Dynamic Characteristic Analysis And Fatigue Life Research Of Reducer Transmission System For Shared Bicycle Lock

In recent years,miniature reducers have been used in monitoring equipment,printing equipment,household appliances,etc.,with a wide range of applications,closely related to people’s daily life,and more and more capitals and enterprises pay attention.This article takes the miniature reducer for the shared bicycle lock as the research object,and aims at the excessive vibration and noise of the reducer in the production process of the miniature reducer and the life of the reducer is not up to standard.The gear transmission of the main components of the reducer for the shared bicycle lock The system has carried out multi-body dynamics analysis to study the method of reducing the system vibration and noise;the dynamic contact analysis and fatigue life analysis of the output stage gear pair in the transmission system that are prone to failure are carried out,and the method of improving the fatigue life of the gear is studied.Finally,after the test Fatigue failure analysis of the output stage gear pair.The main research is as follows:(1)Multi-body dynamics analysis of gear transmission system.Use Solidworks software to establish a three-dimensional model of the gear transmission system of the reducer for shared bicycle locks,and import it into ADAMS for multi-body dynamics analysis.Based on the orthogonal experiment design,the influence of gear modulus,pressure angle,and tooth width coefficient on the maximum dynamic load coefficient of the system is studied,and the optimal gear structure parameters—modulus 0.1,pressure angle 20°,and tooth width coefficient 0.3are obtained.The simulation shows that the maximum dynamic load coefficient of the gear transmission system after optimization is reduced by 49.95%,and the meshing of the gear transmission system is more Stable,reducing gear meshing noise.(2)Dynamic contact analysis of the output gear pair.According to the specific working conditions of the reducer,the force analysis of the output stage gear pair is carried out,and the finite element model of the output stage gear pair is established in ANSYS.Through simulation,the change law of the gear pair driven gear tooth surface contact stress and tooth root bending stress is obtained.And explored the changing law of driven wheel tooth surface contact stress and tooth root bending stress under different load torques.The gear tooth root bending stress obtained by dynamic contact analysis provides a load spectrum for the subsequent output stage gear pair bending fatigue life analysis.(3)Analysis of the bending fatigue life of the output gear pair.Determining the S-N Curve of Gear Pair Material by the Method of Nominal Stress,take the gear tooth root bending stress obtained from the dynamic contact analysis as the load spectrum,perform the bending fatigue life simulation analysis on the output gear pair in the fatigue software n Code Design Life,and the influence of pressure angle and load torque on the bending fatigue life of the output gear pair is studied.Finally,the correctness of the simulation is verified by the reducer bench test.(4)Fatigue failure analysis of the output gear pair.The output gear pair of the reducer after the fatigue test is selected as the research object,and chemical composition analysis,electron microscope analysis and hardness analysis are used on the surface of the gear pair gear.Through electron microscope analysis,it can be seen that the gear has cracks at the root of the gear.It is due to the fact that the subsurface near the root of the gear produces pit defects under the cyclic bending stress.Stress concentration occurs at the pit defect,which leads to the initial crack of the gear.Under the action of fatigue load,the initiation of multiple initial short cracks propagates to each other,forming main cracks on the surface of the gear,and ultimately resulting in bending fatigue fracture of the gear.The hardness analysis shows that the tooth surface hardness of the driven wheel in the gear pair is insufficient.The driven wheel is heat treated to improve the hardness of the tooth surface of the driven wheel,so that the life of the main and driven wheels in the gear pair is similar during use.