Ultra-Low-Power, Temperature Field-Based Condition Monitoring of Particle Contamination and Overheating in Plain Bearings

Hydrodynamic plain bearings are characterized by their high load-carrying capacity, good damping properties and resistance to short-term abrasive wear. Therefore, plain bearings are widely used in heavy-duty applications, e.g., wind turbine drivetrains or ship propulsion systems . However, certain abnormal operating conditions can lead to rapid bearing damage. This may result in failure of the entire drivetrain. Two such abnormal events are mechanical overload causing overheating of the bearing and damage caused by particle contamination. Condition monitoring systems (CMS) exist for hydrodynamic plain bearings and numerous measurement methods currently represent the state of the art. However, most of these systems cannot detect particle contamination and mechanical overloading in a timely manner or are associated with high costs and installation effort that limit their practical applicability. Consequently, there is a need for a CMS approach that enables the timely detection of particle contamination and mechanical overloading. In this paper, temperature field measurement (TFM) is presented as a suitable approach to address this gap. The developed approach is characterized by its low cost and low energy demand. The energy efficiency of the developed Sensor-integrating Plain Bearing (SiPB) allows the CMS to operate autarkically by utilizing the waste heat generated by friction during regular operation within the plain bearing. Timely detection of the aforementioned failure causes requires a correspondingly high sampling rate, which in turn results in relatively high energy consumption. Therefore, the energy requirements of the SiPB prototype are discussed in relation to the measurement strategy and the resulting need to optimize both energy consumption and operating strategy is addressed. Subsequently, the temperature differences required to meet energy demand and ensure autarkic operation of the SiPB are determined. Finally, a measurement strategy for the autarkic operation of the SiPB is defined.