混合式陶瓷轴承的研制及其台架试验研究Ⅱ．滚珠轴承的运行和润滑试验

Development and Rig-Testing Research on Hybrid Ceramic BearingⅡ.Running and Lubricating Experiment of Ball Bearings

混合式陶瓷轴承的性能优异，是一种应用前景十分广阔的新型高速轴承。但是，目前对其研究还不够充分，特别在这种轴承的润滑试验研究方面几乎还是个空白，因此，对混合式陶瓷轴承进行了运行和润滑试验，并且利用扫描电子显微镜对试验后的陶瓷球表面进行了观察。在同种润滑剂润滑下的温升对比试验表明，陶瓷球轴承的温升比钢球轴承的低，可见前者的高速运行性能比后者的好；在其它试验条件相同的情况下，利用２０＃机械油和含３％（ｗｔ）超细石墨金刚石粉的２０＃机械油等６种润滑剂分别进行的润滑试验表明，润滑剂的粘度越大，陶瓷球轴承的温升越高；纯水对陶瓷球轴承的润滑性能良好，利用其润滑时的轴承温升很低。这种结果除与水的粘度非常低有关以外，还同Ｓｉ３Ｎ４陶瓷与水发生的摩擦化学反应有关。扫描电子显微镜观察发现，在含３％（ｗｔ）超细石墨金刚石粉的２０＃机械油润滑下，试验后的个别陶瓷球表面有相当深的麻坑出现，这是陶瓷球毛坯内部气孔等缺陷经过金刚石微粉“抛光”作用而显露出来的结果。

Hybrid ceramic bearings,a new type of high speed bearings,possess a potential forwide application due to its excellent characteristics. However,rescarch on the bearings of tius typeare far from intensive.Especially,experimental research on the hybrid ceramic bearing has notbeen conducted in China.The lubricating experiment of hybrid ceramic bearing is carried out andscanning electron microscope(SEM)is used to observe the surface of the tested ceramic balls.Acomparison of temperature rising is ma de between steel ball bearing and ceramic ball bearinglubricated with a same lubricant,and the result shows that the temperature rise of ceramic bearingsis lower than that of steel bearings, so the good performance of ceramic bearings at high speed isconfirmed.Under the same conditions, lubricating experiments are carried out respectively with sixkinds of lubricants including 20# machine oil and 20# machine oil with superfine graphite-diamondpowder(3%,wt).The results show that the higher the lubricant viscosity,the larger thetemperature rise of the ceramic bearings. Pure H2O has good influence on the lubricating propertiesof ceramic bearings,the temperature rising is very small when it is use d as lubricant.This phenomenon is concerned with the occurence of tribochemical reaction of the Si3N4 ceramic withwater and the low viscosity of water.The surface of some ceramic balls lubricated by 20# machineoil with superfine graphiter-diamond powder(3%,wt)is obeerved with the SEM,and pock marksare found on several ball surface which are caused by the defec ts in the ball blank.