Patent ID: 7946824

Claim:
An impeller for use in an axial flow fan, the impeller comprising: a hub including a radially outer surface and centered on a center axis; and a plurality of blades extending radially outwardly from the radially outer surface of the hub to generate an air flow along the center axis when the hub rotates in a rotational direction, each of the plurality of blades includes a leading edge which is a forward side edge in the rotational direction, a following edge which is a rearward side edge in the rotational direction, and a radially outer edge connecting the leading edge and the following edge; wherein a first corner where the radially outer edge and the following edge meet is arranged forward in the rotational direction relative to a second corner where the radially outer surface of the hub and the leading edge meet in each of the plurality of blades; and the plurality of blades are arranged such that the radially outer edge of each of the plurality of blades is not connected to other radially outer edges of the remaining ones of the plurality of blades.