EFFECTS OF SLIP FLOW ON STEADY PERFORMANCE

OF MICRO GAS BEARING

HUANG Hai¹  MENG Guang¹  ZHAO Sanxing²  LIU Long¹

(1. State key laboratory of Vibration, Shock & Noise, Shanghai Jiaotong University, Shanghai 200240;
2. School of Machinery and Automation, Wuhan Uni-versity of Science & Technology, Wuhan 430081 )

Abstract: Judging with Knudsen number, the flow regime in the micro gas bearing is slip regime instead of the continuum regime. The second-order slip model is adopted and the modified Reynold’s equation for the gas flow is gotten. Solving the Reynold’s equations with the finite difference method (FDM), the gas pressure distributions of continuum flow regime and slip regime are obtained. Consequently, the dimensionless load carrying capacities and attitude angles are acquired. Comparing the solutions between two regimes, it shows that there are distinct discrepancies between the steady performances of the two regimes. At the same rotating speed and eccentricity ratio, the slip effect reduce the gas pressure curvature and hence the load carrying capacity.

Key words: Micro gas bearing Slip regime key words: Modified Reynold’s equation key words: Load carrying capacity Attitude angle

CLC No: TH117

国家自然科学基金资助项目(10325209). Received 20051027, received in revised form 20060316