某型高速挖掘机变速器拨叉强度分析与结构优化  

Strength Analysis and Structural Optimization of Transmission Forkofa High-speed Excavator

作　　者：王波 刘卫军 陈伟 Wang Bo;Liu Wejun;Chen Wei

机构地区：[1]驻贵阳地区某军代室 [2]驻重庆地区某军代局

出　　处：《工程机械》2023年第9期116-119,I0022,共5页Construction Machinery and Equipment

摘　　要：拨叉是变速器的重要组成部分,起到拨动变速器齿轮的作用,其强度性能严重影响着驾驶的平顺性和安全性。某型高速挖掘机在使用过程中出现拨叉断裂失效故障。基于MSC-NASTRAN对变速器拨叉进行强度分析,结果表明,峰值应力为329 MPa,峰值应变为0.003 01 mm。出现峰值应力的薄弱部位位于拨叉根部,而峰值应力高于许用应力。结合材料的许用安全系数,对该拨叉进行结构优化,将薄弱部位进行加厚处理,增强峰值应力部位的强度,在循环应力的作用下减小应变,以降低断裂的可能性。优化后再次进行强度分析,优化后拨叉峰值应力为176 MPa,降低了约47%;峰值应变为0.001 82 mm,降低了约40%;大大降低了断裂失效的可能性,满足使用要求,提高了行驶的安全性。优化后的拨叉在后续的装机测试中没有出现各类失效现象。Fork is an important part of the transmission,playing a role of shifting thetransmission gears, so its strength performanceseriously affects the ride comfortand driving safety. A high-speed excavatorexperienced a fault of fork fractureduring operation.Based on MSC-NASTRAN,the strength of the transmissionfork is analyzed, and the results showthat the peak stress is 329 MPa, and thepeak strain is 0.003 01 mm. The weakpart with a peak stress is the root of thefork,and thepeak stress is higherthanthe permissible stress.Combined withthe permissible safety factor of the material,the fork is structurally optimizedby thickening the weak part to enhancethe strength of the peak stress area andreduce the strain under cyclic stress toreduce the possibility of fracture. Afteroptimization, the strength is analyzed,and thepeak stress of the fork is 176MPa, with a decrease of about 47%,while the peak strain is 0.001 82 mm,with a decrease of about 40%, whichgreatly reduces the possibility of fracturefailure, meets the use requirements andimproves thedriving safety.The optimizedforkdoes not showanyfailures inthe subsequentinstallation tests.

关 键 词：拨叉 有限元分析 强度分析 疲劳损坏 

分 类 号：TU621[建筑科学—建筑技术科学]