Numerical Rolling Test Method Research Of Drive Axle Face-Hobbed Hypoid Gears

FH hypoid gears are processed by the Face-Hobbing method,which has the advantages of high processing efficiency,stable transmission and high strength,so it is widely used in automobile drive axles.Rolling test is an important part of FH hypoid gear manufacturing,and its result is an important reference for evaluating the quality of gear design.The traditional rolling test relies too much on the experience of the technicians,the accuracy is not high.And due to the existence of machining errors and heat treatment deformation,the comparison between the rolling test pattern of the real tooth surface with the design pattern of the theoretical tooth surface has the problem of different evaluation criteria.Therefore,this paper proposes a numerical gear rolling test method(NGRT)for FH hypoid gears of drive axle.This method can replace the traditional rolling test link of the contact pattern,which will effectively reduce the equipment and time costs.This is very beneficial to the closed-loop manufacturing and even intelligent manufacturing of FH hypoid gears of the drive axle.The main research contents of this paper are as follows:(1)The real tooth surface modeling of FH hypoid gear based on the measured tooth surface data.Use the surface interpolation method of Non-Uniform Rational B-Spline(NURBS)to reconstruct the real tooth surface.First,the control vertices and weighting factors are obtained by backcalculating the measured coordinates on the real tooth surface.Then the result of the inverse calculation and the spline basis function are substituted into the surface equation to obtain the true tooth surface equation.Finally,the accuracy of the interpolation fitting tooth surface is verified.The results show that the error of interpolation fitting tooth surface of the NURBS is less than 0.1 μm,which meets the accuracy requirements.(2)Tooth contact analysis of the real tooth surfaces.Through the iterative intersection and equidistant search methods of paired tooth surfaces,the instant meshing point of each meshing position,instant contact path and the complete boundary of the instant contact ellipse are obtained.Furthermore,the complete contact pattern and transmission error of the entire tooth surface from entering meshing to exiting meshing can be obtained,and then the influence of installation errors for patterns and errors is also discussed.(3)Load contact analysis of the real tooth surfaces.Through load contact analysis of the real tooth surface under different load and installation error conditions,the instant contact area,load transmission error,tooth surface contact stress and tooth root bending stress of each meshing point are obtained.Furthermore,the stress curve of the entire tooth surface and the load transmission error of the entire meshing period are obtained.It lays the foundation for accurately obtaining the meshing situation of the real tooth surface under actual working conditions.(4)Tooth surface measurement and rolling test verification.Through the Klingelnberg P65 gear measuring center,the real tooth surface measuring point coordinate data was obtained.And the numerical real tooth surface interpolation fitting is performed.Then the gear rolling test is carried out.Finally,the accuracy and feasibility of the NGRT method in this paper are verified by comparing the results of actual rolling test results and KIMoS5 results.