METHOD FOR REPAIRING A ROTOR OF A MULTI-STAGE AXIAL COMPRESSOR OF A GAS TURBINE

摘要

A method is described for repairing a rotor (10) of a multi-stage axial compressor of a gas turbine, by replacing a given number of last bladed discs (14_N-2, 14_N-1, 14_N) with new bladed discs (14_N-2", 14_N-1", 14_N"), wherein each of the last bladed discs (14_N-2, 14_N-1, 14_N) to be replaced comprises a hub (16) having a central bore (20) and is mounted by interference fit on a shaft (12) of the rotor (10) rotatable about an axis of rotation (x). The method comprises the steps of: a) cutting the shaft (12) at a section plane (P) perpendicular to the axis of rotation (x) of the shaft (12) so as to separate the portion of the shaft (12) on which the bladed discs (14_N-2, 14_N-1, 14_N) to be replaced are mounted from the remaining portion (12') of the shaft (12); b) providing, for each bladed disc (14_N-2, 14_N-1, 14_N) to be replaced, a corresponding new bladed disc (14_N-2", 14_N-1", 14_N") with a respective hub (16") having a solid cross-section; c) providing a new end portion (12") of the shaft with a solid cross-section; and d) clamping the new bladed discs (14_N-2", 14_N-1", 14_N") between the remaining portion (12') of the shaft and the new end portion (12') of the shaft, securing them to the remaining portion (12') of the shaft by anchor bolts (28, 30).