ABNORMALITY DIAGNOSTIC METHOD AND ABNORMALITY DIAGNOSTIC DEVICE OF ROLLING BEARING, SENSOR UNIT, AND ABNORMALITY DIAGNOSTIC SYSTEM OF ROLLING BEARING

摘要

To provide an abnormality diagnostic method and an abnormality diagnostic device of a rolling bearing, a sensor unit, and an abnormality diagnostic system of the rolling bearing, which enable an inexpensive A/D converter at low speed to be used by reducing an amount of data required for abnormality diagnosis of the rolling bearing, and which can execute the abnormality diagnosis while suppressing a calculation amount.SOLUTION: The abnormality diagnostic system includes: a detection section 21 for detecting vibration and a sound generated from a rolling bearing 11; a frequency conversion circuit 28 for performing frequency conversion using amplitude modulation to a detected analog signal; a low-pass filter 29 for filtering the frequency-converted signal; an A/D converter 30 for A/D converting a low-frequency band signal after low-pass filter processing; a frequency analysis section 48 for obtaining frequency spectrum by frequency analyzing a waveform of the A/D converted signal; a comparison determination section 49 for diagnosing abnormality of the rolling bearing 11 by comparing peak generation frequency included in the frequency spectrum with theoretical damage frequency due to damage of the rolling bearing 11; and an output device 51 for outputting a diagnostic result.SELECTED DRAWING: Figure 1