Parametric Analysis of Journal Bearings with Chevron Textures on the Shaft Surface

Surface texturing has proven to be a good technique to improve the characteristics of lubricated contacts. In journal bearings, texturing can increase the load-carrying capacity and reduce friction between the surfaces depending on some texture parameters such as geometry, size, and position. Although many works are studying the influence of textures on journal bearings, most of them apply the texture on the bearing surface (static part of the contact). In this work, chevron-shaped textures are applied on the shaft surface (moving part of the bearing) and a parametric analysis is performed considering some geometric parameters of the chevron. The fluid flow is modeled using the Reynolds equation and a mass-conserving boundary condition is used to deal with the cavitation zones. Due to the moving nature of the texture (imposed on the rotating surface of the shaft), a moving grid technique is employed in the Finite Volumes scheme. The results show the existence of optimal texture shapes depending on the Sommerfeld number of the bearing (operating condition). The textures with optimum shapes can reduce the shaft eccentricity, which indicates an increase in load-carrying capacity. The reason for this increase in load-carrying capacity is explained by an analysis of the lubricant’s flow dynamics in the bearing during operation, where a pumping effect is observed which reduces the leakage flow (the bearing with textured shaft keeps more lubricant in the bearing gap than the plain journal bearing).