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Zaigang Chen Wanming Zhai Kaiyun Wang 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(2):244-267
A gear transmission system is a key element in a locomotive for the transmission of traction or braking forces between the motor and the wheel–rail interface. Its dynamic performance has a direct effect on the operational reliability of the locomotive and its components. This paper proposes a comprehensive locomotive–track coupled vertical dynamics model, in which the locomotive is driven by axle-hung motors. In this coupled dynamics model, the dynamic interactions between the gear transmission system and the other components, e.g. motor and wheelset, are considered based on the detailed analysis of its structural properties and working mechanism. Thus, the mechanical transmission system for power delivery from the motor to the wheelset via gear transmission is coupled with a traditional locomotive–track dynamics system via the wheel–rail contact interface and the gear mesh interface. This developed dynamics model enables investigations of the dynamic performance of the entire dynamics system under the excitations from the wheel–rail contact interface and/or the gear mesh interface. Dynamic interactions are demonstrated by numerical simulations using this dynamics model. The results indicate that both of the excitations from the wheel–rail contact interface and the gear mesh interface have a significant effect on the dynamic responses of the components in this coupled dynamics system. 相似文献
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分析SS4B型机车整流装置在运用过程中各支路元件的负荷情况,指出其设计上的缺陷,并提出一种加装均流电抗器和去除设计不合理的多余元件的方法,以提高整流装置的可靠性。 相似文献
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吴玉兰 《大连铁道学院学报》1992,13(2):28-32
轮轨间的最佳粘着利用对城市轨道车辆节能起着重要作用.本文分析了城市轨道车辆的粘着特点,提出了改善其粘着利用的途径,并指出了装设粘控装置能实现最佳粘着利用,收到良好的节能效果. 相似文献
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利多卡因对脑缺血再灌注损伤大鼠海马组织细胞间黏附分子-1及核转录因子-κB表达的影响 总被引:4,自引:0,他引:4
目的观察利多卡因对大鼠脑缺血再灌注损伤后海马组织细胞间黏附分子-1(ICAM-1)及核转录因子-κB(NF-κB)蛋白和mRNA表达的影响,探讨利多卡因脑保护作用的机制。方法雄性SD大鼠32只,随机分为假手术组(A组)、缺血再灌注组(B组)、利多卡因小剂量组(C组)和利多卡因大剂量组(D组),缺血前10 min腹腔注射。脑缺血10 min再灌注24 h时,断头处死大鼠。用RT-PCR技术检测海马组织ICAM-1及NF-κB mRNA的表达,用免疫组织化学、蛋白印记(Western blot)方法检测ICAM-1及NF-κB蛋白表达情况。结果脑缺血再灌注后海马组织ICAM-1和NF-κB mRNA及蛋白表达水平增高,利多卡因可下调ICAM-1及NF-κB表达;缺血再灌注后,海马区神经元出现明显坏死,利多卡因可减轻海马区神经元损伤。结论利多卡因可能通过抑制ICAM-1与NF-κB基因表达而对脑缺血再灌注损伤起到一定的保护作用。 相似文献
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为提高城市轨道交通列车轮轨黏着力的控制,针对传统组合校正法存在的缺点,对参考速度进行延时补偿、筛选及步长限制,尽可能保证参考速度的准确性;对加速度提取采用低通加高通滤波器的方法,以降低噪声影响;黏着控制过程中,根据设定周期时间内速度差估算当前轨面黏着情况,实时调整下一周期判据阈值;根据上一调节周期触发空转时刻锁存转矩和当前加速度,以及转速差采用分段斜率的方法进行转矩调节。试验结果表明:上述控制方法转矩波动小,列车运行平稳,黏着利用率得到有效提高。 相似文献
48.
在车轮-钢轨高速接触疲劳试验机上开展水、油和树叶等污染下的高速低黏着和增黏试验,通过最高速度200km·h-1的对滚试验,测得不同第三介质条件下的轮轨黏着-蠕滑特性曲线,研究增黏砂粒径和撒砂量对增黏效果的影响。结果表明:喷撒增黏砂可有效恢复各种污染下的轮轨黏着水平,使200km·h-1下轮轨黏着系数保持在0.18以上,低速下更高;增黏砂粒径在0.4~1.0mm范围内增大或撒砂量在40~100g·min-1范围内增加时,增黏效果均稍稍增强,综合考虑确定试验机的最佳撒砂量为40g·min-1、最佳粒径为0.85~1.0mm;考虑试验机与现场轮轨系统的尺寸差异、运行时复杂气流所致砂粒损失及适当冗余度等因素,建议现场最佳撒砂量为115~175g·min-1、最佳粒径为1.0~2.0mm;喷撒增黏砂会造成车轮接触表面的麻坑损伤,也是造成现场车轮踏面常见麻坑损伤的根本原因。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):699-724
In modern railway Automatic Train Protection and Automatic Train Control systems, odometry is a safety relevant on-board subsystem which estimates the instantaneous speed and the travelled distance of the train; a high reliability of the odometry estimate is fundamental, since an error on the train position may lead to a potentially dangerous overestimation of the distance available for braking. To improve the odometry estimate accuracy, data fusion of different inputs coming from a redundant sensor layout may be used. Simplified two-dimensional models of railway vehicles have been usually used for Hardware in the Loop test rig testing of conventional odometry algorithms and of on-board safety relevant subsystems (like the Wheel Slide Protection braking system) in which the train speed is estimated from the measures of the wheel angular speed. Two-dimensional models are not suitable to develop solutions like the inertial type localisation algorithms (using 3D accelerometers and 3D gyroscopes) and the introduction of Global Positioning System (or similar) or the magnetometer. In order to test these algorithms correctly and increase odometry performances, a three-dimensional multibody model of a railway vehicle has been developed, using Matlab-Simulink?, including an efficient contact model which can simulate degraded adhesion conditions (the development and prototyping of odometry algorithms involve the simulation of realistic environmental conditions). In this paper, the authors show how a 3D railway vehicle model, able to simulate the complex interactions arising between different on-board subsystems, can be useful to evaluate the odometry algorithm and safety relevant to on-board subsystem performances. 相似文献