Patent ID: 8172528

Claim:
A steam turbine comprising: a rotor; and a casing that installs the rotor inside, the casing comprising: an upper-half section; and a lower-half section, the upper half-section coupled with the lower-half section by an upper-half flange of the upper-half section and a lower-half flange of the lower-half section, wherein the upper-half section includes: a semi-cylindrical wrapper plate extending in an axial direction of the rotor; end plates coupled with the wrapper plate, each of the end plates being disposed perpendicular to the rotor, wherein at least one of axial ends of the wrapper plate includes a wrapper plate projecting portion that projects from the corresponding end plates in the axial direction; a first end plate reinforcing rib disposed on the outside surfaces of the end plates in a peripheral direction of an inner periphery of the wrapper plate; and a plurality of second end plates reinforcing ribs disposed radially on outside surfaces of the end plates, wherein the second end plates reinforcing ribs couple the wrapper plate projecting portion with the first end plate reinforcing rib, wherein the wrapper plate projecting portion is coupled with the upper-half flange, the upper-half flange including an upper-half flange projecting portion provided at a coupling position of the wrapper plate projecting portion and the upper-half flange, the upper-half flange projecting portion projecting in a direction along the wrapper plate projecting portion.