Experimentally validated finite element analysis of railroad bearing adapter operating temperatures

Currently, railroad bearing temperatures are monitored using wayside infrared devices known as hot-box detectors (HBDs). HBDs take a snapshot of the bearing temperature at designated wayside detection sites which, depending on the track, may be spaced as far apart as 65 km (∼40 mi). Even though these devices have significantly reduced the number of derailments since their implementation, their discrete nature and limited accuracy prevents them from being utilized as a bearing health monitoring system. Future technologies are focusing on continuous temperature tracking of bearings. Since placing sensors directly on the bearing cup is not feasible due to cup indexing during service, the next logical location for such sensors is the bearing adapter. Understanding the thermal behavior of bearing adapters during operation is essential for sensor selection and placement within the adapter (e.g., typical temperature sensors have operating ranges of up to 125°C). To this end, this paper quantifies the steady-state heat transfer to the bearing adapter through a series of experiments and finite element analyses. The commercial software package ALGOR 20.3™ is used to conduct the thermal finite element analyses. Different heating scenarios are simulated with the purpose of obtaining the bearing adapter temperature distribution during normal and abnormal operating conditions. This paper presents an experimentally validated finite element thermal model which can be used to attain temperature distribution maps of bearing adapters in service conditions. These maps are useful for identifying ideal locations for sensor placement.