起落架缓冲支柱柱塞组件故障分析及改进研究

起落架缓冲支柱修理时发现柱塞组件的螺母螺纹发生咬合变形，为探究该故障发生的原因，根据柱塞组件的结构特点与工作原理，构建螺纹咬合变形故障的故障树，并基于历史试验数据、螺纹剩余强度分析以及产品状态检查等方法对故障树底事件逐一分析并进行改进研究。结果表明：螺母设计缺陷和螺母未装配到位是导致螺纹发生咬合变形的原因；将螺距改为2 mm、使用双套筒式专用工装可提高螺纹剩余强度，保证螺母的分解、装配质量。

Research on Fault Analysis And Improvement of Plunger Assembly ofLanding Gear Buffer Steut

The landing gear buffer strut was disassembled for repair, it was found that the nut thread of the plunger assembly was occluded and deformed, which was difficult to disassemble. In order to analyze the cause of the fault, the fault analysis and improvement research were carried out. According to the structural characteristics and usage of the plunger assembly, the fault tree of the nut thread occlusion deformation was constructed. Based on the historical test data, residual strength analysis and products status, the bottom events of the fault three which was analyzed and verified. It was concluded that the design defects of the nut and the nut was not assembled in place could lead to the thread occlusion deformation. In addition, based on residual strength analysis of nut thread, when the thread pitch was 1.5mm, the residual strength was 0.76, while the thread pitch changed to p=2mm, the residual strength was 1.4. Based on the problem that the nut was difficult to be disassembled , the method of bidirectional fixing of the plunger assembly and design of the double sleeve type special tooling was adopted to effectively solve the problem. The research results were great significance to the design improvement and disassemble,assembly quality of nut.