Research On Refined Model Of Internal Excitation Of Herringbone Planetary Gear Transmission System And The Method Of Staggered Phase Tuning To Reduce Vibration

Compared with simple gears,herringbone planetary gear transmission system takes into account the characteristics of herringbone gear and planetary gear system.It has many advantages,such as large transmission ratio,large transmission power,high transmission efficiency,compacting structure,lighting weight and so on.It has a wide range of applications in aerospace,military ships,mining and other fields.However,due to the joint action of external and internal meshing of herringbone planetary gear system simultaneously,and various errors are inevitable in the process of manufacturing,processing and assembly,all these factors lead to adverse consequences such as vibration and noise in the transmission system.Therefore,it is necessary to study the dynamics of herringbone planetary gear trans mission system,grasp the factors affecting the vibration and noise of transmission system in the design stage,and provide a theoretical basis for reasonably formulating the vibration and noise reduction scheme of herringbone planetary gear transmission system.This research is supported by the civil aircraft special project "dynamic optimization technology and verification of GTF engine gearbox system"(Project No.: MJZ-2016-D-33)of the Ministry of Industry and Information Technology.According to the characteristics of herringbone planetary gear transmission system such as large helical angle and high bearing capacity,by means of theoretical modeling,numerical simulation and experiment,this paper focuses on the influence law of basic parameters on time-varying mesh stiffness and tooth surface friction excitation.The action mechanism of typical excitation parameters and working condition parameters on the dynamic response of the transmission system is revealed.A practical and feasible method of stagger tooth phase to reduce vibration is proposed.The main research contents of this paper are as follows:(1)The comprehensive analytical model of time-varying mesh stiffness of herringbone gear is established.Considering the coupling between slice gear,the influence of axial force on the deformation of gear teeth and foundation,and the coupling of foundation structure in multi-tooth mesh area,the deformation and stiffness could be obtained based on the idea of Weber elastic potential energy.Then the comprehensive mesh stiffness of herringbone gear pair could be obtained by reasonable superposition.The finite element dynamic analysis model to solve the mesh stiffness of herringbone gear is established,and the results is compared with analytical model.The effects of basic parameters such as helix angle,tooth width,modulus,and central distance on time-varying mesh stiffness are studied.(2)The refined model to calculate the tooth surface friction excitation of herringbone gear is established.Based on the relationship between axial contact ratio and transverse contact ratio of mesh-in and mesh-out,the length of contact line is discussed.Then,the calculating methods of friction force arm and equivalent curvature radius at any contact point are discussed.On this basis,the calculating formulas of comprehensive friction force and torque of herringbone gear could be obtained.The influence of working conditions parameters such as input speed,load torque and gear basic parameters such as helix angle,tooth width and modulus on friction excitation are studied.(3)The dynamic model of herringbone planetary gear transmission system is established.The overall geometric model is divided into several sub-systems and the dynamic models are established respectively.Then all subsystems are reasonably assembled according to the characteristics of position and connection form,and the system-level dynamic model of herringbone planetary gear system is established.The time-varying mesh stiffness excitation,tooth surface friction excitation,meshing error are considered.The influence law of different working conditions and excitation parameters on the dynamic response of the transmission system are studied.The main factor affecting the vibration of the transmission system is found.These results could provide some references for the vibration reduction design of herringbone planetary gear transmission system.(4)Based on the analysis results of the dynamic response of herringbone planetary gear system,the method of staggered tooth phase to reduce vibration is proposed.The meshing principle of staggered tooth phase gear is studied,and calculation formula the time-varying mesh stiffness of staggered tooth phase gear is deduced.And the mapping relationship between staggered phase and dynamic response is studied.The dynamic analysis about a gear pair of parallel shaft spur /helical is carried out.The spur gear pair and helical gear pair that can realize different staggered phases are designed.The experimental research on the dynamic response of parallel shaft spur / helical gear pair with different staggered phases are carried out.The experimental results are compared with analytical results.The law of staggered tooth phase of parallel shaft is extended to the planetary gear transmission system,and the selection basis of the optimal staggered phase of the planetary gear train is summarized,so as to provide theoretical support for reducing vibration of herringbone planetary gear transmission system.