Gearbox Vibration Source Separation by Integration of Time Synchronous Averaged Signals

This paper describes a simple approach for integrating all the time synchronous average (TSA) signals from multiple shafts of a gearbox to generate a composite time synchronous average which can be subtracted from the original signal to generate a second-order cyclostationary residual. This approach is compared with other techniques including an all-shaft TSA over the least common multiple of shaft rotation periods, high-pass filtering, and self-adaptive noise cancellation (SANC). The results demonstrate that the proposed approach produces an integrated TSA signal that includes only the shaft components, gear mesh components and the sidebands associated with all the shafts, while the residual contains the random vibration components and noise. The results produced by three alternative techniques do not separate the components as well or have a lower signal-to-noise ratio.