Systematic Numerical Investigation of Lubricated Bearing Rolling-Sliding Contacts: Effects of Load, Speed, and Lubrication Parameters on Friction, Wear, Temperature, and Reliability.

This study presents a systematic numerical investigation of bearing contact mechanics and evaluates tribological performance and reliability under different operating conditions. The study emphasizes the computational methodology used to quantify rolling-sliding contact, rather than the general benefits of lubrication and systematically includes the effects of the operating parameters. Initial model parameters (material properties, geometry, lubricant viscosity) were taken from published engineering data and literature. A numerical contact analysis was then carried out to explore the effects of the applied load, the rotational speed and the lubricating-film parameters under the theoretical relationships. The principal performance indicators were the calculated coefficient of friction (α), wear rate (β), contact temperature rise (γ), reliability index (δ), and service-life factor (λ). Under the optimized simulated conditions, the calculated coefficient of friction (α) decreased from 0.15 to 0.05, corresponding to a 66.7% reduction. The calculated wear rate (β) decreased from 1.80 × 10⁻³ mm³/Nm to 0.52 × 10⁻³ mm³/Nm, corresponding to a 71.1% reduction. The contact temperature rise (γ) decreased from 78°C to 48°C, while the reliability index (δ) increased from 0.82 to 0.96. Furthermore, the optimized lubrication parameters produced up to a 2.8-fold improvement in the computed service life factor (λ). From these results, the influence of systematic variation of the operating and lubrication parameters on the behaviors of the rolling- sliding contact was demonstrated. The study also illustrates that limits of operation and reliability related performance indicators for the application of bearing can be quantified by predictive numerical modeling.