Experimental Study On Grinding Surface Performance Of Spiral Bevel Gear 30CrMnTi

Spiral bevel gear has the characteristics of large transmission torque,smooth transmission and low noise,so it is widely used in heavy vehicle transmission system.But the design and manufacture of spiral bevel gear is the most complicated in all kinds of gears,and the quality control is very difficult.Grinding is an important means to improve the meshing accuracy,reduce tooth surface roughness and eliminate the deformation error of heat treatment.However,in the manufacturing process of spiral bevel gear,there is a lack of research on the grinding surface integrity,resulting in a lot of grinding damage and then affecting the product pass rate.Therefore,it is urgent to carry out the experimental study on grinding surface performance of spiral bevel gear,have the optimize control to the surface integrity of the tooth surface,solve the production restriction problems fundamentally,and drive the entire spiral bevel gear manufacturing level to further enhance.The main contents are summarized as follows:1.The basic experimental research on the plane grinding is carried out for the spiral bevel gears common material 30 CrMnTi.The study shows that,with the increase of grinding speed,both the tangential and normal grinding forces of gear steel 30 CrMnTi decrease;with the increase of grinding depth or work piece speed,the grinding force increases.The orthogonal experimental is designed,and the empirical formula of grinding force per unit width is obtained by the multiple linear regression method.The grinding temperature field of gear steel 30 CrMnTi is obtained by ANSYS simulation.The study finds that the maximum temperature of gear steel 30 CrMnTi grinding surface increases with the increase of grinding speed or grinding depth,and decreases slightly with the increase of work piece speed.2.The grinding hardening phenomenon of gear steel 30 CrMnTi under dry grinding is studied.After the grinding test,the surface microstructures of gear steel 30 CrMnTi are acicular martensite,carbides,and a small amount of retained austenite,heart tissue is lath martensite and ferrite.The martensite structure of the hardening layer is relatively uniform;the trend from the grinding surface to the heart is thin to thick,and with depth or speed of grinding increasing,the depth of hardening layer increases.The hardening degree of grinding surface is between 2% to 13%,it increases with the grinding speed decreases or grinding depth increases.3.According to the change of the residual stress of steel gears 30 CrMnTi after grinding,the relevant research is carried out.Based on the thermo mechanical coupling theory,the residual stress ?? of 30 CrMnTi grinding process is obtained,and compared with the experiment,the validity of the simulation model is verified.Grinding will change the distribution of surface residual stress,and the surface is compressive stress.In dry grinding conditions,its size decreases with the depth or speed of grinding increasing;in wet grinding conditions,the compressive stress caused by grinding force plays a leading role,with the depth of grinding increases,the residual compressive stress increases gradually.4.According to the experimental data based grinding experiment,the spiral bevel gear grinding experiment gear machine in Gleason-600 G NC is designed.The study shows that,after the processing the roughness of the tooth surface is between 0.4 and 0.65,and it decreases with the increase of grinding speed,increases with the depth of grinding and gear generating speed increases.After grinding,the compressive stress of the tooth surface is in the range of 300 MPa to 550 MPa,the value of residual compressive stress in nodal region is larger than that of the tooth root region and the tooth top region.Finally,orthogonal experiment is designed,and the empirical formulation of surface roughness and residual stress is obtained and the optimal control of the process parameters is carried out.