JP3191516B2 - Electric blower impeller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller of an electric blower for obtaining a high vacuum pressure used for a vacuum cleaner or the like.

[0002]

2. Description of the Related Art A conventional impeller of this type will be described with reference to FIG. The conventional impeller 1 includes a front shroud 2 having an umbrella-shaped curved surface, a flat rear shroud 3,
It consists of a plurality of blades 4 provided between both shrouds and curved in an arc shape when viewed from above.
The blade 3 and the blade 4 constitute a passage 5 through which the air flows.

In FIG. 4, reference numeral 6 denotes a fan case, 7 denotes an air guide, and 8 denotes a motor. With the above configuration, the impeller 1 rotates at a high speed by the rotation of the motor 8, discharges the sucked airflow at a high speed, and obtains a suction pressure necessary for a vacuum cleaner.

[0004]

However, the impeller having the above-mentioned structure has a low efficiency for the following reasons. That is, the airflow flowing into the impeller 1 becomes a turbulent airflow when passing through a filter, a duct hose, or the like of the cleaner body (not shown). In the impeller 1, when the sucked airflow is discharged at a high speed and guided to the air guide 7, the direction of the airflow is bent at a right angle, and at this time, the passage area of the airflow is sharply expanded. And the airflow is further disrupted. Accordingly, swirl, backflow, and the like are generated at each of the entrance, the inside, and the exit of the impeller 1, so that the airflow passing through the passage 5 does not efficiently flow into the air guide 7, thereby reducing the efficiency of the impeller 1. It is.

In order to obtain a high vacuum pressure, the impeller 1
Need to rotate at high speed, the higher the speed,
The rotational friction resistance of the impeller 1 due to the viscosity of air between the fan case 6 and the front shroud 2 and between the air guide 7 and the rear shroud 3 increases. This, on the contrary, also causes the efficiency of the impeller 1 to decrease.

An object of the present invention is to solve the problems of the conventional configuration as described above, and it is an object of the present invention to obtain an impeller of an electric blower having a high air blowing efficiency.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a front shroud, a rear shroud, and a plurality of blades provided between the shrouds, and is formed by the shrouds and the blades. An impeller of an electric blower provided with a plurality of substantially hemispherical dimples on the surfaces of the airflow passage and the surfaces of both shrouds.

[0008]

According to the present invention, a plurality of substantially hemispherical dimples provided on the surface of the passage and both shrouds suppress the generation of turbulence by the dimple action, thereby reducing the rotational friction resistance of the impeller. This is to improve the air blowing efficiency of the impeller.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. The impeller 11 includes a front shroud 12 having a curved surface, a rear shroud 13 having a flat plate shape, and a plurality of blades 14 provided between the blades and curved in an arc shape when viewed from above. Front shroud 12
The rear shroud 13 has a plurality of substantially hemispherical dimples 16 on its outer surface. Dimples 16 are also provided on the surface of an airflow passage 15 surrounded by the front shroud 12, the rear shroud 13, and the blade 14. In FIG. 1, 17 is a fan case, 18 is an air guide, and 19 is a motor.

Next, the operation of this embodiment will be described.
The plurality of substantially hemispherical dimples 16 on the surface of the passage 15 are:
Due to the dimple action, separation of the airflow is suppressed. Therefore, according to the present embodiment, even if the direction of the airflow is bent at a right angle in the impeller 11, the turbulence of the airflow in the impeller can be suppressed, and the passage area is rapidly increased at the impeller outlet. This also makes it possible to suppress the occurrence of eddies and backflows.

Further, in this embodiment, substantially hemispherical dimples 16 are also provided on the surface portions of the front shroud 12 and the rear shroud 13. Therefore, the rotational friction resistance of the impeller 11 due to the viscosity of the air between the fan case 17 and the front shroud 12 and between the air guide 18 and the rear shroud 13 can be reduced.

The same effect can be expected when a projection protruding from the surface is used in place of the dimple 16, but in this case, for example, when a projection is provided in the passage 15, In this case, the cross-sectional area of the passage 15 is reduced, and the flow of the air flow is rather deteriorated. Therefore, the provision of the projections rather lowers the air blowing efficiency. Also, if the front shroud 12 and the rear shroud 13 are provided with protrusions instead of the dimples 16 on the surface thereof, the protrusions may not be a resistance to the rotation of the impeller.

[0013]

As described above, according to the present invention, a plurality of substantially hemispherical dimples provided on the surfaces of the impeller passage and both shrouds suppress the generation of turbulent air flow by the dimple action, thereby reducing the rotational friction resistance of the impeller. By acting so as to reduce it, an impeller of an electric blower with high blowing efficiency is realized.

[Brief description of the drawings]

FIG. 1 is a side view showing a half section of a state in which an impeller according to an embodiment of the present invention is incorporated in an electric blower.

FIG. 2 is a plan view of the impeller viewed from a front shroud direction.

FIG. 3 is a plan view of the impeller as viewed from a rear shroud direction.

FIG. 4 is a side view showing a state in which an impeller according to a conventional example is incorporated in an electric blower in a half cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Impeller 12 Front shroud 13 Rear shroud 14 Blade 15 Passage 16 Dimple

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04D 29/28

Claims (1)

(57) [Claims] 1. A front shroud, a rear shroud, and a plurality of blades provided between the two shrouds, wherein a plurality of blades are provided on a surface of an airflow passage formed by the two shrouds and the blades, and a plurality of blades are provided on the surfaces of the two shrouds. The impeller of an electric blower provided with a substantially hemispherical dimple.