| Rolling bearing is a key part of rotating machinary and usually used with elastic support for reducing the critical speed of high-speed rotors.So it has become one of the key questions to be solved how to precisely simulate the dynamic characteristics of a high-speed rolling bearing with elastic support.Therefore,considering acting force of groove elastic support on the rolling bearing and the coupled model of deformation between flexible outer ring and elastic support,the dynamic model of roller bearing on elastic support was established based on the tribology,lubricant and contact theories,and then the dynamics characteristics of the cylindrical roller bearing with elastic support were firstly analyzed.The experiments were carried out on the dynamic performance system of aero-engine main-shaft to validate the simulating model of this paper.The research works were elaborated as following:(1)According to the structural features of groove elastic support,a physical model was established with statically indeterminate arch for basic deformation structure.The relation of the radial stiffness and structural parameters groove elastic support was proposed.The effect of the structural parameters on radial stiffness of the elastic support were investigated.And on this basis,the analytic formula to quickly calculate the radial stiffness of groove elastic support was presented.(2)Based on hypothesis of rigid ring,dynamic theory of rolling bearing and the math expression of end reaction of groove elastic support,the dynamics simulation model of cylindrical roller bearing with elastic support was established,and the influence of elastic support's structural parameters and working conditions on the vibration of the cylindrical roller bearing was investigated theoretically.The results indicated elastic support can efficiently decrease cylindrical roller bearing's radial vibration.Considering the ring's flexible deformation of cylindrical roller bearing,the couple model of deformation between the flexible outer ring and elastic support was built which was based on the general expression for the radial displacement of thin ring and the analysis formula of groove elastic support.Combined the couple model and the dynamic theory of roller bearing,the dynamic model of cylindrical roller bearing with thin outer ring and groove elastic support was established and the effect of groove elastic support on the dynamic characteristics of cylindrical roller bearing with thin outer ring was studied.The results show the elastic support can increase the number of loaded rollers,decrease the contact forces between the roller and race,restrain the cage slip and improve the cage stability.Based on the hypothesis of flexible ring and taking into full account of the lubrication state between the race and roller,the cage's dynamics characteristics and stress of high-speed cylindrical bearing with flexible ring and elastic support at start-up and stop stage were analyzed.It shows the groove elastic support can decrease the impact damage of cage and increase the reliability and life of cylindrical roller bearing under frequent start and stop working condition.(3)The experiment rig of cylindrical roller bearing with elastic support was set up,and then the cage slide's rate and vibration spectrum of cage center were tested under different working conditions and were compared with theoretical analysis results.The tests preliminarily validate the dependability of the model of cylindrical roller bearing with elastic support and thin ring in this paper.This paper was focus on the dynamics simulation of cylindrical roller bearing with groove elastic support.The findings of this paper provide the theoretical basis for how to use the elastic support to reduce the bearing vibration and improve cage's stability,as well as to promote transformation of the rolling bearing's dynamic model from rigid ring towards flexible ring. |
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