中文摘要：

针对某型发动机减速器出现的齿轮毂裂纹故障，基于UG建立减速器齿轮传动系统的实体模型，对减速器一级齿轮毂进行柔性体仿真，采用弹簧模拟齿轮毂花键之间的弹性力作用，通过改变弹簧刚度的方法模拟一级齿轮毂存在故障时的状态，对比研究处于正常状态和带有裂纹齿轮毂故障状态的发动机减速器各部件的动态响应，发现故障状态下减速器各部件振动量明显增大，由此确立将振动量作为故障监测特征量的思想。利用所设计搭建的整机振动测试系统对10台次发动机振动状态进行测试，对比研究两种状态下减速器在其特征频带上的振动量大小，结果表明故障状态下振动量明显大于正常状态，从而验证仿真计算的正确性。

英文摘要：

The crack fault of the decelerator gear hub of an engine is analyzed.The entity model of the decelerator geartransmission system is established based on UG.Flexible body simulation is performed for the decelerator gear hub of thefirst-stage.Springs are used to simulate the elastic effects among the splines of the gear hub.Fault condition of the first-stagegear hub is simulated by changing the spring stiffness.The dynamic responds of the decelerator components in the normalcondition and the fault condition with the gear hub cracked are analyzed and compared.It is found that the vibrationamplitude of the decelerator components rises significantly under the fault condition.Thus,the vibration amplitude of thedecelerator components can be used as the characteristic index for fault detection.Then,a complete vibration detectionsystem is designed and established and the vibration conditions of several engines are tested.The vibration amplitudes of thedecelerators in the characteristic frequency band under the normal condition and fault condition is comparatively analyzed.The results indicate that the vibration amplitude of the decelerator under the fault condition is obviously greater than thatunder the normal condition.The correctness of the simulation calculation is verified.