Patent ID: 8596958

Claim:
A crossflow fan comprising an impeller having a plurality of support plates located on a rotation axis of the impeller and a plurality of plate-like blades provided at peripheral portions of the support plates, the blades extending parallel to the rotation axis, each blade being inclined such that its outer edge is located on the leading side of its inner edge with respect to the rotation direction of the impeller, one of the faces of each blade that is on the leading side of the rotation direction of the impeller forms a positive pressure surface, the face on the trailing side of the rotation direction forms a negative pressure surface, wherein a plurality of notches are formed at at least one of the inner edge and the outer edge of each blade, the notches being arranged at predetermined intervals along the rotation axis of the impeller, a basic shape section being formed between each adjacent pair of the notches, and a plurality of grooves are formed on one of the positive pressure surface and the negative pressure surface so that a blade thickness in the vicinity of the bottom of each notch is less than a blade thickness of the adjacent basic shape section, and wherein in a longitudinal cross-section of each of the blades, the other of the positive pressure surface and the negative pressure surface, which does not have the grooves, is flat.