The Effect Of The Tooth Surface Isotropic Finishing Process On The Contact Fatigue Characteristics Of The Tooth Surface

As the core component of the mechanical transmission part of modern industrial equipment,the design and manufacture level of the gear transmission has played an important role in the performance and quality of the whole industrial equipment,and the gear surface quality has great influence on the gear performance.The surface barrel finishing technology has been widely used in aircraft engine,bearing manufacturing,automotive electronics and other fields to obtain isotropic surface and improve the surface quality of parts.At present,the basic data of gear fatigue characteristics in different materials and processing technology in China are seriously deficient.Therefore,it is necessary to carry out research on gear contact fatigue characteristics under the existing materials and finishing conditions in China,and provide accurate data support and design basis for our gear products.In this paper,the study of 18 Cr Ni Mo7-6 gear material for contact fatigue characteristics and the main contents are as follows:(1)The micro-topographic features of the machining surface are analyzed,and two examples of the gear used barrel finishing are introduced.By contrasting the effect of the finishing process,we can get the barrel finishing surface has a typical isotropic characteristic,and the surface stress distribution state after finishing is improved remarkably.(2)The R-S-N curve of the gear material is obtained by the combination of routine grouping method and rapid test method.The quantitative data of the effect of the barrel finishing on the contact fatigue strength of the tooth surface are obtained by the barrel finishing comparison test.(3)The test data are analyzed by using the method of mathematical statistics,and are subjected to logarithmic normal distribution,and the R-S-N curve was fitted by the least squares method.Through the barrel finishing comparison test,we can see that the contact fatigue limit after isotropic barrel finishing is improved obviously.(4)The calculation of contact stress and shear stress of gears is analyzed by Hertz theory,fractal contact model and finite element simulation.The calculation results are compared,which provides the basis for the calculation of contact fatigue strength and prediction of fatigue crack.