Electric pressure fan and electric dust collector having the same

Abstract

The invention provides an electric pressure fan and an electric dust collector having the same, with which the situation that air flow from a shield to a wheel hub becomes uneven is prevented; the matching between a static blade disposed at the downstream of a rotating blade and the airflow is realized; the internal loss of the rotating blade and the peeling loss of the internal static blade are reduced. As for the blade, near an inlet, the shield side of the blade inclines towards a rotation direction and then faces the outer edge of the blade. The inclination of the shield side approaches awheel hub side, turning into an approximately two-dimensional shape facing the outer edge of the blade, and the shield side of the blade inclines towards a direction opposite to the rotation direction. When the blade approaches to the outer edge, the inclination towards the direction opposite to the rotation direction is reduced and an approximately two-dimensional shape is formed near the outer edge. Observed from an axial direction, two approximately two-dimensional shapes are provided from the inner edge of the blade to the outer edge of the blade, and inclining shapes with changed rotation direction are provided before and after the approximately two-dimensional shapes.

Description

technical field [0001] The present invention relates to an electric blower and an electric vacuum cleaner equipped with the electric blower. The electric blower has a fan blade in a twisted shape from an inner edge to an outer edge. Background technique [0002] A conventional electric blower is generally composed of a shroud, a main plate arranged at a position facing it, and a plurality of blades arranged therebetween, as shown in the following patent document 1, for example. The hub side is greatly inclined to obtain air volume and vacuum pressure through high-speed rotation. [0003] In particular, Patent Document 1 describes a rotary fan of an electric blower in which the fan blades are clamped by the front surface shroud and the rear surface shroud (hub) and fixed by riveting. Comparing the radius of curvature of the sheet, by making the front surface shield side more inclined than the rear surface shield side, the inner peripheral side, the front surface shield side ...

AI Technical Summary

Problems solved by technology

In addition, since there is no detailed adjustment of the angle distribution of the fan blades for the air flow at the inlet, there is also the possibility that near the suction inlet, the inclination of the blades of the impeller is inconsistent with the inflow direction of the air, and the air hits the fan blades. The side of the sheet, the impact loss increases

[0008] In addition, in the electric blower (Patent Document 1), since the blades are greatly inclined with respect to the main plate when viewed from the axial direction, there is a problem of buckling due to buckling in the assembly process using sheet metal. Problems on assembly such as blades or riveting are prone to collapse

[0009] In addition, in the conventional electric blower (Patent Document 1), although the front cover side on the inner peripheral side (inflow side) is inclined to the rotation direction, the outer peripheral side (outflow side) is approximately perpendicular to the rear surface cover, Therefore, on the outer peripheral side (outflow side), the flow of air from the front surface shield to the rear surface shield becomes non-uniform, that is, the pressure distribution and velocity distribution become non-uniform from the front surface shield to the rear surface shield, and there is energy risk of increased losses

[0010] In addition, in a conventional fan (Patent Document 2), when a stationary vane (for example, a diffuser) provided to efficiently decelerate the airflow flowing out from the fan to the downstream of the fan is formed, the In the impeller of the centrifugal fan where the position of the shroud-side coupling portion at the rear edge portion of the blade is shifted by a predetermined amount in the opposite direction of the rotation direction than the position of the hub-side coupling portion, since the matching of the air flow with the stationary blade is not realized, Therefore, separation and reverse flow of the airflow tend to occur between the vanes of the stationary vanes, resulting in energy loss (decreased efficiency)

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