Evaluation of Wear Phenomena of Journal Bearings by Close to Component Testing and Application of a Numerical Wear Assessment

Abstract

Hydrodynamic journal bearings are subjected to progressively rough loading conditions leading to an increased share of operation in mixed and boundary lubrication. This results in increased frictional losses, additional wear and a higher chance of failure, which calls for the understanding of wear processes and the necessity of a numerical assessment. We conducted wear investigations of journal bearings by making use of a close-to-component test setting, and the progress of wear could be linked to the introduced frictional energy and in combination with a comprehensive surface analysis tribological effects could be resolved in detail. Achieved wear coefficients were implemented in a novelly developed numerical framework, which allows for the dynamic numerical evaluation of operation in the fluid and mixed lubrication regime and simultaneously occurring wear processes. By comparing numerical and experimental results, we evaluated the numerical framework's capability to conduct holistic simulations including aspects like dynamically changing operation conditions, fluid and mixed lubrication as well as wear.

Study of Vegetable Oil Based Biolubricants and Its Hydrodynamic Journal Bearing Application: A Review

“…This also happens when shock loading occurs. When the shaft speed becomes high enough, sufficient oil film thickness is formed to completely avoid journal contact with the bearing forming REVIEW hydrodynamic lubrication regime and no or minimal wear occur in this regime [4][5][6][7][8]. Fig.…”

A Numerical Model for the Analysis of the Bearings of a Diesel Engine Subjected to Conditions of Wear and Misalignment

“…Particularly, energy losses overcome a great share of the global energy losses that both increase fuel consumption and limit overall efficiency. Therefore, different proposals have been successfully established, such as control strategies, compression ring sealing capacity, hydroxy doping, biofuels, and cylinder bore coatings materials, among others [4,5]. Particularly in mechanical power losses, bearings experience a distinguishing contribution in ICEs, since they enable the transmission of forces and relative movement.…”

“…If the axes and bushing axes are not kept parallel, the protective lubrication film in one area will weaken, producing a risk of surface-to-surface contact [6,7]. Thus, the wear prediction based on numerical methodologies has gradually gained attention as a robust tool to improve the bearing design and further extend the service time [4].…”

Nanofluids for Performance Improvement of Heavy Machinery Journal Bearings: A Simulation Study

“…While the majority of researches evaluate the performance of nanoparticle additives in terms of thermal conductivity [4,27], friction reduction [4,13,26,28], and wear phenomena [29], there are very few that address the effect of nanofluids on load carrying capacity [24,25,30]. These works mainly use a standard reciprocating ring-block tester [24] or ball machine [25] as their test setup.…”