| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a turbine rotor blade having a rotor blade back surface shape improving strength and durability by suppressing occurrence of stress concentration in the root portion of a rotor blade back surface while reducing moment of inertia of the rotor blade without changing a blade shape. <P>SOLUTION: In this turbine rotor blade 1, a shaft-like hub portion 9 connected to a rotating shaft 19 and a plurality of blade portions 11 formed around the hub 9 are integrally formed. The hub portion 9 has a shape with a diameter gradually increased toward the back surface 7 as one end in a rotating shaft direction. An annular recessed portion 21 is formed in the back surface 7 with the center line L of the rotating shaft 19 as a center. The cross-sectional surface shape of the recessed portion 21 in the rotating shaft direction is formed by an elliptical circular arc C formed by dividing an elliptical or oval-shaped curvilineal shape formed to be symmetrical about a long axis by the long axis, and the position of the long axis b is formed to be matched with the back surface 7. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
