摘要
为探究含油轴承基体渗流及压力扩散对接触面间油膜润滑性能的影响,建立双级孔含油轴承系统的渗流润滑模型,研究轴承摩擦面上油膜分布规律与双级孔隙中压力扩散行为,分析摩擦副倾角与轴承表层渗透率变化对油膜润滑性能的影响.结果表明,流体动压力产生于摩擦界面的收敛区,并逐渐由摩擦界面向轴承基体扩散,在油压扩散过程中流体压力的作用面积增大,压力数值降低.油膜的润滑性能随倾角增大或表层渗透率减小而得到改善,相比单层含油轴承,具有致密表层的双级孔含油轴承具有较好的润滑性能.不同表层渗透率下,倾角对油膜摩擦系数的影响差异显著:在本文中计算参数下,当表层渗透率小于7×10^(-15)m^(2)时,油膜的摩擦系数随倾角增大而减小;当表层渗透率高于7×10^(-15)m^(2)时,油膜的摩擦系数随倾角增大而增大.倾角和表层渗透率影响含油轴承基体中的油液渗流和压力扩散行为,最终使油膜的润滑性能发生改变.研究工作为明晰含油轴承润滑机理提供一定理论依据.
Oil bearing is usually prepared by powder metallurgy process,which has the characteristics of selflubrication,lightweight and near net shape forming.It has significant technical advantages in the current situation of mechanical products pursuing high performance,low energy consumption and environmental friendliness.For exploring the influence of seepage and pressure diffusion on the oil film lubrication performance of oil bearing,the seepage lubrication model of two-stage hole oil bearing system was established.The oil film distribution on the friction surface and the pressure diffusion behavior in the two-stage hole were studied.The effects of the variable obliquity and surface permeability on the oil film lubrication performance were analyzed.The main purpose of the study was to reveal the interaction between fluid seepage and pressure diffusion in two-stage porous structure.Results showed that the hydrodynamic pressure was generated in the convergence zone of the friction face.From the friction face to the bottom of the bearing,the fluid pressure gradually diffused to the matrix,the pressure action area increased and the pressure value decreased during the oil pressure diffusion process.The lubrication performance of oil film became better with the increase of obliquity or the decrease of surface permeability.Reducing the surface permeability could decrease the seepage and diffusion effect of oil into the porous matrix in the oil film area,which was conducive to increasing the hydrodynamic pressure of oil film on the friction interface.The lubrication performance of two-stage oil bearing with dense surface was better than that of single-layer oil bearing.Under different surface permeability,the effect of obliquity on friction coefficient was significantly different.Under the calculation parameters in this paper,when the surface permeability was less than 7×10^(−15)m^(2),the friction coefficient decreased with the increase of obliquity.While when the surface permeability was higher than 7×10^(−15)m^(2),the friction coefficient increased with the increase of the obliquity.At lower surface permeability,the hydrodynamic pressure of oil film between friction interfaces increased with the increase of the obliquity.And the lubrication performance became better.At the same time,the seepage and pressure diffusion effects of oil film into the pores of bearing matrix were enhanced,which would hinder the improvement trend of the lubrication performance to a certain extent.When the surface permeability reached a certain value,the bearing capacity of the oil film hardly changed with the increase of the obliquity,and the friction coefficient of the oil film increased with the increase of the obliquity.Under different obliquity and surface permeability,the seepage behavior of oil in porous bearing interacted with pressure diffusion,and finally changed the lubrication performance of oil film.The research provided a theoretical basis for clarifying the lubrication mechanism of oil bearing.
作者
张国涛
蔡伟杰
尹延国
韦习成
ZHANG Guotao;CAI Weijie;YIN Yanguo;WEI Xicheng(School of Mechanical Engineering,Anhui University of Technology,Anhui Maanshan 243000,China;Institute of Tribology,Hefei University of Technology,Anhui Hefei 230009,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;Research Institute for Advanced Equipment Basic Materials,Shanghai University(Zhejiang),Zhejiang Jiaxing 314100,China)
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2023年第5期549-560,共12页
Tribology
基金
国家自然科学基金(52005005,51575151)
安徽省自然科学基金(1908085QE195)资助。
关键词
双级孔隙
含油轴承
渗透率
压力扩散
润滑性能
two-stage hole
oil bearing
permeability
pressure diffusion
lubrication performance