Planetary gearbox fault diagnosis using an on-rotor MEMS accelerometer

Abstract

Abstract-Conventional accelerometers installed on housing often give out less accurate diagnostic results for planetary gearbox because the mesh excitation of planet gears change with carrier movement. Recent significant advancements in low-power and low-cost Micro-Electro-Mechanical Systems (MEMS) technologies make it possible and easier to mount MEMS accelerometers directly on the rotating shaft, enabling more accurate dynamic characteristics of the rotating machine to be acquired and used for condition monitoring. In this paper, two tiny MEMS accelerometers are installed diametrically opposite each other on the lowspeed input shaft of a planetary gearbox to measure the acceleration signals. The acceleration signals sensed by each MEMS will contain both the tangential acceleration and gravitational acceleration, but the latter can be removed by summing the acceleration signals from both sensors in order to characterise the rotor dynamics precisely. The experimental results show that the tangential acceleration measured on the low-speed input shaft of a planetary gearbox can clearly indicate faults, thus providing a reliable and lowcost method for planetary gearbox condition monitoring.

Application of On-Rotor Sensing in Planetary Gearbox Fault Diagnosis

“…Although MEMS accelerometer are convenient to be embedded into the interior of the rotating machinery, the impact of gravity's force brought by the accelerometer themselves should not be ignored, Mones [12] et al installed two MEMS accelerometers radially relative to each other on the input shaft of the planetary gearbox, using the sensor gravity acceleration in the tangential direction of the shaft of the projected direction of the opposite direction of the offset, to reduce the impact of gravity acceleration on the collected signals, and experiments have shown that this approach can be a more accurate characterization of the dynamics of the rotor. Although this method can eliminate the effect of gravity acceleration of the sensors, it requires the installation of two MEMS accelerometers in the relative radial direction, which is not only costly, but also affects the results due to the error caused by the installation position.…”

Feasibility of Low-cost Vibration Monitoring for Ground Vehicles

“…Employing MEMS sensors in PHM is not new (Lee, 2011;Bechhoefer, Wadham-Gagnon, & Boucher, 2012), but only relatively recently low-cost high-frequency MEMS sensors became commercially available. The potential of lower-cost MEMS sensors have been grabbing the attention of PHM researchers: instrumenting planetary gearbox with MEMS accelerometers (Mones et al, 2017); showing the promised of use piezoelectric MEMS accelerometers for PHM in industrial applications (Xuewen Gong, Wu, Liao, & Gong, 2020); and investigating fault detection using capacitive MEMS accelerometer array (Watson & Reichard, 2021). The feasibility of using microphones for Engine diagnostics has been discussed by (Mathew & Zhang, 2020).…”