To achieve high degree stabilization of the operability and quality, adequate equipment maintenance and cost reduction, by arranging one sensor for many parts and thereby monitoring the deterioration of mechanical elements of a rotary body all the time without arranging one sensor for one part of the mechanical element.
A cable-shaped vibration detector 2, wherein a piezoelectric element is sealed, is brought close to parts to be diagnosed of a plurality of mechanical elements 1a of the rotary bodies, whose deterioration is to be diagnosed. The vibrating amount of the mechanical element 1a of the rotary body is determined and compared with the specified threshold value. Thus, the abnormal part at the part to be diagnosed, on which the vibration detector 2 is made to crawl, is judged as the area. Thus, the replacing time of the rotary mechanical part 1a having the above described abnormal part is judged.
KATO TETSUYA
NAKAJIMA SATOSHI
MAEKAWA KENJI
