Abstract: A method for removing a crack in an electromechanical rotor, including: forming a plurality of slots on a periphery of a core portion of an electromechanical rotor along an axial direction thereof; inserting coils into the slots, respectively; forming a plurality of wedges for maintaining the coils in the slots, respectively; and forming a cut hole at at least a part of the core portion from an outer surface of the core portion toward the side of a center axis thereof so as to contain a crack along a circumferential direction thereof.

Abstract: A defect detection method of a turbine generator end ring includes a first ultrasonic testing step of conducting ultrasonic testing by an angle beam technique to the turbine generator end ring, a second ultrasonic testing step of conducting, when an indication echo is detected by the first ultrasonic testing step, ultrasonic testing by a focusing straight beam technique to a portion of the turbine generator end ring from which an indication echo is detected and an interpretation step of interpreting whether the indication echo is a defect echo or a false echo based on a testing result by the second ultrasonic testing step.

Abstract: There is provided a flaw detection testing method applied to a slot dovetail portion of a turbine generator rotor shaft. The flaw detection testing method includes an angle determining step of determining a slot angle of the slot dovetail portion using a variable-angle ultrasonic probe, a flaw detection performing step of, on the basis of a determination result in the angle determining step, using an angle ultrasonic probe or a phased array probe to perform flaw detection to detect a flaw in the slot dovetail portion, and a flaw depth measuring step of, when the flaw is detected in the flaw detection performing step, using an angle ultrasonic probe to measure a depth of the flaw from a surface of the slot dovetail portion.

Abstract: A method for repairing a crack in an electromechanical rotor (10), including forming a plurality of slots (12) on a periphery of a core portion (11) of an electromechanical rotor (10) along an axial direction thereof; inserting coils into the slots (12), respectively; forming a plurality of wedges for maintaining the coils in the slots (12), respectively; and forming a cut hole (20) at the core portion (11) from an outer surface of the core portion (11) so as to remove at least a deeper area of a crack created at the core portion (11) at a contacting surface between the corresponding wedge and the corresponding slot (12).

Abstract: A method of measuring a three-dimensional shape of a connection assembly of a stator coil in a turbine generator, includes first measuring a three-dimensional shape of a measurement area of the connection assembly of the stator coil in a measurement range set in advance by a laser non-contact three-dimensional shape measurement device, second measuring a three-dimensional shape of a measurement area of the connection assembly of the stator coil in a measurement range set in advance by a multi-joint contact three-dimensional shape measurement device, the multi-joint contact three-dimensional shape measurement device including a plurality of arms being coupled via a joint including a built-in encoder, and integrally synthesizing the three-dimensional shape data measured in the first measurement, the three-dimensional shape data measured in the second measurement, and shape measurement data of a local area measured manually, thereby drafting a plan of the stator connection assembly.

Abstract: A method of measuring a three-dimensional shape of a connection assembly of a stator coil in a turbine generator, includes first measuring a three-dimensional shape of a measurement area of the connection assembly of the stator coil in a measurement range set in advance by a laser non-contact three-dimensional shape measurement device, second measuring a three-dimensional shape of a measurement area of the connection assembly of the stator coil in a measurement range set in advance by a multi-joint contact three-dimensional shape measurement device, the multi-joint contact three-dimensional shape measurement device including a plurality of arms being coupled via a joint including a built-in encoder, and integrally synthesizing the three-dimensional shape data measured in the first measurement, the three-dimensional shape data measured in the second measurement, and shape measurement data of a local area measured manually, thereby drafting a plan of the stator connection assembly.

Abstract: An object of the present invention is to control crack propagation, either by predicting shaft dovetail crack propagation with high accuracy, or by determining operation conditions under which the crack does not extend. The crack propagation prediction system includes an operation processing unit, an interface unit, and a memory unit. The operation processing unit includes a stress calculation unit that calculates the mean stress generated in the shaft dovetail, a factor range calculation unit that calculates the stress intensity factor range for the crack in the shaft dovetail, and a crack propagation amount calculation unit that calculates an amount of the shaft dovetail crack propagation for an arbitrary time period, from the obtained mean stress and the stress intensity factor range, an operation pattern, an operation time, and data on the crack.

Abstract: There is provided a flaw detection testing method applied to a slot dovetail portion of a turbine generator rotor shaft. The flaw detection testing method includes an angle determining step of determining a slot angle of the slot dovetail portion using a variable-angle ultrasonic probe, a flaw detection performing step of, on the basis of a determination result in the angle determining step, using an angle ultrasonic probe or a phased array probe to perform flaw detection to detect a flaw in the slot dovetail portion, and a flaw depth measuring step of, when the flaw is detected in the flaw detection performing step, using an angle ultrasonic probe to measure a depth of the flaw from a surface of the slot dovetail portion.

Abstract: A defect detection method of a turbine generator end ring includes a first ultrasonic testing step of conducting ultrasonic testing by an angle beam technique to the turbine generator end ring, a second ultrasonic testing step of conducting, when an indication echo is detected by the first ultrasonic testing step, ultrasonic testing by a focusing straight beam technique to a portion of the turbine generator end ring from which an indication echo is detected and an interpretation step of interpreting whether the indication echo is a defect echo or a false echo based on a testing result by the second ultrasonic testing step.

Abstract: An object of the present invention is to control crack propagation, either by predicting shaft dovetail crack propagation with high accuracy, or by determining operation conditions under which the crack does not extend. The crack propagation prediction system includes an operation processing unit, an interface unit, and a memory unit. The operation processing unit includes a stress calculation unit that calculates the mean stress generated in the shaft dovetail, a factor range calculation unit that calculates the stress intensity factor range for the crack in the shaft dovetail, and a crack propagation amount calculation unit that calculates an amount of the shaft dovetail crack propagation for an arbitrary time period, from the obtained mean stress and the stress intensity factor range, an operation pattern, an operation time, and data on the crack.

Abstract: A method for removing a crack in an electromechanical rotor, including: forming a plurality of slots on a periphery of a core portion of an electromechanical rotor along an axial direction thereof; inserting coils into the slots, respectively; forming a plurality of wedges for maintaining the coils in the slots, respectively; and forming a cut hole at at least a part of the core portion from an outer surface of the core portion toward the side of a center axis thereof so as to contain a crack along a circumferential direction thereof.

Abstract: A method for repairing a crack in an electromechanical rotor (10), including forming a plurality of slots (12) on a periphery of a core portion (11) of an electromechanical rotor (10) along an axial direction thereof; inserting coils into the slots (12), respectively; forming a plurality of wedges for maintaining the coils in the slots (12), respectively; and forming a cut hole (20) at the core portion (11) from an outer surface of the core portion (11) so as to remove at least a deeper area of a crack created at the core portion (11) at a contacting surface between the corresponding wedge and the corresponding slot (12).