Seal ring for steam turbine

摘要

A seal ring provided between a rotating portion and a fixed portion in a rotating machine of steam turbine and the like is improved to accurately carry out predetermined movement so as to not cause deterioration of sealing performance. The seal ring is split into upper, lower, right side and left side seal ring pieces slidably contacting with each other via split planes with spaces being formed in the respective split planes. Springs are interposed in the spaces for activation in upward and downward directions. The upper and lower seal ring pieces are engaged with seal ring guides and the right side and left side seal ring pieces are engaged with seal ring guides so that all of the seal ring pieces are slidable in the upward and downward directions. Further, on the respective tips of the seal ring guides spaces of the upper seal ring piece and spaces of the lower seal ring piece are formed and springs are provided in the spaces for activation in the upward and downward directions. The respective seal ring pieces are prevented from skirmishing with each other and the upper and lower seal ring pieces move toward the inner side at the time of load so as to make narrower the clearances between seal fins and a corresponding rotor surface.