The condition monitoring of helicopter main gearbox (MGB) is crucial for operation safety,flight airworthinessand maintenance scheduling. Currently, the helicopter health and usage monitoring system, HUMS, is installedon helicopters to monitor the health state of their transmission systems and predict remaining useful life of keyhelicopter components. However, recent helicopter accidents related to MGB failures indicate that HUMS is notsensitive and accurate enough to diagnose MGB planetary bearing defects. To contribute in improving the di-agnostic capability of HUMS, diagnosis of a MGB planetary bearing with seeded defect was investigated in thisstudy. A commercial SA330 MGB was adopted for the seeded defect tests. Two test cases are demonstrated in thispaper: the MGB at 16,000 rpm input speed with 180 kW load and at 23,000 rpm input speed with 1760 kW load.Vibration data was recorded, and processed using signal processing techniques including self-adaptive noisecancellation (SANC), kurtogram and envelope analysis. Processing results indicate that the seeded planetarybearing defect was successfully detected in both test cases.
Bibliographical noteThis is an open access article under the CC BY-NC-ND license.
- Helicopter main gearbox
- Planetary bearing
- Self-adaptive noise cancellation
- Envelope analysis
- Condition monitoring