航发主轴中介圆柱滚子轴承保持架刚柔耦合动态特性研究

The aero-engine spindle intershaft bearings work in a harsh condition of high-speed, high-temperature and lightly loaded, data from the airplane indicated that the early failure of the bearings, even accidents of airplane, may occur due to the cage’s slipping and movement instability and crash. The failure mode is thus deviated from fatigue failure, the traditional method of rigid and steady bearing analysis model is not possible to aquire a faithful result. So researches of the dynamic characteristic of the bearing cage are urgently required in order to improve the reliability of aero-engines. The project put forward a rigid- flexible coupling method to study the dynamic characteristic of the bearing’s cage. Regarding the cage as a flexible body, the multi-body dynamics system is set up by combining cage and other bearing components to analyze the interaction between different parts. Experiments on the cage’s characteristic are also planed to verify the mathematic model on the special test platform. The research is carried out theoretically and experimentally to explore the early failure mechanism of bearings and to develop a new cage design method by analyzing the influence of the cage flexibility, cage parameters such as pocket clearance and riding clearance as well as their matching on the cage’s dynamic characteristic. The research will be positive for developing the intershaft cylindrical roller bearings of high-performance aero engines and improving the reliability of aero-engines.

航空发动机主轴中介轴承工作于高速、高温及轻载的苛刻工作状况下，外场数据显示轴承常因保持架发生打滑、运动不稳定、断裂等动态因素引发早期失效，甚至造成重大飞行事故。中介轴承失效模式已偏离疲劳破坏，传统刚性的、稳态的轴承分析模型已无法对轴承动态特性作出可靠预测。本项目考虑中介圆柱滚子轴承苛刻工作条件及其保持架结构柔性，提出以刚柔耦合的方法对轴承保持架进行动态特性研究，将保持架视为柔性体并与内、外套圈和滚子共同组成多体动力学系统来分析零件间相互作用，建立分析模型研究保持架动态特性，并利用专用实验台进行实验研究。项目从理论与实验两方面开展研究，旨在揭示保持架引发轴承早期失效的机理，并通过研究分析保持架柔性及兜孔间隙、引导间隙等保持架结构参数、参数匹配对保持架动力学特性的影响，探索中介圆柱滚子轴承保持架设计的新方法。项目成果对研制高性能航空发动机中介圆柱滚子轴承和提高主轴轴承可靠性具有积极意义。

航空发动机主轴中介轴承工作于高速、高温及轻载的苛刻工作状况下，外场数据显示轴承常因保持架发生打滑、运动不稳定、断裂等动态因素引发早期失效，甚至造成重大飞行事故。中介轴承失效模式已偏离疲劳破坏，传统刚性的、稳态的轴承分析模型已无法对轴承动态特性作出可靠预测。本项目主要研究了以下内容：1 ）建立了中介圆柱滚子轴承刚柔耦合多体系统动力学模型研究 2 ）中介圆柱滚子轴承柔性保持架打滑及动态稳定性研究；3 ）中介圆柱滚子轴承早期失效机理研究；项目通过研究分析保持架柔性及兜孔间隙、引导间隙等保持架结构参数、参数匹配对保持架动力学特性的影响，探索中介圆柱滚子轴承保持架设计的新方法。研究结论如下：1）因保持架的结构特点，兜孔减弱了其强度和刚度，使得保持架的过梁和侧梁结构尺寸较小，保持架整体上按圆环振动的同时，还存在局部振型-过梁和侧梁的弯曲与剪切变形2）保持架的各种振型中，由变形引起的应力对保持架过梁和侧梁影响最大，由振动应力引起的疲劳裂纹大多出现在过梁与侧梁位置，所以保持架的破坏一般发生在过梁和侧梁处。3）中介圆柱滚子轴承柔性保持架打滑及动态稳定性研究从内外圈转速、载荷和保持架结构参数的影响几方面研究了保持架稳定性问题的方法，并针对算例提出了优化结果。项目成果对研制高性能航空发动机中介圆柱滚子轴承和提高主轴轴承可靠性具有积极意义。