【作者】 倪平涛；

【导师】 王开文；

【作者基本信息】 西南交通大学 ， 车辆工程， 2007， 博士

【摘要】 自铁路运营以来，铁道机车车辆的轮对基本上都采用两个车轮紧固在一根车轴两端的形式。这种传统固定轮对的优点在于它具有纵向蠕滑力产生的偏转力矩从而使轮对具有自导向功能；但在纵向蠕滑力矩的作用下，当车辆运行速度较高时就可能产生蛇行失稳。因此，近年来独立旋转车轮日益受到重视，与传统轮对相比，独立旋转车轮不存在纵向蠕滑力产生的偏转力矩，因而不产生蛇行运动，对提高稳定性有好处。但这一优点也同时是它的缺点，因为独立旋转车轮失去了纵向蠕滑力矩的导向作用，因而降低了轮对的直线对中性能和曲线导向性能。鉴于此，国外一些专家学者又提出了耦合轮对的构想，即轮对的左右车轮通过某种形式进行适当的耦合，这样便可产生适量的纵向蠕滑力，从而使轮对既具有导向功能，又能保证车辆具有较高的临界速度，国外在这方面已做了一些开拓性的研究工作，而国内在2001年以前则做得较有较少。我国西南交通大学的池茂儒博士在总结国内外耦合轮对研究成果的基础上，结合当今磁流变技术的发展，于2002年提出了磁流变耦合轮对，并对其进行了不少研究。本文则是在其基础上，进行更深一步的探索，以期待在磁流变耦合轮对的实用化方面跨上一个大台阶。本文首次发现耦合轮对耦合器对磁流变零场粘度的特殊性要求，采用大粘度的润滑脂作为载液，始终利用永磁体提供外加初始磁场，当车辆停止时使磁流变恒为半固体，为此设计了十分简洁的磁流变轮对耦合器，解决了静置时磁粒的抗沉降稳定性问题。首次根据磁流变的双粘度模型，建立了4个轮对全为磁流变耦合轮对(CCCC型)、1位和3位为传统轮对与2位和4位为耦合轮对(TCTC型)、2位和4位为传统轮对与1位和3位为耦合轮对(CTCT型)、1位和4位为传统轮对与2位和3位为耦合轮对(TCCT型)4种车型，以及传统车辆(TTTT型)的空间动力学模型，并为这几种模型编制了计算机仿真软件。通过仿真分析，发现当磁流变屈服应力较小时，磁流变耦合轮对车辆具有较高的临界速度，但磁流变耦合轮对在曲线上的横移量较大，出现了两点接触；若增大屈服应力，则临界速度急剧下降，与传统车辆相比已毫无优势，但磁流变耦合轮对在曲线上的横移量减小；再继续增大屈服应力，则临界速度缓慢下降；当屈服应力增大到一定值后，则临界速度继续缓慢下降，而磁流变耦合轮对在曲线上的横移量增大。当采用抗蛇行减振器后，相对传统车辆来讲，可极大地提高车辆的临界速度。根据对上述4种磁流变耦合轮对在高速和准高速线路上曲线通过性能的比较，遴选出具有较优性能的TCCT型拖车，可在高速铁路上以高速和超高速、在准高速铁路上以准高速交互运行；在TCCT型拖车的传统轮对上安装驱动装置而成为的动车也具有极高的临界速度和良好的横向动力学性能，这说明了磁流变耦合轮对TCCT动车组亦具有类似其拖车的动力学性能。另外，对TCCT型拖车的悬挂参数对临界速度的影响进行了分析和优化；分析了转向架的轴距差、对角线差及线路条件对临界速度的影响，其中前两者对临界速度的影响不大，而线路条件则影响很大。同时对自导向磁流变耦合轮对径向转向架进行了研究，结果表明不能减小轮对在曲线上的横移量，建议不宜采用。经过分析，当磁流变的屈服应力和悬挂参数合理时，TCCT型车不需控制屈服应力的变化，就具有极高的临界速度和在高速与准高速铁路上良好的动力学性能，且该车型具有结构对称，正反运行方向性能相同，简化了转向架的结构，为磁流变耦合轮对投入实际运营奠定了理论基础。另外，提出了轨廓分区法全面计算轮轨接触状态法，在考虑轮对的横移、浮沉、摇头、侧滚和左右钢轨的横移、浮沉、侧滚的条件下，可全面地分别计算左右侧轨顶和轨侧区域与车轮的最小轮轨间隙量，以此来判断轮轨的真实接触状态：正常的一点接触、非正常的一点接触、两点接触和车轮完全悬浮，并根据非线性赫兹接触理论分别求得两接触点处的轮轨法向力，从而使仿真结果更接近于车辆在实际线路上的运行状态。该方法对在传统车辆动力学的轮轨接触关系方面也同样适用。更多还原

【Abstract】 Since railway is plunged into business, the wheelsets with twowheels fixed to two ends of one axle has commonly been adopted in railway vehicle. The advantage of traditional fixed wheelsets is that they have self-steering capability produced by longitudinal creep moments, however it possibly occurs of hunting unstability when the speed becomes higher, so independently rotating wheels（IRW） is attached importance increasingly. IRW don’ t possess longitudinal creep forces, so it doesn’ t occur of hunting and the stability of the vehicle system is improved. But IRW lose self-steering capability without longitudinal creep moments, so its restoration capability and curving performances become worse. Thereupon, the idea of coupled wheelsets is brought forward that the left and right wheels of wheelsets are properly coupled to produce a few longitudinal creep forces. In this way, coupled wheelsets have both self-steering capability and higher critical velocity. Some researches on coupled wheelsets have been carried on abroad while scholars in our country do less works before 2001. In 2002, Dr Chimaoru with Sothwest jiaotong University raise magneto-rheologial fluid coupled wheelsets （MRFCW） on the basis of concluding research achievements at home or aboard and combining technology progress of magneto-rheologial fluid（MRF） nowadays, at the same time, he has done lots of works. This paper explores deeply on the basis of Chimaoru’ s works and hope to stride a big step in MRFCW vehicle.The paper firstly discovers particularity of MRFCW to MRF , adopts big viscidity grease as baseoil and provides magnet field always using permanent magnet. Therefore, MRF is semi-solid all the time when vehicle is still, and then very simple MRFCW device is designed, so magnet particle’ s anti-settling is solved. Dynamic model; are established on the basis of MRF bi-viscidity model including railway vehicles of 4 MRFCW（CCCC model）, of fixed 1^st and 3^rd wheelsets, MRF coupled 2^nd and 4^th wheelsets （TCTC model）, of coupled 1^st and 3^rd wheelsets, MRF fixed 2^nd and 4^th wheelsets （CTTC model）, of fixed 1^st and 4^th wheelsets, coupled MRF 2^nd and 3^rd wheelsets（TCCT model） and traditional vehicle（TTTT）, the dynamics simulating software of these models are programmed.Simulation shows that MRFCW vehicle possess higher critical velocity under the condition of MRF smaller yield stress, but bigger MRFCW lateral displacement, two-point contact occur in the meantime, critical velocity sharply descended in increasing yield stress, MRFCW lateral displacement decreased, yield stress increased continually, critical velocity descended slowly, but lateral displacement become bigger. Anti-hunting damper can raise critical velocity of MRFCW vehicle opposite traditional vehicle to speak. TCCT vehicle possess better dynamic performances in 4 kinds of MRFCW vehicles and it runs on the high-speed and quasi-highspeed track alternatively, this shows TCCT movement group possess better dynamic performances with comparison to its towing vehicle. In addition, influences of TCCT vehicle suspension parameter on critical velocity are analyzed and suspension parameters are optimized. Influence of wheelbase and diagonal difference of bogie, track condition on critical velocity, result demonstrates both former have little influence, but track condition has big influence. Besides, self-steered MRF radial truck is analyzed, but result proves that the bogie can’ t decrease lateral displacement and it isn’ t suitable in reality.TCCT vehicle possesses very high critical velocity and better dynamic performances when MRF yield stress and suspension parameter are appropriate by analyzing under the condition of not controlling MRF yield stress on the highspeed and quasi-highspeed railway, besides, TCCT vehicle possesses symmetrical simplified structure and the dynamic performances in front and behind.In addition, total wheel/rail contact calculation with divided rail outline method are raised. Under the condition of considering the displacement, bouncing, yaw, roll of wheelsets and displacement, bouncing, roll of rails, minimum gap between rail and wheel were calculated by the trochoid method and divided rail outline method, we can easily judge totally real contact states of the wheel/rail such as normal one-point contact, nonnormal one-point contact, two-point contact and wheel complete lift. Wheel/rail normal forces in the two contact point are respectively calculated by nonlinear Hertz contact theory, and then, result of simulation more close to reality on actual track. This method can also be applied in contact of wheel/rail in traditional vehicle dynamics.更多还原