Dynamic Modeling And Analysis Of Planetary Gear Transmission System With Full Structure Flexibility

The planetary gear transmission has the advantages of high transmission ratio,compact structure,high power density and smooth operation in the limited installation space,large power and high-speed transmission occasions,compared with the traditional parallel-axis gear transmission.Therefore,the planetary gear is widely used in aviation,shipping,wind power,metallurgy and mining and other fields.The vibration and noise of planetary gear transmission system has been a hot topic in many fields.Therefore,it is of great theoretical significance and engineering value to establish an accurate planetary gear dynamic model for realizing low noise and high reliability gear transmission.In this paper,the contact analysis model of helical gear pair meshing stiffness is established.Based on slice method and energy method,the meshing stiffness of internal and external meshing gear pair is calculated,and the influence of gear parameters on meshing stiffness is studied.The influence of different inner hole diameter,helix angle,addendum height coefficient and tip clearance coefficient on the stiffness of internal and external meshing in one meshing cycle is considered respectively,and the variation law of stiffness fluctuation is analyzed.Based on the meshing stiffness analysis model of gear pair,a flexible dynamic modeling method of planetary gear system including shaft system,inner ring gear and planetary carrier is proposed.The ring gear unit formed by the discrete inner ring gear is studied in detail.The deformation caused by normal meshing force is coupled with the internal meshing element,and the ring gear flexibility is included.In this paper,the lumped mass model and the fully flexible model are established respectively for the proposed fully flexible model.The natural characteristics and dynamic response of the lumped mass model and the fully flexible model are solved by Fourier series method.It is found that compared with the lumped mass model,the fully flexible model introduces many higher-order natural frequencies,and the vibration modes of the system become more complex and diverse.In this paper,the influence of shaft system flexibility,ring gear flexibility and planetary carrier flexibility on the dynamic response is analyzed,and it is found that the ring gear flexibility has the greatest impact on the resonance frequency.