Fatigue Life Analysis Of The Gear Box Of Beam Pumping Unit

Beam pumping unit is an important ground power driving equipment in oil production system.The working environment of oil pumping unit is bad,and the working condition is changeable,which affects the performance of the pumping unit,such as strength,rigidity and dynamic characteristics,which can easily lead to damage of parts.As an important drive reducer of pumping unit,the Horsehead movement is periodic reciprocating motion,change of suspended load is irregular,so the load pulsation cycle.In order to verify whether the structural fatigue strength of the gearbox and under different working conditions meet the design requirements,subject to the tour reducer as the research object of C228 beam pumping oil machine involute,theoretical analysis of finite element statics,multi-body dynamics,fatigue life based on structural analysis of pumping organ key mechanism based on finite element simulation methods for the analysis of means,the establishment of a joint simulation of oil pumping machine four connecting rod mechanism and the gear shaft bearing box "model,using nCode on the fatigue life of reducer box prediction,provide reliability standard forenclosure structure optimization.(1)Load spectrum acquisition.According to the theory of the polished rod load reducer,maximum torque,axial force applied to the belt wheel,the minimum shaft pumping rod four on the output shaft of the motor force,maximum load box calculation.Enter the Adams entity model,setting material properties,mechanism,loading time,adding force and driving simulation model,extraction time course load reducer output shaft torque and time course of each bearing seat in three directions,both forthe comparison of the results of the analysis.(2)Static and dynamic analysis.Detailed introduces the application of Pro/E to establish the reducer 3D model and the corresponding simplified tetrahedral mesh model by using HyperMesh,given the material properties;using ANSYS to load on the gearbox and applied boundaryconditions.The calculated stress and displacement plot,the maximum stress is 48 Mpa,the position in the output shaft bearing seat on the left side box under the junction area,the maximum deformation direction for box Z regional output shaft bearing hole of the top right area,the displacement of 123.8 M.The first six modal frequencies of the box are extracted and the corresponding vibration modes are evaluated.(3)Fatigue life analysis of box.Use Workbench to set up the analysis system of gear fatigue life box,using the quasi-static method in 18 conditions imposed on the unit load reducer is carried out,build the analysis process of fatigue in the nCode box,the box with the load time history of finite element analysis,material S-N curve and virtual prototype simulation of the reducer casing stress load spectrum the rain flow chart of rain flow counting method and get statistics of 18 conditions,finally get the lowest number of cycles of the gearbox is 7.216E+007 times of the maximum stress position consistent with the weakest position and body static strength.