Patent attributes
An impeller includes: a disk-shaped hub centered on an axis; and a plurality of blades arranged in a circumferential direction and protruding from a surface of the hub facing one side in a direction of the axis. In a cross-sectional view including a blade height direction which is a direction away from the hub toward a tip of each blade, the blade has a recessed surface curved convexly toward a rear side in a rotational direction. In the cross-sectional view, when a distance between an imaginary line connecting a tip-side edge and a hub-side edge of the blade and a midspan of the blade along a direction perpendicular to the imaginary line is defined as a recess amount, the blade has a portion where the recess amount increases from a leading edge side to a trailing edge side.
