Nonlinear dynamic analysis of a rotor-porous air journal bearing system with O-rings mounted

Porous air journal bearings (PAJBs) with O-rings mounted are regarded as a potential choice to offer levitation large load capacity and optimal start/stop characteristics, which required in small-sized high-efficiency turbomachinery. However, the coupling of mechanical properties lubrication induces strong nonlinear thereby affecting dynamic responses rotor. In this study, numerical model, is obtained by excitation frequency-influenced stiffness damping characteristics O-rings, Darcy’s laws, motion equations, rotor bearing presented. The model can efficiently reflect influences actual property between aerodynamic aerostatic effects on performance rotor-PAJB system (RPS). well verified experimental results. different parameters RPS studied analyzing bifurcation diagrams, orbit, Poincaré maps, fast Fourier transform plots. Results show that changed periodic quasi-periodic variation rotational speed, external supply pressure, clearance, porous permeability. With mounted, stability be increased hinder from changing quasi-periodic. effectiveness increasing for styrene butadiene rubber material better than nitrile but weaker methyl vinyl silicone rubber. Moreover, only limited number have enhancing RPS.