采用后轮独立车轮转向架的地铁拖车动力学分析

将后轮独立车轮转向架运用到地铁拖车中,利用SIMPACK动力学分析软件对其进行分析,证明其稳定性和小曲线通过能力均优于传统地铁拖车。讨论轴距对新型地铁车辆的影响,使其在保证稳定性的前提下进一步提高曲线通过性能。     

铝合金车轮重力铸造模具设计与分析

铝合金车轮与传统辐条式钢车轮相比,不仅外观多样化,其抗冲击性能及轻量化设计都得到了市场的认可和青睐,在生产铸造中,重力金属模铸造方式是每个生产企业的首选,生产出来的铝合金车轮要求无明显可见疏松、夹渣、气孔、针孔等铸造缺陷。     

2×110kW推轮的设计及应用

为适应长江、汉江干支运输,本文设计了2×110KW推（拖）轮,介绍了该轮的主要数据及技术性能,并从船体艉部线型、浮心位置、螺旋桨及振动和噪声等方面作了改进,经使用其技术性能,从纵方式、建造质量等均达到了同类船型的先进水平。     

Influence of the track quality and of the properties of the wheel–rail rolling contact on vehicle dynamics

This work describes an analytical approach to determine what degree of accuracy is required in the definition of the rail vehicle models used for dynamic simulations. This way it would be possible to know in advance how the results of simulations may be altered due to the existence of errors in the creation of rolling stock models, whilst also identifying their critical parameters. This would make it possible to maximise the time available to enhance dynamic analysis and focus efforts on factors that are strictly necessary. In particular, the parameters related both to the track quality and to the rolling contact were considered in this study. With this aim, a sensitivity analysis was performed to assess their influence on the vehicle dynamic behaviour. To do this, 72 dynamic simulations were performed modifying, one at a time, the track quality, the wheel–rail friction coefficient and the equivalent conicity of both new and worn wheels. Three values were assigned to each parameter, and two wear states were considered for each type of wheel, one for new wheels and another one for reprofiled wheels. After processing the results of these simulations, it was concluded that all the parameters considered show very high influence, though the friction coefficient shows the highest influence. Therefore, it is recommended to undertake any future simulation job with measured track geometry and track irregularities, measured wheel profiles and normative values of the wheel–rail friction coefficient.     

基于增量谐波平衡法的汽车转向轮非线性摆振的研究

采用振幅作为控制参数,应用增量谐波平衡法,求得方程解的表达式,分析了系统的分岔和极限环振动现象,并用龙格库塔法进行数值计算验证,结果表明:增量谐波平衡法在汽车转向轮摆振分析中有效可靠,有足够的精度,并运用Floquet理论对周期解的稳定性进行分析,进而确定了极限环的稳定性,最后分析了各结构参数对摆振的影响。     

汽车镁合金车轮动态特性分析

与现行被广泛应用的铝合金相比,镁合金车轮能降低车辆质量和燃油消耗,减小车辆的振动和噪声,提高车辆的动力学特性。文中尝试采用新型铸造镁合金代替铝合金开发汽车车轮,并探索利用动态设计方法对某车型的车轮进行轻量化设计与分析,从而评价其强度可靠性及模态特性。     

Method for obtaining the modal properties of articulated trains equipped with independently rotating wheels

Independently rotating wheels in railway vehicles could represent an alternative to standard technology as a solution to dynamic problems such as hunting instability or steering forces in curves. Among the proposed design solutions, the train with independently rotating wheels and with the most practical applications is that developed by Talgo. The Talgo technology is based on the use of a passive steering technique of the wheelset through a mechanism. The absence of automatic control systems means that a careful selection of the mechanical parameters of the vehicle is required to improve its dynamic characteristics. Aspects such as dynamic stability or the effect of vibration on passenger comfort could be analysed by extracting the modal properties of the train from mathematical models. In this article, a methodology for determining the low-frequency modal properties of articulated trains equipped with independently rotating wheels and passive steering system (Talgo-type) is proposed. The singularity of this application based on the use of non-conventional wheelsets necessarily involves the development of a specific methodology.     

70%低地板轻轨车辆的型式比较

阐述了低地板轻轨车辆的发展和70%低地板轻轨车辆的优点.介绍了70%低地板轻轨车辆的几种典型型式.从转向架和车体结构方面比较其各种型式的优缺点,指出模块化是低地板轻轨车辆的发展方向.实现低地板的关键技术在于解决独立车轮转向架中的轮缘磨耗问题.给出了提高独立车轮导向能力的措施.     

某纯电动商用车总里程跳变分析

针对某纯电动商用车的组合仪表里程跳变问题进行了分析,发现其储存芯片存在问题,并针对该问题提出了一种方法。该方法在下电前通过VCU记录组合仪表所发送的里程数据,并在下次上电时发送到总线上,供仪表进行校验,如校验通过,则里程未跳变;如校验失败,则里程跳变,组合仪表改用VCU发送的总里程并继续计算总里程。经验证,该方法可以有效地预防里程跳变,特别是下电后再上电时的里程跳变。     

车轮旋转对汽车流场影响的模拟研究

汽车车轮对汽车空气动力学特性有重要的影响。为了研究车轮旋转对汽车流场的影响,利用CFD方法,采用旋转壁面边界条件模拟汽车车轮旋转。建立了三维不可压缩雷诺平均方程,采用RNG湍流模型,利用二阶迎风差分格式获得控制体积界面上的物理量,应用SIMPLEC算法进行迭代计算．对汽车流场进行模拟仿真,并将结果与车轮静止的情况下进行对比分析。研究结果表明：汽车车轮转动对整车流场有明显的影响,特别是对汽车前后轮周围、汽车侧面和底面有很大的影响：车轮旋转情况下,车轮的上半部分受到的压力明显比静止的时候受到的压力大．但总体上会产生一个向上的气动升力：汽车在车轮旋转情况下,阻力系数和升力系数比车轮静止情况下的低。