Effects of Coulomb Friction on Bump Foil Gas Bearing

In this paper, the friction between the bump foil and the flat foil and between the bump foil and the bearing housing is taken into account to evaluate the effects of coulomb friction on bump foil gas bearing. The displacement of a single bump is calculated using the finite element beam model. Thereafter, the stiffness and damping characteristics of the bearing are evaluated through energy dissipation method. The effects of load reference value, load fluctuation amplitude and friction coefficient on energy dissipation and foil stiffness are analyzed. The results indicate that the energy dissipation increases as the reference value and fluctuation amplitude increase, which is conducive to the operating stability. The stiffness grows rapidly and then asymptoticly stabilizes as the amplitude increases. The stiffness basically does not change with the reference value. When the load decreases from the maximum value, the friction at the bump top still remains as sliding friction at the beginning. After entering the hysterias condition, the sliding friction gradually turns into static friction, and the direction of friction changes from the same direction to the opposite direction. In the bearing design process, the optimal friction coefficient should be selected properly based on the principle in favor of support stiffness or energy dissipation. © 2022 Xi'an Jiaotong University. All rights reserved.