航空发动机高速锥齿轮瞬态动力学分析与试验研究

Transient Dynamics Analysis and Experimental Research of High-Speed Bevel Gear in Aero-Engine

关键词:  航空发动机  中央传动锥齿轮  行波共振  断裂故障  声测法  动力学分析

Key words:  Aero-engine  Central drive bevel gears  Traveling wave resonance  Fracture failure  Acoustic measurement method  Dynamics analysis

摘要:

针对航空发动机中央传动锥齿轮由行波共振引起的掉块故障，采用瞬态接触动力学分析方法与试验验证相结合的手段，对行波共振发生时从动锥齿轮的共振特性和应力分布开展研究。基于声测法开展了航空发动机中央传动锥齿轮行波共振试验，研究中央传动锥齿轮行波共振特性，获取了从动锥齿轮行波共振动频、危险转速以及破坏断裂特征。仿真计算结果与试验结果对比分析表明：试验中出现三节径共振皆是前行波共振，四节径共振是后行波共振；三节径共振危险转速范围为74.2%~76.2%，四节径共振危险转速范围为102.8%~104.2%。数值仿真与试验测试中结构静频值具有一致性，三节径误差小于2%，四节径误差小于5%，验证了仿真计算模型的准确性。仿真计算四节径行波共振时从动锥齿轮齿根处和辐板应力集中，应力分布形式与齿轮故障复现试验断裂形式基本一致，辐板正面应力值大小与试验结果基本吻合，误差在0.5%~9.5%，满足工程级应力预测要求，验证了瞬态接触动力学分析方法对齿轮行波共振应力预测的有效性。试验表明该齿轮结构是否存在初始缺陷是发生齿轮断裂故障的重要因素之一。

Abstract:

Aiming at the fracture failure caused by the traveling wave resonance of the aero-engine central drive bevel gear, the transient contact dynamics analysis method and the experimental verification are used to study the resonance characteristics and the stress distribution of the driven bevel gear when the traveling wave resonance occurs. Based on the acoustic measurement method, the traveling wave resonance test of the central drive bevel gear of aero-engine is carried out. The traveling wave resonance characteristics of the central drive bevel gear are studied. The dynamic frequency, dangerous speed and rupture characteristics of the driven bevel gear traveling wave are obtained. According to the simulation and test results, the three nodal diameter resonance in the test is the forward wave resonance, and the four nodal diameter resonance is the backward wave resonance. Three nodal diameter resonance dangerous speed range is 74.2%~76.2%, four nodal diameter resonance dangerous speed range is 102.8%~104.2%. The static frequency of the simulating calculation keeps consistent with the test. The error of the three nodal diameter static frequency value is controlled within 2%, and the error of the four nodal diameter static frequency value is controlled within 5%, which indicates the accuracy of the simulation method. The results of transient contact dynamics simulation show that the stress distribution of the driven bevel gears at the root and the spoke are concentrated under the four nodal diameter rotation speed. The stress distribution form of the gear is consistent with the fracture mode of the gear failure recurrence test. The values of stress on the front of the spoke are consistent with the test results. The simulation value of stress on the front of the spoke coincides exactly with the results, error is between 0.5%~9.5%, which satisfies the requirements of engineering level stress prediction. It validates the effectiveness of transient contact dynamics simulation method for predicting stress of traveling wave resonance of gears. The test results show that whether the gear structure has initial defects or not is one of the most important factors of gear fracture.