Abstract: Provided is a rotary machine including: a shaft that rotates; a disc that has a substantially cylindrical hub fitted into the shaft and is provided so as to widen outward in a radial direction from a front end to a rear end of the hub; and an impeller having a plurality of blades provided on a surface of the disc. The hub has a tight fit section having an internal radius that is smaller than a radius of the shaft, and a loose fit section having an internal radius that is greater than the internal radius of the tight fit section. The loose fit section is provided on the front end side of the hub with respect to the tight fit section.

Abstract: Provided is a rotary machine including: a shaft that rotates; a disc that has a substantially cylindrical hub fitted into the shaft and is provided so as to widen outward in a radial direction from a front end to a rear end of the hub; and an impeller having a plurality of blades provided on a surface of the disc. The hub has a tight fit section having an internal radius that is smaller than a radius of the shaft, and a loose fit section having an internal radius that is greater than the internal radius of the tight fit section. The loose fit section is provided on the front end side of the hub with respect to the tight fit section.

Abstract: The impeller is provided with: a disc section equipped with a tube section, the grip section of which is fixed by thermal deformation to a rotation shaft that is rotated around the axis line, and a main disc body, which is provided on the other end in the axial direction from the grip section and which extends outward in the radial direction of the rotation shaft; and blade sections that protrude from the main disc body in the axial direction. The disc section is provided with a hoop stress-limiting section, the tube section of which extends further towards the other end in the axial direction than the main disc body.

Abstract: A method for manufacturing a machine component includes a process of estimating post-heat-treatment strength for the intermediate form of a base material after a certain mechanical working process is performed, and a process of comparing the estimated strength with reference strength required for a final form. According to a result of the comparison, heat treatment of the base material is performed after one of the mechanical working processes is performed.

Abstract: The present invention is related to an impeller and a rotary machine including an inner diameter portion, a disk portion, a blade portion, and a cover portion. The disk portion includes a main body portion provided the blade portion, and a fixing portion disposed at an inner side in a radial direction of the rotor than the main body portion and fitted at the outside of an outer peripheral surface of the inner diameter portion. The fixing portion is formed so as to protrude toward the other side in the axial direction from the main body portion.

Abstract: Provided is a rotary machine including: a shaft that rotates; a disc that has a substantially cylindrical hub fitted into the shaft and is provided so as to widen outward in a radial direction from a front end to a rear end of the hub; and an impeller having a plurality of blades provided on a surface of the disc. The hub has a tight fit section having an internal radius that is smaller than a radius of the shaft, and a loose fit section having an internal radius that is greater than the internal radius of the tight fit section. The loose fit section is provided on the front end side of the hub with respect to the tight fit section.

Abstract: A method of manufacturing an impeller including a substantially disk-shaped disk, a cover facing the disk, and a blade provided between the disk and the cover, the method includes: forming a groove in a blade attachment surface of the disk or the cover so as to correspond to the shape of an edge tip of the blade; and bonding an inner surface of the groove to the edge tip of the blade through a bonding agent after inserting the edge tip of the blade into the groove.