航空发动机双转子-滚动轴承耦合系统的动力特性分析

Analysis on dynamic characteristics of a dual rotor-rolling bearing coupling system for aero-engine

在轴承动力学和转子动力学基础上建立了某航空发动机双转子-滚动轴承耦合系统的非线性动力学数学模型,采用Newmark有限元法进行了数值求解,就转子转速、中介轴承的游隙和滚子个数以及支承轴承参数对双转子系统动力特性的影响进行了分析并加以实验验证.研究结果表明:①中介圆柱滚子轴承游隙值对双转子系统动力特性影响很大,其原始游隙值取20μm更利于系统运行的稳定性;②支承轴承内、外沟曲率半径的选取将直接影响着双转子系统动力特性;③高压转子与低压转子耦合节点处位移随高压转子转速的增加而减小,随低压转子转速的增加而增加;④中介耦合轴承节点处位移的理论计算值与实验值较为吻合,最大误差为18.7%.

Based on the bearing dynamics and rotor dynamics models,the nonlinear dynamic mathematical equations were established to describe the dual rotor-rolling bearing coupling system.Newmark finite element method was used to solve the equations.The influences of the rotor speed,intershaft bearing clearance,rollers number and supporting bearing geometry parameters on dynamic characteristics of the dual rotor system were analyzed and verified experimentally.The results shows that：（1） The cylindrical roller intershaft bearing has a significant influence on dynamic characteristics of the dual rotor system,and the stable system operation can be realized when the original clearance is 20 μm.（2） Dynamic characteristics of the dual rotor system can be affected directly by groove curvature radius coefficients of inner and outer rings.（3） The node displacement of coupling between the high-pressure rotor and the low-pressure rotor decreases with the rise of the high-pressure rotor speed,and increases with the drop of low-pressure rotor speed.（4） The theoretical calculation of the coupling node displacement of intershaft bearing is matched with experimental value,and the maximal error is about 18.7%.