Research on wireless passive temperature monitoring technology for connecting rod big end bearings of marine engines

Abstract The operational state of connecting rod big-end bearings of a marine engine is directly associated with its reliability, durability and safety. However, the persistent dynamic nature of connecting rod big-end bearings poses significant challenges for directly monitoring its operating state. Therefore, a wireless passive temperature measurement method based on the radio frequency identification technology is proposed to monitor the operating state of connecting rod big-end bearings. The full life cycle wear curve of the bearing was simulated and analyzed based on the Archard’s wear model. A mapping relationship between the bearing wear and the temperature was calculated based on the thermal elastohydrodynamic theory, the feasibility of assessing the bearing wear via monitoring the temperature of the connecting rod big-end bearing was fully confirmed. Subsequently, the simulation design of the wireless communication antennas was carried out. A wireless passive temperature measurement system, which includes a wireless passive temperature sensor together with a static antenna and a signal processing unit, was successfully developed. Furthermore, the validation experiments of multi-type marine engines demonstrated that the developed system is capable of achieving online monitoring and early warning of the connecting rod big-end bearing.