Rotary Encoder-Based Health Indicators for Early Detection of Gear Pitting in Commercial Gearboxes

This paper investigates the diagnostic capabilities of rotary encoders for condition monitoring of commercial gearboxes, focusing on early detection of gear pitting. Within a multi-sensor framework, high-resolution rotary encoder data were collected alongside accelerometer signals, both mounted on a multistage commercial gearbox subjected to gear pitting. Encoder-based health indicators were developed from the square envelope (SE) of the transmission error (TE), synchronously averaged (SA) to isolate the targeted gear component within the gearbox. By automatically capturing images of the targeted gear during an accelerated life test, these indicators were evaluated for their ability to detect the onset of gear pitting and compared against conventional vibration-based metrics. Results show that encoder-based indicators can provide earlier and more consistent detection of gear pitting. These findings highlight the potential of rotary encoders as a complementary or standalone sensing solution in advanced diagnostic frameworks for commercial gearboxes.