【作者】 雒建斌； 钱林茂； 史兵； 温诗铸；

【Author】 Luo Jianbin Qian Linmao Shi Bing Wen Shizhu (State Key Laboratory of Tribology,Tsinghua University,Beijing 100084)

【机构】 清华大学摩擦学国家重点实验室；

【摘要】 采用光干涉法相对光强原理对点接触中心区进行了润滑膜厚度测量,讨论了膜厚与压力、速度和润滑油粘度之间的关系,观察和分析了流体润滑膜的失效现象。实验结果表明:如果接触压力足够小或润滑油粘度足够高,即使在很低的速度下也能清晰地观察到流体动态润滑效应, 然而,当压力增至某一定值时,在膜厚——速度曲线上可观察到一个转折点,当速度降到此点以下时,润滑膜厚度将很快减小到几个分子层厚,此时,润滑膜不再具有流体润滑特征,即流体润滑膜失效。因此,这点叫做流体膜的失效点,对不同粘度的润滑剂,此失效点会出现在不同的速度和压力下,于是,要使接触区在较高的压力下形成流体膜就必须施加更高的卷吸速度或增加润滑油粘度。最后,本文建立了失效点与压力、速度和润滑油粘度之间的关系。更多还原

【Abstract】 The determination of hydrodynamic film failure has become one of the key aspects in the study of thin film lubrication(TFL)since the hydrodynamic effect of fluid film at nano-scale can be observed with re- cently developed experimental techniques.In the present paper,the relative optical interference intensity(RO Ⅱ)technique with a resolution of 0.5 mm in the vertical direction has been used to measure the film thick- ness.Experimental results show that the hydrodynamic effect can be clearly observed even at very low speed if the contact pressure is sufficiently low or if the viscosity of lubricant is comparatively high.When the pres- sure increases to a certain degree,the film will suddenly drop to the dimension of several layers of molecules and this is where the failure of the fluid film has taken place.For different viscosity of lubricants,the fluid film failure occurs at different roiling speeds and pressures.In addition,when the normal load becomes high- er,a higher speed or larger viscosity is required to form the fluid film in the contact region.Finally,the ef- fects of pressure,viscosity,and velopcity on the occurrence of fluid film failure have been examined and a re- lationship in volving the three parameters is proposed.更多还原