Manufacturing error and misalignment effect on the transient lubrication behavior of dynamically loaded journal bearing with micro-groove

To explore the tribological properties of a seawater-lubricated friction pair, the influence of cavitation and multi-scale texture on the load-carrying capacity is investigated under seawater lubrication conditions. In this paper, a numerical simulation method is proposed to reveal the influence mechanism of cavitation on the load-carrying capacity, and the simulation results are verified by experiments. The results show that cavitation, wedge action, and the vortex flow effect are the main mechanisms responsible for affecting the load-carrying capacity. Cavitation is not always advantageous for the load-carrying capacity. The results indicate that cavitation enhances the load-carrying capacity when the velocity is between 5 and 10 m/s. However, the cavitation effect shows a negative effect with a velocity exceeding 10 m/s. In three different scales of surface textures, the load-carrying capacity of the millimeter-scale texture is the highest, followed by the cross-scale texture and the micrometer-scale texture. The load-carrying capacity of the millimeter-scale texture is almost 10 times that of the micrometer-scale texture. Furthermore, regardless of the texture scale, a texture with a high depth-to-diameter ratio (H = 1) always exhibits a higher load-carrying capacity at low speeds (V < 10 m/s).

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Analysis of flow diffusion of secondary lubricant in water-lubricated bearings

Liang,

Guo

et al. 2023

Physics of Fluids

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To reduce the lubrication failure of water-lubricated bearings under short-term harsh conditions, preliminary experiments have shown that temporarily supplying a small amount of lubricating oil into a bearing as a secondary lubricant can improve the load capacity of the water film therein. However, the physical flow and diffusion state of this secondary lubricant (oil) in water are unclear. Therefore, a mixed lubrication model and a volume-of-fluid model are incorporated to study the diffusion behavior of a small amount of lubricating oil in a water-lubricated bearing. The results show that there is a backflow effect in the local area inside the bearing, where the fluid velocity is in the opposite direction to the linear velocity of the shaft. This backflow effect intensifies with increasing eccentricity ratio, which enlarges the oil-free zone in the middle part of the bearing. In the convergence area at the water inlet end of the bearing, the water supply pressure and backflow effect prevent the lubricating oil from escaping. Increasing the shaft speed has a positive effect on the diffusion of the oil and the load capacity of the fluid. To enhance the assisted lubrication effect of the oil, the oil injection port should be set in the loading zone to avoid the backflow zone. This research provides some fundamental data for reducing the friction and wear of water-lubricated bearings under harsh conditions.

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Manufacturing error and misalignment effect on the transient lubrication behavior of dynamically loaded journal bearing with micro-groove

Cited by 5 publications

References 54 publications

Tribology and Characterization of Dynamically-Loaded Crankshaft Main Bearings with Surface Roughness

Tribology and Characterization of Dynamically-Loaded Crankshaft Main Bearings with Surface Roughness

Combined effect of cavitation and multi-scale texture on the bearing properties of seawater-lubricated friction pair

Analysis of flow diffusion of secondary lubricant in water-lubricated bearings

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