Determining faults in multiple bearings using one vibration sensor

摘要

A diagnostic system includes a vibration sensor mounted on a machine which has vibration-generating components having different vibration characteristics with respect to a common sensor. The vibration sensor measures vibrations and sends vibration signals to a diagnostic module for evaluation of the signals. The diagnostic module has software for processing the vibration signals. From a known natural frequency of a vibration-generating component, the diagnostic module measures the amplitude of the vibration signal at more than one harmonic frequency of the known natural frequency and compares the amplitudes to amplitudes at adjacent harmonic frequencies. When a relatively large amplitude is found at a harmonic frequency, that is a harmonic frequency near a resonant frequency of the physical path between the vibration sensor and the vibration-generating component, the diagnostic system can then analyze the shape and magnitude of the vibration signal around that harmonic frequency to evaluate whether each of the vibration-generating components is healthy, broken or about to break.