Structural Optimization And Software Realization Of Crown Gear Coupling

The crowning gear coupling is an important basic component for mechanical transmission,which is widely used inthe powerbogie for high-speed trains,subway and urban rail transit vehicles,It playsan important role inconnecting thetraction motor and gear box andtransmittingtraction torque.Thereliability of the crowning gear coupling directly affects the safety of the train.It is difficult forthe crowninggear coupling to achievethe compensation of the compound movement displacement of the input and output shafts and large traction torquetransmitin a small structure space,especially the external gear curve parameter optimization is more challenging.The externalgear structure along the tooth is middle thick both ends thin,which allowsa certaininclination angle between the internal and external teeth,and it is conducive to improving the contact statebetween the internal and external teeth.The contact stress between the internal and external teethincreases as the tooth surface crown increases,which affects the bearing capacity of the external teeth.In addition,thecrown curve type and parameters of the external tooth affect the maximum allowableinclination angle,the amount of effective contact teeth and the position of contact points and other meshing status.The meshing state analysis and structural interference check of the internal and external teeth for the crowning gear coupling can be conducted by using the geometric analysis method based on mathematical modeling,and the design of the crown tooth structure parameters optimizationespecially for the crown curve is very meaningful.At present,the gear couplings used in China are almost circular shaped crownteeth,just a few special function gear couplings are non-circular crown teeth,and there are few literatures on the crown curvein China.In order to study the influence of the crown curve on the meshing of the crown teeth,the mathematical model of the crown tooth was established by using the geometric analysis method,and the crown curves include circular arc,ellipse,hyperbola and three arc curves.Firstly,the meshing calculation is carried out to study the effect of the crown curve parameters on the meshing state of the internal and external teeth.Then,the difference of the meshing state between the inner and outer teeth under different crown curves is compared and analyzed.Finally,the parameters of the non-circular crown teeth are optimized to obtain the tooth parameters with good meshing condition in the corresponding working environment.Byanalyzing the influence of the crown curve on the meshing state of the internal and external teeth,the following conclusions can be drawn:(1)In the small axis angle(0.5° below),the meshing states of different crown curve teethare basically the same.The allowable maximum axial tilt angle decreases and the axial displacement of the contact point in the pure transition area increases asthe radius of curvature of the vertex curve increases.The side arc radius of the three arc curves is smaller than that of the remaining curves,which causes the smallest fluctuationsdistribution inboth the minimum clearance of the tooth surface and theminimum clearance position in the axial direction,and the naxmum allowable inclination angle on condition that radius of' curvature of the vertex curve of each crown curve is the same and the contact point is in the side arc.(2)The results shows that the allowable deviation angle increases and the axial displacement of the contact point decreases as theradius of curvature decreases,But the smaller the radius of curvature,the smaller the contact area and the larger the contact stress.For the purpose of good meshing state,uniform bearing load,no concentrated stress,the design and optimization of the parameters of the crown teeth and the influence of the meshing state are studied and analyzed,and the optimization results are verified by finite element method.(3)Based on the Visual Studio C#language,the crown tooth meshing calculation software was compiled.The software realized the fast calculation of the meshing state of the dcrown teeth,and the meshing calculation results were presented directly to the users,which improve the gear design and check efficiency and the straight forwardness and legibility for the results.