Dynamic performance and stability characteristics of a multi pad externally adjustable fluid film bearing

ABSTRACT

Due to the recent advances in the development of smart rotating machineries, there is a high demand for automated support bearings with efficient integrated control systems. Existing research studies have indicated that high-end performance can be attained from automated bearings through effective control and modification of the bearing performance parameters. In this study, an innovative journal bearing geometry with multi-control operations is presented. The four controllable bearing pads enclosed in the bearing casing have a novel feature to translate radially and undergo controlled tilt motions. The multi-control bearing system with radial and tilt pad motions will significantly influence the stability responses of the rotorsystem, which is theoretically analysed in this study. To predict the variation in film thickness for varied pad adjustments, a modified film thickness equation is incorporated in the linearised perturbed model for dynamic analysis. A notable variation in dynamic coefficients and stability parameters are observed for negative radial adjustment and tilt angles. Results indicate that negatively adjusted radial and pad tilt motion can generate improved stability margins at higher eccentricities. Data generated on stability margins at specific pad adjustments will be helpful while developing the control system for the actuation mechanism in the experimental setup.

KEYWORDS:

• Adjustable pad bearing
• dynamic characteristics
• bearing stability

Acknowledgments

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Nomenclature

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Notes on contributors

Raghuvir Pai

Girish H is an Assistant Professor in the Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal. He was an Associate Professor in the Department of Mechanical Engineering, St Joseph Engineering College, Mangaluru. He did his PhD in Tribology from Manipal Institute of Technology, MAHE, India in 2020. He received a Japan Student Services Organisation (JASSO) scholarship in 2018 for a short term study in Kyushu Institute of Technology, Kyushu, Japan. His present research is in the field of externally adjustable fluid film bearings, Ocular Tribology and other research interests include tribology of water lubricated bearings and CFD analysis of blood flow through arteries.

Raghuvir Pai is a Professor in Manipal Institute of Technology, MAHE, India. He did his PhD from IIT Kharagpur in 1992 and was funded by DST, Government of India to do post-doctoral research at Cranfield University, UK in 1995. He held several administrative positions at Manipal Institute of Technology and was the founder Dean, School of Engineering at Manipal Dubai campus and Manipal International University, Malaysia. He was research fellow at Queensland University of Technology, Brisbane, Director Research at MAHE, India and Endeavour Executive Fellow, Federation University, Churchill in 2018. He has supervised 15 Ph.D. thesis and several Master’s thesis and has a number of publications and research grants to his credit.