Patent ID: 11927114
Assignee: MITSUBISHI HEAVY INDUSTRIES COMPRESSOR CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 6:
7. A method for fixing a rotor blade in a rotor of a steam turbine, the rotor comprising:
a shaft core portion formed in a columnar shape about an axis;
a disk portion extending to an outer side in a radial direction with respect to the shaft core portion, wherein the radial direction is based on the axis;
a plurality of rotor blades attached to the disk portion; and
a key configured to restrict movement of each of the plurality of rotor blades with respect to the disk portion in an axial direction in which the axis extends,
the disk portion including a plurality of blade embedding grooves recessed to an inner side in the radial direction from an outer peripheral surface of the disk portion, and formed at intervals in a circumferential direction about the axis, and a circumferential groove recessed to the inner side in the radial direction from the outer peripheral surface and extending in the circumferential direction,
the plurality of blade embedding grooves extending in the axial direction,
each of the plurality of rotor blades including
a blade root embedded in each of the plurality of blade embedding grooves,
a platform arranged on the outer side in the radial direction with respect to the disk portion and protruding to both sides in the circumferential direction with respect to the blade root, and
a blade body extending to the outer side in the radial direction from the platform,

the plurality of rotor blades including a first rotor blade and a second rotor blade adjacent to the first rotor blade on one side in the circumferential direction,
the platform of the first rotor blade including
a first side surface facing the platform of the second rotor blade in the circumferential direction,
a first end surface facing the axial direction, and
an access groove recessed to open in the axial direction and the circumferential direction at a corner portion formed by the first side surface and the first end surface and communicating with the circumferential groove,

the platform of the second rotor blade including
a second side surface facing the first side surface in the circumferential direction, and
a key accommodating groove recessed in the circumferential direction from the second side surface, communicating with the circumferential groove in the radial direction, and communicating with the access groove in the circumferential direction, and

the key being arranged in the circumferential groove and the key accommodating groove, the method comprising:
a step of attaching the second rotor blade to the disk portion;
a step of inserting the key into the circumferential groove;
a step of moving the key in the circumferential direction in the circumferential groove and inserting the key into the key accommodating groove; and
a step of attaching the first rotor blade to the disk portion.