Steam turbine blade, and steam turbine and steam turbine power plant using the blade

摘要

An object of the invention is to provide a steam turbine blade having a high degree of strength reliability that reduces the stress caused by a steam force acting on a steam turbine blade during the operation of a steam turbine and increases rigidity in the circumferential and axial directions of a turbine rotor to suppress vibration of the steam turbine blade resulting from the steam force, and a steam turbine and a steam turbine power plant using the same. A steam turbine blade includes a blade; a shroud attached to a tip of the blade; a blade root projecting toward the radial inner circumferential side of a turbine rotor so as to be fitted into a blade groove provided in an outer circumferential portion of a turbine rotor; and a platform disposed between the blade and the blade root. The blade root is inserted into the blade groove along the axial direction of the turbine rotor. The blade, the shroud, the blade root and the platform are integrally molded. The number of the blade roots is larger than that of the blades.