Patent ID: 8721280
Filing Date: 2014-05-13
Classification: F04D,F05D

Abstract:
1. A propeller fan comprising a hub coupled to a fan motor serving as a drive source and a plurality of blades provided on the outer circumference of the hub, the blades extending radially outward, the propeller fan further comprising a plurality of recesses and a plurality of protrusions, wherein the recesses adjoin each other, each have a recessed surface, extend circumferentially on a positive pressure surface at a trailing end of each blade, and are aligned in the radial direction, and wherein the protrusions are each located between adjacent two of the recesses and each of the protrusions is acute, wherein the recesses have different depths, and the depths of the recesses are formed to decrease as the distance from the hub increases and toward the outer periphery of the corresponding blade.