| As a key transmission component in the RV reducer,the transmission characteristics and load-carrying capacity of the cycloid are an important factor that affects the overall performance.Its failure and failure mode are generally contact fatigue wear caused by cyclic loading.In response to this problem,the cycloid pin wheel in a certain type of heavy-duty RV reducer was used as the research object.The finite element analysis software was used to establish the gear tooth contact equivalent model,and the contact stress distribution of the cycloidal gear tooth surface was obtained and analyzed.The maximum contact stress area,based on dynamic modeling and analysis,using the nominal stress method,using finite element results and load spectrum as input,predicts the life under the corresponding external cyclic load,and provides for the structural design and optimization of the cycloid Theoretical reference has very important theoretical significance and engineering application value for determining the maintenance cycle of the whole machine and preventing major engineering accidents.A mathematical model of cycloid transmission is established based on Hertz elastic contact theory,and the relationship between meshing stiffness,meshing force and basic tooth profile parameters（eccentricity,pin tooth distribution circle radius,pin tooth radius）is analyzed,and the results show that:The shape parameters are mutually restricted,and all have an adjustable range.Within the adjustable range,the increase in eccentricity,the decrease in the radius of the distribution circle,and the increase in the radius of the pin tooth will increase the meshing rigidity,but the meshing force is not only Affected by the tooth profile,but also by the meshing phase angle.Based on Abaqus and Adams,the rigid-flexible coupling dynamic model of RV transmission system is established.The grey relation analysis method is used to verify the correctness of the dynamic model.The simulation results can get the dynamic response curves of the key components’speed,number of meshing teeth,meshing force and dynamic contact stress.By analyzing the stress changes of each node in the contact area,the meshing process of the cycloidal needle teeth is explained in detail,the maximum contact stress and its contact position are confirmed,and the load spectrum of the maximum stress area is obtained,which provides a reference for the calculation of the fatigue life of the cycloid.The four-point rain flow counting method is used to perform statistical analysis on the load spectrum obtained from the dynamic simulation,and the frequency under each stress amplitude is obtained.Combined with the Corten Dolan criterion,the fatigue life of the structure is calculated numerically.The estimated life is 106.63 times,etc.The effective life is 4811h.At the same time,the influence of speed and load on the fatigue life of the structure is also studied;in addition,the finite element model of the equivalent contact between the cycloid and the pin tooth is established,and the finite element analysis is carried out.The finite element results and load spectrum are used as input and simulated by FE-SAFE The fatigue life cloud diagram of the structure is obtained.The minimum logarithmic life is 106.673 times and the equivalent life is 5233h.Since nonlinear factors are not considered,the life expectancy is larger than the Corten Dolan criterion.On the basis of the traditional isometric and shift-distance modification,with the goal of optimizing the load-bearing capacity,a mathematical model for searching the maximum load-bearing capacity of the cycloid is established to obtain the best isometric and shift-distance modification.Co MParison and analysis of the contact characteristics and fatigue life of the cycloid under different combinations of modification methods,the increase of the amount of shift modification makes the meshing gap increase,and the number of meshing teeth will also change.Among them,the cycloidal gear tooth surface contact stress under the optimized load-bearing capacity practice is the smallest and the fatigue life is the highest,which proves the rationality and accuracy of the modification method. |
