PURPOSE: To improve the turbine performance in the title turbine by forming inner and outer end surfaces of respective nozzle vanes radially arranged in an annular passage of the entrance of moving blades in the turbine, and the passage wall surfaces corresponding thereto into flat surfaces right to the turning shaft of the nozzle vane.
CONSTITUTION: The variable pitch nozzle part of an axial turbine has a plurality of nozzle vanes 3 radially arranged in an annular passage between an outside ring 1 and an inside ring 2. By turning respective vanes 3 around an axial turning shaft, a nozzle efflux angle is set to be variable. In this case, the outside end surface E and the inside end surface F of the nozzle vane 3 are formed into the flat surfaces right to the turning shaft. In addition, respective upper surfaces of rings 1, 2 corresponding to the end surfaces E, F are formed into the flat surfaces parallel to the end surfaces E, F. Further, respective upper flat surfaces of the rings are formed into a parallelogram shape in order that the turning range of the nozzle vanes 3 never extends over two or more upper surfaces of the rings.
KIMURA MASANORI
IMAKIRE KOICHIRO
| JP60112602B |