SEAL MECHANISM FOR USE WITH TURBINE ROTOR

摘要

Provided is a seal structure for a turbine rotor in a gas turbine, which can follow the expansion of the turbine rotor in the radial direction without increasing the dimension in the axial direction and which can reliably seal the turbine rotor for a long period of time. The seal structure contains labyrinth seals (91, 93) constituted by a projection (87) provided on a turbine rotor (11B), an external member (67) which is disposed on the outside in the radial direction of the projection (87) and which is supported so as to move in the radial direction, and an internal member (67) which is disposed on the inside in the radial direction of the projection (87) and which is supported so as to move in the radial direction. The coefficient of thermal expansion of the internal member (69) is set so as to be larger than the coefficient of thermal expansion of the external member (67).