Abstract: Aiming at the variable speed and changing load works characteristics of wind power planetary gear transmission system caused by natural wind,the time-varying input speed and torque of the system caused by random wind were calculated by wind speed power spectral density model,and the nonlinear dynamics model of the system was established by considering the time-varying meshing stiffness,comprehensive error and tooth backlash and other internal excitations.The dynamic response of the system with double-tooth crack of the sun gear under the excitation of variable wind load was simulated and analysis,and the influence of tooth cracks along the whole tooth width of the gear on the dynamic characteristics of the system was revealed.The results showed that the gear time-varying meshing stiffness would be decreased with tooth cracks,and the drop was more obvious as the crack deepens.When there was a root crack in the sun gear,there were components in the low order of the system order spectrum with the sun gear partial failure order as the interval,and there were some side orders equally spaced near the mesh fundamental order and its harmonic components.The amplitude increased with the propagation of the crack.The structure of the low-frequency component and sideband was related to the number of healthy teeth between the faulty teeth when the sun gear has non-adjacent double root cracks,which could provide a theoretical basis for the location of the faulty tooth.

Key words: nonlinear dynamic model, varying wind load, double-tooth cracks, dynamic characteristics

摘要： 针对风电行星齿轮传动系统变速变载的工作特点,基于风速功率谱密度模型,计算由随机风引起的系统时变输入转速和转矩,在考虑时变啮合刚度、综合误差和齿侧间隙等内部激励的基础上,建立系统非线性动力学模型,仿真分析变风载下太阳轮含双齿裂纹时系统动态响应,探究沿齿厚贯穿型齿根裂纹对系统动态特性的影响规律。结果表明:齿根裂纹会导致齿轮时变啮合刚度局部下降,且裂纹越深,下降越明显;太阳轮存在齿根裂纹时,系统阶次谱中低阶、啮合阶次及其谐次附近出现以太阳轮局部故障阶次为间隔的成分,且幅值随裂纹扩展而变大;太阳轮存在不相邻双齿根裂纹时,低阶成分和边带阶次的结构与故障齿间隔的健康齿个数相关。

关键词: 非线性动力学模型, 变风载, 双齿裂纹, 动态特性