热膨胀诱导的转子轴向窜动与摩擦振动

对非均匀温度场以及温度时变特征的影响进行量化,研究热膨胀引发的转静件间隙变化及其接触挤压,将Hertz点接触挤压模型改进为环带面接触挤压形式.在此基础上建立了考虑面摩擦作用的转子动力学模型.最后采用数值积分法对模型进行求解,并研究升温时段和恒温时段环带面摩擦力对系统的影响.分析表明热膨胀诱导的转静轴向间隙变化所引发的摩擦是转子系统典型故障之一,也是影响发动机正常运行的重要因素. 

Axial displacement and rubbing vibration of rotor system caused by thermal expansion

The effect of non-uniformity and time varying characteristic of temperature field was quantified and provided as an axial clearance analytical expression when studying the rubbing process,and the rubbing between rotor and stator caused by the axial displacement was approximated as surface contact/squeeze process.Then the point contact or embedment of Hertz contact model was improved to an annulus surface contact or embeded model.On this basis,a new dynamical model of rotor system subjected to the rubbing force caused by axial squeeze was established.Finally,the numerical integration method was employed to solve the dynamical model,and the effect of annulus surface friction on the system was investigated for both the warming and steady temperature periods.The numerical results show that rubbing failure caused by axial displacement of rotor is as important as other rubbing phenomena;the surface rubbing is also an important factor which affects the normal operation of the engine.