Laser pattern-induced unidirectional lubricant flow for lubrication track replenishment

Abstract

Effective oil replenishment to the lubrication track of a running bearing is crucial to its sustainable operation. Reliable practical solutions are rare despite numerous theoretical studies were conducted in the last few decades. This paper proposes the use of surface effect, wettability gradient, to achieve the goal. This method is simple and can be nicely implemented using femtosecond laser ablation. A periodic comb-tooth-shaped pattern with anisotropic wetting capability is devised and its effect on the anisotropic spreading behaviour of an oil droplet is studied. Results show that the comb-tooth-shaped pattern enables the rearrangement of oil distribution, thereby escalating oil replenishment to the lubrication track. The effect is due to the unbalanced interfacial force created by the surface pattern. The influence of the shape and the pitch of teeth, which are the two governing factors, on oil transport is also reported. The effects of the newly devised surface pattern on lubrication are experimentally evaluated under the conditions of limited lubricant supply. These results are promising, demonstrating the reduction in bearing friction and the increase in lubricating film thickness.

Effect of EDM and Femtosecond-Laser Groove-Texture Collision Frequency on Tribological Properties of 0Cr17Ni7Al Stainless Steel

“…Recent years, surface texture has become an effective means to improve the tribological properties of friction pairs. Scholars continue to refine and deepen the research on surface texture, and have conducted a lot of research in sliding direction [23], lubricating oil [24,25], additives [26], fabric [27], hydrophobicity [28], increasing wear [29], corrosion resistance [30] and drag reduction [31]. However, in practice, no matter how the surface texture is prepared or what texture shape is used, friction and collision with the edge of texture will generally occur between friction pairs in the process of sliding friction.…”

Effect of Groove Width on Micromachine Groove Texture Tribology Characteristics of 0Cr17Ni7Al

“…The size of surface texture is generally too large or too small, which is not conducive to giving full play to texture, and even has a negative impact. Therefore, researchers have 2 of 15 carried out research in many aspects, such as research on different sliding directions of textured surfaces [17], surface friction coupled with lubricating oil and surface texture [18,19], research on adding additives to textured surfaces [20], research on the hydrophobicity of the surface texture [21], increasing friction by using a convex surface texture [22], corrosion resistance of surface texture [23], the combination of fabric and surface texture [24], and the reduction of resistance by surface texture [25], etc. Many scholars have tried to use different methods to optimize the design parameters of the surface texture.…”

Investigations for vibration and friction torque behaviors of thrust ball bearing with self-driven textured guiding surface

“…Li et al [24] prepared a functional surface composed of groove textures to achieve unidirectional spreading of oil and analyzed the self-transport mechanism of oil droplets. Liu et al [25] prepared a periodic comb-tooth-shaped microstructures with unidirectional spreading guidance for oil droplets on steel and glass discs, respectively. The textured steel and glass discs were rotating in friction experiments and interferometry film thickness measurement tests (ball on disc model).…”