Multi-state Meshing Dynamics Modeling And Dynamic Characteristics Research Of Face Gear Transmission Syste

A face-gear drive system consists of a driving spur gear and a conjugated face gear.It is used for transmission intersecting shafts and crossing shafts system.It has been widely used in helicopter,aeronautical reducer and other important transmission devices with strict requirements for space occupation and weight because of its numerous advantages such as compact structure and small space occupation,small unit mass,high contact ratio and speed ratio,high transmission power,excellent shunt ability,low noise and so on.It is very important to study its dynamic characteristics to reduce vibration and noise and improve the smoothness of face gear transmission,due to the particularity of the application.The study of its dynamic characteristics is of great significance for reducing vibration and noise and improving the stability of face gear transmission.In this dissertation,he meshing characteristics of face gear are studied based on the meshing principle of gear.Considering the factors such as tooth surface friction,tooth side clearance,time-varying meshing stiffness,meshing damping and comprehensive transfer error,the multi-state meshing dynamic model of face gear transmission system with contact degree greater than 1 is established and its dynamic characteristics are analyzed.Firstly,the working tooth surface equation of face gear is established,the action line equation is deduced,based on the gear meshing principle;the motion of meshing point is analyzed,and the meshing characteristics of face gear transmission are obtained;According to the contact ratio greater than 1,the meshing areas of single teeth and double teeth are divided,and the load distribution ratio of face gear transmission system are calculated,so as to prepare parameters for dynamic modeling.Secondly,the boundary conditions of drive-side teeth engaging,back-side teeth engaging and teeth disengagement are determined according to the backlash and the load acting on the teeth.Using the fourth-order Runge-Kutta method,the phase diagram of the system,the history diagram of the dynamic meshing force with time and the variation diagram of the dynamic meshing force along the meshing position are calculated.The relationship between the dynamic meshing force and the meshing state and the influence of the fluctuation of the dynamic meshing force on the system are analyzed.Finally,the bifurcation diagram,top Lyapunov exponent diagram,phase portraits,portraits mapping and the history diagram of dynamic meshing force are calculated by defined three different Poincaré mapping sections.The effects of load,meshing frequency,comprehensive transmission error,backlash and meshing damping on the dynamic behavior and dynamic characteristics of the system are analyzed.The occurrence process and friction cutting behavior of tooth surface collision and tooth back collision are studied.Nonlinear dynamic models of the face gear systems with multi-state meshing behavior are established,based on the gear meshing characteristics.The changes of dynamic meshing force and meshing state and the influence of system parameters on the meshing behavior and nonlinear dynamic characteristics of the system are analyzed.This research method provides a new theoretical reference for the study of nonlinear vibration in gear transmission.