| 摘要 |
PROBLEM TO BE SOLVED: To make a tip clearance extremely small at the time of a rated operation by adding elastic force which causes a shroud made out of ceramics to be directed to the inner side in the radial direction with respect to a metallic support member, and thereby supporting the shroud by the support member without a hitch. SOLUTION: A shroud 18A employed in this constitution is formed out of a ring body made of ceramics, and covers each turbine rotor blade 13 housed in a housing 11. A metallic support member 20 is supported by the housing 11 so as to be held in such a way as to be freely moved in the radial direction. An elastic force adding means 23 adds elastic force which causes the shroud 18A to be directed relatively in the radial direction with respect to the support member 20. By this constitution, there is no possibility that each turbine rotor blade is brought into contact with the shroud 18A at the transition time in an early stage of operations even if a tip clearance between each turbine rotor blade 13 and the shroud 18A is made sufficiently small at the time of a rated operation. Therefore, the efficiency of a turbine can positively be prevented from being degraded. |
