Theoretical investigation of the effect of offset loads on the static characteristics of a multi-pad adjustable bearing geometry

ABSTRACT

An adjustable or controllable form of bearing geometry embodying four multiple pads circumferentially positioned around the journal is presented in this study. The proposed pad geometry has a novel feature to undergo radial and tilt adjustments in both inward and outward directions from the reference position. The adjustability principle of bearing pads helps to attain a controlled bearing operation in the clearance spaces. This paper investigates the effect of offset loads on the steady-state characteristics of a four-pad adjustable bearing. A modified film thickness equation is applied to take account of the radial and tilt pad adjustments in the theoretical analysis. Variation in fluid film pressures and static characteristics is analysed for different pad adjustment conditions and offset load positions. From the comparative study, superior static performance is obtained for bearing operated with an offset load of χ/α = 0.45 and negative pad adjustment configurations than compared with central load condition.

KEYWORDS:

• Adjustable bearing
• offset loading
• film thickness
• static characteristics

Nomenclature

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Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

H Girish

H Girish is a Ph D student at Manipal  Institute of Technology, MAHE, India. He is pursuing his doctoral degree in Tribology under the supervision of Prof. R. Pai. In 2018 he received a Japan Student Services Organization 9JASSO) scholarship 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, Other research interests include tribology of water lubricated bearings and CFD analysis of blood flow through arteries.

R Pai

R Paiis a Professor in Manipal Institute of Technology, MAHE, India. He did his Ph D from IIT Kharagpur in 1992 and was funded by DST, Government of India to do post doctoral research at Cranfield University, UK in 1995. Subsequently 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 from 2000-2002, Director Research at MAHE, India, Dr T.M.A. Pai endowment Chair in tribology and Endeavour Executive Fellow, Federation University, Churchill, Victoria in 2018. He has supervised 13 Ph.D. thesis and several Master's thesis and has a number of publications and research grants to his credit.