Comparison between angular sampling and angular resampling methods applied on the vibration monitoring of a gear meshing in non stationary conditions

By and large, vibration monitoring tools only achieve their role on the assumption that the stationary condition hypothesis is maintained. Several industries are however demanding to observe mechanical or electrical rotating components behaviour at variable speeds (bucket-wheel excavators, gearboxes in automotive and rail vehicles, ...). Although expensive, angular sampling is a dedicated tool for analysis of vibrations generated in such conditions, since the vibrations of interest are related to engine RPMs. In recent years, offline resampling has become suitable due to enhanced computer speeds and the possibility has been oponed to use regular acquisition system at lower costs. This paper propose an experimental comparison between these angular signal acquisition methodologies through the spectral observation of a gear mesh for different conditions of speed variation and sampling frequency.