Tribological approach on vibration and electrical current response of experimental misalignment and unbalance failure modes

Abstract

In order to maintain sustainability of dynamic mechanical systems, tribology is a crucial prognostic factor. Bearing is the most common rotating element that requires lubrication in priority for preventing the frictional forces. In the situation of greaseless at bearings, intensity of vibration signals and consumption of electricity will increase with respect to the internal frictions. In practice, misalignment and unbalance failures are common problems which have specific vibrational characteristics on time-domain and frequency-domain. It is assumed that symptom levels of the misalignment and unbalance failures will increase since greaseless form of bearing, and ball passing frequencies will be more prominent in the frequency-domain. As the misalignment and unbalance failure are detected by vibrations of bearing element, greaseless effect will influence detection of these failures within positive or negative assist. Additionaly, power spectrum density (PSD) measurements of electrical current variances will assist vibration analysis in order to focus on the failure with higher accuracy. It is concluded that single greaseless phenomenon and misalignment, unbalance failures in greaseless phenomenon are able to be detected and monitored by vibration analysis and electrical current PSD variance analysis.