汽轮机轴承巴氏合金不应修刮芝麻点

汽轮机使用的轴承,包括径向支持轴承和轴向推力轴承,在支持轴承轴瓦内圆表面和推力轴承瓦块表面,浇有一层约1.5毫米厚的轴瓦乌金,又称巴氏合金,牌号是ChSnSb11-6,其中含锑量为10～12％,含铜量为5.5～6.5％,其余部份均为锡。这种合金具有质软、熔点低和良好的耐热、耐蚀性能。     

大型核电汽轮机推力轴承油膜失稳振动研究

针对某些机型核电汽轮机出现轴向振动与径向振动耦合的现象,采用大型核电汽轮发电机组推力轴承可倾瓦块模型,对运行中油膜失稳引起的自激振动进行了机理分析。通过建立转子轴向运动方程,对某650 MW核电机组启机过程中推力轴承载荷进行了测量,计算得出不同轴向载荷和推力轴承间隙比条件下的油膜刚度和阻尼,并分析了推力轴承油膜失稳引起的转子轴向自激振动的频率特点。结果表明:轴向载荷、转速和油膜阻尼是引起推力轴承可倾瓦块轴向自激振动的主要因素;减小推力轴承间隙和增大润滑油压可以抑制转子轴向自激振动。     

基于润滑的曲轴径向圆跳动公差设计

分析了径向圆跳动误差对主轴承润滑的影响机理,提出一种基于润滑的公差设计方法;建立润滑仿真模型计算了主轴颈径向圆跳动公差,并对比分析了不同方案下的设计结果.研究表明:径向圆跳动误差导致轴承径向承载空间大小发生改变,其分布形式改变曲轴实际旋转轴线的位置,这些都影响主轴承的润滑性能;采用旋转轴线为跳动最大值和最小值中线的方案,公差设计效果最佳;基于润滑的公差设计方法能够较好地解释引进机型的跳动公差精度要求,可应用于内燃机曲轴形位公差设计.     

一种飞轮储能系统用被动磁轴承组设计与分析

介绍了一种用于飞轮储能系统的磁轴承组,该磁轴承组由永磁轴承（PMB）和超导磁轴承（SMB）组成。基于Halbach 阵列的永磁轴承设计了一种具有Nd-Fe-B磁环和后轭的PMB的新结构,并与现有结构进行了比较。利用有限元法（FEM）比较2种不同的PMB配置,在2个SMB拓扑的零场冷却（ZFC）和现场冷却（FC）过程中测量径向力和轴向力。对测量结果进行了研究分析,结果表明：轴向磁环充磁的新型拓扑结构的悬浮力大、径向恢复力高,尤其适合飞轮储能样机,因此所提出的新结构对飞轮储能系统用磁轴承新结构的设计提出具有重要指导意义。     

安康水电厂机组轴承温度保护的改进

水轮发电机组的三大轴承是机组的关键部件之一.其上导轴承和水导轴承是机组转动部分的导向轴承,推力轴承用于承受转动部分的重量和轴向水推力.三大轴承运行情况直接影响机组运行的安全稳定性.安康200MW水轮发电机组中,上导轴承和推力轴承各有12块瓦,水导轴承有10块瓦.为监视三大轴承本身的运行情况,设置了测温及温度保护系统.三大轴承中各块瓦上均埋设     

可倾瓦推力轴承不稳定性研究

和径向可倾瓦轴承类似，蒙受轴向载荷的可倾瓦推力轴承的刚度与阻尼系数强烈地依靠于外界扰动频率。通过对一简单可倾瓦推力轴承轴向动特性系数解析解的讨论表明，由于上述频率的影响，在一定条件下动态油膜力有可能产生轴向负阻尼，这在讨论系统轴向瞬态过程或稳定性问题时是应当引起注意的。     

Finite element analysis of a magnetic circuit of radial magnetic bearing for magnetically suspended flywheels

以自行设计的磁悬浮储能飞轮测试样机用径向磁悬浮轴承为例,应用ANSYS有限元分析软件对径向磁悬浮轴承磁路进行仿真与计算,给出了有限元软件仿真分析磁路的具体流程.仿真数据与理论计算数据对比表明,计算结果正确,在设计误差允许范围内,为样机的顺利研制提供了必要帮助.     

工业汽轮机油楔式径向轴承结构及性能分析

介绍了工业汽轮机油楔式径向轴承的结构、性能以及特点.通过对油楔式径向轴承的特性分析以及和可倾瓦轴承的比较,论述了油楔式径向轴承的优越性.总结表明,油楔式径向轴承结构简单、承载力大、运行安全可靠,在工业汽轮机领域,其使用场合远大于可倾瓦轴承.     

滑动轴承的质量保证—概念、一般说明

1、应用范围: 该标准包含按DIN31670第1至第8部分检验滑动轴承概念及一般特性。 2、概念 2.1 滑动轴承的概念。 滑动轴承,一般定义: 为一机械元件,它用来支承机器的运动部件,传递两相互运动表面之间的法向力,相互运动的主要特征为滑动。 不带翻边的径向轴承: 为一滑动轴承,它用于承受与传递径向载荷,即垂直于转轴轴颈的回转轴线,或固定芯轴轴线的载荷。 带翻边的径向轴承: 一测或两侧翻边的径向轴承,必要时用来承承受轴向力。 圆柱滑动轴承: 为一径向滑动轴承,它的滑动工作面为一圆柱面。 卷制滑动套: 为一滑动轴套、它由平板卷制成、接缝可以是开口或锁合的。     

660MW核电汽轮机低频振动机理分析与治理

针对核电660MW汽轮机轴承低频振动问题,通过改变机组转速、功率及润滑油压等试验,分析了低频振动特征,指出转子轴向低频振动引起可倾瓦轴承低频振动。通过建立转子轴向约束简化模型,分析汽轮发电机转子轴向低频振动机理为推力轴承油膜失稳及轴向扰动力引起转子轴向低频共振,并与可倾瓦轴承油膜失稳及瓦块颤振两种故障模式进行了对比。对汽轮机转子轴向低频振动及其引起的可倾瓦轴承低频振动,提出调整推力轴承间隙的措施并消除了低频振动。     

用于高温气冷堆发电设备的闭式循环氦气轮机装置

对HTGR-CT发电装置中的氦气轮机装置作了简要介绍．叙述其循环、工质以及影响循环效率的关键因素,并分析HTGR-CT发电装置布雷顿循环系统当前和近期的参数值。针对氦气轮机装置,论述了涡轮、压气机、热交换器、转子、轴承和热氦气管道等主要部件的设计和结构特点,并简要介绍了应用于氦气轮机的材料。最后指出在开发HTGR-CT发电设备中要重视两个关键技术问题：一是开发出用于大功率机组的安全、可靠的磁性轴承;二是免除放射性污染能进行安全运行和有效维护的问题。     

飞轮储能系统E型径向电磁轴承动态工作区分析CSCD

以10 kW·h飞轮储能系统的电磁轴承为对象,分析了E型12极径向电磁轴承的动态载荷特性。通过电磁轴承动态载荷区图,建立了转子不平衡激励载荷与动态载荷区的联系,以提高最大承载能力为目标,合理匹配了电磁轴承磁铁与功率放大器组合。确定了执行器的主要技术参数和转子动平衡精度等级,为磁悬浮储能飞轮系统总体设计、电磁轴承系统设计提供了设计方法和理论依据。     

基于LabVIEW的声发射信号小波降噪方法研究

针对电厂汽轮机的滑动轴承碰摩故障,提出了一种有效的故障诊断方法.该方法首先采用声发射传感器来采集轴承的声发射信号,然后通过小波降噪的方法对所提取的信号进行去噪处理,再对处理后的声发射信号进行频谱分析,从而判断轴承的碰摩情况.通过在300MW汽轮机转子模拟试验台上实施碰摩试验并进行分析研究,结果表明：运用上述方法能够准确地预测汽轮机的转子碰摩故障,了解碰摩的严重程度,实现对汽轮机的在线监测,大大提高了机组安全性.     

小型Savonius风机的创新设计与仿真分析

Savonius风机是一种典型的垂直轴风力机。针对传统风机的发电机部分采用转子、定子一动一静的设计布局,提出了一种新型的发电机结构,从而提高风机发电效率。通过有限元分析软件ANSYS／CFX,对风力机模型进行流体分析,计算Savonius风力机的效率,验证本设计分析方法的正确性。     

Self-regulating composite bearingless wind turbine

The Composite Bearingless Rotor (CBR) concept has been shown to have characteristics ideally suited for wind turbine applications. Originally developed for helicopters to reduce weight, costs and complexity, the CBR eliminates blade bearings and hinges through the utilization of the unique structural characteristics of uniaxial composite materials. This rotor concept was further developed under an ERDA contract to provide a fully self-regulating and self-aligning wind turbine. Such a system was achieved without the need for auxiliary controls or sensors. These features allow self-starting for wind initiating from any direction and automatic pitch and yaw variations to optimize performance under all normal wind conditions. The work described in this report consists of the design and fabrication of a 4.5 ft dynamically scaled wind turbine model and the successful testing of this model in the United Technologies Research Center low speed wind tunnel.     

Effect of load reduction mechanisms on loads and blade bearing movements of wind turbines

The power control of wind turbines is usually realized via a change in the pitch angle of the rotor blades. Pitching facilitates the exact control of the turbines and the reliable deceleration of the rotor when required. Pitch movements can moreover be used for load control. One of these methods is called individual pitch control (IPC). IPC controls the blades individually and brings about a significant reduction in the fatigue loads and extreme loads placed on the structural components, while at the same time reducing the yield of the turbine only slightly. The lower loads reduce material costs, and thus, the cost of energy (CoE) is reduced, despite the slight reduction in yield. The method is nevertheless not used everywhere since the additional movement cycles put the rotor blade bearings in particular under stress. Special attention must be paid to small amplitude oscillating movements, which carry a high risk of inducing surface damage in the rolling contacts of the blade bearings. This paper uses a cycle analysis of the IWT7.5‐164 reference turbine to illustrate the differences in the movement patterns of wind turbine blade bearings with and without IPC. Moreover, model calculations with single contacts are used to show which of the movement patterns carries a risk of inducing surface damage. The use of IPC leads to the expected load reduction at the blade root. In current literature, IPC is usually assumed to have a negative influence on the life expectancy of blade bearings, but the findings of this study contradict this. The summed blade bearing movement is increased, although the number of very small pitch angles occurring is reduced. This reduction reduces the risk of wear in the blade bearings.     

离网型风力发电机叶片设计方法研究

根据离网型风力发电机实际运行特性,提出根据发电机对蓄电池充电特性曲线、设计叶片的空气动力特性及外形进行叶片设计的新思路,并系统地设计计算了1kW离网型风力发电机叶片。实验结果表明,采用此设计理念可以简化整机的结构、减轻整机重量,所设计的风力机叶片具有低风速运行等特点。     

外转子储能飞轮结构优化设计研究

储能飞轮属于功率型储能技术,利用现代电力电子技术,实现电能与飞轮动能之间的转化。飞轮储能系统利用上、下主动电磁轴承将飞轮旋转体处于无接触悬浮。选择一种阶梯变截面近似等应力转子金属材料飞轮,以获得更高的储能密度,在高形状系数与加工制造难度之间合理优化。针对此飞轮进行强度以及转子动力学分析,此一体化外转子飞轮方案可有效解决飞轮转子轴向长度影响转子动力力学特性并将导致飞轮储能系统结构紧凑性欠佳的问题。     

Dynamic characteristics and enhanced performance of a novel wind turbine rotor analyzed via experiments and numerical simulation

The enormous demand for large wind turbine rotors has led to a need to develop high‐performance and reliable wind turbine rotors. The flexibility of the huge blade was a challenge in creating a balanced design with regard to dynamic behavior, mass, and power output. To enhance the wind turbine rotor, a newly designed wind turbine system with a supporting rod and damper was proposed and investigated. A scaled blade was experimentally tested, with the results indicating an increase in both frequency and damping of the system. Through the use of a self‐coded numerical model, the correlations between the design constraints and the dynamic behavior, tip displacement, and additional mass of the rotor were demonstrated. This showed that the novel rotor has some preferable characteristics in both static and dynamic aspects. In particular, this blade is stiffer and has a smaller tip displacement compared with a traditional cantilevered blade. These characteristics enabled the effective application of the novel rotor to a 5‐MW wind turbine to achieve a 15.16% power output increase based on the blade element momentum theory with Prandtl correction, as well as 5.1% mass savings. Copyright © 2016 John Wiley & Sons, Ltd.