DETECTION OF LOOSENESS OF ROTARY MACHINE

摘要

PURPOSE:To quantiatively detect the state of loosenness of the rotating parts of rolling mills by detecting the change in the peak value of the sound pressure of ultrasonic sound by impact force. CONSTITUTION:When the rolls having loosened owing to the revolutions of a work roll contact with a rolling material, impact force is larger than that when normal rolls contact with the rolling material, and the ultrasonic sound by the impact force increases as well. The detected ultrasonic sound 7 is amplified in an amplifier 2 via a filtering circuit 1. The output signal of the amplifier 2 has a marker 8 detecting one revolution of a specific work roll as its input terminal. The peak value during one revolution of the specific work roll is detected by a peak value detecting circuit 3. An average value detecting circuit 4 detects the average value of the ultrasonic sounds produced during revolving of each work roll. A divider 5 divides the outputs signals of the circuit 3 and the circuit 4. A comparator 6 compares each input signal and a reference level and outputs an alarm when the set level is exceeded.