High temperature self-powered sensing system for a smart bearing in an aircraft jet engine

Integrated health monitoring is beneficial, but due to reliability, weight, size, wiring, and other constraints, the incorporation of instrumentation onto aircraft propulsion systems is limited. Conventional wired sensing systems are not always feasible due to the size, weight constraints, and issues associated with cable routing. This article presents an integrated and self-powered wireless system for high-temperature (above 125 °C) environments powered by a thermoelectric generator (TEG) for bearing condition monitoring. A TEG with an internal oil-cooling chamber is proposed to achieve higher-energy output for small temperature gradient recorded in the jet engine in comparison with other TEGs with heat sinks. The experimental results demonstrate that, under a simulated engine environment, the TEG can provide sufficient energy for a wireless sensing system to collect environmental data every 46 s and transmit every 260 s during the critical takeoff phase of the flight and part of cruise.