To create an intended clearance between a blade tip and a seal face without using thermal expansion and thermal shrinkage.
By a tower shaft 60 connected with a motor 59 and a gear mechanism 62, either one of a low-pressure compressor or a high-pressure compressor is moved with respect to a shroud. The gear mechanism 62 is connected with a rotor assembly, and is provided with a bevel gear 66 and a bevel gear 68 mounted to a ball screw type actuator 70. When a member 74 of the actuator 70 is rotated, a member 76 is moved in the axial direction with respect to the member 74, and as a result, the rotor assembly mounted to the member 76 is moved in the axial direction. Since the blade seal face and blade tip part of the shroud are inclined relative to a rotor centerline, when the rotor assembly is moved in the axial direction, the clearance between the blade seal face and blade tip part is changed.
PERKINSON ROBERT H
SMITH JESSE W
Tomioka Kiyoshi