Performance improvement of foil air journal bearing employing micro-pocket and textures on top compliant surface

Abstract

Investigations to reduce the friction and improve the dynamic performance of a self-acting air foil journal bearing have been performed and presented herein employing the texture, micro-groove and micro-pocket on the top foil. Significant improvements in the static and dynamic performances have been found in presence of micro-pocketed/grooved and textured top foils in comparison to conventional plain foil. The micro-pocketed top foil yields better performance as compared to textured and conventional cases. In the presence of micro-pocket on top compliant foil, the bearing yielded a significant reduction in friction coefficient varying in the range of 8%-11% as compared to conventional one. Moreover, better dynamic stability has also been found even at lightly loaded conditions in the presence of texture and micro-pocket. NomenclatureRECEIVED

Performance studies of self-acting oil-lubricated bump journal bearing under lightly loaded conditions employing pocketed top foils

“…The friction between top foil/bump and bump foil/sleeve foil has been ignored in this work since pocket/texture affects only hydrodynamic friction. 26 The friction force (F s ) can be computed using the expression below…”

“…Furthermore, these numerous micro-features of textures trap contaminants/debris while also providing lubrication. 24–26…”

“…Furthermore, these numerous micro-features of textures trap contaminants/debris while also providing lubrication. [24][25][26] Based on the literature review, there has been a noticeable lack of research into exploiting surface textures/ pockets on top foil to improve the performance behaviours of vertical rotor-bearing systems (such as in Figure 1). Therefore, this paper's objective is to explore, understand and improve the performance behaviours of the oillubricated foil journal bearings employing surface textures/pockets on a compliant surface.…”

Co-optimization for hydrodynamic lubrication and leakage of V-shape textured bearings via linear weighting summation

“…The above mentioned studies have not only demonstrated the influence of texture on the lubricating performance but also shown that the load-carrying capacity is linked to the shape and distribution of the texturing surface. Furthermore, to improve the load-carrying capacity, numerous optimization measures have been proposed in recent years [19][20][21][22]. Shen and Khonsari [20] presented the optimum texture shape for enhancing the load-carrying capacity on parallel surfaces using the sequential quadratic programming(SQP) algorithm: V-shape texture with flat fronts.…”

Analysis of misalignment characteristics for textured foil journal bearing based on multigrid method

“…Surface texturing means intentionally introducing discrete dimples [10,11], protrusions [12], or continuous grooves [13,14] on the lubricated surface. Given the significant discretization efforts [15] introduced by the above micro-structures in journal bearing and the nonlinearity of the compressible Reynolds lubrication equation, thus the early-stage study about textures mainly focuses on incompressible medium flow systems inside sliding and thrust bearing [15].…”