Research On The Dynamic Characteristics Of Novel Torus-involute Gears Transmission System

The torus-involute gear is a new type of gear,which can be used in parallel and intersecting shaft drive,and is insensitive to installation error.In addition,torus-involute gears have good meshing performance and high bearing capacity.In the process of transmission,internal excitations,such as meshing stiffness and friction,have great effect on the system's working performances and life span.This paper mainly works in the dynamic characteristics of torus-involute gear,including the analysis of time-varying meshing stiffness based on finite element method,the analysis of friction coefficient in the elastohydrodynamic lubrication model,the establishment of dynamic model and the analysis of dynamic characteristics of gear transmission system.In the analysis of the geometrical features,the gear profile equations and the principle curvatures are deducted based on torus-involute gears' machining principles;The restricted conditions of tooth width are analyzed by studying the phenomena of tooth undercutting and tooth pointing;The contact ratio of torus-involute gear pair is calculated according to the meshing principle of spur gear.In the study of the time-varying meshing stiffness,the entity models of torus-involute gears are established via the three-dimensional coordinates of points on tooth surfaces;The precise meshing and ststic finite element analysis are conducted to analyze the normal contact stress and the comprehensive elastic deformations;Single-pair meshing stiffness and multi-pair meshing stiffness of torus-involute gears are calculated,and the rules of meshing stiffness when applying different load are analyzed.In the study of the friction excitation,the velocity between tooth surfaces is deducted according to the meshing characteristics of torus-involute gears;The differences of the friction coefficient under different models are compared,and the effects of roughness on the friction coefficient are analyzed based on the elastohydrodynamic lubrication theory;The meshing force and the friction force as well as the friction torque are calculated.In the study of the dynamic characteristics of the torus-involute gear transmission system,six-degree of freedom gear-shaft coupling nonlinear dynamic model is established with the consideration of the time-varying friction coefficient;The dynamic equations of the system are deducted and Runge-kutta method is used to solve the equations to obtain the impact of tooth surface roughness on the dynamic characteristics of the torus-involute gear transmission system;The differences of spur gear and torus-involute gear in dynamic characteristics are compared.