| 摘要 |
PURPOSE:To make it possible to arrange an apparatus in a limited space by providing means such as an acceleration sensor for detecting the vibration acceleration of a bearing, a device for measuring the mechanical vibration based on the detected value in a low frequency band from the sensor, and a device for measuring acoustic emission in a high frequency band. CONSTITUTION:A piezoelectric type acceleration sensor 10 is provided, and its output is supplied to band pass filters 5a and 5b through a broad-band preamplifier 11. The detected value from the sensor 10 is amplified in the amplifier 11. Thereafter, the low-frequency-band signal corresponding t mechanical vibration is extracted through the filter 5a. Meanwhile, the output from the amplifier 11 passes through the filter 5b, and the signal in the high-frequency band corresponding to acoustic emission AE is extracted. The peak value of the mechanical vibration generated in a bearing 1 is operated in a peak operator 7d based on the low-frequency band signal. The AE generating number per unit time is counted in an event counter 9 based on the high- frequency-band signal. In this way, the abnormality of the bearing at the final stage can be detected based on the results of the operations in the operators 7a and 7d. The abnormality of the bearing 1 at the initial stage can be detected based on the result of the operation of an effective value operator 7b and the counted value of the counter 9. |
