柔性支承下风力机低速轴轴承疲劳寿命分析

摘要

The random wind load and the flexible support of tower are easy to make the low-speed shaft bearings of gearbox under complex alternating load,thus resulting in bearing fatigue damage.In order to study the fatigue life of low-speed shaft bearing for wind turbine gearbox under the flexible support and variable load,the dynamic model of flexible support for wind turbine gearbox is established,the dynamic load of low-speed shaft bearing was obtained and the static analysis on bearing was conducted.Finally,the bearing stress spectrum was got according to the qua-si-static analysis,and the fatigue life of low-speed shaft bearing was estimated based on Miner linear cumulative damage rule.The results show that the outer chamfer of contact region between rolling body and inner ring has the maximum stress,which is more consistent with the stress with Hertz theory.Considering that the fatigue life of low-speed shaft bearing is less than the design life,so the flexible support of tower must be considered when designing the wind turbine gearbox low-speed shaft bearing.%随机风载荷和塔架的柔性支承容易使齿轮箱低速轴轴承受到复杂交变载荷，导致轴承疲劳损坏。为研究在柔性支承和变载荷下风力机齿轮箱低速轴轴承的疲劳寿命，文章建立柔性支承下风力机齿轮箱动力学模型，得出低速轴轴承动态载荷，并对轴承进行静力学分析。最后根据准静态学分析法，得到轴承应力谱，并基于Miner线性累积损伤法则对低速轴轴承的疲劳寿命进行估算。分析结果表明，滚动体与内圈接触区域的外侧倒角处接触应力最大，该最大接触应力结果与Hertz理论计算出的应力幅值结果较为一致；考虑塔架柔性支承下得到风力机低速轴轴承疲劳寿命小于其设计寿命，因此在风力机低速轴轴承设计时必须考虑塔架的柔性支承。