JPH0315698A - Impeller of axial blower - Google Patents

Abstract

PURPOSE:To prevent blast noise by providing a suction port in the suction side surface of a hub and a plurality of holes in the hub side of the negative pressure surface side of the blade and providing an auxiliary blade on the inside surface of the hub in association with these holes in an impeller having a plurality of blades fixed to the outer periphery of an approximately cylindrical hub. CONSTITUTION:The impeller 8 of an axial blower has a plurality of blades 2 fixed to the outer periphery of an approximately cylindrical hollow hub 3 which is provided with a suction port 4 on its suction side surface 3a while provided with a plurality of holes 5 formed in the hub side surface 3b on the negative pressure surface side 2e of the blade 2. Auxiliary blades 9 are disposed on the inner peripheral side wall surface 3c of the hub side surface 3b provided with the hole 5... to be formed in a row of blades of a multiblade blower. Thus, at the rotation of the impeller 8, air is sucked from the suction port 4 into the hub 3 and discharged forcibly from a plurality of the holes 5 toward the negative surface side 2e of the blade 2 by the centrifugal blast action of the auxiliary blade 9 to prevent the air flow from exfoliation on the negative surface side 2e and restrain the increase of blast noise along with the turulence of flow caused by the exfoliation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an impeller for an axial blower used in an air conditioner or the like.

BACKGROUND OF THE INVENTION In recent years, the impeller of an axial blower has been widely used as a blower for separate air conditioners, from commercial use to home use, and there is a trend toward lower noise.

Hereinafter, the impeller of the conventional axial flow blower mentioned above will be explained with reference to the drawings.

3 to 7 show the structure of the impeller of a conventional axial blower. 1 is an impeller of an axial flow blower, 2 is a plurality of blades, and 3 is a substantially cylindrical hub with an almost hollow interior; a suction port 4 is provided on the suction side surface 3a; A plurality of holes 6 are provided in the hub side surface 3b of the negative pressure side 2e. The suction side surrounding the outer periphery of the trailing edge side 2b of the six blades 2 is a bellmouth-shaped orifice ring. 7 is a motor that rotates the impeller 1.

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

1. As the motor 7 rotates, the impeller 1 rotates in a predetermined direction, air flows into the impeller 1, static pressure and dynamic pressure are added to it by the action of the blades 2, and the air is discharged outside the impeller 1. It acts as a blower.

Here, since centrifugal force acts on the fluid in the flow between the entire blades of the impeller 1 of the axial blower and in the vicinity of the blades 2, the tip side 2
There is a tendency for the flow rate to be biased toward the tip side 2C and to be larger on the tip side 2C than on the hub side 2d.

Therefore, from the circumferential velocity U at the leading edge 2a' of the blade shown in FIGS. 6a and 6b and the absolute velocity c1 of the inflow air, the formula
The blade population angle β1, which is made to almost match the airflow inflow angle β1' obtained by C1/u, is determined by determining the circumferential speed U from the rotation speed of the impeller 1 and the inlet radius r, and the absolute speed C1 of the inflow airflow from the flow rate. Therefore, the inlet radius r is set to be large on the hub side 2d and small on the tip side 2C, as shown in FIG.

However, as shown in FIG. 4, air is drawn into the impeller 1 not only from the leading edge side 2a but also from the tip side 2C, so the flow rate is further reduced on the hub side 2d. Therefore,
As shown in FIG. 7, the blade population angle β becomes too large compared to the airflow inflow angle β1' on the hub side 2d, and separation of the flow occurs on the suction side 2e of the blade 2, and this separation causes turbulence of the flow. Since the air blowing noise increases, a suction port 4 is provided on the suction side surface 3a of the substantially cylindrical hub 3 having a substantially hollow interior, and a plurality of holes 6 are provided on the hub side surface 3b on the negative pressure surface side 2e of the blade 2. As a result, air is sucked into the inside of the haptic 3 from the suction port 4,
Air is blown from the plurality of holes 5 on the side surface b to the suction side 2e of the hap side 2d of the blade 2, and flows through the suction side 2e, so that the impeller 1 not only has the leading edge side 2a but also the tip side 2, as shown in FIG.
Since the air is sucked into the housing, the flow rate on the hub side 2d is significantly reduced, and the flow is prevented from separating on the negative pressure side 2e since the blade population angle β1 is larger than the airflow inflow angle β1'.

Problems to be Solved by the Invention However, in the above configuration, the pressure difference between the internal cavity of the hub 3 and the negative pressure side 2e of the blade 2 is caused by air flowing from the inside of the hub 3 through the plurality of holes 6 to the blade. 2 negative pressure side 2
Since the air is not so large as to be blown out into the haptic 3, as shown in FIG. The problem was that it was discharged outside the vehicle.

In view of the above-mentioned problems, the present invention has provided air sucked into a cavity inside the hub from a suction port provided on the suction side surface of a substantially cylindrical hub through a plurality of holes provided on the hub side surface on the negative pressure surface side of the blade. The air is forcibly blown out to the negative pressure side of the blade on the hub side, and the blown airflow flows on the negative pressure side, preventing flow separation.
The present invention provides an impeller for an axial blower that suppresses flow disturbances caused by separation.

Means for Solving the Problems To achieve this object, the impeller of the axial blower of the present invention is composed of a plurality of blades and a substantially cylindrical hub having a substantially hollow interior to which the plurality of blades are fixed. A suction port is provided on the suction side surface of the substantially cylindrical hub, a plurality of holes are provided on the hub side surface on the negative pressure side of the blade, and an aileron is provided on the inner peripheral side wall surface of the hub side surface where the plurality of holes are located. has been established.

Depending on the structure, air is sucked into the cavity inside the hub from the suction port provided on the suction side surface of the substantially cylindrical hub, and the sucked air is sucked into the inner peripheral side of the hub side surface where the plurality of holes are located. Due to the blowing action of the ailerons provided on the wall surface, the air is forcibly blown out from the plurality of holes provided on the side surface of the hub toward the negative pressure side of the blade on the hub side,
The blown airflow flows on the negative pressure side of the blade on the hub side, preventing flow separation and suppressing flow turbulence due to separation.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. Incidentally, in order to avoid duplication, the same parts as in the conventional example are given the same numbers and the description thereof will be omitted.

Figures 1 and 2 show the structure of an impeller for an axial blower according to an embodiment of the present invention. 8 is the impeller of the axial blower, and 9 is a substantially cylindrical impeller with an almost hollow interior. These auxiliary blades are arranged on the inner wall surface 3C of the hub side surface 3b on the suction surface side 2e of the blade 2 where the plurality of holes 6 of the hub 3 are located so as to form a blade row of a multi-blade blower.

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

The impeller 8 rotates in a predetermined direction due to the rotation of the motor, air flows into the impeller 1, static pressure and dynamic pressure are added to it by the action of the blades 2, and the air is discharged outside the impeller 8, creating a blowing effect. to do.

Here, an auxiliary m9 is attached to the inner peripheral side wall surface 3C of the hub side surface 3b of the suction surface side 2e of the blade 2 where the plurality of holes 5 of the substantially cylindrical hub 3 having a substantially hollow internal space is provided. As shown in FIG. Due to the centrifugal air blowing action by the ailerons 9 provided at 3C, the negative pressure side 2 of the hub side 2d of the blade 2 is forced through the plurality of holes 5 provided on the hub side surface 3b.
Since the airflow is blown out on the negative pressure side 2e and flows on the negative pressure side 2e, separation of the flow on the negative pressure side 2e of the hub side 2d due to a decrease in the flow rate on the hub side 2d is prevented.

As described above, according to the present embodiment, the suction surface side 2e of the blade 2 has a plurality of holes 5 of the substantially cylindrical hub 3 having a substantially hollow interior.
By arranging the ailerons 9 on the inner wall surface 3C of the hub side surface 3b so as to form a row of blades of a multi-blade blower, the b1 suction port 8
The air sucked into the inside of the hub 3 from the hub side '3b
Due to the centrifugal blowing action of the ailerons 9 provided on the wall C on the inner circumferential side of the blades 2, air is forcibly blown out from the plurality of holes 6 to the negative pressure side 2e of the hub side 2d of the blade 2, thereby reducing the flow rate on the hub side 2d. The airflow necessary to prevent flow separation on the negative pressure surface side 2e of the hub side 2d due to this flow flows on the negative pressure surface side 2e, preventing flow separation,
It can disrupt the flow turbulence caused by separation and prevent an increase in ventilation noise.

Effects of the Invention As described above, the impeller of the axial blower of the present invention is composed of a plurality of blades and a substantially cylindrical hub having a substantially hollow interior to which the plurality of blades are fixed, and the substantially cylindrical hub has a substantially hollow interior. A suction port is provided on the suction side surface of the blade, a plurality of holes are provided on the hub side surface on the side of the suction side of the blade, and an aileron is provided on the inner peripheral side wall surface of the hub side surface where the plurality of holes are located. Inhalation from mouth 1
The air is forcibly blown out from the plurality of holes to the negative pressure side of the hub side of the blade, and the airflow necessary to prevent flow separation on the negative pressure side of the hub side of the blade flows on the negative pressure side of the blade. , it is possible to prevent flow separation, suppress flow turbulence caused by separation, and prevent an increase in ventilation noise.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an impeller of an axial blower according to an embodiment of the present invention, FIG. 2 is a meridional cross-sectional view of essential parts of an impeller of an axial blower according to an embodiment of the present invention, and FIG. The figure is a perspective view of the impeller of a conventional axial flow blower, FIG. 4 is a sectional view of the calf of the impeller of a conventional axial blower, FIG. FIG. 6 is a diagram showing the relationship between the blade inlet angle β1 and the inlet radius r of a conventional impeller, and FIG. 7 is a sectional view taken along line A-A in FIG. 6a. It is a sectional view of a line. 8... Impeller of shaft fan, 2... Vane, 2e... Negative pressure side, 3... Hub,
3a...Suction side surface, 3b...Hub side surface, 3a...Inner peripheral side wall surface, 4...Suction port, 5... ...Multiple holes, 9...Aileron.

Claims (1)

[Claims] It is composed of a plurality of blades and a substantially hollow cylindrical hub that fixes the plurality of blades, and a suction port is provided on the suction side surface of the substantially cylindrical hub, and An impeller for an axial blower, in which a plurality of holes are provided on a side surface of a hub, and ailerons are provided on a wall surface on the inner peripheral side of the side surface of the hub where the plurality of holes are located.