Study On Dynamic Characteristics Of Gear Transmission System Under Variable Loads

With the depletion of fossil energy,wind power generation has gradually become a hot area.The design stability of wind turbines is also receiving increasing attention.Because planetary gears have the advantages of small size,light weight,and high efficiency,they are used in most wind turbines.However,the harsh working environment of wind turbines and the bending of elastic rods during the installation of wind turbine planetary gears will affect the stability of the system work.Therefore,this paper studies the dynamic characteristics of the wind turbine planetary gear transmission system in order to provide a theoretical basis for the stability of wind turbine transmission and has engineering application value.The main contents and research conclusions of this work include:1.Due to the time-varying meshing stiffness of gears in the planetary gear drive system of wind turbines,which is one of the main causes of vibrations in meshing,this paper uses the finite element method to consider the contact characteristics of the tooth and obtains the deformation of the teeth and Hertzian contact.The time-varying meshing stiffness resulting from the combined action of the deformations.The variations of the tooth surface contact characteristics and the meshing stiffness are studied when the eccentric load is present.At the same time,the fluctuation trends of the time-varying meshing stiffness under variable load are studied.The study shows that the time-varying meshing stiffness will change with the change of load and axial eccentric load,and the main variation law of time-varying meshing stiffness can be clearly seen from the tooth surface contact characteristics.2.When the axial partial load changes,the dynamic load of the external meshing of the sun gear and the planetary gear will have a frequency shift component,and the sun’s floating trajectory will also change accordingly,but the effect on the deformation of the internal gear ring will be small,only Affect its floating trajectory.The change of the load has obvious influence on the frequency components of the system,and the amplitude of the meshing frequency decreases with the increase of the load.Considering the phase difference of the time-varying meshing stiffness,it is found that the intrinsic characteristics of the system obtained by the mean method are basically the same,and the influence is small.3.for a fan drive system test bench,through the acceleration sensor 608A11 in the box at the site,using the acquisition card DT9837 will be measured vibration signal,analysis and processing.Aiming at the changes of time-frequency signals under various faulty gear conditions,a comparative analysis is performed.At the same time,magnetic particle brakes are used to apply the load torque to verify the changes in the timefrequency domain under load changes,and compared with the theoretical analysis to verify the reliability of the system.Sex.