起落架开关弹簧断裂故障分析及改进  

Analysis and Improvement of Spring Fracture for Landing Gear Switch

作　　者：雷珊 范建博 李萌 LEI Shan;FAN Jian-bo;LI Meng(AVIC Xi'an Aircraft Industry Group Co.,Ltd.,Xi'an 710089,China)

机构地区：[1]中航西安飞机工业集团股份有限公司,陕西西安710089

出　　处：《液压气动与密封》2025年第4期91-97,共7页Hydraulics Pneumatics & Seals

摘　　要：对飞机起落架开关内部弹簧断裂问题进行分析,通过失效分析得出弹簧为疲劳断裂的结论。理论分析弹簧在腔体内3种状态下疲劳强度和寿命均满足设计要求,弹簧断裂原因为支撑垫圈尺寸设计不合理,造成弹簧底圈与垫圈过油孔槽口钩挂和垫圈啃伤,使弹簧受力异常、应力集中,产生疲劳断裂。根据故障原因对支撑垫圈尺寸进行设计改进,对流阻进行理论计算,垫圈静强度及疲劳强度进行仿真分析,加工试验件进行试验验证,改进效果达到预期。改进设计有较广泛的应用,对工程中出现的该类断裂故障诊断有一定参考价值。This paper analyzes the issue of spring fracture within the landing gear switch,reaching the conclusion through failure analysis that the spring sustained a fatigue fracture.Theoretical assessments confirm that the spring s fatigue strength and lifespan meet the requirements under three distinct states within the cavity,the root cause of the spring fracture is attributed to the unreasonable sizing of the support washer,which leads to the spring s bottom getting hooked on the oil hole groove of the washer and the washer being gnawed.This results in abnormal force application on the spring,stress concentration,and ultimately,fatigue fracture.Based on the fault cause,improvements were made to the design of the support washer s size.Theoretical calculations were conducted for flow resistance,and simulation analyses were performed on the static strength and fatigue strength of the washer.Experimental validation was carried out by processing test pieces,and the improvement effects met the expected outcomes.The revised design has broad application prospects and offers certain reference value for addressing similar fracture failures encountered in engineering projects.

关 键 词：起落架 弹簧 支撑垫圈 断裂 

分 类 号：TH137[机械工程—机械制造及自动化] TH135