Experimental research on compliant foil thrust bearings for high speed turbine expander

For complex constructed foil bearing, it is difficult to theoretically analyze and apply to high speed rotation machinery. Three types of compliant foil bearing, including plate foil bearing, viscoelastic support foil bearing and foil bearing with convex dots, are proposed and investigated. On a test rig of high speed turbo machinery, the bearing-rotor system is driven by gas turbine, and the load capacity of foil thrust bearings is analyzed by hydrostatic gas bearing supporting and applying axial load. To discuss the running stability of foil thrust bearings, fast Fourier transform is chosen to analyze the vibration signals of bearing-rotor system. The results show that plate foil thrust bearings have the highest load capacity of 44 N, the rotor obit of bearing-rotor system gets stable. The fundamental frequency is dominated in frequency domain, and the lower and higher frequencies can be ignored.