JPH0436096A - Impeller for axial flow blower - Google Patents

Abstract

PURPOSE:To prevent flow break-away so as to restrain flow disturbance in order to prevent noise during blowing from increasing, by providing a plurality of auxiliary blades on an inclined surface which is arranged on the side surface of a substantially cylindrical hub on the blade negative pressure side. CONSTITUTION:An impeller 6 is composed of a plurality of blades and a substantially cylindrical hub 7 to which the blades 2 are fixed. In this arrangement, an inclined surface 7b is formed on a hub side surface 7a on the blade negative pressure side 2e. Further, a plurality of auxiliary blades 8 are provided on the inclined surface 7b. With this arrangement, air sucked on the suction side of the hub 7 is forced to blow off onto the blade negative pressure side 2e, and then flows through the blade negative pressure side 2e. Accordingly, it is possible to prevent flow breeak-away, thereby it is possible to restrain flow disturbance due to the flow break-away.

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, impellers of trickle fans have been widely used as blowers for outdoor units of separate air conditioners, from commercial to home use, and there is a trend toward lower noise.

Below, referring to the drawings, Utility Model No. 62-105432
The impeller of the conventional axial flow blower proposed in Publication No. 0 and the like will be explained.

3 to 7 show the structure of the impeller of a conventional axial blower. 1 is the impeller of the axial blower; 2
are a plurality of blades, 3 is a substantially cylindrical hub to which the plurality of blades #12 are fixed, and 4 is a bellmouth-shaped orifice on the suction side surrounding the outer peripheral side of the trailing edge side 2b of the blade 2. 5 is a motor that rotates the impeller 1.

The operation of the impeller of the axial blower constructed as above will be described below. First, due to the rotation of the motor 5,
The impeller 1 rotates in a predetermined direction, air flows into the impeller 1, static pressure and dynamic pressure are applied to it by the action of the blades 2, and the air is discharged outside the impeller 1 to perform a blowing action.

Here, the blade population angle β1 of the impeller 1 of the axial blower is -
For boat fishing, as shown in Figures 5a and 5b, from the circumferential velocity U at the leading edge 2a' of the blade and the absolute velocity C1 of the incoming air, the formula β1' is used.
It is designed to almost match the airflow inflow angle β1° determined by = tan""e l / u, and the absolute velocity c1 is made uniform in the radial direction, and the inlet radius r allows the hub side 2d to be adjusted as shown in Fig. 6. In this case, it is set to be large, and on the chip side 2c, it is set to be small.

Problem to be Solved by the Invention However, with the above configuration, air is sucked into the impeller 1 not only from the leading edge side 2a but also from the tip side 2C, as shown in FIG. At 2d, the flow rate further decreases. Therefore, as shown in FIG. 7, the blade population angle β1 becomes too large compared to the airflow inflow angle β1' on the hub side 2d, causing separation of the flow on the suction side 2e of the blade 2, and this separation causes the flow to The problem was that air turbulence and air noise increased. Therefore, there was a problem in that flow separation on the blade negative pressure side 2e of the hub side 2d had to be suppressed.

In view of the above problems, the present invention provides an impeller for an axial flow blower that prevents flow separation on the negative pressure side of the impeller on the hub side of the impeller of a trickle flow blower, suppresses flow turbulence due to separation, and prevents an increase in air blowing noise. This is what we provide.

Means for Solving the Problems In order to solve the above problems, an impeller of a trickle blower according to the present invention is composed of a plurality of blades and a substantially cylindrical hub to which the plurality of blades are fixed, A sloped surface is provided on the side of the blade negative pressure surface of the hub side surface, and a plurality of ailerons are provided on the sloped surface.

Function: With this configuration, the air sucked in from the suction side of the substantially cylindrical hub is forcibly blown out to the negative pressure side of the blades on the hub side by the blowing action of the plurality of ailerons provided on the inclined surface of the side surface of the hub. By allowing the air to flow on the negative pressure side of the blade on the hub side, separation of the flow is prevented and disturbances due to separation are suppressed.

EXAMPLE Hereinafter, an impeller of an axial blower according to an example of the present invention will be described with reference to the drawings. Incidentally, the same parts as those in the conventional example are given the same numbers, and the description thereof will be omitted.

FIGS. 1 and 2 show the structure of an impeller of an axial blower in an embodiment of the present invention. 6 is an impeller of a trickle blower, 7 is a substantially cylindrical hub with an inclined surface 7b provided on the hub side surface 7a on the negative pressure side 2e of the blade 2;
A plurality of aileron blades 8 are provided on the inclined surface 7b of a.

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

As the motor 5 rotates, the impeller 6 rotates in a predetermined direction, air flows into the impeller 6, static pressure and dynamic pressure are applied by the action of the blades 2, and the air is discharged outside the impeller 6, creating a blowing effect. to do.

Here, an inclined surface 7b is provided on the hub side surface 7a on the suction surface side 2e of the blade 2 of the substantially cylindrical hub 7, and a plurality of ailerons 8f are provided on the inclined surface 7b. The air sucked in from the suction side of the substantially cylindrical hub 7 is forcibly blown out to the suction side 2e of the hub side 2d of the blade 2 by the blowing action of the plurality of ailerons 8 provided on the side, and the suction side 2e of the blade 2 is forcibly blown out. As shown in FIG. 2, as shown in FIG. 2, air is sucked into the impeller 6 not only from the leading edge side 2a but also from the tip side 2c, resulting in a significant decrease in the flow rate on the hub side 2d, and the airflow inflow angle β1. In comparison, the blade population angle β1 becomes too large to prevent flow separation on the blade negative pressure side 2e.

As described above, according to this embodiment, the sloped surface 7b is provided on the hub side surface 7a on the suction surface side 2e of the blade 2 of the substantially cylindrical hub 7, and the plurality of ailerons 8 are provided on the sloped surface 7b. ,
Due to the blowing action of the plurality of ailerons 8 provided on the inclined surface 7b, the air sucked in from the suction side of the substantially cylindrical hub 7 is forced to blow out to the blade negative pressure side 2e of the hub side 2d of the blade 2, and the negative pressure surface By flowing on the side 2e, air is sucked in not only from the leading edge side 2a of the blade 2 but also from the tip side 2C, resulting in flow separation on the blade negative pressure side 2e of the hub side 2d due to a decrease in the flow rate on the hub side 2d. It is possible to prevent flow disturbances caused by separation and suppress an increase in air blowing 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 to which the plurality of blades are fixed, and the impeller on the side surface of the substantially cylindrical hub. By providing an inclined surface on the negative pressure side of the blade and providing a plurality of ailerons on the slope, separation of the flow on the negative pressure side of the blade on the hub side of the blade is prevented, and turbulence of droplets due to separation is suppressed, and the air is blown. This can prevent an increase in sound transmission.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an impeller of a trickle blower according to an embodiment of the present invention, Fig. 2 is a meridional cross-sectional view of an impeller of a trickle blower according to an embodiment of the present invention, and Fig. 3 is a conventional axial flow blower. FIG. 4 is a cross-sectional view of the impeller of a conventional axial blower, FIG. 5a is a plan view of the impeller of a conventional axial blower, and FIG. Fig. 6 is a cross-sectional view taken along line A-A' of a, and Fig. 6 shows the blade population angle β1 of a conventional impeller and the inlet rear r.
FIG. 7 is a cross-sectional view taken along the line B-B'' in FIG. 7...Hub, 7a...Hub side,
7b... Inclined surface, 8... Aileron, 2e
...Negative pressure side. Name of agent: Patent attorney Shigetaka Awano (1 person) Δ product 1

Claims (1)

[Claims] It is composed of a plurality of blades and a substantially cylindrical hub to which the plurality of blades are fixed, an inclined surface is provided on the side surface of the substantially cylindrical hub on the negative pressure surface side of the blade, and a plurality of ailerons are attached to the inclined surface. The impeller of the installed axial blower.