JPH04164194A - Fan of motor-driven blower - Google Patents

Abstract

PURPOSE:To reduce the bending loss in the vicinity of a discharge port by curving the outer peripheral side of a disc in the direction opposite to a shroud. CONSTITUTION:The outer peripheral part of a disc 2 has a curved part 4 in the opposite direction to a shroud 1. Accordingly, the air sucked into a fan 9 passes through the inside of the fan 9 and flows along the curved outer peripheral part of the disc 2 and a fan case 10, and bent by 90 deg., and the stream directed to a diffuser 6 is made smooth. Accordingly, when the air is discharged, passing through the inside of the fan, the generation of turbulent flow and eddy current in the 90 deg. bending up to the inflow into the diffuser 6 is reduced, and the turbulent flow loss at a discharge port can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fan for an electric blower used in a vacuum cleaner or the like.

BACKGROUND OF THE INVENTION Conventional electric blowers of this type generate pressure and obtain air output by rotating a fan at high speed using a motor.

Hereinafter, a conventional electric blower as described above will be explained with reference to the drawings.

FIG. 3 is a half-sectional view of a conventional electric blower.

In FIG. 3, the motor frame 5 and the differential user 6 are fixed together with screws 7, and a fan 9 is attached to a rotating shaft 8, which is covered with a fan case 10. FIG. 4 is a plan view of a conventional electric blower fan. The fan 9 includes an umbrella-shaped shroud 1, a flat disk 2, and a plurality of fan blades 3.
A caulking pawl is provided in the shroud 1 and the disk 2, and the shroud 1 and the disk 2 are fixed by caulking by inserting the caulking pawl into the hole provided in the hole.

The operation of the blower configured as above will be described below. As the rotating shaft 8 rotates, the fan 9 rotates, and the suction port 11 in the center of the fan case 10 is rotated.
Breathe in more air. After passing through the inside of the fan 9 and flowing out from the outlet 12, the air is refracted 90 degrees along the fan case 10 as shown by arrow A, flows to the differential user 6, passes through the inside of the motor frame 5, and exits the motor. be spat out.

Problems to be Solved by the Invention However, with the above configuration, when air flows out from the fan outlet 12, it is immediately refracted along the fan case, resulting in turbulent flow and vortex flow at the time of refraction, as shown by arrow B. This results in a loss.

Note that if you use a passage-like configuration with a thick radius of curvature instead of a refracted shape, turbulence due to refraction will be less likely to occur (but
This configuration cannot be adopted when the outside diameter of the blower is large and there are restrictions on the size of the blower, such as in a vacuum cleaner. Therefore, since turbulent flow loss due to refraction is likely to occur due to the structure, it is necessary to suppress this loss.

In view of the above drawbacks, the present invention provides an electric blower fan with high efficiency by improving the shape of the fan to reduce refraction loss near the outlet of the fan.

Means for Solving the Problems In order to achieve this object, the electric blower fan of the present invention has a configuration in which the outer peripheral side of the disk is curved in the direction opposite to the shroud.

Effect: With the above-described configuration, when air flows out from the fan's outlet, it flows along the curved disk surface of the fan, which reduces turbulence and vortices that occur during refraction, reducing loss. . Furthermore, since the turbulence is reduced, the turbulent impact sound is reduced, resulting in a reduction in noise.

EXAMPLE Hereinafter, a fan of an electric blower according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a half sectional view of a fan of an electric blower according to an embodiment of the present invention. In FIG. 1, 1 is an umbrella-shaped shroud, 2 is a disk, and 3 is a fan blade. The outer circumferential portion of the disk 2 has a curved portion 4 in the direction opposite to the shroud. FIG. 2 is a half-sectional view of an electric blower using a fan according to an embodiment of the present invention. In FIG. 2, the air sucked into the fan 9 passes through the inside of the fan 9, flows along the curved outer periphery of the disk 2 and the fan case 10, is bent 90 degrees, and then flows to the differential user 6. is smooth.

Effects of the Invention As described above, in the present invention, the outer peripheral side of the disk of the rotating fan is curved in the direction opposite to the shroud, so that when air passes through the inside of the fan and is discharged, it flows into the differential user. The turbulent flow and eddy flow that occur when refracting through 90 degrees are reduced, and a high-performance electric blower fan with less turbulent flow loss at the outlet can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a half-sectional view of a rotating fan of an electric blower according to an embodiment of the present invention, Fig. 2 is a half-sectional view of an electric blower incorporating the fan of the present invention, and Fig. 3 is a half-sectional view of a conventional electric blower. FIG. 4 is a plan view of a rotating fan of a conventional electric blower. 1...Shroud, 2...Disk,
3...Fan blade, 4...Disk curved portion, 10...Fan case. Name of agent: Patent attorney Haruaki Koba and 2 others Figure 1-M-Shroud 2--Child Izuku 3-7 Reed wing Figure 2 Figure 3

Claims (1)

[Claims] The shroud includes a plurality of fan blades made of curved thin plates, a thin plate shroud having a gas inlet hole in the center, and a thin plate disk having a rotating shaft hole. An electric blower fan bent in the opposite direction.