Helicopter transmission integrity is critical to the safety operation. Among all mechanical failures in helicopter transmission, the main gearbox (MGB) failures occupy approximately 16%. Great effort has been paid in early prevention and diagnosis of MGB failures. As a commonly employed monitoring technology, vibration analysis suffers from strong background noise due to variable transmission paths from the bearing to the receiving externally mounted vibration sensor. The background noise can mask the signal signature of interest. This paper reports on an investigation to identify the presence of a bearing defect in a CS29 Category `A' helicopter main gearbox with acoustic emission (AE) technologies. This investigation involved performing the tests for faultfree condition, minor bearing damage and major bearing damage conditions under different power levels. The bearing faults were seeded on one of the planet gears of the second epicyclic stage. To overcome the issue of low signal to noise ratio (SNR), AE sensor was directly attached on the dish of planet carrier. The AE signal was transferred wireless to avoid complex wiring inside MGB. The analysis results proved the feasibility of using AE sensor as in-situ bearing defect identification.
|Title of host publication||Prognostics and Health Management (ICPHM), 2016 IEEE International Conference on|
|Publication status||Published - Aug 2016|
|Event||2016 IEEE International Conference on Prognostics and Health Management - Carleton University, Ottawa, Canada|
Duration: 20 Jun 2016 → 22 Jun 2016
|Conference||2016 IEEE International Conference on Prognostics and Health Management|
|Period||20/06/16 → 22/06/16|
Bibliographical noteThis conference paper cannot go in Curve until 15 February 2017 due to a publisher embargo period of 6 months. This paper was given at the Prognostics and Health Management (ICPHM), 2016 IEEE International Conference on, 20-22 June 2016.
- bearing defect diagnostics
- Helicopter main gearbox
- acoustic emission