风电偏航轴承接触力分布与疲劳寿命分析*

根据风电偏航轴承的结构和受载特点,建立轴承的整体有限元模型并求解联合载荷下的接触力分布。为降低模型复杂性和减小计算规模,通过赫兹接触理论获取滚动钢球与滚道的接触力和变形关系;将这些变形特征赋予非线性的弹簧单元,使弹簧单元与钢球的接触变形特征一致,从而模拟钢球与滚道的接触,并通过经验公式和实验验证了模型的正确性。建立轴承局部等效接触模型,分析不同接触角和滚道半径系数下的应力分布情况和轴承疲劳寿命。研究结果表明:随着接触角增大,滚道表层最大应力值减小,而轴承疲劳寿命随接触角增大而提高;滚道半径系数对应力分布的影响最显著,随着滚道半径系数增加,滚道表层最大应力值增大、疲劳寿命减小;不同的接触角和滚道半径系数下,滚道沿表层深度的应力分布基本一致。

Contact Force Distribution and Fatigue Life Analysis of Yaw Bearings in Wind Generator

On the basis of the structural and loading characteristics of yaw bearing in wind generator,a global finite element model of bearing was established,and the contact force distribution under combined external loads was solved.In order to reduce the complexity of the model and the computational scale,the contact force and deformation relationship between ball and raceway were obtained by Hertz contact theory.The non-linear spring elements were used to simulate the contact behavior between ball and raceway,and the effectiveness of this model was proved by empirical formula and experiment.A local equivalent contact model of bearing was developed.The stress distribution and fatigue life of bearing under different contact angles and raceway radius coefficients were systematically analyzed.The results show that the maximum stress of raceway surface decreases with the increase of contact angle,while the fatigue life of bearing increases with the increase of contact angle.The raceway radius coefficient has the most significant effect on the stress distribution,with the increase of raceway radius coefficient,the maximum stress value of raceway surface increases and the fatigue life decreases.Under different contact angles and raceway radius coefficients,the stress distribution of raceway along the surface depth is basically the same.