Dynamic Analysis Of Locomotive Traction Gear Transmission System Based On ROMAX

Gear is one of the most important parts in machine industry.The helical gear has the advantages of large coincidence degree,good meshing performance,compact structure and larger carrying capacity and transmission stability compared with the straight gear.With the development of machinery industry and technology,heavy duty helical gears have been widely used.High load carrying capacity and low noise of the gear transmission system have become a research hotspot.It is of great practical value to study the dynamic characteristics of gear transmission system and improve its performance.In this paper,the locomotive traction gear transmission system as the research object.A complete transmission system model is established based on the theory of gear system dynamics,which takes into account the factors such as shaft deformation,flexible box,motor and wheel rail friction torque.The static,modal analysis and dynamic analysis of the model are carried out.The main contents and conclusions are as follows:(1)The relatively complete transmission system model of rigid flexible coupling model is established,which takes the change of torque instead of the motor and the friction torque is used to replace the wheel-rail contact,considering the shafts deformation,bearings deformation and the influence factors such as the flexible gearbox.The analysis of stress,and the analysis of the contact spot,the deviation of the shafts,the damage of the bearings and the gear meshing misalignment are analyzed,and the corresponding results are obtained.(2)The dynamic response of the gear transmission system is simulated and analyzed.The modal analysis and the resonance analysis of the axle box and the gearbox with constrained state are carried out;The internal and external excitation of the transmission system is studied,such as the transmission error,the external load and so on;The dynamic response of the gear flexibility,the dynamic contact force of the bearings,the vibration acceleration of the gearbox and the dynamic meshing stiffness are simulated and analyzed under the specific transmission error as excitation.The corresponding amplitude frequency curve is obtained.(3)The NVH analysis of the rigid flexible coupling model is carried out.The transmission error(TE)of the model under different working conditions is analyzed,and the numerical value of the TE is obtained.Then the dynamic gear whine analysis is carried out,obtaining the relationship between vibration acceleration and rotating frequency under five working conditions from start to high speed.The rattle of the model is analyzed,and the vibration process curve is obtained.(4)Three kinds of optimization algorithms based on Monte Carlo and Romax are used with the target of minimum transmission error,the tooth profile and lead modification are carried out under the constraint of the modification amount and slope and the maximum transmission error,obtaining the optimal scheme.The transmission error,the contact spot,the damage of the bearings,the gear meshing misalignment and the dynamic response of the vibration acceleration of the gearbox before and after modification are compared.Corresponding conclusions are drawn.