Operational bearing parameters and acoustic emission generation

In further developing the acoustic emission (AE) technology for bearing monitoring, it is essential that a relationship is determined between bearing operational parameters, such as speed and load, and the generation of AE activity. Hitherto, almost all published investigations on the application of AE technology to bearing monitoring have been based on systems that operate at fixed speed and/or load conditions. In reality, a significant proportion of bearings operate under variable speed and load conditions; therefore, the growth of AE technology in monitoring bearings under such conditions requires an understanding of the influence of bearing operational parameters on the generation of AE. This paper presents experimental tests undertaken at near isothermal conditions aimed at understanding the influence of speed and load on the generation of AE. The results of the program lead to the introduction of AE operational maps. It is concluded that under an elastohydrodynamic lubrication regime, AE activity can be directly related to the theoretically predicted specific film thickness within the bearing.