Air layer supported bearing pads, or “air bearings” as they are commonly called, are popular because of their high load capacity and low in-plane coefficient of friction, making them well suited for supporting moving, high accuracy manufacturing stages. Air/vacuum bearings enhance these capabilities by giving the bearing pad load resistance capacity in both the upward and downward directions. Consequently, it is desirable to know how to model the air layer between the bearing pad and the bearing surface. In this paper, a simple finite element modeling approach is presented for investigating the vibrational characteristics of an air layer supported bearing. It was found that by modeling the air layer as a bed of uniform springs who’s stiffness is determined by load-displacement tests of the bearing, a reasonable representation of the response can be obtained. For a bearing supported by air without vacuum, the dynamic response was very similar to that of a freely supported bearing. The addition of vacuum to an air bearing was found to significantly lower its fundamental frequency which could lead to unwanted resonance problems.

Bolasna, S., 1976, “A Computer Simulation Program for the Steady State Analysis of Finite Sized Air Bearings,” IBM Technical Report, January.
Ewins, D. J., 1984, Modal Testing: Theory and Practice, John Wiley & Sons, New York.
Lin, G., and Aoyama, T., 1987, “Analysis of Load Carrying Capacity and Optimal Design or Aerostatic Bearing With Groove Compensation,” Journal of the Japan Society of Precision Engineering, Keio Univ., Scientific and Technical Facility, April.
Motherway, J., 1978, “Pressurized Air-Bearing for Recording Head Suspension,” Thesis, University of Bridgeport, CT, March.
Thomson, W., 1981, Theory of Vibration With Applications, 2nd Edition, Prentice-Hall Inc., New Jersey.
Ural, O., 1973, Finite Element Handbook, Basic Concepts and Applications, Intext Press, New York.
Zienkiewicz, O. C., 1977, The Finite Element Method, Third Edition, McGraw Hill, London.
This content is only available via PDF.
You do not currently have access to this content.