Performance and stability analysis of gas-lubricated journal bearings in MEMS

A mathematical model and a computational methodology are presented to simulate the complicated flow behaviors of the journal microbearing in the slip regime, at which the Knudsen number ranges from 0.01 to 0.06. A modified Reynolds equation is derived with the slip effect. Static performances of the microbearing are analyzed using spectral collocation method. The effects of the length-to-diameter ratio and slip on the stability of the system are analyzed and the corresponding stability boundaries are calculated numerically. The results indicate that the slip-flow boundary condition enhances the stability of the equilibrium points of the gas-lubricated journal bearing-rotor system.