Centrifugal fan and impeller thereof

Abstract

A centrifugal fan includes a fan frame (20) and an impeller (40) received in the fan frame. The impeller includes a hub (41) having a circular top wall (410) and a cylindrical side wall (412) extending downwardly from a rim of the circular top wall, a plurality of blades (42) extending radially from the side wall of the hub and a blade ring (44). The blade ring includes an annular top plate (441), a cylindrical sidewall (442) extending downwardly from an outer periphery of the top plate, and a flange (443) extending outwardly from a bottom of the cylindrical sidewall. The blade ring is arranged on top surfaces of the blades received in an air inlet (24a) defined in a top surface of the fan frame, and the top plate of the blade ring and the top surface of the fan frame are coplanar with each other.

Dependencies are inferred from the claim text.