双转子多盘转子系统的动态特性

Dynamic Characteristics of Dual-Rotor Multi-disks-Rotor System

采用有限元法建立了双转子-轴承系统的动力学模型,计算分析了轴承支承刚度和内外转子的转速比对系统临界转速的影响,并对计算结果的正确性进行了验证.研究发现:各支承位置支承刚度的增大将使系统临界转速逐渐增大,当增大到一定程度时对临界转速的影响并不大,各支承刚度对各阶临界转速的影响程度并不一致;另外,中介轴承对系统临界转速的影响并不大;以内转子为主激励的同步反进动时,系统临界转速随着转速比的升高而降低,正进动临界转速随着转速比的升高而增大;而以外转子为主激励的同步反进动时的临界转速表现出相反的规律.

Based on finite element theory,a dual-rotor-bearing system dynamic model was built,which is adopted to analyze the change law of the system critical speed with the bearing stiffness and inner-outer rotor speed ratio.The accuracy of the calculated results was verified.The research found that the increase of the supporting bearing stiffness will result in that of the critical speed of system.Not much influence on the critical speed exists when the speed increases to a certain degree.The effects of supporting stiffness on the critical speed are not consistent.Besides,the intermediate bearing affects the critical speed little.When the inner rotor is given a main synchronous anti-precession incentive,the system critical speed will decrease with the increase of the speed ratio.The speed of synchronous positive precession will increase along with the increase of the speed ratio.However,the critical speed will perform a contrary regularity on main synchronous anti-precession incentive given to external rotor.