention. The difference from the first embodiment shown in FIGS. 1 and 2 is that the blade outer peripheral portion 8b is
The orifice 10 surrounding the discharge side 8b3 of the blade is provided, and the opening ratio of the small holes 9 provided on the discharge side 8b3 of the blade outer periphery surrounded by the orifice 10 is set to be small on the suction side 8b4 of the blade outer periphery not surrounded by the orifice 10. This is the point that the opening ratio is larger than the opening ratio of the holes 9.

The operation of the blower configured as described above will be described below. First, the impeller 3 is driven by the motor 2.
When the blade rotates in a predetermined rotation direction, air flows into the impeller 3, and static pressure and dynamic pressure are added by the action of the blade 8 to cause the impeller 3 to move.
It is discharged to the outside and blows out to the outside of the blower 1.

Here, in order to promote the inflow of air flow from the outer circumference of the blade 8 and improve the aerodynamic performance, in the case where the orifice 10 surrounds only the outer circumference of the discharge side 8c of the blade 8, on the blade outer circumference suction side 8b4. Since it is not surrounded by the orifice 10, the air flow blown from the vicinity of the pressure surface side 8b1 and the vicinity of the suction surface side 8b2 to the outer periphery not surrounded by the orifice 10 is larger than that when surrounded by the orifice 10. Even if the airflow W3 is blown out from the small hole 9 provided on the blade outer peripheral suction side 8b4 not surrounded by the orifice 10, the vortex U3 generated on the blade suction surface 8b2 becomes large. When this vortex U3 flows into the inside of the orifice 10, the orifice 10 causes the pressure surface side 8 to move at the blade outer peripheral end 8d.
The flow W6 flowing from b1 decreases sharply from the suction side not surrounded by the orifice 10, and the flow W7 discharged from the vicinity of the suction surface side 8b2, which is suppressed by the flow W6 flowing from the pressure surface side 8b1, to the outer periphery becomes large. The vortex U3 is pushed to the outer peripheral side.

Here, the opening ratio of the small holes 9 provided on the blade outer peripheral discharge side 8b3 surrounded by the orifice 10 to the opening ratio of the small holes 9 provided on the blade outer peripheral suction side 8b4 not surrounded by the orifice 10. By making it larger, the air flow W3 blown out from the plurality of small holes 9 on the blade outer peripheral portion discharge side 8b3 surrounded by the orifice 10 to the suction surface side 8b2 increases,
Since the flow W7 discharged to the outer circumference is deflected from the outer circumference to the outer circumference, the movement amount of the vortex U3 pushed out to the outer circumference is reduced, and it is possible to prevent the vortex U3 from coming into contact with the suction side 10a of the orifice 10 and collapsing. The turbulence of the flow on the blade outer peripheral portion discharge side 8b3 inside 10 is suppressed.

As described above, according to the second embodiment, in order to promote the inflow of the air flow from the outer circumference of the blade 8 and improve the aerodynamic performance, the orifice 10 surrounding only the blade outer peripheral portion discharge side 8b3 is provided. The opening ratio of the small holes 9 provided on the blade outer peripheral discharge side 8b3 surrounded by the orifice 10 is set to be larger than the opening ratio of the small holes 9 provided on the blade outer peripheral suction side 8b4 not surrounded by the orifice 10. As a result, since the suction side of the blade outer peripheral portion 8b is not surrounded by the orifice 10, air flows blown from the vicinity of the pressure surface side 8b1 and the vicinity of the negative pressure surface side 8b2 to the outer periphery not surrounded by the orifice 10 to the orifice 10. The vortex U3 generated on the blade suction surface 8b2 becomes larger than that in the case of being surrounded. And
When this vortex U3 flows into the inside of the orifice 10, the orifice 10 causes the pressure surface side 8b1 at the blade outer peripheral end 8d.
The flow W6 sneaking in from the suction side that is not surrounded by the orifice 10 is suddenly reduced, and the flow W7 discharged from the vicinity of the suction surface 8b2, which was suppressed by the flow W6 sneaking in from the pressure surface 8b1, to the outer periphery becomes large, and the vortex is increased. Push U3 outward.

Here, the opening ratio of the small holes 9 provided on the blade outer peripheral discharge side 8b3 surrounded by the orifice 10 to the opening ratio of the small holes 9 provided on the blade outer peripheral suction side 8b4 not surrounded by the orifice 10. By making it larger, the air flow W3 blown out from the plurality of small holes 9 on the blade outer peripheral portion discharge side 8b3 surrounded by the orifice 10 to the suction surface side 8b2 increases,
Since the flow W7 discharged to the outer circumference is deflected from the outer circumference to the outer circumference, the movement amount of the vortex U3 pushed out to the outer circumference is reduced, and it is possible to prevent the vortex U3 from coming into contact with the suction side 10a of the orifice 10 and collapsing. The turbulence of the flow on the blade outer peripheral portion discharge side 8b3 surrounded by 10 can be suppressed, and the vortex U3 can be smoothly discharged to the impeller 3. Therefore, an increase in turbulent noise of the blower 1 and a decrease in aerodynamic performance can be suppressed.

In the second embodiment of the present invention, a plurality of small holes are provided in the outer peripheral portion of the blade, but in addition, the outer peripheral portion of the blade is provided with a breathable porous resin material or a metal sintered material. And the outer peripheral portion of the blade 8b surrounded by the orifice 10
The same effect can be obtained by increasing the opening ratio of 3 from the blade outer peripheral suction side 8b4 not surrounded by the orifice 10.

Further, in the first and second embodiments of the present invention,
Although the axial flow type blower has been described as an example, a similar effect can be obtained with a mixed flow type blower.

[0030]

As described above, the blower of the present invention includes the motor, the hub attached to the motor, the impeller including the plurality of blades provided around the hub, and the blade. By forming a plurality of small holes in the outer peripheral portion of the blade, the airflow blows out from the pressure surface side of the blade outer peripheral portion to the negative pressure surface side through the plurality of small holes, and the blade outer peripheral end portion is formed. The flow flowing from the pressure surface side to the suction surface side between the orifices is reduced, and the air flow blows out to the suction surface side, so that the flow discharged to the outer circumference of the blade is deflected from the outer circumferential direction to the circumferential direction, and the negative pressure on the outer circumference of the blade is reduced. The vortices generated on the pressure surface side can be suppressed to be small, and the turbulence of the flow on the outer peripheral portion of the blade can be suppressed. Therefore, it is possible to suppress an increase in turbulent noise of the blower.

Further, in order to enhance the aerodynamic performance by promoting the inflow of air flow from the outer circumference of the blade, when an orifice surrounding only the discharge side of the outer circumference of the blade is provided, the outer circumference of the blade surrounded by the orifice is provided. By setting the opening ratio of the small holes provided to be larger than the opening ratio of the small holes provided on the outer peripheral part of the blade that is not surrounded by the orifice, the suction side of the outer peripheral part of the blade is not surrounded by the orifice so that the pressure surface The airflow blown from the side vicinity and the suction surface side vicinity to the outer periphery not surrounded by the orifice is larger than that in the case of being surrounded by the orifice, and the vortex generated on the blade suction surface side becomes larger. When this vortex flows into the inside of the orifice, due to the orifice, the flow that wraps around from the pressure surface side at the outer peripheral edge of the blade is suddenly reduced from the suction side that is not surrounded by the orifice,
The flow discharged from the vicinity of the negative pressure surface, which was suppressed by the flow wrapping around from the pressure surface side, to the outer circumference becomes large, and the vortex is pushed out to the outer circumference side.

Here, by setting the opening ratio of the small holes provided on the outer peripheral portion of the blade surrounded by the orifice to be larger than the opening ratio of the small holes provided on the outer peripheral portion of the blade not surrounded by the orifice, it is surrounded by the orifice. The air flow blown from the plurality of small holes in the outer peripheral portion of the blade toward the negative pressure surface side increases, and the flow discharged to the outer periphery is deflected from the outer peripheral direction to the peripheral direction, so the movement amount of the vortex pushed to the outer peripheral becomes small, It is possible to prevent the vortex from coming into contact with the suction side of the orifice and collapsing, to suppress the turbulence of the flow on the outer peripheral portion of the blade inside the orifice, and to smoothly discharge the vortex to the impeller. Therefore, an increase in turbulent noise of the blower and a decrease in aerodynamic performance can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of an axial-flow type blower according to a first embodiment of the present invention.

FIG. 2 is a projection view of the axial-flow type blower according to the first embodiment of the present invention when projected onto a plane orthogonal to the rotation axis.

FIG. 3 is a sectional view of a main part of the blower of FIG. 1, taken along the line A-A ′.

FIG. 4 is a sectional view of an axial-flow type blower according to a second embodiment of the present invention.

FIG. 5 is a projection view of the axial-flow type blower according to the second embodiment of the present invention when projected onto a plane orthogonal to the rotation axis.

6 is a cross-sectional view of a main part of the blower of FIG. 4 taken along the line B-B ′.

FIG. 7 is a sectional view of a conventional axial-flow type blower.

FIG. 8 is a projection diagram when a conventional axial-flow blower is projected on a plane orthogonal to the rotation axis.

FIG. 9 is a cross-sectional view of the main part of the blower of FIG. 7 taken along the line C-C ′.

[Explanation of symbols]

 1 Blower 2 Motor 3 Impeller 4 Hub 6 Orifice 8 Blade 8b Outer peripheral part 9 Small hole

Claims (2)

[Claims] 1. An impeller composed of a motor, a hub attached to the motor, and a plurality of blades provided around the hub, and an orifice surrounding an outer circumference of the blade. Blower with multiple small holes on the outer circumference of the blade. 2. The orifice surrounds the outer periphery of the blade on the discharge side, and the opening ratio of the small holes provided in the outer peripheral portion of the blade surrounded by the orifice is the opening of the small hole provided in the outer peripheral portion of the blade not surrounded by the orifice. The blower according to claim 1, which is larger than the ratio.