Smart sensors for wind turbine sliding bearings
Dr. Gary Nicholas
Value for the audience
The audience will be introduced to the recent trend in the wind industry of transitioning from rolling element bearings to low-speed hydrodynamic sliding bearings for large wind turbines. They will also be exposed to the various sensing techniques available for low-speed hydrodynamic sliding bearings. Furthermore, the presentation will delve into the utilization of ultrasound, strain, acoustic emissions, and eddy current sensors in evaluating the tribological performance of these low-speed hydrodynamic sliding bearings.
Summary
Sliding bearings, typical in hydroelectric plants and marine propellers, are becoming increasingly prevalent in wind turbine (WT) drivetrain applications. They are replacing conventional roller bearings due to their reduced maintenance and failure rate potential. This reduces operational costs and the initial investment capital for large WTs (10MW+). However, little is known of their field operational performance (failure mechanisms, service life) under the slow and transient loading conditions of WT drivetrains. There is also no field experience for their operation in the wind sector.
This project aims to bridge this knowledge gap by developing a comprehensive multi-sensor measurement system tailored for WT hydrodynamic sliding bearings. After evaluating various sensing techniques, five were identified as the most promising and were further refined. The final sensor suite includes thermocouples, eddy current, strain, ultrasonic, and acoustic emission sensors. These are designed to monitor bearing temperature, oil film thickness, pad stress, touchdown events, and wear. Specifically, the ultrasonic and eddy current sensors measure oil film thickness during full-film conditions, while the strain and acoustic emission sensors are geared towards detecting instances where the lubrication transitions into boundary/mixed, and the resulting loading on the tilting pads.
