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Advancing high-speed train gearbox durability:enhanced bearing load and contact stress through transition from helical to herringbone gears
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作者 Hao Wu Jing Wei +2 位作者 Pingbo Wu Fansong Li yayun qi 《Railway Engineering Science》 EI 2024年第4期461-479,共19页
High-speed trains typically utilize helical gear transmissions,which significantly impact the bearing load capacity and fatigue service performance of the gearbox bearings.This paper focuses on the gearbox bearings,es... High-speed trains typically utilize helical gear transmissions,which significantly impact the bearing load capacity and fatigue service performance of the gearbox bearings.This paper focuses on the gearbox bearings,establishing dynamic models for both helical gear and herringbone gear transmissions in high-speed trains.The modeling particularly emphasizes the precision of the bearings at the gearbox's pinion and gear wheels.Using this model,a comparative analysis is conducted on the bearing loads and contact stresses of the gearbox bearings under uniform-speed operation between the two gear transmissions.The findings reveal that the helical gear transmission generates axial forces leading to severe load imbalance on the bearings at both sides of the large gear,and this imbalance intensifies with the increase in train speed.Consequently,this results in a significant increase in contact stress on the bearings on one side.The adoption of herringbone gear transmission effectively suppresses axial forces,resolving the load imbalance issue and substantially reducing the contact stress on the originally biased side of the bearings.The study demonstrates that employing herringbone gear transmission can significantly enhance the service performance of high-speed train gearbox bearings,thereby extending their service life. 展开更多
关键词 High-speed train Herringbone gear Helical gear Gearbox bearings Contact stress
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Rotary-scaling fine-tuning (RSFT) method for optimizing railway wheel profiles and its application to a locomotive 被引量:9
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作者 Yunguang Ye yayun qi +3 位作者 Dachuan Shi Yu Sun Yichang Zhou Markus Hecht 《Railway Engineering Science》 2020年第2期160-183,共24页
The existing multi-objective wheel profile optimization methods mainly consist of three sub-modules:(1)wheel profile generation,(2)multi-body dynamics simulation,and(3)an optimization algorithm.For the first module,a ... The existing multi-objective wheel profile optimization methods mainly consist of three sub-modules:(1)wheel profile generation,(2)multi-body dynamics simulation,and(3)an optimization algorithm.For the first module,a comparably conservative rotary-scaling finetuning(RSFT)method,which introduces two design variables and an empirical formula,is proposed to fine-tune the traditional wheel profiles for improving their engineering applicability.For the second module,for the TRAXX locomotives serving on the Blankenburg–Rubeland line,an optimization function representing the relationship between the wheel profile and the wheel–rail wear number is established based on Kriging surrogate model(KSM).For the third module,a method combining the regression capability of KSM with the iterative computing power of particle swarm optimization(PSO)is proposed to quickly and reliably implement the task of optimizing wheel profiles.Finally,with the RSFT–KSM–PSO method,we propose two wear-resistant wheel profiles for the TRAXX locomotives serving on the Blankenburg–Rubeland line,namely S1002-S and S1002-M.The S1002-S profile minimizes the total wear number by 30%,while the S1002-M profile makes the wear distribution more uniform through a proper sacrifice of the tread wear number,and the total wear number is reduced by 21%.The quasi-static and hunting stability tests further demonstrate that the profile designed by the RSFT–KSM–PSO method is promising for practical engineering applications. 展开更多
关键词 Wheel profile optimization Wear reduction Rotary-scaling fine-tuning Particle swarm optimization Kriging surrogate model
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新型含吡啶基3-硫醚-4-吲哚亚氨基-4H-1,2,4-三唑衍生物的设计、合成及体外生物活性评价 被引量:2
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作者 漆亚云 刘佳敏 +5 位作者 李成朋 胡伟男 唐思雨 邵利辉 王贞超 欧阳贵平 《有机化学》 SCIE CAS CSCD 北大核心 2021年第4期1670-1682,共13页
设计、合成了一系列含吡啶基的新型3-硫醚-4-吲哚亚氨基-4H-1,2,4-三唑衍生物17a-17r.采用噻唑蓝(MTT)法对目标化合物在人类四种癌细胞A549、PC-3、HepG2、K562和大鼠正常肾细胞NRK-52E进行抗增殖活性评价.结果显示部分化合物表现出一... 设计、合成了一系列含吡啶基的新型3-硫醚-4-吲哚亚氨基-4H-1,2,4-三唑衍生物17a-17r.采用噻唑蓝(MTT)法对目标化合物在人类四种癌细胞A549、PC-3、HepG2、K562和大鼠正常肾细胞NRK-52E进行抗增殖活性评价.结果显示部分化合物表现出一定的抗增殖活性,其中乙基(E)-2-((4-(((2-氯-1-乙基-1H-吲哚-3-基)亚甲基)氨基)-5-(吡啶-4-基)-4H-1,2,4-三唑-3-基)硫代)乙酸酯(17k)对PC-3表现出较好的抗增殖活性,IC50值为9.90μmol/L,且对NRK-52E的细胞增殖毒性低于对照药5-氟尿嘧啶.同时,采用细胞迁移试验、4,6-二脒基-2-苯基吲哚(DAPI)染色、线粒体膜电位分析以及细胞凋亡、周期分析,进一步研究了化合物17k的作用机制,证明化合物17k能够有效抑制肿瘤细胞的迁移,诱发细胞凋亡,还可以浓度依赖性方式将人前列腺癌细胞PC-3的细胞周期阻滞在G2期.此外,还探究了目标化合物对水稻白叶枯病菌(Xanthomonas oryzae pv.Oryzae,Xoo)的抑制活性,初步抗菌活性结果显示:化合物17b、17e和17h在50和100μg/mL时,对水稻白叶枯病菌表现出一定的抑制活性,优于对照药叶枯唑(BMT)和噻菌铜(TDC). 展开更多
关键词 1 2 4-三唑 吲哚 抗肿瘤活性 杀菌活性
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