Topological Modification And Load Contact Analysis Of Helical Gears Grounded By Forming Method

Helical cylindrical gears are widely used in high-speed and heavy-load occasions due to their advantages of smooth transmission,large coincidence and good meshing performance.However,under the condition of high-speed operation of the equipment,due to the large load of the gear,it is easy to produce gear vibration noise,large meshing in and out impact and other problems,which will cause various failure modes of the gear and reduce the transmission accuracy and service life of the gear pair.With the continuous development of high-precision equipment,the requirements of various mechanical parts for gears are getting higher and higher.In the actual transmission process of gears,due to the influence of installation and manufacturing errors,load bearing deformation,there are often failure modes such as eccentric load on the tooth surface,gluing,and root fracture.By micro-trimming the tooth surface,the contact area of the tooth surface can be optimized and the gear meshing performance can be improved.The main research contents and innovations of this article are as follows:1.A topological modification method for forming helical gears by gear grinding is proposed.Based on the basic parameters of the gear pair and the topological modification expression of the tooth surface,the tooth surface equations of the driving wheel and the standard driven wheel after the modification are established in Mathematica.The tooth surface point set is exported,and the 3D solid modeling of the gear is carried out in UG.2.According to the gear meshing principle and the coordinate system transformation theory,a TCA mathematical model of tooth meshing is established in MATLAB.Set different modification coefficients,solve the TCA equations,and get the transmission error of the gear pair and the contact area of the tooth surface under different modification parameters.The effects of second-and fourth-order modification curves on the contact characteristics of gears were investigated respectively.3.Using ANSYS-Workbench,the transient dynamic analysis of the gear pair was carried out,the contact stress of the tooth surface was compared,the shear stress and the maximum equivalent stress were distributed in the tooth surface,and the influence of different modification parameters on the bearing capacity of the gear pair was compared.Using Romax simulation software as the platform,a simplified gear pair model was established,with the minimum transmission error of the tooth surface and the minimum unit load as the optimization goals,the gear modification parameters were optimized and selected,and the optimal tooth modification program was selected.4.Grinding processing of modified driving wheel and standard driven wheel on CNC forming gear grinding machine.The vibration loading test was carried out on the gear pairs before and after the modification,and the reliability of the selection of the modification parameters was verified by the vibration spectrum and the contact marks on the tooth surface.