Rotary machine

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.

1 - 9 . (canceled) 
     
     
         10 . A rotary machine comprising:
 a shaft that rotates;   a disc that has a hub fitted into the shaft and is extended with the increasing distance toward 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, wherein   a rear surface of the disc is formed with a groove portion which is recessed from the rear end toward the front end so as to surround the hub, and   the groove portion is continuously formed to the rear end of the hub from the rear surface of the middle of the disc.   
     
     
         11 . The rotary machine according to  claim 10 , wherein
 the hub comprises a tight fit section, and   the tight fit section is configured to be fitted to the shaft having an fastening margin therebetween.   
     
     
         12 . The rotary machine according to  claim 10 , wherein
 the groove portion protrudes to the front end side than the position of the rear-most end of the disc, in the axial direction of the shaft.   
     
     
         13 . The rotary machine according to  claim 11 , wherein
 the tight fit section is configured such that an fastening force is increased by a rotation of the shaft.   
     
     
         14 . The rotary machine according to  claim 10 , wherein
 in the state in which the shaft is rotated, the rear end of the hub tilts, and a tight fit section is fixed to the shaft.