Patent attributes
The present invention provides an axial fan including a hub adapted for rotation about a central axis and a plurality of blades extending radially outwardly from the hub and arranged about the central axis. Each of the blades includes a root, a tip, a leading edge between the root and the tip, and a trailing edge between the root and the tip. Each of the blades defines a blade radius between the blade tips and the central axis. Each of the blades defines a decreasing skew angle within the outer 20% of the blade radius. The ratio of blade pitch to average blade pitch increases from a lowest value to a highest value within the outer 20% of the blade radius. The highest value is about 30% to about 75% greater than the lowest value.