Experimental And Simulation Reseach On Grinding Surface Integrity Of Spiral Bevel Gear

Spiral bevel gear is widely used in the power transmission systems of heavy vehicle because of its advantages such as small noise,smooth transmission and large torque transmission.The spiral bevel gear can meet the needs of heavy load capacity,low energy consumption,high safety and long use time.The design and manufacture of spiral bevel gear is complex,and the processing quality is extremely difficult to control,resulting in premature failure in use and the life span of heavy vehicles is affected.The widely used production process of spiral bevel gear is milling,heat treatment,and final grinding.If the grinding process is properly controlled to achieve good surface integrity,the size accuracy and fatigue strength of spiral bevel gears will be improved and the service life will be extended.At present,the research on the surface integrity of the spiral bevel gear grinding is less,which leads to the low production efficiency and the poor product qualification rate.In the grinding process of spiral bevel gear,the grinding wheel type,abrasive grain size,grinding process parameters,cooling mode,grinding force and grinding heat generated by grinding process have different effects on the integrity of grinding surface.It will cause grinding defects,grinding cracks and grinding burns.Therefore,it is urgent to study the surface integrity of the spiral bevel gear grinding,to improve the productivity of the spiral bevel gear and to reduce the scrap rate.The metal grinding theory,heat conduction theory,geometric motion principle and stress strain theory is applied.Surface integrity,such as surface hardness,metallographic structure,grinding burn,surface topography,surface roughness and residual stress are studied through experimental analysis,finite element simulation and numerical simulation.The main contents are as follows:(1)For the spiral bevel gear material 18Cr2Ni4 WA,it is easy to cause grinding burn and seriously affect product qualification rate during dry grinding.The changes of microhardness gradient,surface morphology and metallographic structure of grinding burn were analyzed by single factor experiment,and the mechanism of grinding burn was revealed.Combined with the orthogonal experiment,the change law of grinding force with the grinding process parameters is explored,and the prediction model of grinding force is summed up.Based on the grinding force model,the ANSYS finite element simulation software is used to simulate the grinding surface temperature field.The prediction method of grinding burn is proposed,and the effectiveness of the proposed prediction method is verified by experiments.(2)Aiming at the problem of the product stability is affected by the nonconformity of the surface morphology of the spiral bevel gear,the experimental and simulation research of grinding surface topography are carried out.Combined with single factor experiment and orthogonal experiment,the influence rule of grinding parameters on the surface topography is analyzed,and the prediction experience model of grinding roughness is summarized.The distribution model of abrasive grain on the wheel surface is established by normal distribution,and the prediction and analysis of the grinding surface topography of spiral bevel gear is carried out based on the trajectory of grinding wheel abrasive grains when grinding spiral bevel gear.(3)Aiming at the problem of the decrease of fatigue strength caused by the lack of residual stress,the experiment and simulation of the residual stress on the surface of the spiral bevel gear grinding are carried out.Combined with single factor experiment and orthogonal experiment,the distribution rule of surface residual stress under different technological parameters is studied,and the prediction experience model of residual stress on grinding surface is concluded.The residual stress is analyzed synthetically before and after grinding,and the residual stress produced in the actual grinding process is obtained.Based on the finite element analysis of the ANSYS finite element simulation software,the prediction and analysis of the residual stress in the surface of the grinding surface are realized.