Clearance Gear System Nonlinear Dynamics Study And Transmission Accuracy Reliability Analysis

Gear system is widely used in modern machinery and mechanical equipment and its dynamic characteristics and transmission precision have an important influence on the whole machine.Therefore,in the process of gear design,especially for high speed,overloaded,precision gear transmission design,the dynamic behavior and the dynamic accuracy of gear is must be considered.This thesis based on the gear system as the research object.By analyzing the nonlinear dynamic model of gear clearance,the influence of parameters on the dynamic characteristics of gear system is studied,The sensitivity of parameters on the dynamic transmission error is analyzed.The precision gear transmission system reliability analysis method is explored.The main content of this paper include the following aspects:(1)Dynamic motivation types and properties of the gear system is described.With material mechanics method,the time-varying mesh stiffness is calculated,and gear mesh Fourier function is established;(2)Clearance gear system nonlinear dynamics features is analyzed.Clearance gear system nonlinear dynamic model is established,considering the time-varying meshing stiffness,backlash,the gear error such as nonlinear factors.Using Runge-Kutta numerical method for solving the modle and the results show that this method has high calculation precision.The influence of meshing frequency,damping ratio,mesh stiffness and external torque on gear system time response is analyzed.Gear system dynamic sensitivity analysis method is analyzed.Newmark-beta method is adopted to improve the vibration differential equation and the dynamic sensitivity analysis was carried out on the gear system.The influence of the meshing stiffness,torque,moment of inertia and damping is evaluated on the gear system dynamic response.(3)Gear system dynamic accuracy reliability and reliability sensitivity analysis method is studied.Combined with multiple degrees of freedom nonlinear random vibration system reliability analysis for the first time overrun damage theory,gear dynamic accuracy reliability model is established.In view of the gear system is difficult to solve dynamic error function,numerical calculation is too time-consuming,the function fitting method of artificial neural network is put forward.First order and second moment is used for reliability analysis,with Monte Carlo method verifying the result.The gear system dynamic accuracy reliability sensitivity problem is studied,evaluating the influence of external torque,elastic modulus,gear tooth width,damping,moment of inertia on the reliability of the dynamic accuracy.(4)A kind of precision gear transmission test-bed is designed.The test-bed can test the spur gear and bevel gear transmission error,and can realize static error and dynamic error test.