Study On Modification Techniques Of Involute Spur Gears

Due to the influence of manufacturing errors,installation errors,gear deformation,and other factors,there will be load impact and great fluctuation of transmission error during the transmission of involute spur gears.They may result in the phenomenon of vibration.Moreover,the phenomenon of uneven load distribution along the axial direction also occurs when gears are meshing,which will cause stress concentration and uneven load.These problems will reduce gear strength and seriously affect the service life of involute spur gear transmission system.To deal with the mentioned issues,a novel profile modification method and an axial modification method are proposed based on obtaining the best meshing performance,modified tooth surface equation is deduced,and an accurate modeling method for modified tooth surface is researched based on the principle of surface fitting.And suitable modification parameters can be obtained for gear pairs working in different conditions using proposed methods in this paper.Thus,the best modification effect can be acquired.According to the finite element analysis technology,the method of transient meshing analysis for modified gear pair is researched,and a method of evaluating meshing performance is also put forward in this paper.When analysis is finished,tooth contact stress and root bending stresses during the meshing process can be obtained,and it can be find out that whether the gear pair meets the strength requirement.Besides,profile modification effect can be analyzed by observing the fluctuation of transmission error and gear load distribution.And axial modification effect can also be analyzed by observing the location and shape of the contact area,and contact stress distribution along the tooth width direction.Moreover,the specific influence of key modification parameters on gear meshing performance is also studied in detail.Research results show that different modification lengths,different modification amounts,and different modification curves will not affect the strength of gear pair when it is modified with profile modification.But they will obviously affect the fluctuation of transmission error and load impact.Besides,using different modification center positions,different axial modification amounts,and different modification curves to modify gear pair can find that these factors not only affect gear strength,but also affect the distribution of contact stress.And when axial modification parameters are not suitable,it will be unable to improve the uneven load distribution and will reduce gear strength.Finally,based on the orthogonal test method,the optimization method of modification parameters is researched.Considering the efficiency and effect of optimization test,a suitable orthogonal table is chosen to arrange the test.Meshing simulation analyses of gear pair using various modification ways are carried out,in order to obtain the best meshing performance,the optimum modification way can be optimized by comparing the analysis results.In addition,a set of gear pairs is taken as an example to verify the effectiveness of the method.