On the linear stability analysis of journal bearings – Consideration of coupled effects of anisotropic slip and surface roughness

Abstract An average modified Reynolds equation (AMRE), considering the coupled effects of anisotropic slip and roughness, is linearized at the operation point to obtain the static and dynamic AMREs. The bearing is modelled as a spring-damper with the dynamic coefficients. The stability analysis of the rigid rotor/bearing system showed that slip length B has negative effects on load capacity W and critical mass M cr . Slenderness ratio progressively strengthens the negative effects of B on M cr for circumferential-slip, yet weakens those negative effects for axial-slip. For short and square bearings, W and M cr for Peklenik number γ  = 9 are greater than those for γ  = 1, followed by γ  = 1/9; for long bearings, W and M cr for γ  = 1/9 are greater than those for γ  = 1, followed by γ  = 9.