JPH0145011B

• Main Authors: MATSUSHITA OSAMI, KIKUCHI KATSUAKI, HIOKI SUSUMU, FURUDONO MASUO, SATO MOTOHIRO
• Format: Patent
• Language: English
• Published: 02.10.1989
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

PURPOSE:To readily detect the position, time, frequency, etc. of the abnormality occurrence of a revolving shaft by subjecting the revolution pulses and the acoustic signals from both ends of a revolving shaft to specified processing. CONSTITUTION:When the time difference of the acoustic signal waveforms from the acoustic sensors 9, 9' at both end of a revolving shaft is detected with a time difference measuring instrument 14 and is subjected to division by the acoustic propagation speed in the shaft 6 in a divider 15, the acoustic generating position with the center of the shaft 6 as a reference is determined. On the other hand, the circuit pulse signal which a revolution pulse detector 13 generates at each rotation of the shaft 6 and the acoustic signal of the sensor 9 are applied to a histogram processing means 16, where the histogram of the rotating angle-acoustic generating frequency waveforms synchronized to the revolution pulses is made. If this histogram is subjected to delay correction according to the generating position mean value signal from the means 17 by a time delay means 20, it becomes the histogram of the acoustic generating position. Hence, the signal superposing the AC component corresponding to the histogram on the DC component corresponding to the acoustic generating position is generated from an adder, whereby the abnormality of the rotating machaine is readily and accurately detected.