An improved electromechanical spectral signature for monitoring gear-based systems driven by an induction machine

Even under normal operating conditions, Gear-based systems naturally generate four particular frequencies: the input and output mechanical speeds as well as the gear meshing and the hunting tooth frequencies. Thereby, through amplitude monitoring of these components and their harmonics, the gear state can be easily monitored and successfully assessed. Based on this fact, this paper discusses the fitness of the vibration data and the load torque (mechanical signature) to detect these frequencies. Furthermore, when the system is driven by an induction machine these frequencies will affect the stator currents. Thus, the appropriateness of the spectral analyzing techniques based such amounts as alternate for monitoring gear-based systems will also be discussed. Moreover, for improving the sensitivity detection of these particular frequencies an original preprocessing technique is proposed and its effectiveness is evaluated for spectral analysis of mechanical as well as electrical experimental data.