IMPELLER AND ROTATING MACHINE PROVIDED WITH SAME

摘要

An impeller comprises a disc that rotates about an axis, and blades a plurality of which are disposed in the circumferential direction of the disc with intervals therebetween. Of the angles formed by a tangent line to a projection curve line which is a center curve line of the thickness of the blade projected from the axis direction to the disc, and an imaginary line orthogonal to a line connecting the axis and a tangent point between the projection curve line and the tangent line, if the angle formed at the rotation direction rear-side and the outer peripheral side of the disc is defined as a blade angle, then the blade angle of the blade has a prescribed gradual increase region and gradual decrease region from the center towards the outside, and at the center of an inflection region of the gradual increase region and of the gradual decrease region, provided is a partial gradual decrease region having a smaller blade angle decrease amount than the blade angle increase amount of the gradual increase region.