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1、专业好文档大功率风力发电机组齿轮箱减振支撑的结构特点与应用胡伟辉，林胜，秦中正，张亚新 (株洲时代新材料科技股份有限公司，湖南 株洲412007 )摘要：风力发电机齿轮箱是风力发电机组的关键部件之一，必须保证其在正常工作状态下运转平稳且无冲击振动或异常噪音，则应采取必要的减振降噪措施，使噪声声压级符合要求，最常用的解决方法就是安装减振支撑。鉴于此，介绍了目前大功率风力发电机组中主要采用的几种齿轮箱减振支撑方法，并分析了各种减振支撑的结构形式、性能特点、载荷的计算和适用的载荷工况，为风力发电机的传动系统选择适当的齿轮箱减振系统提供了可靠的依据。关键词：风力发电机组；传动系统；齿轮箱减振支撑中图分
2、类号：TK83 文献标识码：A 文章编号：10060316 (2010) 03000000The structure and application of gearbox suspension in high-power wind turbineHU Wei-hui，LIN Sheng，QIN Zhong-zheng，ZHANG Ya-xin （Zhuzhou Times New Material Technology Co., Ltd, Zhuzhou 412007）Abstract：Gearbox is one of the most important components assemb
3、ly in Wind Turbine, which must run stationary with no impact and abnormal noise in normal operation. The level of noise must meet the requirement by taking the anti-virbration action. The most common method of anti-virbration is the installation of virbration damper. In view of this, several gearbox
4、 suspensions mainly used at present are briefly introduced in High-power Wind Turbine. The Structures, performance features, load calculations and applicable conditions of gearbox suspensions are analysed, which provides a reliable basis for the selection of gearbox anti-vibration system in drive sy
5、stem。 Key words：wind turbine；drive system；gearbox suspension风能是一种清洁的永续能源，与传统能源相比，风力发电不依赖外部能源，没有燃料价格风险，发电成本稳定，也没有碳排放等环境成本。正是因为有这些独特的优势，风力发电逐渐成为许多国家可持续发展战略的重要组成部分。风能开发能减轻空气污染和水污染，但如果处理不当，则会增加噪声污染1。风力发电机组中的齿轮箱是一个重要的机械部件，作为传递动力的部件，在运行期间同时承受动、静载荷。齿轮箱正常工作时，齿轮箱的主要噪声来自于齿圈齿轮的啮合，一个好的解决办法就是安装弹性支撑。【2】利用齿轮箱弹性支撑还
6、可以减少从齿轮箱传递到机舱结构和塔架的振动，从而将齿轮箱的机械振动控制在规定的范围之内。1 风力发电机组坐标系为了便于对风力发电机及其零部件所承受的载荷进行计算，根据风力机系统的结构形式、运动特点和计算需要，在风力发电机的几个特殊位置设置了适当的坐标系，一般有以下四种坐标系【3】：叶片坐标系（S）：坐标原点位于叶片的各分段翼型轮廓半径的基点上；叶根坐标系（B）：坐标原点位于叶片与轮毂连接面的中心；塔架坐标系（T）：坐标原点位于塔架与机舱连接面的中心；轮毂坐标系（N）：坐标原点位于轮毂的中心，如图1所示。MZNFZNZNFYNMYNYNFXNXNMXNMZN根据轮毂坐标系（N）的叠加计算结果，能
7、够计算轮毂所受的载荷，进而可以用于传动系统的设计计算。齿轮箱作为传动系统中的重要部件，其主要承受了风轮、主轴和发电机等施加的外部载荷。齿轮箱的载荷形式、大小与整机的传动系统结构有关，其又直接影响着齿轮箱减振支撑的受力方式。下面介绍各种齿轮箱减振支撑的结构形式与性能特点。 图1 轮毂坐标系2 轴瓦式齿轮箱减振支撑目前大部分采用三点支撑系统（单轴承结构，见图2所示）的风力发电机组，其齿轮箱减振系统主要采用的是轴瓦式弹性支撑，见图3所示。轴瓦式齿轮箱减振支撑由上、下两瓣弹性体组成，根据橡胶层数的不同，结构有所差异。弹性体采用偏心式结构设计，在一定的温度和压力下硫化成型。安装时利用产品的偏心量，通过预
8、压缩的方式将其固定于齿轮箱支撑座中。这种结构的齿轮箱减振支撑的承载能力强，能够承受来自径向（ZN和YN）和轴向（XN）的冲击载荷，有着良好的阻尼及减振性能。一般要求弹性支撑的减振效率大于80%，阻尼不小于0.05。支撑座轴承座图2 三点支撑系统图3 轴瓦式齿轮箱减振支撑MW级以下的风力发电机中，减振支撑的弹性体一般通过芯轴压装于齿轮箱扭力臂中，见图4所示。这种结构的减振支撑，其上、下弹性体安装困难，且在端部无挡板，在轴向（XN）无约束，呈自由状态，在长期的交变载荷作用下可能出现轴向窜出，从而影响了产品的减振性能。在MW级以上的风机中，其减振支撑采用另外一种结构形式，如图5所示。减振支撑的弹性体
9、安装在齿轮箱两侧的支撑座内，每台4对，在弹性体的两端设置有挡块，可以防止弹性体发生轴向窜出，并且弹性体安装简单，拆卸方便，所以在MW级以上的风机中普遍采用这种结构。齿轮箱芯轴弹性体齿轮箱支撑座弹性体挡块 图4 弹性体安装图 图5 减振支撑系统结构图LMXNR1R2G轴瓦式减振支撑在正常工作过程中主要承受齿轮箱的重量、低速轴的扭转载荷和部分重量。弹性支撑载荷的计算方法如图6所示，设齿轮箱两侧弹性支撑的载荷分别为R1和R2，见式（1）、式（2）所示。图6 载荷计算简图 （1） （2）式中：MXN 为低速轴施加的扭矩；L为两支撑座间的距离；G为齿轮箱的重量加上主轴的部分重量（通常为1/2）。为了获得
10、优良的减振效果，需要根据载荷的大小来确定齿轮箱减振支撑的刚度指标。齿轮箱减振支撑主要承受低速轴施加给齿轮箱的扭转载荷，因此减振支撑的径向（ZN和YN）刚度性能需要严格控制;根据标准EN13911和TB/T2843中的相关规定，产品的刚度性能要求应该取较为严格的公差等级，即在15%范围之内。为了防止在传动系统出现严重的过约束问题，则要求减振支撑的轴向（XN）刚度越小越好。3 叠簧式齿轮箱减振支撑叠簧式齿轮箱减振支撑主要用于四点支撑系统（双轴承结构）的风力发电机组当中，采用的是金属框架式结构，如图7、图8所示。在齿轮箱扭力臂上、下各设置有一个橡胶垫。齿轮箱支撑安装时使上、下橡胶垫各产生一定的预压缩
11、量，齿轮箱工作时的振动就在预压缩量的范围内进行。调节螺栓齿轮箱扭力臂橡胶垫图7 四点支撑系统图8 齿轮箱支撑结构图在这种结构的传动系统中，齿轮箱的重量主要由低速轴来承担，减振支撑主要承受低速轴传递的扭转载荷，因此其所承受的载荷为 （3）依据齿轮箱载荷的特点，减振支撑的垂向（ZN）刚度大，则扭转刚度大；其他方向刚度应尽量小。在齿轮箱支撑两端各有一个调节装置，通过调整螺栓可实现对齿轮箱安装高度的微调，以避免系统出现过约束，使齿轮箱与主轴连接处受附加弯矩的作用；同时也可以调整减振支撑整体的刚度性能以实现产品的变刚度设计。根据风力发电机组齿轮箱的工况与所承受载荷的不同，可以调整橡胶的硬度和预压缩量。这
12、种齿轮箱弹性支撑具有出色的阻尼及减振性能，可大大减少结构噪声的传递，承载大，且安装方法简单，更换方便。4 液体复合齿轮箱减振支撑液体复合齿轮箱减振支撑即可用于三点支撑系统中，也可以用于四点支撑系统当中。液压减振支撑是在叠簧式减振支撑的基础上，并结合液体流动时优良的阻尼特性而发展起来的。这种减振支撑的橡胶弹性体的外形结构和叠簧式减振支撑类似，皆采用金属橡胶复合结构，内部设有压力膜（橡胶），腔体，密封机构，液压管路等，如图9所示。压力膜腔体图9 弹性体的截面图齿轮箱一侧的减振支撑上弹性体与另一侧减振支撑的下弹性体通过液压油管连接在一起，如图10所示。当齿轮箱发生振动，齿轮箱支撑受载其腔体的体积发生
13、变化，液体在上、下腔体之间流动产生阻尼，消耗振动能量，达到衰减振动的目的4。LRFZNFYNMXN上弹性体油管下弹性体 图10 液体复合减振支撑的工作示意图液体减振支撑在正常状态下，当齿轮箱受扭转载荷MXN时，左侧上弹性支撑和右侧下弹性支撑承载，两橡胶弹性体的体积同时压缩，腔体体积减小，管内压力急剧增加，从而扭转刚度KM也随之大幅增加。当齿轮箱受垂向载荷FZN时，左右两侧的上弹性体同时承载，两下弹性体同时卸载，因此两上弹性体的液体流向下弹性体，主要通过橡胶的垂向变形来承载，从而垂向刚度KZN较小。当齿轮箱受水平载荷FYN时，则主要是通过橡胶的剪切变形来承载，因此产品水平方向的刚度KYN非常小。
14、液体复合减振支撑三个方向的刚度性能曲线如图11所示，正是由于液体复合减振支撑这种独有的刚度特性，所以在大功率风力发电机组中得到了广泛的应用。扭转刚度121086420栽荷0 1 2 3 4 5 6 7 8变形垂向刚度水平刚度图11 液体复合减振支撑的性能曲线图与叠簧式齿轮箱减振支撑的性能相比，在获得相同的扭转刚度的情况下，液体复合减振支撑的垂向刚度小，从而可以大大减少由于安装所产生的过约束对系统的影响，这种减振支撑也是齿轮箱减振系统的发展方向，具有非常广阔的前景。5 结论双馈式风力发电机组多采用三点式或四点式支撑系统。在三点式支撑系统中根据载荷的特点与系统的要求可采用轴瓦式减振支撑或者液体复合
15、减振支撑，采用这种结构的风力发电机组，其齿轮箱载荷较复杂，对齿轮箱的要求较高。在四点式支撑系统中可采用叠簧式减振支撑和液体复合减振支撑，采用这种结构的风力发电机组，其齿轮箱载荷比较简单，齿轮箱的维护成本较低。风力发电机组中齿轮箱减振系统的选择与设计应根据具体的载荷形式来定，并依据载荷的大小、特点和减振的要求来确定减振支撑的性能指标，以实现最佳的减振效果。参考文献：1李俊峰，王仲颖，马玲娟，等. 2008年中国风电发展报告M. 北京：中国环境科学出版社，2008.2Tony Burton等著，武鑫等译. 风能技术M. 北京：科学出版社，2007.3郭建. 风力发电机整机性能评估与载荷计算的研究D
16、. 大连：大连理工大学，2003.4赵熙雍，张亚新. 金属橡胶液体复合弹簧的发展和应用J. 机车电传动，2002，（2）：9-12.5韩坤，谢歆，季翼鹏，陈国柱. 大功率直驱风力发电系统直流侧电压复合控制策略J. 机电工程，2009，26（6）：50-53.Editors note: Judson Jones is a meteorologist, journalist and photographer. He has freelanced with CNN for four years, covering severe weather from tornadoes to typhoons.
17、Follow him on Twitter: jnjonesjr (CNN) - I will always wonder what it was like to huddle around a shortwave radio and through the crackling static from space hear the faint beeps of the worlds first satellite - Sputnik. I also missed watching Neil Armstrong step foot on the moon and the first space
18、shuttle take off for the stars. Those events were way before my time.As a kid, I was fascinated with what goes on in the sky, and when NASA pulled the plug on the shuttle program I was heartbroken. Yet the privatized space race has renewed my childhood dreams to reach for the stars.As a meteorologis
19、t, Ive still seen many important weather and space events, but right now, if you were sitting next to me, youd hear my foot tapping rapidly under my desk. Im anxious for the next one: a space capsule hanging from a crane in the New Mexico desert.Its like the set for a George Lucas movie floating to
20、the edge of space.You and I will have the chance to watch a man take a leap into an unimaginable free fall from the edge of space - live.The (lack of) air up there Watch man jump from 96,000 feet Tuesday, I sat at work glued to the live stream of the Red Bull Stratos Mission. I watched the balloons
21、positioned at different altitudes in the sky to test the winds, knowing that if they would just line up in a vertical straight line we would be go for launch.I feel this mission was created for me because I am also a journalist and a photographer, but above all I live for taking a leap of faith - th
22、e feeling of pushing the envelope into uncharted territory.The guy who is going to do this, Felix Baumgartner, must have that same feeling, at a level I will never reach. However, it did not stop me from feeling his pain when a gust of swirling wind kicked up and twisted the partially filled balloon
23、 that would take him to the upper end of our atmosphere. As soon as the 40-acre balloon, with skin no thicker than a dry cleaning bag, scraped the ground I knew it was over.How claustrophobia almost grounded supersonic skydiverWith each twist, you could see the wrinkles of disappointment on the face
24、 of the current record holder and capcom (capsule communications), Col. Joe Kittinger. He hung his head low in mission control as he told Baumgartner the disappointing news: Mission aborted.The supersonic descent could happen as early as Sunday.The weather plays an important role in this mission. St
25、arting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher
26、 than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause), he can expect a lot of turbulence.The balloon will slow
27、ly drift to the edge of space at 120,000 feet (22.7 miles/36.53 kilometers). Here, Fearless Felix will unclip. He will roll back the door.Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool
28、 that he wants to land on, but not too hard. Still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 69
29、0 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be depl
30、oyed to slow him down. His team hopes its not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachut
31、e that will open automatically if he loses consciousness at mach speeds.Even if everything goes as planned, it wont. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).It might not be the
32、moon, but Kittinger free fell from 102,800 feet in 1960 - at the dawn of an infamous space race that captured the hearts of many. Baumgartner will attempt to break that record, a feat that boggles the mind. This is one of those monumental moments I will always remember, because there is no way Id miss this.