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AssigneeHitachi, Ltd.
InventorsAtsuya HIRANO, Masaaki TAKAHASHI
Estimating the term…
In manufacturing a multi-finger pinned root pin-coupling a turbine blade made of a high-strength material and a rotor disc, a reamer used to ream a pin insertion hole formed through a turbine blade attachment base is removed from the pin insertion hole while being rotated so as to cause a scratch formed by a chip on the inner surface of the pin insertion hole to be inclined with respect to the axial direction of the pin insertion hole. This brings the direction of the scratch on the inner surface of the pin insertion hole and the direction of tensile stress generated on the inner surface of the pin insertion hole adequately close to be parallel to each other. As a result, the fatigue strength reduction caused by the scratch can be inhibited.
A method for manufacturing a multi-finger pinned root for turbine blade attached to a turbine rotor, the multi-finger pinned root coupling a turbine blade and a rotor disc of the turbine rotor, wherein a pin insertion hole is formed through a turbine blade attachment base through steps of:
A turbine blade to be pin-coupled to a rotor disc of a turbine rotor, wherein a scratch formed on an inner surface of a pin insertion hole formed through the turbine blade is inclined with respect to an axial direction of the pin insertion hole.
A turbine blade for use in a last stage of a low-pressure turbine, the turbine blade being made of a high-strength material and having a blade fork portion to be pin-coupled with a rotor fork formed on a rotor disc of a turbine rotor, wherein a scratch formed on an inner surface of a pin insertion hole formed through the blade fork portion is inclined with respect to an axial direction of the pin insertion hole.
Dependencies are inferred from the claim text.