Wang Hongtao, Bie Wenbo, Zhang Shaolin, Liu Tengfei
College of Mechanical and Power Engineering, Zhengzhou University, Zhengzhou 450001, China.
Henan Province Engineering Research Center of Ultrasonic Technology Application, Pingdingshan University, Pingdingshan 467000, China.
Micromachines (Basel). 2023 Feb 28;14(3):577. doi: 10.3390/mi14030577.
The proposed lubrication theory of textured journal bearing is a major innovation in the study of the tribological properties of surface morphology. When it comes to the study of surface topography, it is essential to consider the effect of surface roughness when analyzing the characteristics of journal bearing. In this paper, a Reynolds equation containing longitudinal roughness is established for journal bearing and solved by the finite difference principle to obtain the bearing load and friction characteristics. Subsequently, a combination of laser etching and ultrasonic vibration milling processes was used to prepare 5 µm, 20 µm, and 40 µm bearing friction subsets with square micro-texture surfaces. The analysis of the results shows that the surface roughness distributed in the non-texture region can substantially increase the oil film pressure. When the roughness profile and the surface weave work together, the presence of a surface texture with an optimum depth of 5 µm within a roughness range of less than 1.6 µm can improve the load-bearing characteristics by a maximum of 43%. In the study of the preparation of textured bearing friction substrate, it was found that laser etching can ablate the surface of the friction substrate to a depth greater than 20 µm with the ideal effect, while the surface texturing to a depth of 5 µm is more suitable using an ultrasonic vibration processing process. In the simplified journal bearing operating condition, the frictional wear test shows that if the effect of roughness is considered, the frictional force of the depth of 20 µm and 40 µm is significantly reduced and changes less with increasing load, while the frictional force of the textured frictional pair with a depth of 5 µm is improved but significantly affected by the load carrying capacity. Therefore, when the difference between the roughness profile and the depth of the texture is of a small order of magnitude, it indicates that the effect caused by the roughness factor is not negligible.
提出的纹理滑动轴承润滑理论是表面形貌摩擦学特性研究中的一项重大创新。在表面形貌研究中，分析滑动轴承特性时考虑表面粗糙度的影响至关重要。本文针对滑动轴承建立了包含纵向粗糙度的雷诺方程，并采用有限差分原理求解以获得轴承载荷和摩擦特性。随后，采用激光蚀刻和超声振动铣削工艺相结合的方法制备了具有方形微纹理表面的5 µm、20 µm和40 µm轴承摩擦子集。结果分析表明，分布在非纹理区域的表面粗糙度可大幅提高油膜压力。当粗糙度轮廓与表面纹理共同作用时，在粗糙度范围小于1.6 µm内，最佳深度为5 µm的表面纹理可使承载特性最大提高43%。在纹理轴承摩擦基体的制备研究中发现，激光蚀刻可将摩擦基体表面蚀刻至大于20 µm的深度，效果理想，而采用超声振动加工工艺使表面纹理深度达到5 µm更为合适。在简化的滑动轴承工况下进行的摩擦磨损试验表明，如果考虑粗糙度的影响，20 µm和40 µm深度的摩擦力显著降低，且随载荷增加变化较小，而深度为5 µm的纹理摩擦副的摩擦力有所改善，但受承载能力影响显著。因此，当粗糙度轮廓与纹理深度的差异处于小数量级时，表明粗糙度因素所引起的影响不可忽略。
