关键词: 磁流体轴承；应力偶；粗糙表面；随机广义雷诺方程；润滑特性

Abstract: In order to study the effects of couple stress and rough surface morphology effect on the lubrica.tion performance of magnetic fluid bearing，the Monte-Carlo method was used to characterize the random surface roughness with Gaussian distribution，and compared with the actual surface morphology under scanning electron. ic microscope，the stochastic generalized Reynolds equation was deduced by the Christensen’s stochastic model and Stokes micro-continum theory，the finite difference method was used to simulate the magnetic fluid bearing under the micro-scale condition，and the effects of different parameters on the lubrication characteristics underthe transverse and longitudinal rough models were analyzed. The results show that the actual rough surface of theproject has anisotropy，the influence of different rough models on the load carrying performance is related to the aspect ratio，when the roughness parameter is 0.3，and the aspect ratio is 0.5，the longitudinal rough model will increase the maximum dimensionless pressure by 3.9%，while the transverse model will weaken the pressure lev. el. When the aspect ratio increased to 2.0，the transverse rough model will increase it by 5.7%，thus improving the load carrying performance. The increase of the dynamic parameters，magnetic coefficient and couple stress pa. equation；Lubrication performance rameters can increase the pressure level in different degrees，and the increase of the latter two will significantly increase the effect of the rough models，while the bearing capacity increases and attitude angle decreases. Whenthe couple stress parameter increases from 0.2 to 0.5，the demarcation point between the bearing capacity withthe change of aspect ratio in the rough model will increase from 1.70 to 1.95.

Key words: Magnetic fluid bearing；Couple stress；Surface roughness；Stochastic generalized Reynolds