Diagnostics of Journal Fluid-Film Bearing Failure Using a Data Manager System – Case History

The journal fluid-film bearing is a vital part of a rotary machine, which has a high load-carrying capacity. Babbitt bearings are commonly used to support the shafts of high-speed machines. Severe damage to the babbitt layer can lead to damage of the shaft journal. Fluid-film bearings installed in high-speed machines are exposed to damage due to the action of various mechanisms. It is very important to diagnose bearing damage at an early phase to prevent the possible failure of the machine. A machine monitoring system of shaft vibrations and bearing temperatures is very useful for early diagnosis of machine bearing condition. In this paper, a practical example of diagnostics of journal fluid-film bearing failure in a gear unit using a specialized data manager system is given. The bearing damage was confirmed by inspections performed during the downtime of the gear unit. Based on the visual investigation, the most likely primary cause of bearing damage was electrical pitting.