Patent ID: 10619505

Abstract:
A clearance-control-type seal structure including a plurality of arc-shaped grooves (23) formed side by side in the axial direction with respect to an inner circumferential surface of a housing (22) of a turbine; and abradable seal rings (11, 12) having fitting parts (11a, 12a) that are fitted into the grooves so as to leave a prescribed gap, that have extended parts (11b, 12b) that are exposed from the housing in the radial direction toward the inside and expand in the axial direction, and that, during operation, due to back pressure inside the grooves, receive a force that moves in the radial direction toward the inside. One extended part has a protruding part extending even further in the axial direction toward the upstream side, and the other extended part has formed in an outer circumferential surface of a downstream-side end part thereof a recessed part that corresponds to the protruding part.