航空发动机传动轴承多支承台架试验失效机理分析

作为航空发动机的关键部件之一，传动系统的工作性能直接决定整机的运行状态与可靠性。传动系统的支承轴承因工作环境恶劣，在其工作过程中极易出现早期失效故障。针对某航空发动机传动系统支承球轴承台架试验中出现早期失效的问题，采用有限元方法，建立了多点支撑柔性传动系统动力学模型，分析了转速和轴承游隙对系统各支承轴承的动态载荷与弹性变形的影响规律，确定了支承轴承发生失效的位置及其原因；采用Lundberg和Palmgre的疲劳寿命计算方法，基于多点支撑柔性传动系统动力学模型获得的轴承内部动态载荷，计算了台架系统中出现早期失效的支承球轴承的疲劳寿命。结果表明，支承轴承的游隙匹配会导致各轴承内部载荷存在较大差异，该差异是导致其疲劳失效的主要原因，该仿真结果与实际情况基本一致。论文的研究可为该型航空发动机传动系统支承轴承的优化设计提供新的思路和理论支撑。

A Failure Analysis of the Support Bearings of an Aero Engine in a Bench Test with Multiple Supports

As a key part of the aero engine, the operational status and reliability of the whole system are directly determined by the performances of the transmission system. Since the rugged working conditions of the support bearings in the transmission system, some incipient failures are often produced. To analyze the incipient failures in the support bearings in the transmission system of an aero engine in a bench test with multiple supports, a dynamic model based on the finite element method for the flexible transmission system with the multiple supports is proposed. The effects of the rotor speed and bearing clearance on the dynamic loads and displacement of the support bearings are studied, which are used to determine the failure location in the support bearings. According to Lundberg and Palmgre's method, the fatigue life of the selected support bearing is calculated by using the dynamic loads from the proposed dynamic model. The results show that different bearing clearance cases can produce a very different bearing loads, which is the main fatigue failure reasons of the support bearing. The simulation results are very close to the practical situation. This work can provide some new guidance and theoretical support for the optimization design of the support bearings in the transmission systems of the aero engine.