Dynamics Analysis And Applied Research Of High-Speed Full-Ceramic Ball Bearing

The ceramic bearings as an important mechanical component has many superior performances compared to metal bearings.Ceramic bearings have good comprehensive properties including long-life,high temperature resistance,corrosion resistance,super-high speed,which make ceramic bearing widely used in many special working conditions such as high temperature,high speed,corrosion resistance,vacuum,nonmagnetic,non-lubricated,light weight and so on.Currently,ceramic bearings have been used successfully in high-speed numerical control machine tools and ultra-high-speed precision machinery.Based on the domestic and foreign researches,the full-ceramic bearings used in high-speed spindle CNC machine tool are studied,and its comprehensive performances are also studied.The following is the specific content of this thesis.Firstly,the summary of full-ceramic bearings and the background of dynamics research were presented.Based on the traditional bearing theory,the theoretical analysis on the geometry,kinematics,mechanics and failure mechanism of HIPSN full-ceramic ball bearings applied in high-speed spindle was conducted.Considering the effect of centrifugal force,the life theory and the related calculation method for full-ceramic bearing were studied,and the key factors affecting bearing life calculation was analyzed.Secondly,the static and dynamic behaviors of full-ceramic ball at high speed were investigatived.The contact stress and strain were analyzed for the preloaded full-ceramic ball bearing by the finite element analysis software,and the drag force and drag torque between rolling element and drag torque were also calculated by the established static model,then,the dynamics characteristics for the full-ceramic ball bearing was analyzed.Thirdly,based on the static and dynamic analysis results of the bearing,the bearing stiffness,contact angle,and contact force were all calculated and the influence of ceramic materials on the bearing motion characteristics and mechanical properties was analyzed.Based on the bearing deformation,the radial stiffness was solved and companed with that obtained by the testing.Then,the interior scale parameters of the bearing used in the high speed condition was optimized.Finally,the characteristics of the high-precision full-ceramic ball bearing applied in CNC machine tools high motorized spindle system including the temperature rise,vibration and noise were analyzed by the experimental test.The experimental results showed that the full-ceramic bearings was benefical for improving the dynamic characteristics under high speed operating conditions.The temperature of the front and rear ceramic bearing was steady when the preload was less than 600N.The contact stress of bearing was small when the vibrations was not more than 0.8mm/s,which met the design requirements and guarantee the long service life of full-ceramic ball bearings.When the noise was controlled below 75 db,the bearing at the highest speed can keep steady state.The practical value of the research work is as follow.The domestic enterprises can refer to these analysis to choose a reasonable dynamics analysis data,which avoid blindness and wasteful of the trial and provide a reference value for the future design of the same type of full-ceramic bearings.