风电增速箱结合部刚度分析及振动噪声预估

Junction stiffness analysis and vibration noise prediction of wind power speed-increase gearbox

为了研究风电增速箱的振动特性和辐射噪声,基于轴承支承刚度及齿轮副啮合刚度分析,建立了风电增速箱轴系扭转振动模型,运用Matlab求解振动微分方程,得出轴系扭振频率及对应振型;综合考虑刚度激励、误差激励及冲击激励,建立了风电增速箱动力学有限元模型,仿真得出增速箱的动态响应。以箱体表面节点振动位移为边界条件,建立了增速箱声学边界元模型,采用直接边界元法求解得到箱体表面声压及场点的辐射噪声。结果表明,风电增速箱扭振频率与激励频率及其倍频相差较大,不会出现共振现象;增速箱结构噪声和辐射噪声的峰值主要出现在高速级齿轮啮合频率的二倍频附近。

In order to study the vibration characteristics and radiation noise of wind power speed-increase gearbox,a torsional vibration model of wind power speed-increase gearbox is established based on the analysis of supporting stiffness of bearing and contact stiffness of gear pairs.By solving the vibration differential equation with the help of Matlab,the frequency and corresponding vibration mode are obtained.With taking stiffness excitation,error exaction and meshing impact exaction into account,the dynamic finite element model of speed-increase gearbox is set up,and the dynamic response simulation is carried out.Regarding vibration displacement of the nodes on gearbox surface as boundary condition,an acoustic boundary element model of speed-increase gearbox is built.The surface acoustic pressure of gearbox and the radiation noise of field points are solved by the direct boundary element method.The results show that there is a great difference between torsion frequency and excitation frequency of wind power speed-increase gearbox,and so the resonance doesn＇t occur.The maximum structural noise and radiation noise mainly appear near the double octave of the gears meshing frequency of high-speed grade.