基于高速图像特征提取的滑动轴承空化特性试验研究及其数值仿真分析

Experimental Study Based on High-speed Image Feature Extraction and Numerical Simulation Analysis of Cavitation Characteristics of Journal Bearings

空化现象广泛存在于各种大型旋转机械的滑动轴承中,严重影响轴承的运行稳定性和承载能力。为研究其特性,本研究设计并搭建了一套滑动轴承油膜可视化试验系统,利用高速摄像机捕捉高速旋转下的油膜空化演变图像,提出了油膜空化特征图像处理及提取方法。结合数值模拟方法和试验手段进一步研究油膜空化特征及其影响因素。研究结果表明:径向滑动轴承空化气泡在油膜发散端呈现不规则轮廓的条状分布;油膜空化发展程度与轴颈转速和润滑油黏度成正相关,与供油压力成反相关。试验测试发现主轴转速从1 000 r/min增大至5 000 r/min,空化区域增大148%;润滑油黏度从50 mm^(2)/s增大至150 mm^(2)/s,空化区域增大170%;供油压力从0.025 MPa增大至0.150 MPa,空化区域减小77%。

The phenomenon of cavitation widely exists in the journal bearings of various large rotating machinery,which affects the operational stability and load-bearing capacity of the bearings.The author designed and manufactured a set of oil film visualization experimental equipment for journal bearings,captured oil film cavitation images using high-speed cameras,and proposed an image processing method to extract oil film cavitation features.Further combining experimental research and numerical simulation research,the influencing factors of the degree of oil film cavitation in sliding bearings are explored.The research results indicate that the cavitation bubbles in radial journal bearings exhibit an irregular strip like distribution at the divergent end of the oil film;The degree of oil film cavitation is positively correlated with journal speed and lubricating oil viscosity,and inversely correlated with oil supply pressure.In the experiment,it was found that when the spindle speed increased from 1000 r/min to 5000 r/min,the cavitation area increased by 148%;The viscosity of lubricating oil increases from 50 mm^(2)/s to 150 mm^(2)/s,and the cavitation area increases by 170%;The oil supply pressure increases from 0.025 MPa to 0.150 MPa,and the cavitation area decreases by 77%.