Vibrational analysis of a journal bearing

A Statistical Energy Analysis (SEA) approach is used to investigate the vibrational behavior of a journal bearing. In developing the SEA model, consideration is given to the determination of coupling loss factors between non-conservatively coupled substructures. In the case of the journal bearing, the oil film between the rotating shaft and the bearing liner represents non-conservative coupling. The coupling loss factors are estimated using experimentally measured point mobility functions. The internal loss factors are directly measured with the bearing structure disassembled. Additionally, estimates for the coupling and internal loss factors are obtained in-situ using an energy ratio approach. Using the determined coupling and internal loss factors in an SEA model, estimates for the average mean square velocities on the surface of the bearing subcomponents are obtained for both static and dynamics conditions. The SEA estimates match well with directly measured results for the spatial average surface velocities at medium to high frequencies.