JPH0650286A - Blower - Google Patents

Abstract

PURPOSE:To reduce the trailing width in the trailing edge of a blade to the most extent by newly forming the structure of a blade itself of a blower by a hollow porous body, and sucking and discharging some of an air flow flowing along the blade surface through the blade hollow part. CONSTITUTION:In a blower comprising an impeller 1 including a boss part 4 pivoted on a rotary shaft 3 and many blades 5, 5... radially attached to the outer periphery of the boss part 4, the blades 5 of the impeller 1 are formed by a hollow body having many micropores 6, 6..., and there is provided sucking means (e.g. suction pump 13 or the like) for sucking and discharging some of air flowing on the surfaces of the blades 5 through blade hollow parts 7.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Generally, a blower used as a blower for an air conditioner comprises a boss portion pivotally attached to a rotary shaft and a large number of blades radially attached to the outer periphery of the boss portion. An axial fan provided with an impeller, a centrifugal fan provided with a main plate pivotally attached to a rotary shaft, and a plurality of blades axially erected on an outer peripheral portion of the main plate, and a centrifugal fan provided with a rotary shaft. BACKGROUND ART A mixed flow fan or the like having a bladed wheel having a truncated cone-shaped boss attached thereto and a large number of blades radially attached to a conical surface of the truncated cone-shaped boss is well known.

In recent years, the demand for noise reduction of air conditioners has been increasing more and more, and it is an important issue to be solved to reduce the operation noise of the blower which is the main sound source in the air conditioner. Therefore, attempts have been made to significantly reduce the operating noise by optimizing the blade shape of the impeller of the blower. Although such an effect can be obtained to some extent, further noise reduction is required.

By the way, as a cause of the operation noise of the blower, there is an increase in the width of the air flow (that is, the width of the wake) accompanied by a speed loss at the trailing edge of the blade (that is, the end on the outlet side).

That is, when the impeller of the blower is rotated, as shown in FIG. 15, a boundary layer develops in the air flow F flowing along the positive pressure surface 2a 'and the negative pressure surface 2b' of the blade 2 ',
Since the separated flow E is generated, the wake width D is increased, which causes deterioration of aerodynamic performance and increase of operating noise. This is described in [Proceedings of the Japan Society of Mechanical Engineers (B) 5
Volume 3 Number 492 (Sho 62-8) Paper No. 86-0912
This is also clear from the report in "A]]" Flow characteristics of turbulent noise of low-pressure axial blowers and its sound pressure level prediction ".

Therefore, it has already been proposed to reduce the wake width by suppressing the development of the boundary layer by forming a large number of dimples on the suction surface of the axial fan. JP-A-60-35119
(See Japanese Patent Publication).

[0007]

The reason for forming dimples on the blade suction surface as in the above-mentioned known example is to suppress the development of the boundary layer by causing a secondary flow of air in the dimples. However, depending on the shape or size of the dimples, the development of the boundary layer may not be sufficiently suppressed, and the effect is limited.

The present invention has been made in view of the above points, and is a novel one in which the structure of the blade itself of the blower is made of a hollow porous body, and at the same time along the blade surface via the blade hollow portion. The purpose is to suck and discharge a part of the flowing air flow so that the width of the wake at the trailing edge of the blade can be made as small as possible.

[0009]

In the invention of claim 1, as means for solving the above-mentioned problems, as shown in the drawings, a boss portion 4 pivotally attached to a rotary shaft 3 and a boss portion 4 of the boss portion 4 are provided. In a blower equipped with an impeller 1 consisting of a large number of blades 5, 5 radially attached to the outer periphery, each blade 5 of the impeller 1 is a hollow body having a large number of fine holes 6, 6. In addition, the suction means for sucking and discharging a part of the air flowing on the surface of each blade 5 through the blade hollow portion 7 is attached.

According to the second aspect of the present invention, as a means for solving the above-mentioned problems, as shown in the drawings, a main plate 20 pivotally mounted on the rotary shaft 3 and an axially erected outer peripheral portion of the main plate 20 are provided. In a blower provided with an impeller 1 including a large number of blades 5, 5, ..., Each blade 5 of the impeller 1 is formed of a hollow body having a large number of fine holes 6, 6 ,.
A part of the air flowing on the surface of each blade 5 is replaced by a hollow portion 7 of the blade.
Suction means for sucking and discharging through the is attached.

In the invention of claim 3, as means for solving the above-mentioned problems, as shown in the drawings, a truncated cone-shaped boss 23 pivotally attached to the rotary shaft 3 and the truncated cone-shaped boss 23. A large number of blades 5, 5, ... Radially attached to the conical surface 23a
In the blower equipped with the impeller 1 consisting of and, each blade 5 of the impeller 1 is formed of a hollow body having a large number of fine holes 6, 6, ... A suction means for sucking and discharging a part of the suction air through the hollow portion 7 of the blade is additionally provided.

In a fourth aspect of the invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the blower of the first aspect, the fine holes 6, 6 ... It is formed only on the side.

According to a fifth aspect of the present invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the blower according to the first or fourth aspect, the rotary shaft 3 is communicated with the hollow blade portion 7. While forming the hollow portion 10, the suction means is a suction pump 13 installed in the stationary portion and connected to the rotary shaft hollow portion 10.

According to a sixth aspect of the invention, as a means for solving the above problems, as shown in the drawings, in the blower according to the first or fourth aspect, the suction means is formed on the outer periphery of the rotary shaft 5. .. sandwiching the discharge holes 15, 15, ... And a plurality of plates 16, 16, ..

According to a seventh aspect of the present invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the blower according to the second aspect, the suction means is formed on the main plate 20 and the blade hollow. An annular hollow portion 22 that communicates with the portion 7 and is open on the outer peripheral side is formed.

According to an eighth aspect of the invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the blower of the third aspect, the suction means is a conical surface of the truncated conical boss 23. An annular hollow portion 25 is formed in a portion constituting 23a, communicates with the hollow portion 7 of the blade, and has an outer peripheral side that is open.

In the invention of claim 9, as means for solving the above-mentioned problems, as shown in the drawings, said claim 1,
In the blower described in 2, 3, 4, 5, 6, 7 or 8, a shroud 17 is integrally formed at an end portion of the blades 5, 5, ...
7 is composed of a hollow body having a large number of fine holes 6, 6 ..., And the shroud hollow portion 18 and the blade hollow portion 7 are made to communicate with each other.

According to a tenth aspect of the invention, as a means for solving the above-mentioned problems, as shown in the drawings, the blower according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth aspect is provided. At the rear edge of each blade 5, an opening communicating with the blade hollow portion 7 is formed.

[0019]

According to the first, second or third aspect of the invention, the following actions can be obtained by the above means.

That is, part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 passes through the fine holes 6, 6 ... By the suction force of the suction means to the hollow portion 7 of the blade. After being sucked, it is discharged to the outside, and the development of the boundary layer on the surface of each blade 5 is effectively suppressed.
Therefore, the wake width D at the trailing edge of each blade 5 can be suppressed as small as possible.

According to the invention of claim 4, the following effects can be obtained by the above means.

That is, due to the rotation of the impeller 1, a part of the airflow F flowing along the surface of each blade 5 (in particular, the velocity of the airflow flowing along the blade surface is large, which greatly affects the operating noise. (A part of the air flow on the outer peripheral portion of the blade 5) passes through the fine holes 6, 6 ...
After being sucked in, it will be discharged to the outside.

According to the invention of claim 5, the following effects can be obtained by the above means.

That is, a part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 is sucked by the suction pump 13.
. Is sucked into the blade hollow portion 7 through the fine holes 6, 6 ... And then discharged to the outside through the rotary shaft hollow portion 10.

In the sixth aspect of the invention, the following actions can be obtained by the above means.

That is, a part of the air flow F flowing along the surface of each blade 5 by the rotation of the impeller 1 is finely divided by the viscous suction force generated between the plates 16, 16 ... After being sucked into the blade hollow portion 7 through the holes 6, 6, ..., It is discharged to the outside through the rotary shaft hollow portion 10 and the discharge holes 15, 15 ,.

According to the invention of claim 7, the following effects can be obtained by the above means.

That is, part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 is caused by the viscous suction force generated in the hollow portion 22 formed in the main plate 20 to form the fine holes 6, 6. After being sucked into the hollow portion 7 of the blade, it is discharged to the outside through the hollow portion 22 of the main plate.

According to the eighth aspect of the invention, the following effects can be obtained by the above means.

That is, a part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 is a hollow portion 25 formed in a portion forming the conical surface 23a of the truncated conical boss 23. .. are sucked into the blade hollow portion 7 by the viscous suction force generated in the above and then discharged to the outside through the main plate hollow portion 25.

According to the ninth aspect of the invention, the following actions can be obtained by the above means.

That is, a part of the air flow F flowing on the surface of the shroud 17 integrally formed at the ends of the blades 5, 5 ,.
The boundary layer generated on the suction side of the shroud 17 is sucked by the suction means (for example, the suction pump 13) through the fine holes 6, 6 ... The development of is effectively suppressed.

In the tenth aspect of the invention, the following actions can be obtained by the above means.

That is, a part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 is absorbed by the suction means (for example, the suction pump 13) so that the trailing edge of each blade 5 is moved. After being sucked into the hollow portion 7 of the blade through the opening 26 formed in the outer peripheral portion of the blade 5 and discharged to the outside, the wake width D at the trailing edge of each blade 5 can be further reduced.

[0035]

According to the invention of claim 1, 2 or 3, a part of the air flow F flowing along the surface of each blade 5 by the rotation of the impeller 1 is made into a fine hole by the suction force of the suction means. The blades 5 are sucked into the hollow portion 7 of the blade 5 and then discharged to the outside so that the development of the boundary layer on the surface of the blade 5 can be effectively suppressed. The wake width D at the trailing edge is suppressed as small as possible, and there is an excellent effect that the operating noise of the blower can be reduced and the aerodynamic performance can be significantly improved.

According to the invention of claim 4, in the blower of claim 1, a part of the air flow F flowing along the surface of each blade 5 (in particular, flowing along the blade surface) by the rotation of the impeller 1 After sucking a part of the air flow of the outer peripheral portion of the blade, which has a large velocity of air flow and has a great influence on the operation noise, through the fine holes 6, 6 ... Since it can be discharged to the outside, it is sufficient to form the fine holes 6, 6 ... Only in a more effective portion, and there is an excellent effect that the strength reduction of the blade 5 can be prevented.

According to the invention of claim 5, in the blower according to claim 1 or 4, a part of the air flow F flowing along the surface of each blade 5 by the rotation of the impeller 1 is transferred to the suction pump 13. By suction force, the fine particles 6, 6 ... Are sucked into the hollow portion 7 of the blade and then discharged to the outside through the hollow portion 10 of the rotary shaft. Therefore, the structure of the blade 5 and the rotary shaft 3 should be devised. By adding a very simple means of stiffening and additionally attaching the suction pump 13, there is an excellent effect that the wake width D at the trailing edge of the blade 5 can be made as small as possible.

According to the sixth aspect of the invention, in the blower according to the first or fourth aspect, a part of the air flow F flowing along the surface of each blade 5 by the rotation of the impeller 1 is converted into the rotary shaft 3. By viscous suction force generated between the co-rotating plates 16, 16, ..
After sucking into the hollow part of the rotary shaft 10 and the discharge holes 15,15
.. Since it can be discharged to the outside via
And the structure of the rotary shaft 3 is devised, and by adding an extremely simple means of externally fixing the plates 16, 16 ... to the rotary shaft 3, the wake width D at the trailing edge of the blade 5 is reduced as much as possible. It has an excellent effect that it can be made smaller.

According to the invention of claim 7, in the blower according to claim 2, a part of the air flow F flowing along the surface of each blade 5 is formed on the main plate 20 by the rotation of the impeller 1. Due to the viscous suction force generated in the hollow portion 22, the fine holes 6,
After sucking into the hollow portion 7 of the blade through 6 ...
Since it can be discharged to the outside through the main plate 20,
By adding an extremely simple means of elaborately devising the structure of the above, there is an excellent effect that the wake width D at the trailing edge of the blade 5 can be made as small as possible.

According to the eighth aspect of the present invention, in the blower according to the third aspect, a part of the air flow F flowing along the surface of each blade 5 by the rotation of the impeller 1 is converted into a truncated conical boss 2.
Hollow part 2 formed in the part that constitutes the conical surface 23a of No. 3
The viscous suction force generated in 5 causes suction to the blade hollow portion 7 through the fine holes 6, 6 ... And then discharges it to the outside through the hollow portion 25. With the addition of an extremely simple means of elaborating,
There is an excellent effect that the wake width D at the trailing edge of the blade 5 can be made as small as possible.

According to the invention of claim 9, claims 1, 2 and
In the blower described in 3, 4, 5, 6, 7 or 8,
Shroud 17 integrally formed at the ends of blades 5, 5, ...
A part of the air flow F flowing on the surface of the
The suction force of the suction pump 13 or the like) allows suction through the fine holes 6, 6, ... To the hollow portion 7 of the blade and then discharges it to the outside, so that the development of the boundary layer on the suction side of the shroud 17 is effective Therefore, there is an excellent effect that the operation noise of the blower can be reduced and the aerodynamic performance can be significantly improved.

According to the invention of claim 10, claim 1,
In the blower described in 2, 3, 4, 5, 6, 7, 8 or 9, a part of the air flow F flowing along the surface of each blade 5 by the rotation of the impeller 1 is sucked by a suction means (for example, suction means). The suction force of the pump 13 or the like causes the blade 5 to be sucked into the hollow portion 7 of the blade 5 through the opening 26 formed at the trailing edge of the blade 5 and then discharged to the outside. The width D can be further reduced,
There is an excellent effect that the operation noise of the blower can be reduced and the aerodynamic performance can be significantly improved.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIGS. 1 and 2 show a blower according to Embodiment 1 of the present invention. The present embodiment relates to claims 1, 4 and 5.
It corresponds to the invention of.

The blower of this embodiment is used as a blower for an air conditioner, and as shown in FIG. 1, a boss portion 4 pivotally mounted on a rotary shaft 3 connected to a motor 2. And a plurality of pieces radially attached to the outer periphery of the boss portion 4
It is an axial fan provided with an impeller 1 composed of (for example, four) blades 5, 5, ....

In the case of this embodiment, each of the blades 5 is a hollow body made of synthetic resin (or a metal plate), and a large number of fine holes 6, 6 ... Are formed only on the outer peripheral side thereof. There is.
The fine pores 6, 6 ... Have a size that allows the passage of air, and may be, for example, interparticle gaps in the foamed porous body.

Further, the boss portion 4 has a hollow blade portion 7,
A communication chamber 8 that communicates with the rotary shaft 3 is formed, while a hollow portion 10 that communicates with the bottom wall of the communication chamber 8 and a through hole 9 formed in the rotary shaft 3 is formed in the rotary shaft 3. Has been done.

Further, the hollow portion 10 of the rotating shaft 3 is communicated with a connecting pipe 12 connected to the rotating shaft 3 via a joint 11, and the connecting pipe 12 serves as a suction means. It is connected to the pump 13. The suction pump 13 has a low operating noise like a diaphragm pump, for example, and is appropriately installed in a stationary portion. Reference numeral 14 is a communication hole formed in the rotary shaft 3.

The blower configured as described above operates as follows.

The airflow F (see FIG. 2) flows from the leading edge to the trailing edge of each blade 7 due to the rotation of the impeller 1 due to the rotational driving of the motor 2, and the air flowing along the surface of each blade 5 at that time. A part of the flow F (particularly, a part of the air flow on the outer peripheral portion of the blade, which has a large velocity of the air flow along the blade surface and has a great influence on the operation noise), has fine holes generated by the suction force of the suction pump 13. After being sucked into the blade hollow portion 7 through 6, 6, ...
It is discharged to the outside through the communication chamber 8, the rotary shaft hollow portion 10 and the connection pipe 12. The arrow M indicates the rotation direction of the blade 5.

Therefore, the development of the boundary layer on the surface of the blade 5 is effectively suppressed, and the wake width D (see FIG. 2) at the trailing edge of the blade 5 is suppressed as small as possible. As a result, it is possible to reduce the operating noise of the blower and significantly improve the aerodynamic performance. To reduce turbulent noise by reducing the wake width D, refer to
Volume 53, No. 492 (Sho 62-8) Paper No. 86-091
It is also clear from the report in "Flow characteristics of turbulent noise of low-pressure axial blower and its sound pressure level prediction" published in [2A].

In the case of this embodiment, the fine holes 6, 6, ...
Is formed only on the outer peripheral side of the blade 1, which is a more effective portion, so that the reduction in strength of the blade 5 can be prevented.

Embodiment 2 FIG. 3 shows a blower according to Embodiment 2 of the present invention. The present embodiment corresponds to the inventions of claims 1 and 5.

In the case of this embodiment, each blade 5 in the blower of Embodiment 1 is made of a porous hollow body made of hard synthetic resin (or metal). That is, the fine holes 6,
.. are formed on the entire surface of each blade 5. According to this structure, a part of the airflow can be sucked into the hollow portion 7 of the blade 5 over the entire surface of the blade 5,
Boundary layer development can be suppressed more effectively. The blade 5
There is a possibility that the strength of No. 1 will be slightly lower than that of Example 1, but this is not a problem in operation. Other configurations, functions and effects are the same as those of the first embodiment, and the description will be omitted to avoid duplication.

Embodiment 3 FIG. 4 shows a blower according to Embodiment 3 of the present invention. The present embodiment corresponds to the inventions of claims 1, 4 and 6.

In the case of the present embodiment, instead of the suction pump in the blower of the first embodiment, a disk-shaped outer casing is fixed at a slight interval in the axial direction with the discharge holes 15, 15 formed on the outer periphery of the rotary shaft 3 interposed therebetween. The plates 16, 16, 16 are used as suction means. Since other configurations are the same as those in the first embodiment, the description will be omitted to avoid duplication.

With the above construction, a part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 due to the rotational driving of the motor 2 (particularly, the outer periphery of the blade 7 where the boundary layer easily develops) Part of the air flow) is sucked into the blade hollow portion 7 through the fine holes 6, 6 ... by the viscous suction force generated between the plates 16 and 16 rotating together with the rotary shaft 3.
Communication chamber 8, through hole 9, rotary shaft hollow portion 10 and discharge 1
It will be discharged to the outside via 5, 15. The other functions and effects are the same as those of the first embodiment, and the description thereof will be omitted to avoid duplication.

Embodiment 4 FIG. 5 shows a blower according to Embodiment 4 of the present invention. The present embodiment corresponds to the inventions of claims 1 and 6.

In the case of the present embodiment, each blade 5 in the blower of the third embodiment is constituted by a porous hollow body made of hard synthetic resin (or metal). That is, the fine holes 6,
.. are formed on the entire surface of each blade 5. According to this structure, a part of the airflow can be sucked into the hollow portion 7 of the blade 5 over the entire surface of the blade 5,
Boundary layer development can be suppressed more effectively. The blade 5
There is a possibility that the strength of No. 1 will be slightly lower than that of Example 3, but this is not a problem in operation. Other configurations, functions, and effects are the same as those in the third embodiment, and the description will be omitted to avoid duplication.

Embodiment 5 FIG. 6 shows an air blower according to Embodiment 5 of the present invention. The present embodiment corresponds to the inventions of claims 1, 4, 5 and 8.

In the case of this embodiment, a shroud 17 is integrally formed at the outer peripheral ends of the blades 5, 5, ... In the blower of the first embodiment (that is, the end portions parallel to the suction direction). The shroud 17 is for preventing a gap flow that occurs when a separate shroud is provided on the outer peripheral side of the impeller 1. The shroud 17 of this embodiment is composed of a hollow body having a large number of fine holes 6, 6 ... (For example, a hard synthetic resin porous hollow body or a metal porous hollow body). The portion 18 is to be communicated with the blade hollow portion 7 through a communication hole 19. Since other configurations are the same as those in the first embodiment, the description will be omitted to avoid duplication.

With the above-mentioned structure, a part of the air flow F flowing on the surface of the shroud 17 integrally formed on the blades 5, 5, ... Through shroud hollow part 18
After being sucked into the blade hollow portion 7 through the communication hole 19, it is discharged to the outside in the same manner as in the first embodiment. Therefore, the development of the boundary layer generated on the suction side of the shroud 17 is effectively suppressed, and the operation noise of the blower can be reduced and the aerodynamic performance can be significantly improved. The other functions and effects are the same as those of the first embodiment, and the description thereof will be omitted to avoid duplication.

Embodiment 6 FIG. 7 shows a blower according to Embodiment 7 of the present invention. The present embodiment corresponds to the inventions of claims 1, 5 and 8.

In the case of this embodiment, each blade 5 in the blower of the fifth embodiment is made of a porous hollow body made of hard synthetic resin (or metal). That is, the fine holes 6,
.. are formed on the entire surface of each blade 5. According to this structure, a part of the airflow can be sucked into the hollow portion 7 of the blade 5 over the entire surface of the blade 5,
Boundary layer development can be suppressed more effectively. The blade 5
There is a possibility that the strength of No. 1 will be slightly lower than that of Example 5, but this is not a problem in operation. Other configurations, functions and effects are the same as those of the fifth embodiment, and the description will be omitted to avoid duplication.

Embodiment 7 FIG. 8 shows a blower according to Embodiment 7 of the present invention. The present embodiment corresponds to the inventions of claims 1, 4, 6 and 8.

In the case of the present embodiment, the shroud 17 is integrally formed at the outer peripheral ends of the blades 5, 5, ... In the blower of the third embodiment (that is, the end portions parallel to the suction direction). The shroud 17 is for preventing a gap flow that occurs when a separate shroud is provided on the outer peripheral side of the impeller 1. The shroud 17 of this embodiment is composed of a hollow body having a large number of fine holes 6, 6 ... (For example, a hard synthetic resin porous hollow body or a metal porous hollow body). The portion 18 is to be communicated with the blade hollow portion 7 through a communication hole 19. Other configurations are similar to those of the third embodiment, and the description will be omitted to avoid duplication.

By virtue of the above construction, a part of the air flow F flowing on the surface of the shroud 17 integrally formed at the end portions of the blades 5, 5, ... Microscopic holes 6, 6 due to viscous suction force of
After being sucked into the shroud hollow portion 18 through the ..., It is sucked into the blade hollow portion 7 through the communication hole 19 and then discharged to the outside in the same manner as in the third embodiment. Therefore, the development of the boundary layer generated on the suction side of the shroud 17 is effectively suppressed, and the operation noise of the blower can be reduced and the aerodynamic performance can be significantly improved. Other functions and effects are the same as those of the third embodiment, and therefore the description thereof will be omitted to avoid duplication.

Embodiment 8 FIG. 9 shows a blower according to Embodiment 8 of the present invention. The present embodiment corresponds to the inventions of claims 1, 6 and 8.

In the case of this embodiment, each blade 5 in the blower of the seventh embodiment is made of a porous hollow body made of hard synthetic resin (or metal). That is, the fine holes 6,
.. are formed on the entire surface of each blade 5. According to this structure, a part of the airflow can be sucked into the hollow portion 7 of the blade 5 over the entire surface of the blade 5,
Boundary layer development can be suppressed more effectively. The blade 5
There is a possibility that the strength of No. 1 will be slightly lower than that of Example 7, but this is not a problem in operation. Other configurations, functions and effects are the same as those of the seventh embodiment, and the description thereof will be omitted to avoid duplication.

Ninth Embodiment FIG. 10 shows a blower according to a ninth embodiment of the present invention. The present embodiment corresponds to the inventions of claims 2 and 7.

The blower of this embodiment has a blade composed of a main plate 20 on a rotary shaft 3 connected to a motor 2 and a large number of blades 5, 5, ... Standing on the outer periphery of the main plate 20 in the axial direction. Car 1
The centrifugal fan is provided with an end portion of the blades 5, 5, ... (that is, an end portion parallel to the suction direction) for preventing a gap flow generated at the axial end of the impeller 1. Shroud 1
7 are integrally formed.

Each blade 5 has a large number of fine holes 6, 6, ...
And a hollow body (for example, a rigid synthetic resin porous hollow body or a metal porous hollow body).

On the outer peripheral portion of the main plate 20, there is formed an annular hollow portion 22 which is in communication with the blade hollow portion 7 through the communication hole 21 and whose outer peripheral side is open. The hollow portion 22 is to generate a viscous suction force with the rotation of the impeller 1, and acts as a suction means.

With the above-mentioned structure, a part of the air flow F flowing along the surface of each blade 5 due to the rotation of the impeller 1 due to the rotational driving of the motor 2 has an annular shape formed on the main plate 20. After being sucked into the blade hollow portion 7 through the fine holes 6, 6, ... By viscous suction force generated in the hollow portion 22,
It will be discharged to the outside through the hollow portion 22 of the main plate.
Therefore, the development of the boundary layer on the surface of the blade 5 is effectively suppressed, and the wake width D (see FIG. 2) at the trailing edge of the blade 5 is suppressed as small as possible. As a result, it is possible to reduce the operating noise of the blower and significantly improve the aerodynamic performance.

Embodiment 10 FIG. 11 shows a blower according to Embodiment 10 of the present invention. The present embodiment corresponds to the inventions of claims 2, 7 and 9.

In the case of the present embodiment, the shroud 17 in the blower of the ninth embodiment is provided with a hollow body (for example, a hard synthetic resin porous hollow body or a metal porous hollow body) having a large number of fine holes 6,6. ), The shroud hollow portion 18 is made to communicate with the blade hollow portion 7 through the communication hole 19. Since other configurations are similar to those of the ninth embodiment, the description will be omitted to avoid duplication.

With the above structure, a part of the air flow F flowing on the surface of the shroud 17 integrally formed on the blades 5, 5, ... Due to viscous suction force generated in the
After being sucked to the shroud hollow portion 18 through the ..., It is sucked to the blade hollow portion 7 through the communication hole 19 and then discharged to the outside in the same manner as in the ninth embodiment. Therefore, the development of the boundary layer generated on the suction side of the shroud 17 is effectively suppressed, and the operation noise of the blower can be reduced and the aerodynamic performance can be significantly improved. Other functions and effects are the same as those of the ninth embodiment, and the description will be omitted to avoid duplication.

Embodiment 11 FIG. 12 shows an air blower according to Embodiment 11 of the present invention. The present embodiment corresponds to the inventions of claims 3 and 8.

In the blower of this embodiment, a truncated cone-shaped boss 23 pivotally mounted on the rotary shaft 3 connected to the motor 2 and a conical surface 23a of the truncated cone-shaped boss 23 are radially attached. It is a mixed flow fan having an impeller 1 composed of a large number of blades 5, 5, ....

Each blade 5 has a large number of fine holes 6, 6, ...
And a hollow body (for example, a rigid synthetic resin porous hollow body or a metal porous hollow body).

An annular hollow portion 25, which is in communication with the blade hollow portion 7 through the communication hole 24 and is open on the outer peripheral side, is formed in a portion of the truncated conical boss 23 which constitutes the conical surface 23a. ing. The hollow portion 25 is to generate a viscous suction force in association with the rotation of the impeller 1, and acts as a suction means.

With the above-mentioned structure, a part of the air flow F flowing along the surface of each blade 5 is formed in the truncated cone-shaped boss 23 by the rotation of the impeller 1 by the rotational driving of the motor 2. After being sucked into the blade hollow portion 7 through the fine holes 6, 6 ... By viscous suction force generated in the formed annular hollow portion 25, it is discharged to the outside through the boss hollow portion 22. Therefore, the development of the boundary layer on the surface of the blade 5 is effectively suppressed, and the wake width D (see FIG. 2) at the trailing edge of the blade 5 is suppressed as small as possible. As a result, it is possible to reduce the operating noise of the blower and significantly improve the aerodynamic performance.

Twelfth Embodiment FIG. 13 shows a blower of the present invention according to a twelfth embodiment of the present invention. The present embodiment corresponds to the inventions of claims 3, 8 and 9.

In the case of this embodiment, the gap flow generated on the outer peripheral side of the impeller 1 is blocked at the end portions of the blades 5, 5, ... (In other words, the end portions parallel to the suction direction) in the blower of the eleventh embodiment. The shroud 17 for doing so is integrally formed. The shroud 17 of this embodiment has a large number of fine holes 6,6.
.. is constituted by a hollow body (for example, a hard synthetic resin porous hollow body or a metal porous hollow body), and the shroud hollow portion 18 is communicated with the blade hollow portion 7 through a communication hole 19. It is supposed to be done. Other configurations are similar to those of the eleventh embodiment, and the description thereof will be omitted to avoid duplication.

With the above configuration, a part of the air flow F flowing on the surface of the shroud 17 integrally formed on the blades 5, 5, ..., End portions is hollow in the frustoconical boss 23. After being sucked into the shroud hollow portion 18 through the fine holes 6, 6 ... By the viscous suction force generated in the portion 25, the blade hollow portion 7 is sucked through the communication hole 19,
After that, it is discharged to the outside as in the eleventh embodiment. Therefore, the development of the boundary layer generated on the suction side of the shroud 17 is effectively suppressed, and the operation noise of the blower can be reduced and the aerodynamic performance can be significantly improved. Other functions and effects are the same as those of the eleventh embodiment, and the description will be omitted to avoid duplication.

Embodiment 13 FIG. 14 shows a blade structure of a blower according to Embodiment 13 of the present invention. The present embodiment corresponds to the inventions of claims 1 to 10.

In the case of the present embodiment, an opening portion 26 communicating with the blade hollow portion 7 is formed at the trailing edge of each blade 5 of the impeller 1. With this configuration, the impeller 1
Of the air flow F flowing along the surface of each blade 5 by the rotation of
Part of the blade 5 is sucked into the blade hollow portion 7 through the opening 26 formed at the trailing edge of the blade 5 by the suction force of the suction means (for example, the suction pump 13 or the like). The wake width D at the trailing edge can be further reduced. As a result, it is possible to reduce the operating noise of the blower and significantly improve the aerodynamic performance.

In each of the above embodiments, the fine holes are formed on the positive pressure surface and the negative pressure surface of the blade, but the fine holes may be formed only on the negative pressure surface where the boundary layer is significantly developed. . Further, also in the integrally molded shroud, the fine holes are formed on the entire surface in the above-mentioned embodiment, but it may be formed only on the inner peripheral surface which has a great influence on the driving noise.

The invention of the present application is not limited to the configuration of each of the above-described embodiments, and it goes without saying that the design can be appropriately changed without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is a side view showing a cross section of a part of a blower according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a blade cross section in the blower according to the first embodiment of the present invention.

FIG. 3 is a side view in which a part of the blower according to the second embodiment of the present invention is shown in section.

FIG. 4 is a side view in which a part of the blower according to the third embodiment of the present invention is shown in section.

FIG. 5 is a side view showing a cross section of a part of the blower according to the fourth embodiment of the present invention.

FIG. 6 is a side view in which a part of a blower according to a fifth embodiment of the present invention is shown in section.

FIG. 7 is a side view in which a part of the blower according to the sixth embodiment of the present invention is shown in section.

FIG. 8 is a side view in which a part of a blower according to a seventh embodiment of the present invention is shown in section.

FIG. 9 is a side view showing a cross section of a part of the blower according to the eighth embodiment of the present invention.

FIG. 10 is a side view showing a cross section of a part of a blower according to a ninth embodiment of the present invention.

FIG. 11 is a side view showing a cross section of a part of the blower according to the tenth embodiment of the present invention.

FIG. 12 is a side view showing a cross section of a part of the blower according to the eleventh embodiment of the present invention.

FIG. 13 is a side view in which a part of a blower according to a twelfth embodiment of the present invention is shown in section.

FIG. 14 is a sectional view showing a blade sectional structure in a blower according to a thirteenth embodiment of the present invention.

FIG. 15 is a cross-sectional view showing a blade cross-section structure in a conventional blower.

[Explanation of symbols]

1 is an impeller, 2 is a motor, 3 is a rotating shaft, 4 is a boss, 5
Is a blade, 6 is a fine hole, 7 is a blade hollow portion, 10 is a rotary shaft hollow portion, 13 is a suction pump, 15 is a discharge hole, 16 is a plate, 17 is a shroud, 18 is a shroud hollow portion, 20
Is a main plate, 22 is a hollow part of the main plate, 23 is a truncated cone boss, 2
3a is a conical surface, 25 is a hollow part, and 26 is an opening.

Claims (10)

[Claims] 1. A boss portion (4) pivotally attached to a rotating shaft (3),
A large number of blades radially attached to the outer periphery of the boss (4)
A fan having an impeller (1) consisting of (5), (5), ..., Wherein each blade (5) of the impeller (1) is provided with a large number of fine holes.
(6), (6) ··· and a hollow body having a part of the air flowing on the surface of each blade (5)
A blower characterized by being provided with suction means for sucking and discharging via (7). 2. A main plate (20) pivotally attached to a rotary shaft (3),
A large number of blades axially erected on the outer periphery of the main plate (20)
A fan having an impeller (1) consisting of (5), (5), ..., Wherein each blade (5) of the impeller (1) is provided with a large number of fine holes.
(6), (6) ··· and a hollow body having a part of the air flowing on the surface of each blade (5)
A blower characterized by being provided with suction means for sucking and discharging via (7). 3. A frusto-conical boss pivotally mounted on a rotating shaft (3).
A blower equipped with an impeller (1) consisting of (23) and a large number of blades (5), (5), ... Radially attached to the conical surface (23a) of the truncated conical boss (23). And said impeller (1)
Each of the blades (5) is composed of a hollow body having a large number of fine holes (6), (6) ,. (3) A blower characterized by being provided with suction means for sucking and discharging via (1). 4. The blades (5) having the fine holes (6), (6) ,.
The said 1st aspect characterized by forming only on the outer peripheral side.
Blower described. 5. The rotary shaft (3) is provided with a hollow portion (10) communicating with the blade hollow portion (7), and the suction means is installed in a stationary portion and the rotary shaft hollow portion (10). The blower according to claim 1 or 4, wherein the suction pump (13) is connected to the blower (10). 6. A plurality of plates (a plurality of plates) externally fixed to said suction means with discharge holes (15), (15) ,. 1
The blower according to claim 1 or 4, wherein the blower is constituted by 6) and (16). 7. The suction means is an annular hollow portion (22) which is formed in the main plate (20) and communicates with the hollow portion (7) of the blade, and which is open to the outer peripheral side. The blower according to claim 2, wherein 8. The frusto-conical boss is used as the suction means.
The annular hollow portion (25) is formed in a portion of the conical surface (23a) of (23), communicates with the hollow portion (7) of the blade, and further has an annular hollow portion (25) whose outer peripheral side is open. The blower according to claim 3. 9. A shroud (17) is integrally formed at an end portion of the blades (5), (5) ... In parallel with the suction direction, and the shroud (17) is provided with a large number of fine holes (6). , (6)
A hollow body having a shroud and having a hollow portion (18)
9. The blower according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the blade hollow portion (7) is communicated. 10. A blade hollow portion at the trailing edge of each blade (5).
The blower according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein an opening (26) communicating with (7) is formed.