| 摘要 |
PURPOSE:To nondestructively detect a damaged bearing with high reliability by the AE method even when an escalator is rotated at a low speed. CONSTITUTION:An AE (acoustic emission) sensor 2 detecting the AE of a specific frequency or above at high sensitivity is installed on a low-speed rotating machine bearing 1, the detection signal is inputted to a signal processing circuit 3 set to a specific frequency, the signal of a specific frequency or above is extracted and fed to a detecting circuit 4, and it is fed to a duration judging circuit 5 set to a specific duration. Signals with the specific duration or below are extracted, the number of the extracted signals is counted by a counter 6, and normality and abnormality are identified and displayed by a judgment indicator 7 provided with a threshold value based on the number of the extracted signals. The AE signal and noise are discriminated by the AE sensor 2, signal processing circuit 3, and duration judging circuit 5. |
