A Comprehensive Review on Advancements in Structural Design and Material Selection of Gas Foil Thrust Bearings

Gas foil bearings (GFBs), which employ gas, typically air, as the lubricating medium, have garnered significant attention in high-speed and high-temperature applications. GFBs are renowned for their superior speed, damping, and environmentally friendly attributes compared to traditional bearings. Despite numerous advantages, GFBs have insufficient load-carrying capacity, which restricts their usage in turbomachinery. Despite multiple research papers exploring GFBs, only a few review papers have addressed the structural advancements in GFBs over the years. These GFBs may be of journal or thrust bearings depending upon the load application. The research carried out on gas foil journal bearings (GFJBs) are more abundant than the gas foil thrust bearings (GFTBs). This review aims to bridge this gap by providing an in-depth analysis of the GFTBs. This analysis is based upon the modification of structural design and implementation of advanced materials to enhance the static characteristics. It also elucidates the effect of alterations in foil design, manufacturing methodologies, and coating materials on the behavior of GFTBs. These aspects have consistently captivated the attention of researchers and academicians in their quest to enhance the performance of GFTBs. Furthermore, the review encapsulates insights gained from diverse fabrication methodologies and experiments from the work of different researchers and scientists worldwide.