Towards health monitoring of hybrid ceramic bearings in aircraft starter/generators

On-board electrical power demands in modern aircraft are substantially increasing. Scaling-up the size of the current starter/generators to provide the additional power requirements inevitably increases their mass. Instead, aircraft electrical designers are considering to increase the rotational speed of these machines. This imposes severe loading demands in the current starter/generator bearings. Hybrid bearings offer the most potential to deal with these demands. However, not much is known about their wear behavior in this new application.

Our research is assessing the degradation of hybrid ceramic bearings in the newest generation of starter/generators for condition monitoring and health management. This paper discusses bearing degradation as foundation for the definition of relevant health condition assessment and decision making approach, and the integration of a monitoring system into a prototype test bearing to be used for data generation and algorithm validation. Initial results indicate this approach can effectively diagnose bearings faults. Validation was conducted by using repository data.