0
research-article

NUMERICAL AND EXPERIMENTAL INVESTIGATIONS ON PRELOAD EFFECTS IN AIR FOIL JOURNAL BEARINGS

[+] Author and Article Information
Marcel Mahner

Technical University of Darmstadt, Institute of Applied Dynamics, Department of Mechanical Engineering, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany
mahner@ad.tu-darmstadt.de

Pu Li

Technical University of Darmstadt, Institute of Applied Dynamics, Department of Mechanical Engineering, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany
li@ad.tu-darmstadt.de

Andreas Lehn

Technical University of Darmstadt, Institute of Applied Dynamics, Department of Mechanical Engineering, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany
lehn@ad.tu-darmstadt.de

Bernhard Schweizer

Technical University of Darmstadt, Institute of Applied Dynamics, Department of Mechanical Engineering, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany
schweizer@ad.tu-darmstadt.de

1Corresponding author.

ASME doi:10.1115/1.4037965 History: Received July 19, 2017; Revised July 25, 2017

Abstract

A detailed elasto-gasdynamic model of a preloaded three-pad air foil journal bearing is presented. Bump and top foil deflections are herein calculated with a nonlinear beamshell theory according to Reissner. The 2D pressure distribution in each bearing pad is described by the Reynolds equation for compressible fluids. The assembly preload is calculated by simulating the assembly process of top foil, bump foil and shaft. Most advantageously, there is no need for the definition of an initial radial clearance in the presented model. With this model, the influence of the assembly preload on the static bearing hysteresis as well as on the aerodynamic bearing performance is investigated. For the purpose of model validation, the predicted hysteresis curves are compared with measured curves. The numerically predicted and the measured hysteresis curves show a good agreement. The numerical predictions exhibit that the assembly preload increases the bearing stiffness (in particular for moderate shaft displacements) and the friction loss of the bearing. It is observed that the effect of the fluid film on the overall bearing stiffness depends on the assembly preload: For lightly preloaded bearings, the fluid film affects the overall bearing stiffness significantly while for heavily preloaded bearings the effect is rather small for a wide range of reaction forces. Furthermore, it is shown that the assembly preload increases the friction torque significantly.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

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