| 摘要 |
PURPOSE:To foreknow a residual service life of a bearing with high accuracy by detecting an acoustic emission signal of a specific frequency band, which appears as a symptom of flaking of a rolling bearing. CONSTITUTION:An AE (acoustic emission) signal which is detected by a sensor 1 attached to a bearing is inputted to band pass filters 3.1-3.n through an amplifier 2, and only an AE signal of a specific frequency band of width extending from 5Hz to 20kHz between 150kHz-400kHz is inputted to comparing circuits 4.1-4.n. The comparing circuit compares a power value of the AE signal with a reference value, inputs the signal to an OR circuit 5, when the power value exceeds the reference value, and the OR circuit 5 generates an alarm, when the signal is received from one of the comparing circuits. In such a way, a state that the operation time of the bearing is 70%-90% of the flaking time can be detected, and a residual service life of the bearing can be foreknown with high accuracy. |
