Patents Assigned to Junichi Kurokawa
  • Axial-flow type hydraulic machine
    Patent number: 6736594
    Abstract: In an axial flow hydraulic machine, a plural number of grooves 5 are formed on an inner surface of a casing, directed into a pressure gradient direction, for connecting between an inlet side of an impeller 1 and an inside of blade residing region on the casing inner surface. With movement of movable members 6 provided on the casing inner surface, the grooves appear within the blade residing region in an unstable operation region, while the grooves cause no interference with the blades of the impeller in a stable operation region.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: May 18, 2004
    Assignees: Hitachi, Ltd., Junichi Kurokawa
    Inventors: Kouichi Irie, Tomoyoshi Okamura, Yoshio Anzai, Junichi Kurokawa
  • Turbo machines
    Patent number: 6302643
    Abstract: A turbo machine comprising: an impeller having a plurality of blades therewith; a casing having a flow surface defined therein and being positioned with the impeller therein; and a plurality of grooves being formed in the flow surface of the casing, for connecting between an inlet side of said impeller and an area on the flow surface of the casing in which the blades of said impeller reside, on a periphery thereof, wherein an index of determining a form of the grooves is obtained by a following equation: JE No.
    Type: Grant
    Filed: September 20, 1999
    Date of Patent: October 16, 2001
    Assignees: Hitachi, Ltd., Junichi Kurokawa
    Inventors: Junichi Kurokawa, Hitoharu Kimura, Tomoyoshi Okamura, Takahide Nagahara, Sumio Sudo, Akira Manabe, Norimitsu Kuwabara