Study On Dynamics Of Involute Spur Gear Drive System Considering Friction Of Teeth

Gear transmission is widely used in various industries.During the transmission process,the friction and clearance between components are important and complex for the system.Tooth surfaces of friction,backlash and other factors shall be considered in this paper,which exerts a further study in the dynamic response related-problems of Involute spur gear transmission system.Firstly,the linear contact lubrication model of the gear pair is constructed to obtain the tooth surface friction coefficient.Then,the dynamic model of the six-degree-of-freedom gear nonlinear system considering tooth surface friction is established,and the dynamic response of the system is obtained by using Runge-Kutta method.Finally,the dynamic response results of the dynamic model simulation are tested and verified by using mechanical power flow closed gear test platform which applies for involute spur gear transmission.The specific contents of this paper are as follows:1.According to the Hertz contact theory,the contact of the gear pair belongs to the line contact.After considering the lubrication effect of the tooth surface,it can be treated as line contact lubrication problem.In this paper,the line contact elastohydrodynamic lubrication theory is studied and the lubrication model of gear pair meshing is established.The friction coefficient of the gear pairs in the lubrication state is obtained after solving the equation without dimensionalization,which provides the basis for determining the friction force of the power equation of the gear system.2.In this paper,considering the gear meshing backlash,According to the interaction between the components of the system,a pair of six degree of freedom dynamic equations of meshing gears were obtained,with MATLAB software to establish a nonlinear system dynamics model of gear pair,which takes into account the tooth surface friction,after dimensionless treatment of the system equation,the dynamic model is solved by using the five-step variable step Runge-kutta method.So dynamic response of gear system and the influence law of tooth surface friction to dynamic response is obtained.3.According to the research requirements and relevant regulations,a mechanical power flow closed gear test bench is built.Under the standard test plan,suitable gear test pieces with different types and parameters oils,a perfect test detection mechanism is set up and the corresponding gear transmission vibration test is implemented.So the experimental data are extracted and analyzed,and the time and frequency response of different precision gear pairs in different working conditions and lubrication conditions are obtained.4.Firstly,comparing the gear test results and simulation results under different lubrication conditions,this paper verifies the theoretical model creditability to the simulations of lubricating,the lubricating oil parameters on the effects of gear system dynamic responses,obtaining influence rule that the lubricating oil parameters affect gear system dynamic responses.Then comparing the test results of dynamic response under different load conditions to simulation results of theory,it verifies the creditability of the theoretical simulation model's impact on load conditons.At the same time the influence law of the load cases gear to system dynamic responses is acquired.Finally comparing test results of the different tooth surface precisions' the dynamic response and the theoretical simulation results,it proves that the theory of the simulation model is credible,and the influence law of tooth surface precision on the vibration response of gears is obtained.The results demonstrate that the simulation results of the theoretical model are consistent with the test results in the lubrication of the tooth surface,the transmission load and the accuracy of the tooth surface,verifying the credibility of the nonlinear system dynamics model of six degrees of freedom involute spur gear.It provides an important reference for later theoretical researches,and guidance for the design of low vibration and low noise gear transmission system in practical engineering.