高速动车组齿轮油选型研究

以我国某型号时速350 km高速动车组齿轮箱为研究对象,结合实际运行工况,计算确定齿轮啮合在弹性流体动压润滑状态下对油品黏度的需求;通过有限元方法模拟计算齿轮箱温升平衡后的温度场,确定油品类型;结合实际运行中环境温度范围,确定油品的低温要求。综合该型号高速动车组齿轮箱的黏度需求、抗高温氧化性能要求及低温要求,确定合适的润滑油类型,为高速铁路列车齿轮油类型的选择及匹配油品的设计提供理论依据。     

动车组齿轮箱润滑油更换周期优化

目前齿轮箱润滑油更换是按照供应商提供的换油周期执行，缺乏对实际运用条件下齿轮箱润滑油性能状态变化情况的跟踪和研究分析。为准确确定CRH380B平台动车组齿轮箱润滑油合理的换油周期，通过理化性能分析以及污染物含量和磨损元素含量变化趋势分析，开展齿轮箱润滑油关键指标变化趋势研究；建立关键指标随油品运行里程变化的数学模型，并对油品运行里程进行预测。结果表明：CRH380B平台动车组齿轮箱润滑油更换周期延长至60万km可行；Fe元素含量变化可作为齿轮箱润滑油重点监控的指标；通过Fe元素含量随油品运行里程变化的数学模型，预测CRH380B齿轮箱润滑油在运行至80万km后仍满足使用要求。     

高速列车齿轮箱润滑油黏度指数的计算方法研究

高速列车齿轮油不仅承担高转速啮合齿轮间的润滑,通常也承担齿轮箱两端轴承的润滑,其黏度指数的确定和选择需要对润滑规律进行更严格的揭示与分析。采用机械设计计算查表法、黏度经验公式法、弹流润滑分析法、弹流润滑经验公式等方法,以CRH380A动车组齿轮箱为研究对象,计算高速列车齿轮箱所需润滑油的40 ℃黏度与100 ℃黏度,并得到选型的黏度指数,为高速列车齿轮油的选型提供了模型和理论依据。研究发现,由于高速下齿面接触应力很大、温度高、圆周速度大,高速列车齿轮润滑油还应当提高抗磨性、热安定性与氧化安定性等,并能够在较宽温度范围的运转,且要着重考虑齿轮油对齿轮箱内轴承的润滑及安全特性。     

高速动车组齿轮油换油周期研究

高速动车组齿轮箱的润滑是高速列车运行安全的关键技术之一。为了研究高速动车组在用齿轮油的衰变特性,指导现场定置换油,提出了高速动车组齿轮油换油周期方法。通过在京沪专线动车组上选取CRH6444车6部齿轮箱在用油连续9次的跟踪监测,采用理化指标评估法、污染变化评估法、添加剂消耗评估法、磨损情况评估法对CRH动车组齿轮箱在用润滑油的换油周期进行了评估。研究结果表明,高速动车组齿轮箱在用的车辆齿轮油平均换油周期里程不超过35万公里为宜。研究结果可以为我国CRH动车组齿轮箱检修和安全运行提供在用润滑油更换技术参考。     

某型高速动车组齿轮箱温度故障原因分析及处理

某型高速动车组在进行型式试验过程中,出现“03车最大速度Vmax级别1被要求”故障及“小齿轮MS FM1：超过温度限制1”报警。针对此故障,对03车1轴、2轴电机及齿轮箱进行外观检查及点温测试,均正常。后续对03车1轴齿轮箱进行温度监控,发现温度上升至118℃,通过切除03车牵引,限速280km/h的方式维持运行。经检查及故障分析,判断小齿轮箱温度较高的原因为齿轮箱润滑系统虽能满足该轴承润滑能力,但润滑效果偏弱,高速动车组长时间运行后热量容易积累,当室外温度较高时,容易引起小齿轮箱温度较高。更换03车1轴轮对及齿轮箱温度传感器,解除故障。     

高速动车组驱动齿轮箱的约束模态分析与结构改进

以某高速动车组驱动齿轮箱为研究对象,采用APDL语言建立齿轮箱约束模态分析参数化模型,应用弹簧单元模拟轴与箱体之间的结合面,通过有限元分析得到齿轮箱前4阶约束模态振型及其固有频率;运用Sobol局部灵敏度分析方法,确定影响齿轮箱固有频率的关键结构参数,分析关键结构参数对固有频率的影响规律;在此基础上,对关键结构的尺寸参数做出改进,使齿轮箱的1阶、2阶固有频率提高了5％以上,提高了齿轮箱的抗振能力.为高速动车组驱动齿轮箱的改进设计提供了理论依据.     

时速350km中国标准动车组驱动齿轮箱的研制

介绍了高速动车组用齿轮箱的结构特点、性能参数、仿真计算分析、样机试制及型式试验等内容。齿轮箱的各项性能指标符合设计规范,能够满足中国标准动车组的运用要求。     

高速动车组齿轮箱内部流场仿真分析及搅油损失计算

为精确、快速地获取操作过程中高速列车齿轮箱中复杂内部流场的真实运动和分布状态,通过合理简化高速动车组驱动齿轮箱的三维模型,采用运动粒子仿真(Moving Particle Simulation,MPS)开展仿真分析.基于箱体内部油液不同瞬时分布状态,研究正、反转工况、油液浸没深度和润滑油黏度等参数对齿轮箱内部流场分布的...     

基于试验模态分析的某型号动车组齿轮箱有限元模态分析研究

针对动车组齿轮箱未达到强度破坏极限就已损坏的问题,对动车组的驱动部件也是关键部件的齿轮箱进行有限元模态分析及试验模态分析,提出基于试验模态分析方法上的有限元模态分析,建立了试验模态分析方法的理论模型,并利用齿轮箱的试验模态分析结果来验证齿轮箱有限元模态分析结果的可靠性。研究结果表明,试验模态分析方法与有限元模态分析方法得出的结果非常相近,印证了有限元模态分析方法的可靠性,为掌握该型号齿轮箱的动态特性及优化该型号齿轮箱提供了理论及实验依据。     

高速动车组齿轮箱稳态温度场分析

高速动车组齿轮箱运行时会产生大量的热使其温度场平衡温度升高导致其出现热轴、箱体表面出现裂纹等故障现象,为了获得齿轮箱温度场分布规律,对某型高速动车组齿轮箱进行稳态温度场分析。建立了齿轮箱稳态温度场数学模型并确立了边界条件,通过有限元法对齿轮箱温度场进行数值模拟分析,并与试验结果对比以验证建立模型的可靠性。结果表明:小齿轮两个圆柱滚子轴承处温度最高,出现热轴故障的可能性最大;温度以热源为中心向周围扩散,依次递减;仿真结果与试验结果误差小于3.36%,建立的仿真模型可有效预测齿轮箱温度分布。通过分析获得齿轮箱温度场的分布规律,为齿轮箱故障分析和润滑流道结构改进提供理论依据。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.