US Patent 9869324 Fan, molding die, and fluid feeder

A fan includes a plurality of blade portions arranged spaced apart from each other in a circumferential direction, each blade portion having a blade surface including a pressure surface disposed on a rotational direction side of the fan and a suction surface disposed on a back side of said pressure surface. The plurality of the blade portions include a first blade portion and a second blade portion in which when they are rotated around the rotation axis of the fan and overlapped on one blade portion, one of an inner edge portion and an outer edge portion is disposed to be coincident with each other, and the other of the inner edge portion and the outer edge portion is disposed to be displaced from each other.