US Patent 10400604 Axial fan with grooved trailing edge and outdoor unit

An axial fan includes: a hub; a plurality of blades arranged in a circumferential direction of the hub; a cutout in a rear edge part of each of the plurality of blades, the cutout divides the rear edge part into an outer rear edge part and an inner rear edge part; a first groove part disposed in the outer rear edge part, the first groove part including a plurality of grooves extending toward the front edge part; and a second groove part disposed in the inner rear edge part, the second groove part including a plurality of grooves extending toward the front edge part, the plurality of grooves of the first groove part and the plurality of grooves of the second groove part having different shapes when viewed in a rotational axis direction of the hub.