Root cause and vibration signal analysis for gearbox condition monitoring

The paper presents the root cause analysis of the gearbox vibration signals taking into consideration design, technology, operation, and change of condition factors. It includes a review of vibration signal analyses used for the condition monitoring of gearboxes. The methods of vibration signal analysis are broadly divided, taking into consideration load factors influencing the vibration signal. The vibration signals are generated under a steady or almost steady level of an external load and under a randomly-variable cyclic load, so load conditions determine the methods of signal analysis. Signals generated by mathematical modelling and computer simulations and signals measured in industry during normal operation of gearboxes are considered. Signals are measured from housings of cylindrical, bevel and planetary gearboxes. The signals are analysed for the condition monitoring of gears and rolling element bearings and other specified elements depending on the design factors of a composed train of driving/transmission systems. The interpretation of signals is based/supported by consideration of design, technology, operation and change of condition factors.