Patent ID: 7866020

Claim:
A method for repairing a crack in an electromechanical rotor, comprising: providing an electromechanical rotor, the electromechanical rotor having a core portion, a plurality of slots formed on an outer surface of the core portion along an axial direction of the electromechanical rotor, the slots being configured to receive a coil, and a groove formed on both side walls of the slots, the groove being configured to hold a wedge for maintaining the coil in the slots, the core portion including a crack developed from a contact surface between the wedge and one of the slots; and forming a hole on said core portion from the outer surface of said core portion to remove at least a deeper portion of the crack, wherein said forming of the hole is performed so that an additional value (Ca+Cb) of an outer thickness Ca and Cb of a remaining portion between adjacent slots across the hole on the outer surface of said core portion after forming the hole is set to 20% or more of an initial outer thickness C between the adjacent slots on the outer surface of said core portion before forming the hole, and a thickness b 2 of an outer portion in a radial direction and a thickness a 2 of an inner portion in the radial direction of a remaining portion between adjacent slots across the hole in the groove of said core portion after forming the hole are set to 50% or more of an initial thickness b 1 of an outer portion in the radial direction and an initial thickness a 1 of an inner portion in the radial direction between adjacent slots in the groove of said core portion before forming the hole, respectively.