The Effects of Surface Irregularities on Roller Bearing Vibrations

Abstract A mathematical model is proposed to illustrate the frequency characteristics of roller bearing vibrations due to surface irregularities which come from manufacturing errors. The bearing vibration is modeled as the system output when it is subjected to the excitations from surface waviness and surface roughness through the lubricating film. It is shown that the vibration spectrum of a normal bearing under a preloaded condition has a pattern of equal frequency spacing distribution (EFSD) which is similar to that of a defective bearing. Consequently, the application of frequency analysis, such as the high frequency resonance tecnique, on bearing monitoring should be undertaken with great care.