Gearbox Corrosion PHM via Oil Condition Sensing and Model Fusion

Continued development of compact, high-reduction ratio gearboxes, including the F-35 Joint Strike Fighter Lift Fan Gearbox, relies on the use of advanced steel alloys and high-temperature fracture-tough coatings to create gear configurations with low noise and vibration characteristics. All gearbox materials, including the housing, must be sufficiently lightweight, affordable, and have the durability to operate in both high-and low-temperature lubrication environments. Due to the critical nature of these systems, it is imperative, wherever possible, to detect and correctly classify sources of contamination that could lead to premature equipment failure or retirement. To address corrosion effects with an innovative prognostics and health management (PHM) capability, Impact proposes implementing it’s Smart Oil Sensor (SOS) and fusing in vibro-acoustic information gained from existing on-board PHM sensors (primarily accelerometers). The SOS is a broadband electrochemical spectroscopy sensor with embedded processing capable of detecting contaminants and corrosion precursors, including salt and fresh water, well below existing Navy condemning limits. This information will be coupled with appropriate corrosion failure mode prediction models and prognostic algorithms to provide actionable maintenance information prior to significant corrosion progression.BENEFITS: The proposed corrosion sensor system could be implemented in a wide range of military as well as commercial applications in the propulsion, prime mover and power transmission arena. Within the DoD, land vehicles, shipboard systems and aircraft could benefit from improved in-situ corrosion monitoring. The developed technologies could also be applied to commercial land and water vehicle drive systems, industrial actuation systems, fluid power transmissions, and robotic applications. By providing an on-line assessment of fluid condition involving corrosion precursors, health management systems will be able to provide better inferences on a platform’s ability to complete a mission. More accurate predictions of current and future state can also reduce costly inspection routines and premature replacements by using a risk-based, maintenance optimization technique (Condition-based Maintenance, CBM). The end benefits of the CBM and integrated health management approach is a reduction of total ownership costs, increased readiness and reliability, and improved safety and mission assurance for platform machinery systems. The integration of this sensor-diagnostic package to also monitor for corrosion precursors within liquids including fuels, hydraulic fluids, and coolants systems is anticipated.