On Hydrodynamic Instability of Gas-Lubricated Journal Bearings

[+] Author and Article Information
V. N. Constantinescu

Institute of Applied Mechanics, Rumanian Academy, Bucharest, Rumania

J. Basic Eng 87(3), 579-587 (Sep 01, 1965) (9 pages) doi:10.1115/1.3650611 History: Received August 21, 1964; Online November 03, 2011


Paper starts with a study of static stability response of gas-lubricated bearing, followed by a general small perturbations theory of the dynamic stability of journal bearings. Then the pressure equation for bearings subjected to variable forces and velocities is analyzed, by pointing out the existence of a limiting solution which can occur both for high speeds or for high frequency of the bearing eccentricity. At the same time the squeeze effect can be strongly altered by the lubricant compressibility so that, for motions with high tangential speeds or with high frequencies, the pressures depend only on the thickness h and not on the derivative with respect to time ḣ as is the case of incompressible films. Finally, the analysis of the stability conditions reveals that bearings operating at low numbers H are unstable according to the small perturbations theory. The same situation occurs to the bearings operating with small eccentricity ratios, for any number H. The frequency of undamped oscillations is proportional to the shaft angular speed ω for low numbers H but tends to a bounded value ω0 * for high number H. Quasi-resonant conditions may also occur when the number H is increasing, a fact which allows the deduction of a simple half-empirical stability condition.

Copyright © 1965 by ASME
Your Session has timed out. Please sign back in to continue.






Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In