高速磁力泵滑动轴承的试验研究

高速磁力泵滑动轴承的优劣直接关系到泵机组能否可靠运行。设计研究高速磁力泵滑动轴承。对采用F50C复合材料制成的滑动轴承进行了径向和端面磨损试验,考察了其耐磨性能。经实际使用考核,用F50C复合新材料制成的滑动轴承,具有优良的耐磨性能、抗冲击性和自润滑性能,能满足高速磁力泵的使用要求。     

弹性金属塑料瓦径向滑动轴承启动过程热弹流分析

研究了采用弹性金属塑料轴瓦时径向滑动轴承的瞬态润滑特性。建立了该轴承的三维热弹流模型，通过数值求解对比了启动过程中采用弹性金属塑料轴瓦和金属材料轴瓦时油膜和轴瓦的瞬态温度场分布、轴瓦的热弹变形量，以及转子轴心轨迹。结果表明，在启动初期弹性金属塑料瓦径向滑动轴承的瓦体温度要高于金属瓦，转子偏心率也要大于采用金属瓦时的偏心率；因润滑油在弹性金属塑料瓦径向滑动轴承轴瓦表面存在一定的滑移速度，随着油膜边界滑移作用的出现，采用弹性金属塑料瓦径向滑动轴承时的油膜温度最终低于采用金属瓦时的温度，且转子的偏心率也最终小于采用余属瓦的偏心率。     

多瓦可倾瓦径向滑动轴承热弹流润滑分析

考虑轴瓦弹性变形,建立多瓦可倾瓦径向滑动轴承热弹流润滑(TEHD)分析的数学模型,对比分析多瓦可倾瓦径向滑动轴承热流体动力润滑(THD)与TEHD模型的润滑性能差异,分析轴瓦弹性变形对轴承润滑性能的影响.结果表明,轴瓦弹性变形导致最小油膜厚度减小、流体动压力的梯度下降,但对瓦面温度的影响较小;THD模型高估了轴承的承载能力,在高速重载的场合,这种误差可能导致轴承润滑失效.因此,在滑动轴承设计中有必要考虑轴瓦弹性变形对轴承润滑性能的影响.     

磁力泵滑动轴承磨损监测装置设计

针对磁力泵滑动轴承磨损发生后易造成隔离套磨穿事故的特点,设计了一种磁力泵滑动轴承磨损实时检测装置。简要介绍磁力泵滑动轴承磨损实时检测装置的工作原理,并对该检测装置零件设计进行了技术说明,最后对该装置实时监测的可行性进行了理论分析。分析表明该监测装置能够有效满足实时监测的设计要求,对提高磁力泵运行可靠性,减少工业事故的发生有着一定的实际意义。     

船用电机滑动轴承的试验研究

针对所设计的船用电机滑动轴承，搭建了船用电机滑动轴承试验台，对不同工况试验条件下的滑动轴承进行了试验，得到了滑动轴承在不同试验条件下的润滑油温升情况、轴瓦温度的变化情况，以及轴瓦的磨损情况。试验数据表明，该船用电机滑动轴承能够满足各种实际工况的需要，验证了结构设计的合理性和正确性。     

GCB型高速磁力泵系列开发

GCB型高速磁力驱动泵体积小、重量轻、无泄漏、安全可靠,能满足船舶、航空等特定场合的使用要求。本课题组开发了400Hz高速磁力泵系列,给出了该泵的系列参数,介绍了该系列泵的结构特点:隔离套和泵轴构成一体,是静止件;内磁钢和叶轮为一体,构成内磁转子。这种结构保证了泵机组尺寸小、重量轻。阐述磁力泵吸入口设置轴向可变位的导流栅解决高转速下易导致的汽蚀问题;设计采用了密集型聚磁磁性联轴器缩小了转子外径;利用冷却循环回路的压力降来平衡轴向力以及采用F50C新型耐磨滑动轴承提高泵的使用寿命等关键技术。经试验验证,本高速磁力泵抗汽蚀性能好、噪声低、运行平稳,可广泛推广应用。     

EMP径向滑动轴承温度场和压力场测试研究

弹性金属塑料瓦(EMP)径向滑动轴承是一种新型的轴承,由于轴瓦所采用的复合材料的特殊特性使得其油膜温度场和压力场分布情况与传统金属瓦轴承的油膜温度场和压力场分布情况有所不同。本文对呻径向滑动轴承油膜温度场和压力场进行了实验研究,为从理论上揭示EMP径向滑动轴承的流体动压润滑机理并进而进行型面设计提供实验依据。     

可倾瓦径向滑动轴承流体润滑性能分析

本文研究了可倾瓦径向滑动轴承流体润滑性能。推导了可倾瓦径向滑动轴承油膜厚度,得到可倾瓦径向滑动轴承的Reynolds方程,应用Matlab软件计算得到了油膜压力分布、油膜厚度分布,油膜承载力。计算结果表明:轴瓦的油膜压力3D分布呈现抛物面形分布,且下瓦油膜压力最大,油膜厚度最小,当偏心率较小时,承载力缓慢增大,当偏心率较大时,承载力急剧上升。该结论为轴承的设计与选用提供理论依据。     

支点摩擦力对可倾瓦径向滑动轴承润滑特性的影响

为了研究轴瓦支点摩擦力对其润滑性能影响,建立可倾瓦径向滑动轴承的支点摩擦力的数学模型,分析其对轴承的润滑特性,如油膜压力、厚度、摩擦阻力、功耗及轴承承载力和流量的影响,得出支点摩擦力的影响作用较大的结论,因此在设计可倾瓦径向滑动轴承的过程中,考虑支点摩擦力的影响很有必要.     

混合流态下鲨鱼皮织构滑动轴承静特性分析

轴瓦表面的织构会导致油膜厚度分布不均匀，整个流场中雷诺数差异较大，形成紊流和层流并存的混合流态。另外在高速运转工况下润滑油温度会大幅升高，从而影响其黏度及轴承承载能力等性能。鉴于鲨鱼皮结构在减阻、防污方面的成功应用，根据鲨鱼的盾鳞结构抽象建立了类鲨鱼皮二维织构的数学模型；同时考虑紊流以及油膜温度的作用，将类鲨鱼皮织构用于滑动轴承轴瓦形面的设计上，从鲨鱼皮织构的周向和轴向分布位置、织构深度、转速4个方面，对比分析了鲨鱼皮织构与球坑以及圆柱坑织构对滑动轴承静特性的影响。结果表明：1)织构位置分布对径向滑动轴承的性能影响非常大；2)不同织构深度下，鲨鱼皮织构始终表现出良好的减摩效果；3)高速紊流状态下的鲨鱼皮织构滑动轴承相比其他轴承减阻效果更加明显。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

基于多目标非支配解提取法的电力系统无功优化

针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.