Method of and apparatus for detecting crack condition

摘要

Disclosed is a method for detecting the condition of a crack generated in a rotor of a rotary machine during an operation thereof to check whether the crack is developing or not. The number of revolutions of the rotor and oscillations of journal end portions of the rotor born by the bearings are continually detected. The detection of the crack condition is made on the basis of the detected signal corresponding to the waveform of each half of at least one cycle of the detected rotor oscillation. Disclosed also is an apparatus for carrying out the method.