Thermal elastohydrodynamic lubrication analysis of large scale composite thrust bearing with sector pad faced by PTFE
Abstract
Purpose
The purpose of this paper was to construct lubrication model closer to the fact of thrust bearings and to calculate the bearings characteristics of lubrication for understanding how structures influence bearings performances and, importantly, what can be the most beneficial. Large-scale composite thrust bearings with Polytetrafluoroethylene (PTFE)-faced sector pad backed by steel base are used increasingly in equipment. But there are plenty of puzzled problems in design and application.
Design/methodology/approach
The authors established a 3D thermal elastohydrodynamic lubrication (TEHL) model. Oil film was formulated by Reynolds equation for pressure, and by energy equation for temperature varying through oil film thickness. Meanwhile, pad temperature was formulated by solid heat transfer equation. Elastic and thermal deformations of pad surface were calculated. Viscosity and density of oil were valued separately under different pressure and temperature. Load balance was considered as well as overturning moment balance. Finite difference method was applied to discrete these equations.
Findings
PTFE layer and steel base have either helpful or detrimental impact on contact strength and full film lubrication of thrust bearing depending on their relationship in thickness. Temperature lag between middle layer of steel base and pad surface depends on PTFE layer, but not on the steel base. PTFE layer thickness should be considered when alarming threshold value of the bearings temperature is chosen.
Originality/value
Three-dimensional TEHL model of large-scale composite thrust bearings was established, which included more factors close to the actual. Conclusions were drawn. These proposals are helpful to design the bearings.
Keywords
Acknowledgements
Support from the China Postdoctoral Science Foundation through grant No. 20100471262 is acknowledged.
Citation
Wang, S., Tan, Q. and Kou, Z. (2016), "Thermal elastohydrodynamic lubrication analysis of large scale composite thrust bearing with sector pad faced by PTFE", Industrial Lubrication and Tribology, Vol. 68 No. 1, pp. 67-75. https://doi.org/10.1108/ILT-03-2015-0031
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited