JPH07158591A - Blower impeller - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a blower impeller designed to reduce noise by controlling turbulence. [Structure] A plurality of thick blade blades 12 are provided around a hub 11, and a large number of grooves 14 having a V-shaped cross section are formed concentrically with the hub 11 on a pressure surface 13 and a suction surface 14 of the blade 12. It is provided to reduce the frictional resistance of the turbulent boundary layer generated on the surface of the blade 12 when the impeller rotates, to improve the aerodynamic performance of the impeller and to reduce noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan impeller provided with blade-shaped blades having a low noise effect.

[0002]

2. Description of the Related Art A conventional fan impeller provided with airfoil blades having this kind of thickness is constructed as shown in FIGS. That is, a plurality of thick wing type blades 2 are provided around the substantially cylindrical hub 1. As a blower, this impeller is housed in an appropriate casing, the hub 1 is fixed to a shaft of a motor, and the hub 1 is rotated in a direction of an arrow in FIG. By the way, the wing type blade 2 is shown in FIG.
As shown in, both the pressure surface and the suction surface are flat.

[0003]

However, the blower impeller having such a structure exhibits much lower noise than a blower impeller having thin blade blades, but the blade surface is not flat. However, the turbulent flow control on the blade surface cannot be performed, and further noise reduction cannot be achieved, reaching the limit.

The present invention solves such problems, and an object of the present invention is to provide a blower impeller with further reduced noise.

[0005]

In order to solve this problem, the present invention is provided with a plurality of thick wing type blades around a hub, and at least the negative pressure surface among the pressure surface and the negative pressure surface of the blade. In addition, a large number of fine grooves are provided concentrically with the hub.

[0006]

By providing a large number of fine grooves on at least the negative pressure surface of the blade, the frictional resistance of the turbulent boundary layer generated on the surface of the blade during rotation of the impeller can be reduced and the aerodynamic performance of the impeller can be reduced. Is improved, resulting in low noise.
That is, low noise can be realized by turbulent flow control.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, the first embodiment shown in FIGS. 1 and 2 will be described. 11 is a hub having a substantially cylindrical shape, and a plurality of thick blade type blades 12 are provided around the hub 11. Further, a large number of fine grooves 15 having a V-shaped cross section are provided concentrically with the hub 11 on both the pressure surface 13 and the negative pressure surface 14 of the airfoil blade 12. 16 is a chip.

Then, the fan impeller is housed in an appropriate casing, and the hub 11 is fixed to the shaft of the motor.
By rotating in the direction of the arrow, a blowing effect is produced. At this time, air enters from the leading edge 17 of the airfoil blade 12 and flows out from the trailing edge 18 to perform aerodynamic work.

As described above, since the fine grooves V having a V-shaped cross section are provided on both the pressure surface 13 and the negative pressure surface 14 of the blade blade 12, the disturbance generated on the surface of the blade when the impeller rotates. The frictional resistance of the flow boundary layer can be reduced, the aerodynamic performance of the impeller is improved, and as a result, noise reduction can be achieved. That is, low noise can be realized by turbulent flow control.

Next, the second embodiment shown in FIG. 3 will be described. In the second embodiment, a large number of grooves 15 having a V-shaped cross section are formed concentrically with the hub 11 only on the suction surface 14 of the blade blade 12. It is provided.

According to this embodiment, since the fine groove 15 having a V-shaped cross section is provided only on the negative pressure surface 14, the number of processing steps can be reduced and the cost can be reduced as compared with the first embodiment.
In particular, effective turbulent flow control can be performed for the characteristic separation of the suction surface 14.

Next, the third embodiment shown in FIG. 4 will be described. In the third embodiment, at least the negative pressure surface 14 of the pressure surface and the negative pressure surface of the airfoil blade 12 has an arcuate peak in cross section. In addition, a large number of fine grooves 19 are provided concentrically with the hub 11.

According to this embodiment, the airfoil type blade 12 is provided with a large number of fine grooves 19 having arcuate peaks in a sectional shape in a concentric circle with the hub 11. The noise reduction can be realized, and the machining is significantly easier than the fine V-shaped groove of the above-described embodiment, and as a result, the cost can be reduced.

[0014]

As described above, according to the present invention, a large number of fine grooves are provided concentrically with the hub on at least the negative pressure surface among the pressure surface and the negative pressure surface of the blade type blade, so that the rotation of the impeller is reduced. At times, the frictional resistance of the turbulent boundary layer generated on the surface of the blade can be reduced, the aerodynamic performance of the impeller is improved, and as a result, noise reduction can be achieved. That is, low noise can be realized by turbulent flow control.

[Brief description of drawings]

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

FIG. 2 is an enlarged sectional view of the same.

FIG. 3 is an enlarged sectional view of an impeller according to a second embodiment of the present invention.

FIG. 4 is an enlarged sectional view of an impeller according to a third embodiment of the present invention.

FIG. 5 is a perspective view of an impeller in a conventional example.

FIG. 6 is an enlarged sectional view of the same.

[Explanation of symbols]

 11 Hub 12 Airfoil blade 13 Pressure surface 14 Suction surface 15 Groove 19 Groove

Claims (3)

[Claims] 1. A blower comprising a plurality of thick blade vanes around a hub, and a plurality of fine grooves concentrically formed with the hub at least on the negative pressure surface of the pressure surface and the negative pressure surface of the blade. Impeller. 2. The blower impeller according to claim 1, wherein the groove has a V-shaped cross section. 3. The blower impeller according to claim 1, wherein the groove has a circular arc shape in the cross section.