Dynamic Performance Analysis And Parameter Optimization Of Wind Power Speed-up Machine Planetary Gear Trains

At present, the development of wind power equipment is moving in the direction of large-scale and high reliability, therefore, a higher demand for wind turbine design, operation and maintenance is raised. Wind turbine drive system faces with the unique dynamics problems, and the complex random load course of wind power equipment in the life-cycle interval also makes the design and calculation of the wind turbine drive system have different characteristics. All these make wind power equipment dynamics basic theory and dynamic performance analysis have a very profound meaning.The study object of this paper is the two-stage planetary gear trains in the high-power wind power speed-up machine. The dynamic characteristics and vibration behavior of the two-stage planetary gear trains were studied based on the vibration theory of the gear dynamics and by means of the numerical simulation analysis. The design parameters of the gearbox were optimized in order to achieve the purpose of reducing vibration and noise.First, the system dynamics model and analysis model were created. According to the own characteristics of the gear system, the bend-twist-axis coupled nonlinear dynamics model of two-stage planetary gear trains was established by use of the lumped mass method. The model was built in full consideration of the error incentive, the time-varying meshing stiffness excitation, backlash and other influencing factors. On the basis of the dynamics model, the nonlinear time-varying analysis model of two-stage planetary gear trains was established.Second, the dynamic characteristic of the system was analyzed. Based on inherent characteristic computation theory, the natural frequency of the first-stage, the second-stage and two-stage coupled planetary gear trains were calculated and the respective vibration modes were summarized. Furthermore, how the parameters such as the time-varying meshing stiffness, the torsional stiffness of the planet carrier, the support stiffness of the sun gear and planetary gear and the quality of every gear have an influence on the natural frequency of the system was studied.Third, the vibration behavior of the system was studied. The external variable load incentive of the wind turbine gearbox was simulated by use of two-parameter Weibull distribution. Nonlinear variable parameter differential equations of two-stage planetary gear trains were made into dimensionless ones. The dimensionless equations were solved to obtain the displacement amplitude response of every degree of freedom, the phase diagram curve and Poincare figure of every twist degree of freedom. The effect of the input speed and the torsional stiffness of the connection shaft on the amplitude of each degree of freedom was studied.Finally, the design parameters of the system were optimized in order to reduce vibration and noise. Parameter optimization design model based on dynamics was established as the goal of system acceleration peak minimum. Ensuring the correct drive of the planetary gear trains and making the system strength meet the requirements are the constraint conditions. The parameters were optimized. The contrast of results before and after optimization shows that the maximum acceleration peak of the system has been reduced, the other accelerations are maintained at a lower value, and the system volume are also reduced. The purpose of reducing vibration and noise and making the volume lightweight was achieved.