Fault diagnosis of planetary gearboxes via processing the on-rotor MEMS accelerometer signals

Planetary gearboxes are widely used in drivetrains of helicopters, wind turbines, and heavy industrial applications. Since the role of complex planetary gearboxes is quite important and their failure may cause a shutdown of the entire train resulting in major economic losses, condition monitoring of planetary gearboxes has received significant attention. The installation of conventional accelerometers on the machine's housing can fail to provide accuracy in diagnosing planetary gearbox faults, due to the alterations in planet gear mesh excitation with the carrier. Advances in low-cost and low-power Micro-Electro-Mechanical Systems (MEMS) technology allow the MEMS accelerometer to be installed onto the rotating shaft directly, and this implies that the rotating machine's dynamic features can be measured more accurately. This paper examines the characteristics of the rotating acceleration signals measured by on-rotor MEMS accelerometer installed on the low-speed input shaft of a planetary gearbox. The experimental results show that by investigating the frequency spectra of the on-rotor accelerometer measurements, different faults of planetary gearbox can be clearly diagnosed, thus providing a reliable and low-cost method for the condition monitoring of planetary gearbox.