This paper reports the development and implementation of an autonomous, wireless bearing monitoring sensor system (ABMS) powered from a thin film thermal electric generator (TEG) as an energy harvesting device. Bearing vibration data can be used with vibration predictive health maintenance (PHM) algorithms to determine the occurrence of a bearing fault by comparing the bearing vibration signature vs. baseline vibration performance. PHM systems offer many cost and safety benefits. The most obvious cost savings benefit comes from condition based maintenance which allows operators to forego preventative schedule based maintenance and only repair, replace, or refurbish components when necessary. This leads to longer component lifetimes, reduced downtime, and the ability to schedule necessary maintenance well in advance. However, a PHM system can easily negate the supposed benefits if it requires constant maintenance. Often, the data required by the PHM algorithms necessitates installation of sensor nodes in difficult-to-service areas, and constantly accessing these areas to replace batteries becomes a burden. Drop-in, low maintenance PHM systems require energy harvesting technology in order to free the end user from system interruption just to replace a battery on a sensor node. Multiple energy harvesting methods are available and being developed, and choosing the correct technology requires intimate knowledge of the target operating environment, sensor node voltage and power requirements, and data rates necessary for the PHM algorithms. Energy harvesting technologies can take advantage of system vibration, temperature gradients, access to sunlight, angular momentum, or ambient electromagnetic noise. Each PHM application requires an individual design to take advantage of environmental parameters. The situation becomes more complex if the component of interest in located in a high temperature environment (>200 °C). This is problematic because components located in high temperature environments are more likely to fail due to thermal cycling and fatigue; however, these are many of the components that would benefit the most from PHM. While environmental energy may be available to harvest, available energy harvesting technology for this temperature range is lacking.
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