Effect of cylindrical micro-pit texture on the performance of misaligned radial journal bearing

Abstract The aim of this work is to further enhance the tribological lubrication performance of journal bearings on the premise of a slight improvement in the bearing’s load carrying capacity. To this end, the effect of such parameters as the circumferential distribution position, axial proportion, depth, inclined angle, and area rate of the texture on the lubrication and tribological characteristics of misaligned radial journal bearings is examined by machining the cylindrical micro-pit texture onto the bearing shell. The findings show that the bearing’s load carrying capacity increases with the presence of cylindrical micro-pit texture in the boost area, particularly when the axial ratio is close to 55%. Furthermore, the journal bearing that incorporates this micro-pit texture within the boost area exhibits a lower friction coefficient relative to those within fully texturing, texturing within the bucking zone, or an entirely smooth surface. The micro-pit texture can both enhance or diminish the load capacity of the bearing, when the texture axial proportion is 55%, the depth is 2.5 μm and the texture inclined angle is 90°, the tribological and lubrication performance of the bearing with texture in the boost area is the best and the load carrying capacity is slightly improved. Additionally, there is a direct linear relationship between the area ratio of the cylindrical micro-pit texture and both the load carrying capacity and the friction force. Machining the texture of suitable parameters onto the bearing shell’s smooth surface is conducive to improving the bearing’s properties, with the effect becoming more pronounced as the journal misalignment angle was reduced. The analysis indicated that machining cylindrical micro-pit texture with the appropriate parameters onto the bearing shell’s smooth surface can effectively lower the friction coefficient, reduce mechanical wear and improve bearing performance while ensuring a slight increase in the bearing load carrying capacity. In addition, this research can provide a beneficial parameter reference for texture design.