Sealing structure between turbine rotor disk and interstage disk

A sealing structure for a gas turbine including a plurality of turbine rotor disks, the sealing structure comprising:

• a turbine rotor disk of the plurality turbine rotor disks;
• a turbine blade fastened to a coupling slot formed in a circumferential surface of the turbine rotor disk, the turbine blade including
• a root having a shape corresponding to the coupling slot,
• a platform positioned radially outward from the root,
• a blade extending from the platform, and
• a blade circumferential surface that is formed on a radially inner side of the platform and protrudes in an axial direction, the blade circumferential surface extending in a circumferential direction of the turbine rotor disk and mutually engaging with a disk circumferential surface formed circumferentially on the turbine rotor disk;
• an interstage disk interposed between adjacent turbine rotor disks of the plurality of turbine rotor disks, the interstage disk including a rim portion extending radially outward and a groove formed in the rim portion;
• and
• a plurality of static ring seals mounted in the groove of the interstage disk, each static ring seal having an outer circumferential surface facing toward the blade circumferential surface and the disk circumferential surface, the plurality of static ring seals configured such that the outer circumferential surface of all of the plurality of static ring seals contact the blade circumferential surface and such that the outer circumferential surface of at least one of the plurality of static ring seals does not contact the disk circumferential surface.