Failure Modes And Prognostic Techniques For H-60 Tail Rotor Drive System Bearings

The failure modes and diagnostic/prognostic signatures for the oil cooler and hanger bearings used in the tail rotor drive system of the H-60 series of helicopters are being researched. The overall goal is to develop a prognosis system to track and predict bearing degradation and to integrate those technologies with the open architecture IMD-HUMS. This paper summarizes the challenges and advancements that have been experienced while improving the diagnostic capabilities for the bearings. The causes and effects of bearing contamination and lubricant exhaustion are addressed, while the focus is placed on detection methods of these failure modes. Interesting and encouraging results were found for both the oil cooler bearings and the hanger bearings, but at the present time, the potential is greatest for the development of detection methods and PHM algorithms for oil cooler bearings. The anticipated system will enable fault diagnosis, damage tracking, and the prognosis of useful life remaining.