Rotary shaft support structure and turbine and gas turbine including the same

A turbine configured to generate power by a passage of combustion gas supplied from a combustor, the turbine comprising:

• a rotary shaft passing through a center of a gas turbine;
• a turbine casing for accommodating a turbine rotor provided on a circumferential surface of the rotary shaft, the turbine rotor including a plurality of turbine blades coupled to a turbine disk rotated by the rotary shaft;
• and
• a rotary shaft support structure comprising:
• a first support mounted to the turbine casing to support one end of the rotary shaft and arranged around a circumferential surface of the rotary shaft, the first support including a first configuration of each of:
• a main body having an inner circumferential surface in which a mounting groove is formed;
• a pad member for supporting the rotary shaft, the pad member disposed between the main body and the rotary shaft and biased against the circumferential surface of the rotary shaft;
• a pivot protrusion protruding from the pad member toward the main body;
• a pivot housing inserted into the mounting groove and configured to receive the pivot protrusion and to rotatably support the pad member;
• and
• a hemispheric leaf spring that is disposed between the pivot housing and a bottom surface of the mounting groove and includes a convex side disposed toward the pivot housing, the hemispheric leaf spring configured to elastically support the pivot housing by contacting a supporting surface of the pivot housing.

A gas turbine comprising:

• a compressor casing for accommodating a compressor configured to suck and compress air;
• a combustor configured to produce combustion gas by burning fuel mixed with the compressed air;
• and
• a turbine configured to be supplied with the combustion gas, comprising:
• a rotary shaft passing through a center of the gas turbine;
• a turbine casing for accommodating a turbine rotor provided on a circumferential surface of the rotary shaft, the turbine rotor including a plurality of turbine blades coupled to a turbine disk rotated by the rotary shaft;
• and
• a rotary shaft support structure comprising:
• first and second supports respectively mounted to each of a compressor casing and a turbine casing of a gas turbine to support opposite ends of a rotary shaft passing through a center of the gas turbine, each of the first and second supports being arranged around a circumferential surface of the rotary shaft and including:
• a main body having an inner circumferential surface in which a mounting groove is formed;
• a pad member for supporting the rotary shaft, the pad member disposed between the main body and the rotary shaft and biased against the circumferential surface of the rotary shaft;
• a pivot protrusion protruding from the pad member toward the main body;
• a pivot housing inserted into the mounting groove and configured to receive the pivot protrusion and to rotatably support the pad member;
• and
• a hemispheric leaf spring that is disposed between the pivot housing and a bottom surface of the mounting groove and includes a convex side disposed toward the pivot housing, the hemispheric leaf spring configured to elastically support the pivot housing by contacting a supporting surface of the pivot housing.