Fluid machine

Abstract

A fluid machine including a shaft and an impeller, wherein the impeller has a shaft bore into which the shaft is inserted, and wherein the impeller is coupled to the shaft by an interference fit. The fluid machine further includes a positioning part provided between the shaft and the impeller, for positioning the impeller at a predetermined position on the shaft; a fitting part provided inside the shaft bore and adjacent to the positioning part, for forming the interference fit between the shaft and the impeller; and a loose-insertion part provided inside the shaft bore and adjacent to the fitting part, for forming a clearance between the shaft and the impeller.

1 . A fluid machine comprising: 
 a shaft;    an impeller having a shaft bore into which said shaft is inserted, said impeller being coupled to said shaft by an interference fit;    a positioning part provided between said shaft and said impeller, for positioning said impeller at a predetermined position on said shaft;    a fitting part provided inside said shaft bore and adjacent to said positioning part, for forming said interference fit between said shaft and said impeller; and    a loose-insertion part provided inside said shaft bore and adjacent to said fitting part, for forming a clearance between said shaft and said impeller.    
   
   
       2 . A fluid machine as set forth in  claim 1 , wherein said positioning part comprises a member separated from said shaft and said impeller.  
   
   
       3 . A fluid machine as set forth in  claim 1 , wherein said positioning part comprises a part of at least one of said shaft and said impeller.  
   
   
       4 . A fluid machine as set forth in  claim 1 , wherein said fitting part and said loose-insertion part are formed by varying, along an axial lengthwise direction, at least one of an outer diameter of said shaft and an inner diameter of said shaft bore of said impeller.