风机的齿轮箱和发电机分别通过钢板弹簧和弹性橡胶与具有一定刚度的底座相连，具有“双弹性支撑” 的结构特点．该特点导致风机运行时固有地存在齿轮箱输出轴和发电机轴之间的轴不对中，使得齿轮箱振动信号出现严重的高阶啮合频率和平稳调制现象．文中通过对 1000 多组现场测试数据的详细分析，得出齿轮箱、主轴承、发电机轴承和辅助设备的振动特性，验证了“双弹性支撑”对齿轮箱频率特性的影响;鉴于风机自身的结构特点和测试分析结果，分析了传动系统故障诊断的难点和可能的解决途径．

In wind turbine,there exists a so- called double- elastic support,i.e.,the gearbox and the generator arerespectively linked to the base with certain stiffness by leaf springs and elastic rubbers.Due to this special charac-teristic,there exists a natural axial misalignment between the output shaft of gearbox and the shaft of generator,which makes vibration signals of normal gearbox blend with serious high- order gear mesh frequency and smoothmodulation.In this paper,based on the detailed analysis of more than 1000 sets of field data,the vibration charac-teristics of gearbox,the main bearing,the generator bearing and the supporting equipment in wind turbine are dis-covered,and the influences of double- elastic support on the frequency characteristic of gearbox is verified.Moreo-ver,according to the structural characteristics of wind turbine and the analysis results of test data,the difficulties offault diagnosis in the transmission system of wind turbine and some possible solutions are analyzed.