Four Stages of Bearing Failure Development

Four Stages of Bearing Failure Development

     Inspect bearings removed from equipment during regular maintenance, operation inspection and replacement of peripheral parts to determine whether they can be reused or whether they are in good or bad condition.

      Initial stage, normal noise, normal temperature, can be measured by ultrasonic, vibration peak energy and acoustic emission, the outer ring of the bearing is defective, the total amount of vibration is relatively small, there is no discrete bearing fault frequency peak, and the residual life is greater than 10%.

      The second stage, noise slightly increased, normal temperature, ultrasonic, acoustic emission, vibration peak energy has a big increase, bearing outer ring is defective, the total amount of vibration slightly increased (vibration acceleration total amount and vibration velocity total amount), the bearing fault frequency can be clearly seen on the logarithmic scale spectrum, rarely seen on the linear scale spectrum, the noise level significantly increased, residual life of 5%.

      In that third stage, the audible noise, the slight temperature rise, the very high ultrasound, the acoustic emission, the vibration peak energy, the failure of the out ring of the bear, a large increase in the total amount of vibration acceleration and vibration velocity, a clear increase in the bearing failure frequency and its harmonics and sidebands on the linearly scale frequency spectrum, vibration spectrum noise horizon, and a residual life of less than 1%.
      The fourth stage, the intensity of the noise changes, the temperature rises obviously, ultrasonic, sound emission, vibration peak energy increases rapidly, then gradually decreases, the outer ring of the bearing is in the fault state before damage, the total amount of vibration velocity and vibration displacement increases obviously, the total amount of vibration acceleration decreases, and the lower self-aligning roller bearing fault frequency dominates the vibration peak. The noise level in that vibration spectrum is very high and the residual life is less than 0.2%.