Research On Intelligent Modification Design Of Involute Helical Gear Transmission System

Gear system is an important components of mechanical driven system,which plays an non-substitutable role in transportation,wind power generation,mining metallurgy,space navigation,etc.As science and technology develop and the rapid growth of mechanical engineering requirements,in addition to meeting the basic mechanical system load capacity requirements,gear transmission system put forward a low vibration,low noise and other higher performance requirements.Gear modification technology is an effective method to reduce vibration and noise.Through the research of gear transmission system dynamics,the best gear modification parameters are obtained,which is an effective way to improve the dynamic performance of gear transmission system.It has very important research significance and engineering value.In this thesis,the involute helical gear transmission system is taken as the research object.The main contents of this thesis include:(1)On the basis of analysising the research status and development of gear dynamics,gear parameterized modeling and gear modification technology,the significance and purpose of this thesis are put forward.(2)The nonlinear dynamic analysis model of involute helical gear transmission system is established by means of the lumped mass method,and then considering the time-varying meshing stiffness,meshing damping,tooth side clearance,gear error,tooth surface friction,gear modification,gravity and bearing support,The differential equation of nonlinear dynamics analysis of involute helical gear transmission system with multi-factor coupling is established by using Newton’s law.Using Runge-Kutta method,the differential equations are solved by Matlab.The effects of time-varying meshing stiffness,gear error,meshing damping,friction coefficient and modification for the dynamic characteristics of involute helical gear transmission system are studied.(3)The accurate mathematical models of involute,tooth root transition curve,tooth top modification curve and helix are established.The parametric three-dimensional modeling of involute helical gear transmission system is developed using Creo.Based on the 3D model of involute helical gear,the modal neutral file of involute helical gear is generated by ANSYS.Finally,on the basis of 3D modeling and modal neutral file of involute helical gear transmission system,the nonlinear dynamics simulation analysis of involute helical gear transmission system is realized based on ADAMS.Compared simulation results of ADAMS with numerical result obtained in the above chapter,the numerical model of nonlinear dynamics of involute helical gear transmission system established in this thesis is proved to be correct.(4)Based on the gear modification theory,the mathematical model of optimization of modification parameters of involute helical gear transmission system is built by taking the minimum fluctuation of dynamic transfer error as objective function and the maximum modification of tooth top and modification length as design variables.An improved particle swarm optimization algorithm is used to optimize the modification and length of the parabola modified involute helical gear transmission system,and the optimal modification parameters are obtained.The optimized maximum modification and modification length of the top of the main and slave drive gear are brought into the nonlinear numerical analysis equation of the involute helical gear transmission system,and the dynamic response of the involute helical gear transmission system is obtained under the load condition of the involute helical gear transmission system.After the dynamic response of involute helical gear transmission system is compared with that of unmodified involute helical gear system,the realization of intelligent modification design of involute helical gear transmission system is realized.