行星齿轮是风力机齿轮传动的关键组成部分之一，其本身结构复杂、具有丰富的内部激励和非线性因素，加上在运行过程受到输入转速波动、重力、基础运动等因素的影响，其振动和噪声问题一直没有得到很好的解决，故障率居高不下。因此，本文围绕风力机行星齿轮传动在输入转速波动、重力作用、基础运动等工况下的典型动力学问题展开了研究。针对转速波动问题，建立了考虑转速波动的行星齿轮纯扭转模型，采用数值方法和多尺度法分析了行星齿轮传动在两种转速波动模型下的参数失稳现象，得到了不稳定区边界的近似解析表达式。详细讨论了转速波动参数、系统阻尼对不稳定区的影响，提出了通过调整转速波动参数来抑制特定不稳定区的方法。为研究存在基础运动时行星齿轮传动的动力学特性，给出了基于坐标变换和拉格朗日方程的动力学建模流程，分别推导得到了仅基础平动、仅基础俯仰运动、重力和基础俯仰运动同时作用的弯-扭-轴耦合非线性动力学模型，并从受力分析角度对模型进行了解释和验证，分析了不同基础运动形式的作用机理以及基础俯仰运动对重力激励的影响。基于建立的行星齿轮弯-扭-轴耦合模型，采用龙格-库塔数值积分获得风力机行星齿轮传动在三种不同工况下（基础平动、基础俯仰运动、重力和基础俯仰同时作用）的振动响应，通过傅里叶变换获得响应频谱图，分析了基础运动和重力对系统振动响应和频谱特征的影响。重力和基础运动引起的附加作用力会破坏行星齿轮受力周期对称性进而导致系统不均载，分析了有无重力情况下基础运动参数对均载特性的影响规律。针对风力机齿轮箱柔性支承设计，分析了重力和基础运动作用下齿圈支承刚度对系统振动响应和均载特性的影响。分析表明，支承刚度存在最佳值使系统均载达到最优，低于最佳值时，该支承刚度越小，系统不均载越严重。通过实验得到了行星齿轮箱体加速度信号和输出轴振动位移信号，研究了齿轮箱支承方式、基础定轴转动、基础平动对系统振动响应和频谱特征的影响，分析了转速、基础运动幅值和频率对振动幅值的影响。通过实验研究对理论研究进行了验证和扩展。

Planetary gear is one of the key elements of the wind turbine gear transmission. In itself, the planetary gear has complex structure, rich internal excitations and nonlinear factors. Considering the special operation environment of the wind turbine, the planetary gear may be subjected to input speed fluctuations, gravity effect and base motions. Because of the combined effect of the above two factors, the problems of vibration and noise have not been well solved, and its failure rate remains high. Therefore, this paper focuses on the typical dynamic problems of the planetary gear under input speed fluctuations, gravity and base motions.Considering speed fluctuations, a pure rotational model of the planetary gear is set up. The parametric instabilities of the planetary gear under two different speed fluctuations are analyzed using both numerical method and the method of multiple scales, and the approximate analytical expressions of the instability boundaries are derived. The influences of speed fluctuation parameters and damping on the instabilities are discussed in detail, and a new approach to minimize certain instability is presented by adjusting the speed fluctuation parameters.Based on coordinate transformations and the Lagrange equation, the dynamic modeling process of the planetary gear under base motions is given to consider the influence of base motions. Based on the presented modeling process, the nonlinear translational-rotational-axial models of the planetary gear under translational base motions, pitching base motion, or gravity and pitching base motion are presented, respectively. These models are explained and validated from the perspective of force analysis. The mechanisms of action of different base motions and the influence of pitching base motion on gravity excitations are analyzed.Based on the presented translational-rotational-axial models of the planetary gear, the dynamic responses of a wind turbine planetary gear under three conditions are obtained using Runge-Kutta numerical integration: base motions (translational motion, pitching base motion), gravity, and pitching base motion combined with gravity. Response spectra are derived through the Fourier transform. The influence of the base motion and the gravity on system response and spectrum is investigated. Gravity and the additional effect caused by base motions destroy the force symmetry of the planetary gear, and thus induce unequal load sharing. The influence rules of base motion parameters on the load sharing are obtained with and without gravity. Considering the flexible support of the wind turbine gearbox, the influence of the support stiffness of the ring on the dynamic response and the load sharing is analyzed in the presence of gravity and base motions. The results indicate optimal support stiffness in terms of load sharing. When the support stiffness is less than the optimal value, the unequal load sharing becomes more serious as the support stiffness decreases.The acceleration signal of the planetary gearbox and the vibration signal of the output shaft are obtained to experimentally investigate the influence of the gearbox bearing, base rotations and base translations on the responses and the spectra. The influences of the rotating speed, base motion amplitude, and base motion frequency are analyzed. Through the experimental research, the theoretical research is verified and expanded.