Patent ID: 9624942
Date: 2017-04-18
CPC Classifications: F04D

Claim:
1. A turbo machine that is provided with an impeller that is rotated, and with a shaft that transmits rotation power to this impeller, comprising: a differential screw having an impeller screw portion that is provided at one end thereof and that is screwed into the impeller and a shaft screw portion that is provided at another end thereof and that is screwed into the shaft, and that fastens the impeller and the shaft together, and wherein, in the differential screw, a thread diameter of thread ridges that are formed on the impeller screw portion is formed the same as a thread diameter of thread ridges that are formed on the shaft screw portion, a screwing direction of the thread ridges that are formed on the impeller screw portion is formed as the same direction as a screwing direction of the thread ridges that are formed on the shaft screw portion, and a pitch between the thread ridges that are formed on the impeller screw portion is formed smaller than a pitch between the thread ridges that are formed on the shaft screw portion.