循环冲击激励下某发动机附件传动系统的振动特性研究

Study on Vibration Characteristics of Accessory Transmission System of an Engine Under Cyclic Impact Excitation

考虑到某涡桨发动机中附件传动系统动力学建模困难的问题,本文基于子结构总体耦合矩阵法,将同轴多转子耦合系统和斜交弧齿锥齿轮耦合多转子子系统的动力学模型加以综合和扩展,建立了主转子与附件传动系统耦合系统的动力学模型,并推导了动力学方程,使用变阶次Adams-Bashforth-MoutlonPECE算法对动力学方程进行求解,获得不同循环冲击载荷谱下,系统的动态响应,研究了该型航空发动机主转子与附件耦合系统的振动特性。结果表明:该下斜附件传动系统由于第三级齿轮副传递扭矩较大,同时斜齿轮副相较于弧齿锥齿轮副运转平稳性差,故两种交变载荷下各级齿轮副的最大法向相对位移、最大动载系数均值及最大法向振动加速度均方根均发生在斜传下斜齿轮副上;各级齿轮副沿法线方向的振动均为周期振动,且一个负载周期中同时包含有多个啮合周期。

Considering the difficulty of dynamic modeling of accessory transmission system in a turboprop engine,based on the substructure global coupling matrix method,the dynamic model of the coupling system of main rotor and accessory transmission system is established by synthesizing and extending the dynamic model of coaxial multi-rotor coupling system and skew spiral bevel gear coupling multi-rotor subsystem,and the dynamic equations are derived.The variable order Adams-Bashforth-MoutlonPECE algorithm is used to solve the dynamic equation,and the dynamic responses of the system under different cyclic impact load spectra are obtained.The vibration characteristics of the aero-engine main rotor and accessory coupling system are studied.The results show that the shock excitation produced by the cyclic impact load spectrum has a great influence on the vibration characteristics of the system.Because the transmission torque of the third stage gear pair is larger,and the running stability of the helical gear pair is worse than that of the spiral bevel gear pair,the maximum normal relative displacement,the mean value of the maximum dynamic load coefficient and the root mean square of the maximum normal vibration acceleration of the helical gear pair under two kinds of alternating loads all occur on the helical transmission helical gear pair.The vibration of all gear pairs along the normal direction is periodic,and a load cycle contains multiple meshing periods at the same time.