直驱风力发电机主轴承载荷分布数值分析

Numerical Analysis on Load Distribution of Main Bearing for Direct-Driven Wind Turbine

针对直驱风力发电机主轴承的结构特点,采用考虑轴承刚度耦合性和非线性的数值计算方法,推导得到了轴承单元刚度矩阵的解析表达式。采用考虑剪切变形的欧拉-伯努利梁单元,建立直驱风力发电机转轴的空心轴模型。将轴和轴承的刚度矩阵进行组合,构建了考虑轴系刚度非线性的直驱风力发电机轴系数值计算模型,利用牛顿-拉夫逊法进行求解,得到了主轴承在极限载荷作用下轴承的载荷分布。并以某型号直驱风力发电机2TS主轴承为例,通过数值计算得到其载荷分布,与有限元模型结果的误差在允许范围之内。搭建试验台测试了主轴承摩擦力矩,与计算模型误差较小。

According to structural characteristics of main bearing for direct-driven wind turbine,the analytical expression of bearing element stiffness matrix is derived by using numerical calculation method considering coupling and nonlinearity of bearing stiffness.The Euler-Bernoulli beam element considering shear deformation is used to establish the hollow shaft model.By combining the stiffness matrix of shaft and bearing,the numerical calculation model of direct-driven wind turbine shafting considering nonlinear stiffness of shafting is established,the Newton-Raphson method is used to solve the model,and the load distribution of main bearing under the action of limit load is obtained.Taking 2TS main bearing of a direct-driven wind turbine as an example,the load distribution is obtained by numerical calculation.Compared with the results of finite element model,the error is within the allowable range.The friction torque of main bearing is tested on a test bench,and the error between friction torque and calculation model is small.