Patent ID: 9664055
Date: 2017-05-30
CPC Classifications: F01D,F04D

Claim:
1. An impeller comprises: an inner diameter portion, one side of which, in a direction of an axis of a rotation shaft of a rotary machine, is fitted at a radially outward side of the rotation shaft; a disk portion fitted at a radially outward side of the inner diameter portion at another side in the direction of the axis; a blade portion protruding from a surface facing toward the one side in the direction of the axis; and a cover portion formed in a single-piece together with the blade portion and the disk portion and covering the blade portion from the one side in the direction of the axis, wherein the inner diameter portion includes: a thin portion formed at the one side in the direction of the axis, and fitted to the rotation shaft, a thick portion formed at the other side in the direction of the axis, and having a thickness which is thicker than the thin portion, and an expanding diameter portion formed between the thin portion and the thick portion, and having a diameter which expands gradually toward the other side in the direction of the axis, wherein an inner diameter of the expanding diameter portion and an inner diameter of the thick portion are formed so as to be larger than an outer diameter of the rotation shaft, wherein the disk portion includes: a main body portion adjacent to the blade portion; and a fixing portion disposed at a radially inward side of the main body portion and fitted at a radially outward side of an outer peripheral surface of the thick portion, wherein the fixing portion protrudes from the main body portion toward the other side in the direction of the axis, wherein the inner diameter portion includes a positioning portion that allows positioning of the disk portion in the direction of the axis, and wherein the positioning portion includes a lightening portion at a contacting surface contacting a surface of the one side in the direction of the axis.