共查询到19条相似文献,搜索用时 140 毫秒
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自升式平台升降系统齿轮失效分析 总被引:2,自引:0,他引:2
通过对某自升式平台齿轮齿条升降系统的失效齿轮及全新齿条分别进行化学成分分析、金相检验和硬度测试,分析了造成该系统中齿轮失效的原因。结果表明:齿轮的失效形式为接触疲劳失效;齿轮材料表面热处理不均匀,节圆附近无硬化层,导致其失效面的表面硬度低于与其相啮合齿条的表面硬度,这是造成该齿轮长期服役后在节圆附近发生接触疲劳失效的主要原因。 相似文献
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在某装载机驱动桥大螺旋齿轮的开发过程中发现,齿轮在工作一段时间后出现早期断齿失效的情况。通过宏观检验、断口分析、化学成分分析、硬度以及金相检验等方法,对大螺旋齿轮断齿失效原因进行了分析。结果表明:齿根圆角曲率半径和啮合斑点尺寸过小以及轮齿心部硬度较低,导致齿轮根部应力集中作用加强是该大螺旋齿轮轮齿过早疲劳断裂失效的主要原因。最后根据断齿失效原因,对大螺旋齿轮进行了相应的改进,并取得了良好的效果。 相似文献
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李安民 《理化检验(物理分册)》2013,(3):189-190,193
通过宏观检验、化学成分分析、非金属夹杂物检验、硬度测试以及金相检验等方法,对塔机提升系统输入齿轮失效的原因进行了分析。结果表明:该输入齿轮损坏属于接触疲劳失效,趋网状分布的铁素体降低了材料的硬度、耐磨性和疲劳寿命,是造成齿轮早期失效的主要原因。同时提出了预防控制措施。 相似文献
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王荣 《理化检验(物理分册)》2019,55(10)
齿轮(齿轴)是风能发电机组上非常重要的结构件。对齿轮的主要失效形式及其特征做了介绍。从齿轮正常服役时的受力特点、选材特点、工艺特点以及使用特点等几个方面论述了齿轮失效的内在原因和外部原因。结合实际案例分析,对经常失效的风能发电机组上齿轮(齿轴)的失效原因做了归纳,发现疲劳断裂和氢脆型断裂是其最常见的失效形式,材料的冶金质量是目前国产风能发电机组上齿轮(齿轴)发生失效的主要原因,提出了风能发电机组上齿轮(齿轴)失效的预防措施。 相似文献
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机械传动齿轮的正常运转是保证机械工作的必要条件,本文通过分析机械齿轮失效形式,探讨机械齿轮的失效原因,加深对于齿轮的失效原理的了解和认识。 相似文献
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靳萍 《中国新技术新产品》2011,(20):131-131
齿轮失效在机械设备中较为常见,特别是煤矿设备因负荷大、易超载、工作环境差等,齿轮失效最为突出。通过对齿轮失效原因的分析,提出了若干可行的预防措施。 相似文献
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This study aims to investigate the cause of failure of an 845 mm external diameter reducing gear that operated during 30 months in a petrochemical plant. The failure analysis procedure included material characterisation (microstructure, chemical composition and microhardness), fracture surface evaluation, and stress distribution by finite elements on critical regions of the gear. Fracture mechanics and fatigue crack growth were also used to develop a da/dN–ΔK curve and then determine the gear material crack growth resistance. Results indicate that the gear was not properly manufactured and failure occurred as a result of a fatigue process facilitated by a manufacturing defect. 相似文献
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A systematic and practical methodology was adopted to determine the root cause(s) of the premature failure of a pelletizer mixer timing gear. The investigation activities covered all possible causes of failure and included field examination, interview of engineers and operators, lubrication analysis, metallurgical examination. Fracture surfaces and microstructure of gear material were examined, and hardness profiles were developed. Analyses of shaft misalignment and teeth profiles were performed and found to be within acceptable limits. Results clearly indicate the surface hardness deficiencies in many locations specifically at center of the driven gear, area of severe pitting. The developed hardness profile for all locations is lower than that specified by the manufacturer. Fractographic analysis revealed that failure occurred by pitting followed by crack propagation. A number of cracks are seen to branch in different directions indicating the presence of high contact stresses combined with weak surface strength. Bending fatigue and pitting fatigue stress calculations revealed that the safety factor under contact is well below the desired value. 相似文献
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某飞机中心传动装置从动锥齿轮使用95.85 h后,在高空发生断裂;对该从动锥齿轮断口进行了宏观分析和金相检验,并对从动锥齿轮的组织、硬度和化学成分进行了检验,分析了断裂原因。结果表明:中心传动装置从动锥齿轮的断裂是由于铆钉失效或粘接剂老化,造成衬套滑出与从动锥齿轮大圆端面摩擦烧伤,致使裂纹形成,最终裂纹扩展造成疲劳断裂。 相似文献
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Z. W. Lian Z. Y. Fan G. N. He B. Jiang L. Y. Zhou F. B. He Y. Z. Liu 《Materialwissenschaft und Werkstofftechnik》2023,54(10):1240-1248
The causes of corrosion failure of 20CrMnTi rusted gear were analyzed by quantitative analysis of the composition, observation of the microstructure, hardness test and electrochemical test. The microstructure characterization showed that the proportion of retained austenite in the rusted gear was slightly higher and the length-width ratio of martensite on the surface of addendum of rusted gear was slightly larger than that of the normal gear. However, the corrosion resistance of the rusted gear surface was similar to that of the normal gear. The lubricating oil of the gear was detected to contain water molecules. Further investigation showed that continuous rainy days during the period from installation to disassembly led to a relatively high humidity environment and also the block cover was not installed at that time. Therefore, the corrosive medium continuously entered the gearbox through the block cover hole and destroyed the protection of lubricating oil film, resulting in serious erosion of the gear near the block cover hole. After securing the problem, the block cover was kept installed all the time and no such corrosion failure occurred again. 相似文献
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《Engineering Failure Analysis》2007,14(1):85-100
An intermediate gearbox of a helicopter failed resulting in an accident. A systematic failure analysis was conducted to find out the cause of failure. Examination revealed that fatigue fracturing of the driving gear was responsible for the gearbox failure. The teeth of the gear were severely damaged by spalling. Fractographic study revealed multiple fatigue crack initiation at the tooth root regions. It was established that the failure was caused due to improper assembly of the gear. A detailed analysis of the failure is presented in this paper. 相似文献
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A failure mode analysis of a diesel motor (110 kW) crankshaft from an automobile vehicle is presented. After 120,000 km in service, an abnormal vibration was detected which was increasing with the time. The diesel motor was first disassembled for determining the root cause, however without success. No defect was detected, but since a suspicion of damage was present, and being this failure recurrent in this type of diesel motor series, the crankshaft was disassembled again. Then the crankshaft was subjected to a simple vibration analysis and a preliminary indication of possible existence of a crack was concluded. The crankshaft was then replaced by a new one, and the old was subjected to a failure analysis for determining the root cause. A crack was found at the crankpin web-fillet and after a complete opening of the crack, the failure analysis showed that fatigue was the dominant failure mechanism. Observations were carried out by optical and Scanning Electronic Microscope. Material defects at the crack initiation zone were not found. The root cause of damage seems to be a misalignment of the main journals and a weakness of design close to the gear at the region where the crack was initiated. Therefore, probably a poor design and a deficient assembling of the crankshaft helical gear coupled to the main journal end was the first cause of the failure. 相似文献
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PG6531B型燃气轮机减速箱齿轮断齿原因分析 总被引:3,自引:1,他引:2
对PG6531B型燃气轮机减速箱齿轮断齿材料的化学成分、力学性能和显微组织进行了分析,并对齿轮断口作了宏微观观察。认为,减速箱齿轮失效的主要原因是齿轮表面脱碳,因而硬度不足,以及脉动偏载荷等造成的。提出了预防措施。 相似文献
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对频繁出现轮齿早期断裂的变速箱六档齿轮进行了分析。通过对齿轮断裂特征、显微组织、硬度等方面的综合分析,确定了其断裂形式为低应力高周疲劳断裂。由裂纹扩展过程判断齿轮轮辐设计强度不足是导致其大批量早期疲劳失效的根本原因。据此通过改进齿形、油孔等设计措施,降低齿根部的设计应力水平,解决了这一问题。 相似文献