Steam turbine blade, steam turbine rotor, steam turbine with those blades and rotors, and power plant with the turbines

摘要

A steam turbine blade in which the turbine blade has a blade root of the axially-inserted fir tree type and a larger number of turbine blades can be attached in a restricted outer peripheral region of a turbine rotor by arranging the blade root to be oriented in a direction forming a predetermined angle α larger than 0° relative to the axial direction of the turbine rotor. The steam turbine blade can suppress peak stresses generated at the bottoms of notches formed in the blade root and a blade groove and also suppress fretting fatigue from being induced by contact between peak stress generating areas and areas opposed to the peak stress generating areas at the notch bottoms. The steam turbine blade includes an airfoil, and a blade root attached to a turbine rotor and having plural stages of hooks in the radial direction of the turbine rotor.