Patent ID: 9404373
Filing Date: 2016-08-02
CPC Classification: F01D,F05D

Claim Text:
1. A turbine-blade retaining structure comprising: blade grooves that extend through a rotor disc in a disc-thickness direction so as to receive blade roots of turbine blades arranged in a circumferential direction; a protruding portion that protrudes, as a whole, outwards in the disc-thickness direction such that an outer circumferential end is located at an inner side of an inner circumferential end of the blade grooves in the radial direction; a ring-shaped locking groove that is formed in a circumferential edge portion of the protruding portion along the circumferential direction so as to open towards an outer side in the radial direction; a step portion that protrudes outwards in the disc-thickness direction in a circumferential edge portion on an inner circumferential side of the blade root so as to face the locking groove; and plate-like locking pieces arranged in the circumferential direction and received in the ring-shaped locking groove, the locking pieces being fitted between the locking groove and the step portion; wherein the circumferential edge portion of the protruding portion is provided with, along the circumferential direction, at least one insertion window portion that is cut out in the disc-thickness direction such that an inner circumferential surface thereof is flush with an inner circumferential surface of the locking groove, and end portions of adjacent locking pieces, exposed through the insertion window portion, are joined to each other by means of welding; and at least one of the end portions of the adjacent locking pieces exposed through the insertion window portion is provided with a thick-plate portion expanding in the disc-thickness direction so as to be inside the insertion window portion.