To enlarge the actuation range of a centrifugal compressor used for a compressed air feeder such as a compressor for a turbocharger or an industrial compressor.
In a circulation flow path 6, there are formed fourth circulation flow path parts 16 located at two appropriate positions of the inner peripheral surface of a casing 2 and a third circulation flow path part 17. The circulation flow path 6 is constituted with an inner surface 12 and an outer surface 11. Local curved surfaces are formed on the inner surface 12 and the outer surface 11 of the circulation flow path 6 to thereby increase the circulation flow rate. As a result, a decrease in the surging flow rate or an increase in the choking flow rate is promoted so as to enlarge the actuation range.
IBARAKI SEIICHI
SHIRAISHI KEIICHI
MIKOGAMI TAKASHI
